# Dive bomber accuracy in perspective.



## davebender (May 5, 2013)

Ju-87 with average pilot had a 25% chance to place 1,000kg bomb within 30 meters of target.

Ju-88 under test conditions (presumably expert pilot) could place 50% of bombs within 50 meter circle.

What accuracy could be expected from a Vietnam era Skyraider with 2,000 lb iron bomb? 

What accuracy could be expected from a modern day A-10 with 2,000 lb iron bomb?


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## Zipper730 (Nov 24, 2016)

The CEP figures are usually based on putting 50% of the bombs within a given radius, so the Ju-87 figures don't really give much for CEP computation.

Regardless the Ju-88 had a CEP of 50m or 164'0.5"

No idea about the Skyraider or A-10


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## BiffF15 (Nov 24, 2016)

The CEP for the A-10 with iron bombs is probably pretty good due to the death dot (CCIP) or Constantly Computed Impact Point. It's like a red dot sight for aircraft. Dot on, push pickle button, target hit, period dot. As for the Spad, I would think it's a bit better than WW2 iron. The predominate reason is time between WW2 and Vietnam gave room for much improvement in academics, techniques, tactics and procedures. Heck, range rides in the OV-10 would have almost all the BDU-33s falling inside 150' (non-combat dropping understood). The more you drop, the better you get.

Cheers,
Biff

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## Greyman (Nov 26, 2016)

*AFDU testing Hurricane II - 250 lb bombs*:

low level attacks - 50 feet altitude

average error varied between 16.5 yards and 22.4 yards
most accurate form of attack - but unsatisfactory against point targets in action due to 11-sec fuses and bomb ricochet

dive attacks - 3,000 feet down to 1,000 feet (1,500 feet release) & 4,000 feet down to 2,000 feet (2,500 feet release)

average error was 27 yards and 24 yards respectively
form of attack judged vulnerable to AA fire, 45 degrees found to be the best angle for attack

*AFDU testing of Mustang III - 500 lb bombs*:

60 degree adive attacks - 8,000 feet down to 2,600 feet (release at 4,700 feet)

average MPI error of 27 yards
distance between bomb impact points 5 to 112 yards, average 46 yards

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## pinehilljoe (Nov 27, 2016)

davebender said:


> Ju-87 with average pilot had a 25% chance to place 1,000kg bomb within 30 meters of target.
> 
> Ju-88 under test conditions (presumably expert pilot) could place 50% of bombs within 50 meter circle.
> 
> ...



1 in 4 hitting within 30 meters, you can see why the RN lost so many ships around Dunkerque, and Crete.

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## stona (Nov 27, 2016)

Greyman said:


> *AFDU testing Hurricane II - 250 lb bombs*:
> 
> low level attacks - 50 feet altitude
> 
> ...



The figures for 'real' dive bombing in 1944/5, by Typhoons and Spitfires, were nowhere near as good as this.

Cheers

Steve

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## pinehilljoe (Nov 27, 2016)

Consider Enterprises Air Group of VS-6 and VB-6, 30 SBDs got 8 hits on Kaga and Akagi, that is better than 1 in 4, similar to Stuka accuracy.

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## stona (Nov 27, 2016)

ORS 2nd TAF examined the accuracy of Typhoon bombers on operations between October 1944 and April 1945. Nine 'pin-point' bombing targets were analysed by plotting both bomb distribution from aerial photographs and examination of the targets on the ground. The average radial error for these attacks was 158 yards with only 50% of bombs falling within 130 yards of the target. The chances of actually destroying such a target are consequently rather slim.
Similar results were found in other surveys. For example a survey of seventeen railway line targets, 320 bombs dropped, found the average line error to be 69 yards with only 50% of bombs falling within 50 yards, either side of the target.

The Typhoons and Spitfires involved in these surveys were obviously not purpose built dive bombers but fighter bombers which employed various dive bombing techniques and this may be reflected in their relative inaccuracy. Their pilots may well have been less well trained in the arts of dive bombing than those from a unit established with this specific role and .at least some of the targets may have been defended. On the other hand these poor results are for targets which were easily visible from the air, such as bridges, railway lines and road or rail crossings. Results for other targets, which might be small and camouflaged, such as gun positions, would inevitably be far worse.

Cheers

Steve

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## BiffF15 (Nov 27, 2016)

stona said:


> The figures for 'real' dive bombing in 1944/5, by Typhoons and Spitfires, were nowhere near as good as this.
> 
> Cheers
> 
> Steve



The differences probably lie somewhere between training and reality. To little of the former and AAA of the latter...

Cheers,
Biff


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## davebender (Nov 27, 2016)

not purpose built dive bombers but fighter bombers
I suspect purpose built dive bombers have features such as a better bomb release mechanism and superior bomb sights. In addition to crew that are fully trained (hopefully!) in that type of mission. Many of them such as Ju-87D and A-10 also have significant armor for protection against ground fire. There are other features too such as stability while diving that improve weapon accuracy.


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## parsifal (Nov 27, 2016)

true divebombing was deadly to the RN until they began to beef up with AA able to reach to the top of the typical dive envelope. Bombs had to be dropped from a certain height so that they achieved sufficient vertical velocity for armour penetration. Varied of course with target, but for Illustrious the typical heights at which the ordinance was dropped was around 3000', not high enough to ensure penetration of the main armoured hangar deck

The record of hit on the Illlustrious were, according to Norman Friedman's British Carrier Aviation, which I think should be a fairly definitive source.

On 10th January there were eight hits:
1. 500lb bomb on S2 pom-pom
2. 1000lb bomb through port forward end of flight deck, bursting above the water outside the ship
3. 1000lb bomb through the aft lift exploding above the lift platform
4. 1000lb bomb through the flight deck on the centreline, exploding above the hangar deck
5. 500lb bomb on the edge of the aft lift, exploding high in the well
6. 1000lb bomb through P1 pompom, hit edge of armour deck but did not explode, did cause fire
7. 1000lb bomb near miss starboard side aft
8. 500lb bomb down aft liftwell.

delivered by 43 Ju 87s, some of which were diverted to attack other ships (15 from memory, no results recorded in the first attack)

As Aa suites increase, Divebomber loss rates began to climb alarmingly. A divebomber is a vulnerable target both during its form up and also during the dive, most vulnerable to CAP during form up and approach, and most vulnerable to attack from Flak during actual dive. beef up either of these defences and the divebomber as a concept is toast.

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## parsifal (Nov 27, 2016)

stona said:


> ORS 2nd TAF examined the accuracy of Typhoon bombers on operations between October 1944 and April 1945. Nine 'pin-point' bombing targets were analysed by plotting both bomb distribution from aerial photographs and examination of the targets on the ground. The average radial error for these attacks was 158 yards with only 50% of bombs falling within 130 yards of the target. The chances of actually destroying such a target are consequently rather slim.
> Similar results were found in other surveys. For example a survey of seventeen railway line targets, 320 bombs dropped, found the average line error to be 69 yards with only 50% of bombs falling within 50 yards, either side of the target.
> 
> The Typhoons and Spitfires involved in these surveys were obviously not purpose built dive bombers but fighter bombers which employed various dive bombing techniques and this may be reflected in their relative inaccuracy. Their pilots may well have been less well trained in the arts of dive bombing than those from a unit established with this specific role and .at least some of the targets may have been defended. On the other hand these poor results are for targets which were easily visible from the air, such as bridges, railway lines and road or rail crossings. Results for other targets, which might be small and camouflaged, such as gun positions, would inevitably be far worse.
> ...




Agree completely however, a bomb 250lb or larger dropped within 50yds of a train, or most other targets except an AFV was likely to destroy the target. Trains were usually attacked in squadron strength, to ensure a kill for the train. Such was the effect on german train movements that by 1944 a train movement in western Europe was a rare thing. The germans didn't restrain themselves like this because they were not afraid of allied airpower....

Rockets were notoriously inaccurate, with about the same lethality as a 5/38" naval shell. During the landings at Gela, in Sicil, it was noted that shells falling within the 50yds radius were usually enough to de-track the attacking tigers, or upend them. a 5/38 however lacked the actual strength to actually knock out a tiger.

For Normandy. the statistics for hard AFV targets being knocked out by rocket firing typhoons were negligible, however the soft support vehicles were generally cut to pieces, and many of the heers precious tanks were lost due to fuel shortages and breakdowns. Aircraft working with the ground forces were deadly, aircraft trying to do their own thing were basically useless. Given enough time, a broken down tank can be repaired, or refuelled.

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## pinehilljoe (Nov 27, 2016)

parsifal said:


> true divebombing was deadly to the RN until they began to beef up with AA able to reach to the top of the typical dive envelope. Bombs had to be dropped from a certain height so that they achieved sufficient vertical velocity for armour penetration. Varied of course with target, but for Illustrious the typical heights at which the ordinance was dropped was around 3000', not high enough to ensure penetration of the main armoured hangar deck
> 
> The record of hit on the Illlustrious were, according to Norman Friedman's British Carrier Aviation, which I think should be a fairly definitive source.
> 
> ...



Eight hits on a carrier size target by about 25 Stukas, that's what I would call deadly accurate.


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## parsifal (Nov 27, 2016)

the attacks on illustrious was essentially a training exercise. the form up point was 10000', well above the CAP which was caught low and out of position. Diving singly or in pairs the Ju-87 would initially descend to 5000' stop briefly. 5000' is the equivalent of point blank range. but still well above effective range of the main LAA weapon available to the RN at that time (40mm pom poms). Peeling off individually from that intermediate, the stukas would then descend even lower to about 3000 feet where the ordinance was released. it was in the runs out of the target area that the late arriving Fulmars finally tucked in and shot a few up.

it doesn't get better than 10 January 1941 for the divebombers


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## Shortround6 (Nov 28, 2016)

davebender said:


> Many of them such as Ju-87D and A-10 also have significant armor for protection against ground fire.



Depends on the ground fire.

British army AA in 1940 was 4 Bren guns on individual mounts on the back of small trucks per battalion. In 1941 the mounts were changed to twin mounts. Heavier guns were pretty much WW I 3in/20cwt guns that weren't much use against dive bombers. By 1944 a British division had 54 40mm Bofors guns and an assortment of 20m guns. Carrying protection against 20mm guns for a Ju 87 is dubious
and against 40mm guns is impossible. 

Grouping the Ju-87 and the A-10 together is laughable. While both do the same sort of missions (sort of) the A-10 weighs empty about 3 times as much as JU-87D, around what a B-26 Marauder weighed, and loaded it weighs about what an early B-17 weighed. For power they are so far apart it is almost impossible to compare. An A-10 has more thrust than an F-100 Super Sabre and about 20% more power than a Canberra bomber. Between the engine power and metallurgy (titanium armor) they is no way that the protection of an A-10 and a Ju-87 are comparable.

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## pbehn (Nov 28, 2016)

What a dive bomber can achieve depends on the target, a trawler/destroyer is much more difficult to hit than a carrier and not just because of its size it can also change direction much more quickly.


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## stona (Nov 28, 2016)

pbehn said:


> What a dive bomber can achieve depends on the target, a trawler/destroyer is much more difficult to hit than a carrier and not just because of its size it can also change direction much more quickly.



This is correct, but it was not obvious at the beginning of the war. The Royal Navy's _"Air Defence Instructions, 1939"_ forbade fast avoiding action against dive bombers. Many ships' commanding officers took a different view and the matter was referred to the director of the Naval Air Division in 1940. He conceded that avoiding action might cause a reduction in bombing accuracy because it would cause the pilot to adjust his aim, which was not regarded as easy, but in conclusion reinforced the official view that avoiding action should not be taken at the expense of throwing off the ship's AA fire.
Maneuverable ships, like destroyers, might be better able to 'dodge' bombs than others. It has been suggested that the destroyer _Gurkha_ was lost to air attack in the Norwegian campaign because her Captain was a 'gunnery officer' who believed in the efficacy of AA fire and chose to keep a steady gun platform without weaving, thereby also presenting a steady target.
Later 'dodging' became the norm.
Alec Dennis was on board the destroyer _Griffin_ as part of Force B off Crete when attacked (along with _Greyhound, Gloucester and Fiji_) by JU 87s. Twenty Ju 87s made the first attack comingdown in,
_"groups of three, one after the other, dividing their attention among all four ships. It was a classic attack, technically interesting, physically terrifying and, actually, ineffectual."_
Dennis described how all the bombs missed as they weaved about at full speed with the cruisers (_Gloucester and Fiji_) throwing up large amounts of flak.
Clearly evasive action did work. _Fiji_ would later endure nearly 13 hours of air attack before finally being hit. She had run out of ammunition and was defiantly firing practice ammunition, solid shot, at the attacking aircraft! 
The destroyer _Kipling_ was attacked 83 times in one three hour period, but was not hit.
The light cruiser _Naiad_ managed to dodge 36 near misses in one ten minute period before eventually being hit.
It was these stories, and many like them, that led Cunningham to write (in 'A Sailor's Odyssey'):
_"The hasty conclusion that ships are impotent in the face of air attack should not be drawn from the Battle of Crete."_
His colleagues in the USN would soon find reason to agree.

Cheers

Steve

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## RCAFson (Nov 29, 2016)

Fairey Swordfish as divebomber:

The Swordfish was also capable of operating as a dive-bomber. During 1939, Swordfish onboard HMS _Glorious_ participated in a series of dive-bombing trials, during which 439 practice bombs were dropped at dive angles of 60, 67 and 70 degrees, against the target ship HMS _Centurion_. Tests against a stationary target showed an average error of 49 yd (45 m) from a release height of 1,300 ft (400 m) and a dive angle of 70 degrees; tests against a manoeuvring target showed an average error of 44 yd (40 m) from a drop height of 1,800 ft (550 m) and a dive angle of 60 degrees.
Fairey Swordfish - Wikipedia​

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## michaelmaltby (Nov 29, 2016)

Didn't Louis Mountbatten lose his destroyer Kelly off Crete to a dive bomb down the ship's funnel? Now _that's _a pickle in a barrel.


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## stona (Nov 29, 2016)

Not quite. 
On that day, having survived two earlier attacks, _Kelly_ and _Kashmir_ were attacked by Ju 87s. _Kashmir _was hit first. Kelly continued to carry out evasive manoeuvres, dodging some bombs, before being hit, in Mountbatten's words, _"square on X gun-deck."_
He lost control of the ship which started to list badly. He would later write
_
"I realised the bomb must have torn a gaping hole down near X magazine, as we had lost our stability and were rolling right over. I suddenly saw the water rise on our port side in a raging torrent of over 30 knots and thinking, ‘Whatever happens I must stay with the ship as long as I can. I must be the last to leave her alive."_

I'd say_ 'square on X gun deck' _was still a pretty good effort, from a German point of view, even if not quite as dramatic as a bomb down the funnel.

I'm not sure what the fate of the fictional _Torrin_ was in that awful film (In Which We Serve) in which Noel Coward plays a thinly disguised Mountbatten, but maybe the bomb down the funnel comes from there?

Cheers

Steve

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## Shortround6 (Nov 29, 2016)

Bomb _down_ the funnel was popular description but _rarely_ achieved in practice. On a destroyer it makes no difference. On A cruiser or battleship the funnel area is gap in the armor deck making it easier for a bomb to reach the boiler rooms. However even battleships had armored grates in the funnels to make getting a bomb (or shell) though the area much harder. On a destroyer with no deck armor any hit on the deck over the machinery spaces is going to penetrate into the machinery spaces. 
Boiler rooms were sealed compartments and pressurized by fans with the funnel as an exit with the boiler fireboxes as the conduit, explosions that affected the funnel or uptakes _could _momentarily reverse the airflow and "blow out" the fires. Which then take a while to relight. 
Arizona was famously reported to have been sunk by a bomb down the funnel, later research has concluded it was an AP bomb (modified naval shell) that penetrated the armor deck over a magazine.


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## Greyman (Oct 10, 2017)

stona said:


> ORS 2nd TAF examined the accuracy of Typhoon bombers on operations between October 1944 and April 1945. Nine 'pin-point' bombing targets were analysed by plotting both bomb distribution from aerial photographs and examination of the targets on the ground. The average radial error for these attacks was 158 yards with only 50% of bombs falling within 130 yards of the target. The chances of actually destroying such a target are consequently rather slim.
> Similar results were found in other surveys. For example a survey of seventeen railway line targets, 320 bombs dropped, found the average line error to be 69 yards with only 50% of bombs falling within 50 yards, either side of the target.



Was just reading a book and it referred to a British study of Stuka accuracy against their positions in the Western desert; CEP of about 30 yards when unmolested and 70 yards when being engaged by anti-aircraft fire.

Similar results were seen in Stuka attacks against British shipping; CEP of 70 yards (while being engaged).


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## parsifal (Oct 10, 2017)

in my opinion, the most accurate divebombing attacks were those that sank the cruisers Cornwall and Dorsetshire. 5th April 1942. Attacks delivered 5th April 1942, in the space of less than 8 minutes by Vals of 1st mob flt. 53 attackers, at least 28 direct hits on the ships, and at least 15 near misses. That's a hit rate in excess of 80%. I don't think that level of accuracy against a high speed target has ever been matched since.


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## Ascent (Oct 10, 2017)

Is there any information out there on the accuracy of dive bombing in the Burma theatre? On another forum I've read a veterans account of flying Vultee Vengeances out there.

He seemed to feel they were pretty accurate with their vertical dive. Also I believe Japanese AA was much lighter than would be encountered in the ETO.


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## Greyman (Oct 10, 2017)

Sounds like the Vengeances were very, very accurate. Though as you say, the AA fire was a way different animal in Burmese jungle than it was in NWE. An anecdote from a Vengeance pilot mentions 800 foot bombing altitude!

Compare that with the 6,000 feet the Typhoons dive-bombed at ... heavily defended targets anyway.


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## Zipper730 (Oct 10, 2017)

Greyman said:


> *AFDU testing Hurricane II - 250 lb bombs*:
> 
> low level attacks - 50 feet altitude
> 
> ...


Seems that the lower the bomb was released seemed to dictate accuracy the best


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## Greyman (Oct 10, 2017)

Reading around about the Vengeance, it seems like 2,000 feet was a much more common drop height used by the RAF. Also came across this bit from Eric Brown:

_True dive bombers like the Ju 87, the Dauntless and the Vengeance were of course always superior in that role to fighters adapted for dive-bombing as a secondary role. The Vultee Vengeance I was a poor aircraft, which, by modification to become the Vengeance IV, eradicated all the original faults, until it was probably the nearest in efficiency to the Ju 87_.

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## RCAFson (Oct 10, 2017)

pinehilljoe said:


> Eight hits on a carrier size target by about 25 Stukas, that's what I would call deadly accurate.



Actually the 8 hits were delivered in 3 separate attacks, IIRC, with at least 50 attacking stukas. The initial attack delivered 6 hits from ~30 attackers, of whom 3 were shot down by AA.

Operation Excess: HMS Illustrious off Malta, January 10, 1941


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## RCAFson (Oct 10, 2017)

Of course we all know that these were the most feared strike aircraft in the Allied inventory and here is some of their practise dive bombing results:

The Swordfish was also capable of operating as a dive-bomber and in 1939 HMS Glorious used her Swordfish for a series of dive-bombing trials, during which 439 practise bombs were dropped at dive angles of 60, 67 and 70 degrees, against the target ship HMS Centurion. Tests against a stationary target showed an average error of 49 yd (45 m) from a release height of 1,300 ft (400 m) and a dive angle of 70 degrees. Tests against a manoeuvring target showed an average error of 44 yd (40 m) from a drop height of 1,800 ft (550 m) and a dive angle of 60 degrees.[36] The Fairey Albacore was also designed to act as a dive bomber and was used extensively in this role during World War Two.[37]
Dive bomber - Wikipedia​

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## Ascent (Oct 11, 2017)

Greyman said:


> Sounds like the Vengeances were very, very accurate. Though as you say, the AA fire was a way different animal in Burmese jungle than it was in NWE. An anecdote from a Vengeance pilot mentions 800 foot bombing altitude!
> 
> Compare that with the 6,000 feet the Typhoons dive-bombed at ... heavily defended targets anyway.




800 feet seems unlikely as the bombing altitude unless that's the height they finished the pull up at. Remember the vengance dived at 90°, if you release and start to pull up there I can't see you avoiding the ground.


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## Peter Gunn (Oct 11, 2017)

parsifal said:


> *SNIP*
> 
> it doesn't get better than 10 January 1941 for the divebombers



Possibly, I'd posit 4 June 1942 wasn't too bad either.

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## Peter Gunn (Oct 11, 2017)

parsifal said:


> in my opinion, the most accurate divebombing attacks were those that sank the cruisers Cornwall and Dorsetshire. 5th April 1942. Attacks delivered 5th April 1942, in the space of less than 8 minutes by Vals of 1st mob flt. 53 attackers, at least 28 direct hits on the ships, and at least 15 near misses. That's a hit rate in excess of 80%. I don't think that level of accuracy against a high speed target has ever been matched since.



True, it is a good example of how well trained the IJN pilots were, so I rather agree. Although Cornwall and Dorsetshire were alone without CAP and not exactly throwing up a storm of AA fire whilst the attack came out of the sun, so the dive bombers were on them rather quickly.

Although at Midway, Yorktown was attacked by I think 7 bombers, three of which were shot down before they dropped too close to the carrier, so out of the remaining four, I think they scored three hits? And that was against a carrier moving at high speed and turning with two cruisers and five destroyers slinging lead and Yorktown's CAP active. Not too shabby a performance either.

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## Glider (Oct 11, 2017)

In Burma one of the reasons the Hurricane was kept in service was due to its accuracy as a dive bomber. The thick wings of the Hurricane meant that it didn't tend to 'mush' when pulling out of a dive and as a result they would drop from a much lower height than other bombers.

Another interesting weapon was the use of modified depth charges in the Jungle. The much higher percentage of explosive to weight in depth charge was use to basically make an instant clearing taking the cover off the Japanese making them vulnerable to further attack


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## Greyman (Oct 11, 2017)

Ascent said:


> Remember the vengance dived at 90° ...



Not necessarily. RAF fighter-bombers/dive-bombers had tactics for a variety of angles. Though in that anecdote he does indicate a very, very steep angle.

Perhaps there was a typo somewhere along the line and he meant the attack was started at 800*0* feet.


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## Zipper730 (Oct 12, 2017)

RCAFson said:


> Tests against a stationary target *showed an average error of 49 yd (45 m)* from a release height of 1,300 ft (400 m) and a dive angle of 70 degrees. Tests against a manoeuvring target *showed an average error of 44 yd (40 m)* from a drop height of 1,800 ft (550 m) and a dive angle of 60 degrees.


Ironic that they were more accurate against a moving target than a fixed one.

Admittedly, most people shoot basketballs better when just practicing than in a game and, while I was never a spectacular shooter, I was often better under pressure with somebody coming right at me, than just standing there -- I'm not sure why that's so, but I'm often a person that has trouble with anxiety, and yet in emergency situations I usually can respond just fine.


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## Ascent (Oct 13, 2017)

Greyman said:


> Not necessarily. RAF fighter-bombers/dive-bombers had tactics for a variety of angles. Though in that anecdote he does indicate a very, very steep angle.
> 
> Perhaps there was a typo somewhere along the line and he meant the attack was started at 800*0* feet.



Certainly for the pilot who's anecdotes I've seen that was there only attack profile. Their sighting mechanism was in fact a yellow line painted on the cowl.

They pass the target until it appeared behind the right wing, then wing over and point the nose at the target in a vertical dive. If they were perfectly vertical and lined the yellow line up with the target then they could be very accurate. I can't remember what altitude they started or pulled out though. I'll look but it's hidden in the middle of a thread over 500 pages long.


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## Greyman (Oct 13, 2017)

... during the Battle of Ngakyedauk Pass ...two Vengeance squadrons flew no less that 269 sorties in just over a week in tactical support of ground forces holding this position. Up to 50 sorties were mounted a day, with a maximum of two dozen aircraft on some targets. But most attacks were made by boxes of six diving from 8000 ft at 320 mph and pulling out around 2000 ft.

... 19 March 1944 ... enemy artillery batteries on Hill 1301, which were holding up the advance of Allied troops who were within 200 yards of the target, 'hence precision bombing was required to destroy this strong gun position'. The mission was led by Squadron Leader Prasad with six aircraft. They attacked at 1130 in a steep dive from 9000 ft down to 2000 ft with 6000 lb of GPTI bombs. Direct hits on the guns were scored by Prasad himself and Warrant Officer Lamb. The remaining bombs burst in a close concentration within 30 yards all round.

... the third mission this day saw all 12 aircraft, led by Squadron Leader Prasad and Curtis in two boxes, attacking PT162 once more. Prasad again made a perfect approach and dived from 8000 ft ...

'We went on operations immediately,' said Hugh Seton with 8 Squadron ... 'Dives were usually commenced at 10,000 ft to 12,000 ft above the target, with release of the bombs and immediate pull-out usually made at about 3500 ft. ...'

... the mission was to cut Japanese lines of communications at Apakuwa ... at 1535 they tipped over into the steep attack dive from 9000 ft down to 2000 ft at 300 mph.

... next day another six-plane attack was mounted against buildings thought to be a Japanese HQ on the northern side at the foot of a hill at Point PN3030. Twelve 500 lb bombs were dropped in steep dives from 11,000 ft down to 2000 ft ...

The target was a Japanese forward position at Point 124. The weather was good, slightly hazy, and the leader and his vic attacked at 1710, as specified by the Army, in a north to south run and was then followed by the second vic on south to north-west steep dives from 10,000 ft down to 2500 ft at 310 mph ...

... on the last day of the year a similar attack was mounted against buildings at Kanwa and Linfu with dives from 11,000 ft down to 3000 ft.

'... we usually went into our dive at about 10,000 to 12,000 ft at an angle of 75 degrees plus, reaching a speed of about 350 mph with our dive brakes out and then retracting our brakes after dropping bombs and pulling out at about 3000 ft. ...'

' ... I can remember greying out. You went from 10,000 ft to 2,000 ft; it seemed like a long time. Four or five seconds hanging on the brakes, but it seemed like a long time and you wondered if you were going to come out of it.'

'The high dive-bombing phase from 12,000 ft was, however, not without incidents. The only hands usually approached the target, rolled over and down on the target and selected dive brakes out in a well coordinated operation. The difficult part was to judge the release of the bomb and the pull-out from the dive. Here the old hands counted to themselves on the way down at 300 knots, released the bomb, broke the dive at about 2000 ft, and, at an angle of about 60 degrees to the ground, selected dive brakes in, and escaped at high speed at ground level.'

'I commenced each dive from about 12,000 ft, releasing my bombs between 2000 and 3000 ft.'

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## davebender (Oct 15, 2017)

Skip bombing was highly accurate too but like torpedo bombers was vulnerable to AA fire.


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## wuzak (Oct 15, 2017)

davebender said:


> Skip bombing was highly accurate too but like torpedo bombers was vulnerable to AA fire.



Weren't dive bombers also vulnerable to AA fire?


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## parsifal (Oct 16, 2017)

once in the dive they were. up until that point they were about the same as any other aircraft.

Typically the D/B would approach at about 10000ft, then push into dives in twos and threes, descending to about 5000 ft . Whilst in that steep attack, they were vulnerable as the pilot struggled to stay conscious and the aircraft virtually froze up. Diving straight, they were ideal targets.

the problem was the release height. At 5000 ft, they were beyond the effective ceiling of the two pounder pom poms and 20mm guns. They were beyond the effective ceiling of the IJN 25mm guns, and the DKM C-38 37mm guns were too slow to be considered effective. the bofors was the only really effective medium calibre AA weapon in mass scale service that could be considered effective

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## Milosh (Oct 16, 2017)

I cab see the pilot going unconscious during the pullout but why in the dive?

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## Shortround6 (Oct 16, 2017)

The dive bomber was flying a straight "course" (or nearly so, aiming corrections not evasive maneuvers) _in _the dive, after bomb release and from the start of the pullout the plane pretty much continued "on course" with pilot "greying out" if not momentarily blacking out so any evasive maneuvers are going to be minimal at best. At least until the plane is nearly horizontal.
Ju-87s had an "automatic" dive recover system initiated by the bomb release, which helped lower the release height. Less chance of pilot error (not holding quite enough "G"s in the pullout) making contact with the ground/sea. 

The rapid (or not so rapid) proliferation of light AA guns, both at sea and on land, raised the losses of dive bombers for the results achieved and lead to the decline in it's importance. 

Really light AA guns, rifle caliber mgs, heavy machineguns and 20mm cannon were almost "revenge" weapons. They could shoot down dive bombers but probably not before the release point. They could force the dive bombers to release from higher altitudes and thus have less accuracy.
The slightly larger guns could force the release point a bit higher and as Parsifal said, the 40mm Bofors was in a class of it's own as far as both altitude and destructive effect. At least among the common AA guns used both afloat and ashore. 

I would note that it was much faster to refit ships with large suites of AA guns than it was to develop new dive bombers and depending on which army the ground units sometimes saw a large change in AA guns in just a few years so while some countries did develop new dive bombers some of these faced greatly increase AA defenses and some did not. The Japanese Army and Navy facing vast numbers of late war aircraft (or at least 2nd generation) with 1st generation AA weapons and often a 1st generation scale of issue in the Army's case.


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## pinehilljoe (Oct 28, 2017)

parsifal said:


> in my opinion, the most accurate divebombing attacks were those that sank the cruisers Cornwall and Dorsetshire. 5th April 1942. Attacks delivered 5th April 1942, in the space of less than 8 minutes by Vals of 1st mob flt. 53 attackers, at least 28 direct hits on the ships, and at least 15 near misses. That's a hit rate in excess of 80%. I don't think that level of accuracy against a high speed target has ever been matched since.



I vote for the SBD initial attacks at Midway (but I'm biased) crippling the three carriers.

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## parsifal (Oct 28, 2017)

they certainly are up there, plus it would have to be said that this attacks were probably the most decisive of the war

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## JAG88 (Nov 7, 2017)

pinehilljoe said:


> I vote for the SBD initial attacks at Midway (but I'm biased) crippling the three carriers.



Mostly unaware targets, no flak, barely any maneuvering, no fighter opposition...

That same day Lt. Kobayashi led 18 Vals against Yorktown, eight were shot down by the CAP, three more dropped their bombs and engaged the F4Fs to give the other bombers a chance to complete their mission, the remaining seven attacked Yorktown while being chased by fighters and facing a wall of flak, still they did it as planned with the aircraft armed for flak suppression diving first and getting a hit, then the remaining four attacked using armor piercing bombs and got two hits.

A 42% hit rate while under attack, against heavy AA fire and after taking heavy losses... cant beat that for skill, valor and professionalism.

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## JAG88 (Nov 7, 2017)

parsifal said:


> the attacks on illustrious was essentially a training exercise. the form up point was 10000', well above the CAP which was caught low and out of position. Diving singly or in pairs the Ju-87 would initially descend to 5000' stop briefly. 5000' is the equivalent of point blank range. but still well above effective range of the main LAA weapon available to the RN at that time (40mm pom poms). Peeling off individually from that intermediate, the stukas would then descend even lower to about 3000 feet where the ordinance was released. it was in the runs out of the target area that the late arriving Fulmars finally tucked in and shot a few up.
> 
> it doesn't get better than 10 January 1941 for the divebombers



Well, they did sent in the Italians first in order to get the fighters out of the way, so credit for good planning and knowing how to take advantage of enemy weapon and procedure limitations.


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## JAG88 (Nov 7, 2017)

parsifal said:


> in my opinion, the most accurate divebombing attacks were those that sank the cruisers Cornwall and Dorsetshire. 5th April 1942. Attacks delivered 5th April 1942, in the space of less than 8 minutes by Vals of 1st mob flt. 53 attackers, at least 28 direct hits on the ships, and at least 15 near misses. That's a hit rate in excess of 80%. I don't think that level of accuracy against a high speed target has ever been matched since.



I always found that claim a bit suspect, who made the count? The IJN pilots were deadly accurate, but still, 80%? Maybe since they got 42% with opposition I shouldnt be so sceptic...


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## parsifal (Nov 7, 2017)

The circumstances of the sinking were made in reports to the admiralty, with the numbers of bomb hits and/or near misses studiously recorded in those reports. We also know the numbers of IJN Vals committed to the attack, so combining those two sources of information it is not hard to verify that the hits to bombs dropped works out at an 80% hit rate.

WWII cruisers has a good summary of the damage suffered by the two cruisers:

“The Dorsetshire (Captain Agar) and Cornwall (Captain Mainwaring) had sailed from Colombo at 2200 4th April. During the night orders were received from the commander in chief to join him at 1600 5th April and at about 0700 course was altered for this rendezvous. About an hour later the report of strong enemy forces to the east of the cruisers was received in the Dorsetshire, and speed was increased to 27.5 knots, the maximum Cornwall was able to proceed, in order to join the commander-in-chief as soon as possible.

It was a calm day, with little or no cloud, and a slight haze over of the sun; visibility was extreme. At about 1100 a single aircraft was sighted by the Cornwall and reported to the Dorsetshire. It was a long way astern estimated at about 20 miles, and was lost sight of before it could be identified. Two other aircraft were sighted about 1300, one some 14 miles ahead, and judged to be friendly, and one astern, which closed to within 14 miles and was considered hostile. In view of the proximity of the rendezvous and the risk of the enemy aircraft detecting the commander-in-chief, it was decided to break wireless silence and make a shadowing report.

At about 1340, 5th April, three aircraft was sighted by the Dorsetshire overhead at high altitude: assuming them to be hostile, she opened fire immediately, but within a few seconds they dived on the Cornwall which was about a mile on the port quarter, and released their bombs at a low altitude, the first striking the after hangar and the second scoring a near-miss port side forward. Simultaneously, a separate formation of three aircraft attacked the Dorsetshire; avoiding action was taken to starboard, but all three bombs hit, one through the quarter deck disabling the steering gear, the second through the catapult, disabling both wireless offices, and the third port side amidships, putting out of action all the port anti-aircraft armament, except the pom-pom. Attacks by a succession of formations of three followed at intervals of a few seconds. Hits were received through the base of the foremost funnel, putting A boiler room out of action; on the quarterdeck, disabling X turret, and at the base of the after funnel bringing it down and at the same time blowing up the H.A. magazine. This bomb also put both pom-poms out of action.

Four minutes after the initial attack the ship took a definite list to port; all communication between the bridge and other parts of the ship had gone, and looking down from the bridge aft, all that could be seen was flames and smoke extending to the stern. At least four more hits were received making a total of 10, in addition to several near-misses, and two minutes later the captain realising the ship was sinking, ordered all hands on deck. This was followed in half a minute by the order to abandon ship, by which time she was slowly turning on to her beam-ends. Enemy aircraft were still flying low over the ship and using their machine guns, and it was possible to get a clear picture of them and their occupants. Almost immediately afterwards she capsized and sank stern first. It was incredible how quickly the ship sank - she just took one plunge by the stern, and as we were thrown into the water, the bows towered up almost vertically alongside us. All around was wreckage of sorts and oil fuel, though not very thick. 

Meanwhile Cornwall, though still afloat, had not fared much better. For the next two minutes after the initial attack, bombs fell almost continuously, some scoring direct hits, but the majority were very near misses. Explosions followed each other so quickly that no exact idea could be formed of their sequence, or of the separate effect of each bomb. Altogether 8 hits and six near misses were sustained; only 2 complete misses were observed.

A near miss port side, abreast the Bridge, flooded large sections of the port bilges and dislocated electric power suppliers all over the ship. All personnel in the after engine room were killed (it is believed) by a near-miss on the starboard side, abreast the hangar, and both boiler rooms were flooded by near-misses and had to be evacuated. A bomb on the water line abreast the hangar, burst in the foreward engine room, which rapidly filled with steam and smoke and had to be evacuated, most of the personnel being saved; hits were also received between X and Y turrets, near the Dynamo room, in the sick bay flat and in the recreation space. Many of the Bridge personnel were killed or wounded by splinters of a bomb which exploded on the Starboard paravane; in one case at least the Bridge was also machine gunned. An oil bomb produced a flame which enveloped the starboard pom-pom and fore starboard superstructure, swept right over the air defence position and 8in director. Battledress and anti-flash gear saved all except the gun crew whose clothing caught fire. In less than five minutes after the attacks started all power had failed, and both boiler rooms and both engine rooms were flooding rapidly. The port gunwhale of the ship was awash, and the starboard outer propeller was breaking surface, the ship being slightly down by the bows. Thick black smoke was issuing from the foremost funnel uptake casings on both sides of the upper deck.

By 1351 the last bombs had been dropped, the Dorsetshire had sunk, and endeavours were being made in the Cornwall to correct the list to port and to get away a report by wireless. It soon became evident the ship was sinking, and the Captain, who continued to direct operations though wounded in the right shoulder, gave orders to prepare to abandon ship. He then with the remaining Bridge personnel, left the Bridge and making his way aft saw to the launching of all available floats. At 1355 the final order to abandon ship was given.

While this was being done, the Japanese aircraft, which had ceased attacking, either because it was obvious the ship was doomed, or more probably because they had expended all their bombs, formed up and flew over the survivors. 27 dive bombers and one floatplane were counted; there was no machine gunning of the men in the water.

The end was not long in coming. Some four minutes later the Cornwall heeled over to about 70 degrees and went down by the bows, taking her final plunge at an angle of about 30 degrees to the vertical and making singularly little disturbance. Once again the Japanese airmen had attacked and their dive bombing had been as successful as the torpedo and high-level bombing used against the Prince of Wales and Repulse. The attacks were carried out by single-engine 2 seater planes diving steeply at an angle of from 60 degrees to 80 degrees from ahead or fine on the bow. Their tactics were facilitated by the ships being on a southerly course, thus enabling them to combine the advantages of attacking down sun and from ahead - the cruisers blind spot for AA defences. The attacks were well pressed home, the height of release estimated at from 500 ft to 1000 ft and the bombing was remarkably accurate. The bombs were dropped in such a manner as to have one falling at the moment the previous one was exploding. The size of the bombs dropped was thought in the Cornwall to be between 250 and 500 pound. Some burst on impact and in some the explosion was delayed. The great effect of the near-misses which burst underwater was remarked on. So sudden and severe was the attack that the main HA armament of both cruisers was put out of action before more than a few rounds could be fired. The short range weapons continued to be fought right up to the last; the Cornwall is credited with having damaged one aircraft and probably destroyed another which was seen to hit the water.

A surprisingly large number from each cruiser survived these devastating attacks. They found themselves adrift in a shark-infested ocean, 300 miles from land, and with the scantiest of boat accommodation. Of the Dorsetshire there remained only 2 whalers - leaking badly - a skiff, a floatanet, 2 Carley floats, some rafts and odd bits of wreckage. The wounded were placed in the boats or rafts, and the remainder swam round collecting wreckage and joining it up as rafts around the boats. In a short time all survivors from the ship numbering over 500, formed one single body in the water, and were under perfect discipline and control. A couple of miles away Cornwall's survivors were doing much the same. In their case a whaler, a motor boat, 2 large oiling fenders and six floats formed the rallying point. Help could not be expected to reach them for 24 hours, but they were cheered in the late afternoon by the appearance of an Albacore, followed shortly by a Fulmar, which passed them a message to hold on.

About sunset an aircraft believed to have been hostile was sighted flying very high overhead. Then the night closed down. All that night and the following day they drifted in an oily calm, the wounded and exhausted in the boats, which were loaded almost gunwhale under, and the remainder in the water, holding on to what they could. The spirit, fortitude and discipline of the officers and men of both ships throughout this ordeal, as well as during the action, is described as beyond all praise. Soon after sunrise, 6 April, the heat became intense, and head coverings were fashioned from pieces cut from battle dress. Sharks were numerous; but these seemed content to wait for the corpses which were from time to time committed to the sea, and made no attempt to molest anyone living. Both parties were short of food and drink; what they had was sparingly doled out at intervals. In the late afternoon, 6th April, the appearance of an Albacore put good heart into everyone, and shortly afterwards the masts of a cruiser and two destroyers were sighted over the horizon to the south-west. These proved to be the Enterprise, Paladin and Panther, and their 30 hours ordeal was nearly at an end. 1122 men in the water, for the most part exhausted and with a large number of wounded, were brought on board within the space of an hour without the loss of a single life.

19 officers and 215 ratings were lost from Dorsetshire and 10 officers and 180 ratings from Cornwall”.

From this source;

http://www.armouredcarriers.com/battle-for-ceylon-hms-indomitable-formidable/

“In total, the strike included 18 Vals from Soryu, 18 from Hiryu and 17 from Akagi.

By 1348, Dorsetshire’s bow lifted as her stern began to slip beneath the waves. In all, she’d been hit by 17 500lb bombs

Japanese reports are cited as saying 13 bombs were dropped on Cornwall, with 11 direct hits. The heavy cruiser went under, bow first, at 1400

Egusa’s dive-bomber crews had set a record for bombing accuracy: Every bomb either struck the heavy cruisers, or burst right alongside.

Spotted some two hours later by a Swordfish sent to investigate the scene, a rescue destroyer would be recalled by Somerville under the mistaken belief the Japanese main force was nearby”.

The Japanese reports are more or less confirmed by the after action reports to the RN admiralty.

It should be noted that Akagi’s Air Group did not actually participate in the sinkings. By the time this air group had arrived, the two cruisers were sinking already. Akagi’s air group was several minutes behind the attck formation led by Lt Obusa and Tomonaga.

You can play games with these reports all that you like, but it appears that from the available source information that the IJN achieved 30 hits out of 36 attacks. That’s a hit rate of 83%.

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## JAG88 (Nov 8, 2017)

IMpressive, thanks for the report, that is outstanding accuracy, it is a shame that the IJN didnt take better care of its elite crews.

And makes you wonder what would have happened if those crews had been at Coral Sea.


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## parsifal (Nov 8, 2017)

There were a lot of missed opportunities for the Japanese. The quality of their aircrews were outstanding, and yet strangely they tended to think of them as being expendable. the IJN never developed an advanced system for SAR of its downed aircrews, never developed a system of unit or crew rotations, so that green new formations being raised had that vital sprinkling of seasoned veterans to lead the way and work the unit up to steam. They never developed their training schools to churn out reasonably proficient aircrew, so that the quality of aircrew remained. IJN pilot training before the war, it took 5 years minimum for a new recruit to gain his carrier qualifications. the average service time for aircrew aboard Cardivs 1 and 2 was 9 years!. These were irreplaceable assets.

Cardiv 5 (shokaku and Zuikaku) were the strike force at Coral Sea. They were less well trained than the 4 carrier goups that made up most of the forces in the indian ocean. The RN forces in the indian ocean were hastily thrown together, with equipment unsuited to massed strikes, ships unused to working together, and caught badly out of position. in terms of planes on the decks, the RN was badly outnumbered. Worse, they committed the cardinal sin of underestimating the Japanese in every way imaginable

The US CAGs committed to coral sea were still short on training, but the C&C of their forces was far better. even though the training proficiency of the USN groups was still less than the IJN, they were probably the best trained formations in the USN at the time, with the most experience. The raids at tulagi just before the battle honed the skills of the USN CAGs. At Coral sea, the IJN CAGs did pretty well, but not well enough to make a strategic difference to the outcome. moreover it was the Japanese now making the strategic blunders. They were fatally overconfident, committed far too few forces to the attack, and their logistics were not up to the task anymore

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## Peter Gunn (Nov 8, 2017)

^^^ Not much to add to what parsifal said except to echo what Parshall and Tully said in "Shattered Sword" in that the IJN should have either committed all six fleet carriers to Coral Sea or none at all. They (IJN) were a finite asset, not so the USN opposing them.

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## JAG88 (Nov 8, 2017)

parsifal said:


> They never developed their training schools to churn out reasonably proficient aircrew, so that the quality of aircrew remained. IJN pilot training before the war, it took 5 years minimum for a new recruit to gain his carrier qualifications. the average service time for aircrew aboard Cardivs 1 and 2 was 9 years!. These were irreplaceable assets.
> 
> ...
> 
> The US CAGs committed to coral sea were still short on training, but the C&C of their forces was far better. even though the training proficiency of the USN groups was still less than the IJN, they were probably the best trained formations in the USN at the time, with the most experience. The raids at tulagi just before the battle honed the skills of the USN CAGs. At Coral sea, the IJN CAGs did pretty well, but not well enough to make a strategic difference to the outcome. moreover it was the Japanese now making the strategic blunders. They were fatally overconfident, committed far too few forces to the attack, and their logistics were not up to the task anymore



The worst part is that they really didnt give them much importance, very few pilots were officers, simply it was no path for professional advancement for a career savvy officer.

I recall reading somewhere that at Coral Sea the IJN did use a C&C aircraft to coordinate the strike, but I have found nothing further on the matter.



Peter Gunn said:


> ^^^ Not much to add to what parsifal said except to echo what Parshall and Tully said in "Shattered Sword" in that the IJN should have either committed all six fleet carriers to Coral Sea or none at all. They (IJN) were a finite asset, not so the USN opposing them.



Yeah, risking a partial force at Coral Sea was dumb...

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## Koopernic (Nov 9, 2017)

Computing bombsights were added to dive bombers and these increased accuracy and standoff distance. If one reads Eric Browns account of the Ju 87 he praises it as the only true vertical dive bomber but he also notes that aiming was simply by lines painted on the cowling. Anyone who has seen the precision a cricket bowler or baseball pitcher can achieve knows this can be considerable but at a certain point of range it fails and requires enormous training.

Above is a Stuvi 5B mounted on a Ju 87 upper window frame. In the pictures below of the reflector sight view one can see the cross hairs the moving “wurfabkomen” or “release solution” which showed where the bombs would go. The pilot would preset the release altitude, release velocity (fairly constant in the Ju 87) and dive angle. He might have to make adjustments to the dive angle. At the preset altitude a buzzer would let him know to release the bombs and an automatic pull up could commence. This would allow greater standoff distances and more accurate releases from non vertical angles.

When mounted on the Ju 88, Arado 234, Me 410, Do 217, He 177 the bomb sight was attached to a computer called the BZA “Bomb Ziel Automat” which continuously entered air speed, dive angle and altitude so that the impact point was calculated continuously. Typical dive angle might be 22 degrees which could be done without dive brakes. The attack could commence from as low as 8000ft and be complete by 5000 thus keeping the bomber some distance from AAA. The Stuvi worked from vertical to level so it was similar to the British Mk XV.

All light bombers were vulnerable, nothing unique about dive bombers. On the Ar 234 a periscope sight called the _Pilotvisiers (PV 1 B) _was used. I suppose it could have been fitted to fighters such as the Me 262 or even Fw 190 that didn’t have a good over the nose view. In the Ar 234 it was reversible so that the pilot had tail coverage and could aim fixed rearward firing guns. Both the EZ42 and EZ45 were being modified to deflect the mirror allow toss bombing, dive bombing and radar blind fire attacks.

Computing bombsights gave accuracy that eliminated the need for vertical dive bombing.

As can be seen from the illustration of the Ju 88 Installation there was a complex set of power supplies, sensors, inverters involved.

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## Peter Gunn (Nov 9, 2017)

pinehilljoe said:


> I vote for the SBD initial attacks at Midway (but I'm biased) crippling the three carriers.



See post #31


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## Peter Gunn (Nov 9, 2017)

JAG88 said:


> Mostly unaware targets, no flak, barely any maneuvering, no fighter opposition...
> 
> That same day Lt. Kobayashi led 18 Vals against Yorktown, eight were shot down by the CAP, three more dropped their bombs and engaged the F4Fs to give the other bombers a chance to complete their mission, the remaining seven attacked Yorktown while being chased by fighters and facing a wall of flak, still they did it as planned with the aircraft armed for flak suppression diving first and getting a hit, then the remaining four attacked using armor piercing bombs and got two hits.
> 
> A 42% hit rate while under attack, against heavy AA fire and after taking heavy losses... cant beat that for skill, valor and professionalism.



Agree, see my post #32, according to "Shattered Sword" seven dive bombers started their runs, three were shot down before they could drop coming in from astern of Yorktown, four managed a beam attack (Starboard) and got three hits. Not sure how anyone wants to count it, but I'd say 75% hits (3 out of 4) unless you want to count the three shot down astern in the mix, then yeah, 42% hit rate.


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## Peter Gunn (Nov 9, 2017)

Koopernic said:


> View attachment 471203
> Computing bombsights were added to dive bombers and these increased accuracy and standoff distance.
> 
> *SNIP*



Not to mention the hole in the wing bigger than the guy's head standing next to it...


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## stona (Nov 9, 2017)

"The Stuvi worked from vertical to level so it was similar to the British Mk XV."

Mk XIV? The Mk XV never entered production, if I remember correctly it was originally intended for Coastal Command.

Cheers

Steve


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## Koopernic (Nov 9, 2017)

stona said:


> "The Stuvi worked from vertical to level so it was similar to the British Mk XV."
> 
> Mk XIV? The Mk XV never entered production, if I remember correctly it was originally intended for Coastal Command.
> 
> ...




I’m relying on Wikipedia article on the Mk XIV Bomb sight.
Mark XIV bomb sight - Wikipedia

“The Mk. XV was a version designed for the Royal Navy and Coastal Command for attacking submarines. As these operations took place at low altitudes, even small changes of altitude air pressure could lead to large errors in calculations. The Mk. XV allowed the altitude input to be taken directly from a radar altimeter, eliminating these inaccuracies and any instrument lag.[13] The Mk. XVII was a Mk. XV modified for the very high attack speeds of the Naval Mosquito at more than 400 mph (640 km/h). As the Naval Mosquito did not have a bomb aimer's position, the sight head was unstabilized and mounted in front of the pilot.[13]”

Note it says there was a high speed version for the Mosquito known as the Mk XVII.

I just assumed it saw service.


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## stona (Nov 9, 2017)

I'll definitely check, but I don't believe either entered service or even series production. I could be wrong...wouldn't be the first time 
Cheers
Steve


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## JAG88 (Nov 9, 2017)

Peter Gunn said:


> Agree, see my post #32, according to "Shattered Sword" seven dive bombers started their runs, three were shot down before they could drop coming in from astern of Yorktown, four managed a beam attack (Starboard) and got three hits. Not sure how anyone wants to count it, but I'd say 75% hits (3 out of 4) unless you want to count the three shot down astern in the mix, then yeah, 42% hit rate.



I seem to recall that at least two if not all of the first three got to drop their bombs, getting one hit, so I counted them, AFAIK the other four got only 2 hits.

Let me check.


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## JAG88 (Nov 9, 2017)

Inquest claims 7 drops, Shattered claims at least 5 with one of the bombs detaching itself from the disintegrating bomber and hiting the carrier nonetheless... I would count that one as a good drop, but anyway, anywhere from 60% to 42% depending on the source.

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## Koopernic (Nov 10, 2017)

JAG88 said:


> Inquest claims 7 drops, Shattered claims at least 5 with one of the bombs detaching itself from the disintegrating bomber and hiting the carrier nonetheless... I would count that one as a good drop, but anyway, anywhere from 60% to 42% depending on the source.



Reading these accounts of successful dive bomber attacks, mainly by the Japanese, what I find remarkable is how ineffective the ships anti aircraft defences were. Was there some tactic such as a simultaneous attack that split and saturated the defences the IJN aviators were good at.

The enemy of the dive bomber was the fighter not AAA it seems. 

Dive bombers shot down by AAA in the dive should count as misses because a tactic of releasing a bomb at greater range and altitude would naturally produce more misses but also more successful releases by bombers that have escaped damage or destruction by AAA.


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## parsifal (Nov 10, 2017)

The magic and usual drop altitude was about 5000 ft for skilled crews. They could drop from that altitude on a normally manouvering ship and stood a reasonable chance of hitting it . That was above the effective ceiling of most fast firing Lt AA except the bofors.


However by slight increases in the spacing of ships, it was found that hit percentages dropped away. Further, Task Groups began to form specif defensive groups to protect high value targets like carriers. Each carrier, or carrier group would be assigned both an inner screen 9with ships as close as 700 yards from the target) in which both Lt and Hy AA could be brought to bear..

The outer screen was generally a couple of thousand meters from the primary target, and tended to concentrate on its long range AA fire to disrupt the incoming attack. 

Advances in gunnery fire control, radar direction but most importantly the introduction of the 40mm bofors on a massive scale made divebomber attacks far more difficult. add to that the falling training standards of the air crew, and the introduction of kamikaze tactics, made the final approach runs of tahe attackers a lot lower in altitudes than previously was the case. By the latter part of 1942, attackers from all sides would regulalrly press onto point blank range

Japanese defences were more based on manoeuvre, probably because of the limited ranges of their primary weapon against a/c, the 25mm. I'm not certain what DKM tactics were, for the british it tended to follow USN practices later on, which were superior anyway to the home grown tactics.

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## Koopernic (Nov 10, 2017)

parsifal said:


> The magic and usual drop altitude was about 5000 ft for skilled crews. They could drop from that altitude on a normally manouvering ship and stood a reasonable chance of hitting it . That was above the effective ceiling of most fast firing Lt AA except the bofors.
> 
> 
> However by slight increases in the spacing of ships, it was found that hit percentages dropped away. Further, Task Groups began to form specif defensive groups to protect high value targets like carriers. Each carrier, or carrier group would be assigned both an inner screen 9with ships as close as 700 yards from the target) in which both Lt and Hy AA could be brought to bear..
> ...



Japanese Navy Bomber Tactics. Bombers entered a shallow dive, then a steep 55 degree dive from 1500m followed by release at around 600m. Doesn’t look like they used the full Vertical attacks of the Ju 87. The Japanese attacks were highly coordinated.

_View: https://www.youtube.com/watch?v=MLfbYHPWx2o_

This video has an analysis of the attack on Yorktown.

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## JAG88 (Nov 10, 2017)

Koopernic said:


> Reading these accounts of successful dive bomber attacks, mainly by the Japanese, what I find remarkable is how ineffective the ships anti aircraft defences were. Was there some tactic such as a simultaneous attack that split and saturated the defences the IJN aviators were good at.
> 
> The enemy of the dive bomber was the fighter not AAA it seems.
> 
> Dive bombers shot down by AAA in the dive should count as misses because a tactic of releasing a bomb at greater range and altitude would naturally produce more misses but also more successful releases by bombers that have escaped damage or destruction by AAA.



The main purpose of the flak is to protect the target, if it does so by disrupting the attack run and causing a miss it did achieve its purpose.

Of course, when you are dealing with higly trained and determined pilots the flak loses quite a bit of its disuasive and disruptive qualities and the target is down to hoping their flak crews shoot them down, which is something thay may diminish the effects of the strike, but never prevent them. AT least back then and in spite of the IJN pilots presing to within 300m-400m before droping.

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## JAG88 (Nov 10, 2017)

parsifal said:


> Japanese defences were more based on manoeuvre, probably because of the limited ranges of their primary weapon against a/c, the 25mm. I'm not certain what DKM tactics were, for the british it tended to follow USN practices later on, which were superior anyway to the home grown tactics.



I think the IJN simply expected enemy pilots to do as theirs did and disregard flak, in which case drastic maneuver is the only real option leading to their open AA formations with plenty of space for the carriers to turn as they pleased. Besides, it seems they were quite happy with the 25mm until the realities of war showed them otherwise.

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## Shortround6 (Nov 10, 2017)

Just about everybody's light AA was woefully inadequate to the needs/requirements of actual combat in the early years. 
and many Navies had designed ships to strict weight limits (even if cheating was more or less rampant in some navies) which means you have to sacrifice surface weapons for AA weapons or A/S weapons for AA. There is only so much top weight you can put on a ship before stability becomes an issue. A pre war destroyer may be able to have a few few swinging heavy machineguns/20mm added without much problem but large mounts, especially powered, were a problem. Especially as they usually had to mounted high up. 
The US being one of the few navies to actually take dive bombing seriously from both offensive and defensive points of view. 
The US 1.1 in machine cannon and mount being one of the few combinations to really try to counter dive bombing. Please note I said TRY as neither the gun or the mounting turned out to be all that successful in service.





Please note the geared rack in line with the guns which allowed for a small amount of "slew" independent of the normal traverse/turning of the mounting. This was to allow the guns to follow the path of a dive bomber at high angles of elevation when traversing the entire mount would throw the guns off. This _may _be the only mount that allowed that type of motion and shows that the US Navy was thinking about the problems of high angle gunnery.
The gun and the mounting were over complicated and required large amounts of maintenance. 
Weights went form 4.7 to 6.25 tons and while late mounts lost the slewing feature they gained remote power control. 
Scale of issue was 4 mounts for large ships and 1 or 2 for destroyers which is almost laughable compared to the outfits of 40mm Bofors guns later in the war. Especially when you consider the next step below these guns was the .50 cal machinegun and not the 20mm in the the late 30s through 1942.

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## JAG88 (Nov 10, 2017)

I have always liked the idea behind the 28mm and its mount, too bad they didnt make it work in time, but I would guess that by trying to keep formation and give their gunners a more stable gunnery platform they also made themselves easier targets.

Trade offs.


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## stona (Nov 16, 2017)

In pre-war exercises from 1932 to 1940 the USN ran comparisons of the accuracy of dive bombing and level bombing against ships taking various evasive actions (simple, radical, unrestricted, zig-zag etc.).

Dive bombing was invariably more accurate, the percentage of hits being remarkably consistent in all scenarios, between 12% and 23%.

For level bombing the results were almost invariably a single figure percentage of hits, typically between 1% and 4%. In 1933 and 1934, from 8,000 feet, no hits were scored. In 1937, against a ship making 'steady' manoeuvres, from 10,000 feet a high of 11.1% of hits were achieved. This was comparable with the 12.7% achieved that year by dive bombing, but stands out in the tables as an anomaly.

Cheers

Steve

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## Shortround6 (Nov 16, 2017)

That is a real problem with limited tests and statistics. 
11.1% is one bomb out of nine. or 10 bombs out of 90. The first could obviously be a fluke. The second is probably well in excess of the number of bombs actually dropped in such a peace time test. Even two hits out of 18 dropped doesn't really give you a good basis to extrapolate from as the sample is too small. 

also to be considered is what was considered a hit? and on what?




US target ship in the 30s 
Or were the practice bombs dropped on a towed raft with observers judging hits and misses?


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## stona (Nov 16, 2017)

The target ship was the USS Utah, what was dropped I have no idea. I don't even know if there was consistency, year on year. All I have is a table of results.
There would be more in the Army Air Corps Board, Report No.4, Vol.4 of 1941. That's the source of the table.

Cheers

Steve


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## Shortround6 (Nov 16, 2017)

Thank you,
I was just pointing out that such tables could have some rather scattered results due to small number of samples.
You have done a great job of bringing up such subjects and data.

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## Zipper730 (Nov 16, 2017)

stona said:


> In pre-war exercises from 1932 to 1940 the USN ran comparisons of the accuracy of dive bombing and level bombing against ships taking various evasive actions (simple, radical, unrestricted, zig-zag etc.).


Steady maneuvers would go under simple right?


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## stona (Nov 16, 2017)

The manoeuvres are different, year by year.

1932 *Simple* 18.2% hits dive bombing, 5.6% level bombing from 8.000 feet

1933 *Radica*l 20% hits dive bombing, 0 hits level bombing from 8,000 feet

1934 *Radical *13% hits dive bombing, 0 hits level bombing from 8,000 feet

1935 *Restricted* 17.3% hits dive bombing, 9.4% level bombing from 8,000 feet

1936 *Radical *23.7% hits dive bombing, 8.3% level bombing from 10,000 feet

1937 *Sharp Turns* 11.3% hits dive bombing, 5.6% level bombing from 10,000 feet
1937 *Steady* 12.7% hits dive bombing, 11.1% level bombing from 10,000 feet

1938 *Steady* 13.9% hits dive bombing, 4.1% level bombing from 12,000 feet
1938 *Sharp Turns* 14.5% hits dive bombing, 2.4% level bombing from 12,000 feet.

1939 *Zig Zag *21.8% hits dive bombing, 4.4% level bombing from 17,000 feet
1939 *Unrestricted* 18.1% hits dive bombing 1.1% level bombing from 17,000 feet

1940 *Zig Zag* 19.1% hits dive bombing, 1.9% level bombing from 17.000 feet
1940 *Unrestricted* 23.1% hits dive bombing, 1.9% level bombing from 17,000 feet.

About the only conclusion to de drawn is that dive bombing was usually more accurate than level bombing, whatever the target was doing.

In the confusion it is hardly surprising that a unified doctrine was never formed. The Navy had established three ways of attacking ships (including torpedo bombers) and would not give up any of them. The Air Corps was too young to be bound by traditions and a hierarchical rank structure, it was relatively young officers who developed the doctrine of 'high' altitude precision bombing. The Navy's inability to develop a unified doctrine left hundreds of torpedo bomber crewmen vulnerable and exposed to enemy defences and caused the Navy to hold on to thousands (yes, thousands) of Norden bomb sights at a time when the Air Force had a critical need for them. I know we Brits sometimes say that the Americans don't get irony, but surely the irony of the failure of the USN in WW2 to use the bomb sight which it had developed, while the US Army, which did use the sight but had to subordinate its needs for the device to the Navy would not be lost on them 

Cheers

Steve

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## Zipper730 (Nov 16, 2017)

stona said:


> The manoeuvres are different, year by year.


That I didn't know, but I'm guessing you don't know what they meant by steady?

A pattern I notice is that level bombing is very ineffective when maneuvers are unrestricted!


> In the confusion it is hardly surprising that a unified doctrine was never formed. The Navy had established three ways of attacking ships (including torpedo bombers) and would not give up any of them.


Ironically, it gave them great versatility. Though I would personally say that level bombing would be largely useless for attacking ships, though against harbors & shipyards it'd probably work well enough.


> The Air Corps was too young to be bound by traditions and a hierarchical rank structure, it was relatively young officers who developed the doctrine of 'high' altitude precision bombing.


Their idea of level bombing was to avoid being attacked by guns on the ground. It's of course not as accurate...


> The Navy's inability to develop a unified doctrine left hundreds of torpedo bomber crewmen vulnerable and exposed to enemy defences and caused the Navy to hold on to thousands (yes, thousands) of Norden bomb sights at a time when the Air Force had a critical need for them.


I think they should have used dive-bombers more liberally if you ask me, though I'll admit that the torpedo bombers did prove useful for certain things (air-borne battle-control, anti-sub, etc)


> I know we Brits sometimes say that the Americans don't get irony, but surely the irony of the failure of the USN in WW2 to use the bomb sight which it had developed


The US Navy used it on the Catalina, and the Avengers sometimes (bombing Japan)


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## Peter Gunn (Nov 17, 2017)

Shortround6 said:


> *SNIP*
> 
> Or were the practice bombs dropped on a towed raft with observers judging hits and misses?



As far as I recall, they dropped the practice bombs on the ship and if I'm not mistaken, UTAH was actually radio controlled for the exercises, both bombs and gunnery until she was sunk at Pearl Harbor.


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## Shortround6 (Nov 17, 2017)

I would note that at any given time during the 1930s and very early 40s that the dive bombers were rather restricted in the size/weight of the bomb they could carry. The torpedo bomber, if used as a level bomber, could either carry multiple bombs or a single of much larger size than the dive bomber. 
Armor piercing bombs needed to be dropped from certain altitudes to achieve max penetration and in the days of biplane dive bombers, the speed achieved in the dive wasn't enough to compensate for the lower release altitude.
It wasn't until 1943 or early 44 that the Japanese battleships ceased to be a large bugaboo to allied naval forces.


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## vikingBerserker (Nov 17, 2017)

For level bombing by both the Navy and Air Corps, practice bombs were dropped on the USS Utah, they were normally US Navy Mark VII water fillable bombers weighted to 50lb bombs after being filled with water which could be colored to track the aircraft or squadron that made hits. The Utah had double layers of timber placed on top of her deck to prevent damage from them. I'm not sure how they handled Dive Bombers

Here is a view of her front:

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## Shortround6 (Nov 17, 2017)

As a note to the bombing results so kindly provided Stona the Douglas TBD torpedo bomber was only issued to the first two squadrons to use it in Oct and Dec of 1937. First monoplane on american carriers. 
The first US monoplane dive bomber was the Northrop BT




only 55 built and deliveries didn't start till 1938. 
So the tests in 1932-37 would have been done by a variety of biplanes. How many of the later tests were done by biplanes I have no idea but the Hornet still had 2 squadrons of Curtiss SBC-4s aboard in Dec of 1941.




In regards to another thread note the auxiliary fuel tank

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## stona (Nov 19, 2017)

The relationship between dive angle and height of release is also vitally important.

For bombing angles from 50-90 degrees, up to a release height of about 5,000 feet the accuracy was not markedly different.

I've attached this diagram, a poor picture taken with my phone as I'm not at home but happen to have my copy of 'America's Pursuit of Precision Bombing' with me! It is just about legible.






It was the dive bombers, not the torpedo bombers which were decisive at Midway. 42 attacking Devastators failed to score a hit (and many (36?) were lost. However, the USN launched 1,287 aerial torpedoes during the war of which 514 struck their target, a success rate of 40%. Several of those targets were already dead in the water.

The percentage of hits to bombs dropped by the Dauntless dive bombers and Midway makes for better reading.
5 out of 9 hit the _Kaga_ (44.4%), 2 of 3 the _Akagi_ (66.7%), 3 of 8 the _Soryu _(37.5%) and 4 of 7 the _Hiryu_ (57.1%). 

Arnold claimed that the Army dropped 322 bombs in level bombing at Midway, scoring 22 hits and 46 near misses. In fact Japanese records later confirmed that they suffered no hits and no damage from high level bombing. The only major warship confirmed sunt by Army Air Forces during the war was the Japanese light cruiser _Abukuma_, already disabled by PT boats. She was sunk on 27th October 1944 by 44 B-17s and B-24s of the 5th and 13th Air Forces.

Cheers

Steve

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## Shortround6 (Nov 19, 2017)

You have to remember that the US Torpedoes weren't much good at the Battle of Midway (and for over a year after) which rather skews the results. While aerial torpedoes weren't quite as bad as the submarine torpedoes running too deep (under the target) means a miss that should have been a hit. Defective exploders (fuses) means hits that were duds. 

The Arizona was sunk by level bombers using armor piercing bombs dropped by torpedo bombers as the Val couldn't carry the weight. 

To sink a ship you have to hit it. Then the hit has to cause fatal damage. In the 1930s the dive bombers could not inflict fatal damage on battleships. Send them to ship yards for months, yes, but not sink them. For the US that capability came with later models of the Dauntless with higher powered engines and the Curtiss SCB2 that could carry 1000lb GP bombs and 1000lb &1600lb AP bombs. 
Some books and web sites list some fairly outrageous bomb loads for the Dauntless and while I have no doubt the plane/s could get of the ground/deck with them i doubt they were going very far. 
SBD-3 had a 1000hp engine and the manual lists a variety of loads. Like a 1000lb bomb with 100 gallons of fuel, and a 500lb with 140 gallons of fuel. For scouting work the plane could hold 180 gallons or more. (up to 310 gallons if the fuel tanks were unprotected) 
SBD-5s got 1200hp engines and SBD-6s got 1350 engines so obviously capability increased but the load of one 1600lb and two 325lbs sometimes listed should be viewed with suspicion as an operational load.

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## stona (Nov 19, 2017)

Also, since this thread is about dive bombing, I would like to point out that by the US inter-war definition, attacks using angles of approach between 40 and 70 degrees were classified as 'glide bombing'. Only those with angles of attack between 70 and 90 degrees were classified as 'dive bombing'.
These classifications had broadened somewhat by WW2, and diving attacks at very moderate angles of 40 to 50 degrees were considered to be dive bombing.

The issues for the Americans in the 1930s were that dive bombers could hit ships, but rarely sink larger ones. They were the least vulnerable, most accurate, but least deadly. In terms of relative accuracy they were by far the best of the three options available.

Torpedo bomber could hit ships where it really counted, below the water line, but the torpedoes were hopelessly unreliable and some required tactics for dropping which were little short of suicidal. The Mark XIII was supposed to be dropped at a speed of less than 100 knots, from 80 feet and at 1,000 yards from the target (and then it was unlikely to work properly). They were potentially the most deadly, but also by far the most vulnerable.

Level bombers, despite a huge investment in bomb sights and other technology and the development of tactics like pattern bombing simply couldn't hit a ship. They were the least vulnerable, the most inaccurate and therefore not at all deadly.

Cheers

Steve

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## Shortround6 (Nov 19, 2017)

The US was using 18in Bliss-Leavitt MK 7 torpedoes (of several different models) for air dropping until 1938-39 when the MK 13 was issued (first in 1938, how long to fully equip all carriers?).
Since just about all drops were from biplanes the drop 'envelope' was probably no better than the MK 13. Unfortunately the drop envelop of the MK 13 was more suited to biplanes than to monoplanes and was most certainly not adequately tested. 
This was the latested torpedo bomber the USN had when it was replaced by the Devastator. 









it and it's nearly identical predecessor would have been the planes the navy was using for level bombing in the 1932-37 trials.


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## RCAFson (Nov 19, 2017)

stona said:


> The relationship between dive angle and height of release is also vitally important.
> 
> For bombing angles from 50-90 degrees, up to a release height of about 5,000 feet the accuracy was not markedly different.
> 
> ...



Unless torpedo hit stats are compiled based upon post war enemy records, they have to be taken with the same large grain of salt as per the USAAF bomb hit claims at Midway.

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## Zipper730 (Feb 17, 2019)

Peter Gunn said:


> As far as I recall, they dropped the practice bombs on the ship and if I'm not mistaken, UTAH was actually radio controlled for the exercises, both bombs and gunnery until she was sunk at Pearl Harbor.


They had the whole ship unmanned and running on radio?


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## Greyman (Feb 17, 2019)

re: effect of AA fire earlier in the thread; came across some figures from ORS reports on Allied dive bomb attacks vs. road and rail bridges in Italy.

*Effort in Relation to Direct Hits (Bridge Size 225' x 30')**.
A.A. Opposition.* ---- *Effort per Direct Hit.*
Zero or Slight (e.g. 3 L.A.A.) ---- 1 direct hit per 30 bombs
Medium (e.g. 3 L.A.A. + 6 H.A.A.) ---- 1 direct hit per 100 bombs
Intense (e.g. 12 L.A.A. + 6 H.A.A.) ---- 1 direct hit per 150 bombs

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## fliger747 (Feb 18, 2019)

It seems as if everyone had torpedo exploder issues early in the war, except for the Japanese. Combined arms often were the combo that proved fatal warships, Dive bombers with some degree of distraction, distraction of topsides AA and fire control. or just slowing a ship could make the task of the "Torpeckers" more achievable. Yamato and Musashi died agonizing deaths by the Lilliputian swarms. With a strong list Yamato probably took some torpedo hits on her bottom, the most vulnerable area.


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## Peter Gunn (Feb 19, 2019)

Zipper730 said:


> They had the whole ship unmanned and running on radio?



Correct, there was a radio control station on another ship that was able to manipulate the engines and rudder, I'm not sure if she shipped a crew standing out of harbor and then they left via small craft and returned to take her back in after the exercise was over, or if she was remote controlled for the entire exercise.

From Wiki (FWIW):
"On 7 April, _Utah_ left Norfolk for sea trials to train her engine room crew and to test the radio-control equipment. The ship could be controlled at varying rates of speed and changes of course: maneuvers that a ship would conduct in battle. Her electric motors, operated by signals from the controlling ship, opened and closed throttle valves, moved her steering gear, and regulated the supply of oil to her boilers. In addition, a Sperry gyro pilot kept the ship on course. She passed her radio control trials on 6 May, and on 1 June, the ship was operated for 3 hours under radio control. On 9 June, she again left Norfolk, bound for San Pedro, California, where she joined Training Squadron 1, Base Force, United States Fleet. Starting in late July, the ship began her first round of target duty, first for the cruisers of the Pacific Fleet, and then for the battleship _Nevada_. She continued in this role for the next nine years; she participated in Fleet Problem XVI in May 1935, during which she served as a transport for a contingent of Marines.[5] In June, the ship was modified to train anti-aircraft gunners in addition to her target ship duties. To perform this task, she was equipped with a new 1.1-inch (28 mm)/75 caliber anti-aircraft gun in a quadruple mount for experimental testing and development of the new type of weapon."

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## fliger747 (Feb 19, 2019)

Someone once described attempting to level bomb ships at sea maneuvering as trying to drop a ball bearing on a mouse scurrying around on the floor. Dive bombing did bring the chances of a "hit" up considerably. For vulnerable ships such as carriers, destroyers and even cruisers chances of considerable damage with a hit are excellent. Certainly Battleships weren't immune but several hits weren't likely to be fatal. The main issue of the effectiveness of a strike by a dive bomber is the low release altitude, which isn't an issue for an HC bomb, but deprives an AP bomb of necessary kinetic energy. 

A Japanese Destroyer captain, whose ship was sunk in the Solomons by level bombers said (more or less) "Even the B-17's get lucky once in a while".

From altitude, surrounding a ship with near misses such that the ship disappears in a shower of spray is very spectacular and looks like a certain "kill". USAAF took much of the credit for the Midway victory!


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## stona (Feb 20, 2019)

Dive bombing was by far the most effective way of bombing a ship. It was something that exercised the minds of the Admiralty, particularly after many destroyers were damaged by bombing during 'Dynamo'.

This graph is compiled from an Admiralty report and includes all ships damaged by bombing in the period. A successful attack was classified as one that damaged a ship, not necessarily sinking it. It includes ships attacked while stationary or in port.






In a 1942 newspaper article no less a figure than Dowding recognised that events in the war so far had shown that air power had become an essential adjunct to sea power. He was a career airman, and stopped short of admitting that it was British sea power which had prevented an invasion and was keeping open the possibility of liberating Europe at a future date. Dowding never really bought into the popular myth of the BoB, but he would hardly publicly undermine it at the height of a world war.

Cheers

Steve

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## parsifal (Feb 20, 2019)

I stumbled onto this report concerning US torpedoes

A Brief History of U.S. Navy Torpedo Development - Part 1


Despite the bad press US torpedoes have generally received over the years, th eir torpedo success rate was actually not too bad. At Page 43 of that report, it is stated....."the overwhelming majority of torpedoes fired during World War II were from submarines in the Pacific theater. Approximately 14,750 torpedoes were fired from submarines at 3184 of the approximately 8200 ships sighted. Of these, 1314 ships were sunk for a total of 5,300,000 tons. In addition, submarines received "probable" credit for another 78 ships of 203,306 tons. The confirmed total included one battleship, eight aircraft carriers, three heavy cruisers and eight light cruisers. These Joint Army Navy Assessment Committee (JANAC) confirmed sinkings (1314) accounted for 55 percent of all Japanese ship losses. The remaining 45 percent were lost to Army and Navy aircraft bombs, mines, and other causes".

People often carry on about how effective the SBD was, but really in comparison to the various torpedo carrying vehicles, the a/c was small potatoes

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## Zipper730 (Feb 20, 2019)

fliger747 said:


> Someone once described attempting to level bomb ships at sea maneuvering as trying to drop a ball bearing on a mouse scurrying around on the floor.


Interesting way to look at it, but when you have a whole bunch of dive-bombers dropping all at once (and possibly from different axes), the odds go up greatly. And if I recall the USN would use multiple aircraft at once.


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## tomo pauk (Feb 20, 2019)

parsifal said:


> People often carry on about how effective the SBD was, but really in comparison to the various torpedo carrying vehicles, the a/c was small potatoes



Out of Japanese CVs sunk in crucial year of 1942, SBD sunk perhaps 80%? While subs sunk none?

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## fliger747 (Feb 20, 2019)

Comment above was for LEVEL bombing. Ships could and did appraise the fall of bombs and maneuver out of the way. Level bombers could not really follow the maneuvers of a ship and maintain any sort of aiming integrity. A formation might have some better chance just due to the shotgun effect. 

Especially in the Med the RN suffered badly from the Stukas.

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## michaelmaltby (Feb 20, 2019)

... likewise the Soviet navy in the Black Sea


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## Peter Gunn (Feb 20, 2019)

fliger747 said:


> Comment above was for LEVEL bombing. Ships could and did appraise the fall of bombs and maneuver out of the way. Level bombers could not really follow the maneuvers of a ship and maintain any sort of aiming integrity. A formation might have some better chance just due to the shotgun effect.
> 
> Especially in the Med the RN suffered badly from the Stukas.


Re: the shotgun effect.
I think it was on the Hyperwar site that had the USAAC doctrine for level bombers attacking a moving ship and you're right, the idea was a formation left right and center over the ship so no matter which way it turned you'd stand a good chance of getting a hit. However there were VERY few instances in the Pacific where there was a large enough (and more importantly, trained to hit moving targets) formation to succeed. 

At midway, Colonel Sweeney had 15 fortress's in the morning attack on the Japanese carriers, he chose to split his force and have ~3 attack each CV, had he kept all 15 together and attacked one CV there is a good possibility they could have put down a carrier. Heck, even with only three Forts, one of his formations only missed Hiryu by less than 500 meters.

But yes, I agree, dive bombing is the best way to put a bomb on a moving target like a ship.


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## parsifal (Feb 20, 2019)

tomo pauk said:


> Out of Japanese CVs sunk in crucial year of 1942, SBD sunk perhaps 80%? While subs sunk none?


1942 was the year of Japanese successes asa far as sunk or damaged naval assets were concerned…..two USN CVs sunk outright, one CV heavily damaged (twice)……..USN subs came into their own in 1944. Two subs sank more CV tonnage than more than 1000 USN carrier a/c could manage for the entire year.... IJN was not defeated solely by the USN carrier fleet. With access to less than 2% of the USN resources, the Submarine arm sank more than 0% of Japanese merchant fleet and from memory 60% of the IJN naval tonnages lost.


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## tomo pauk (Feb 20, 2019)

parsifal said:


> 1942 was the year of Japanese successes asa far as sunk or damaged naval assets were concerned…..two USN CVs sunk outright, one CV heavily damaged (twice)……..USN subs came into their own in 1944. Two subs sank more CV tonnage than more than 1000 USN carrier a/c could manage for the entire year.... IJN was not defeated solely by the USN carrier fleet. With access to less than 2% of the USN resources, the Submarine arm sank more than 0% of Japanese merchant fleet and from memory 60% of the IJN naval tonnages lost.



Nobody said that IJN was solely defeated by USN carrier feet. I've just pointed out that in 1942 SBDs sunk perhaps 80% or IJN carriers, 0% was sunk by subs.


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## Brooke (Feb 21, 2019)

stona said:


> This is correct, but it was not obvious at the beginning of the war. The Royal Navy's _"Air Defence Instructions, 1939"_ forbade fast avoiding action against dive bombers. Many ships' commanding officers took a different view and the matter was referred to the director of the Naval Air Division in 1940. He conceded that avoiding action might cause a reduction in bombing accuracy because it would cause the pilot to adjust his aim, which was not regarded as easy, but in conclusion reinforced the official view that avoiding action should not be taken at the expense of throwing off the ship's AA fire.
> Maneuverable ships, like destroyers, might be better able to 'dodge' bombs than others. It has been suggested that the destroyer _Gurkha_ was lost to air attack in the Norwegian campaign because her Captain was a 'gunnery officer' who believed in the efficacy of AA fire and chose to keep a steady gun platform without weaving, thereby also presenting a steady target.
> Later 'dodging' became the norm.
> Alec Dennis was on board the destroyer _Griffin_ as part of Force B off Crete when attacked (along with _Greyhound, Gloucester and Fiji_) by JU 87s. Twenty Ju 87s made the first attack comingdown in,
> ...



The hit probability of AA fire depends a lot on what type of fuze is used. It a "timed" fuze the probability of a hit is very low (see any W.W.II movie showing "flak"). However, if a proximity fuze is used you have a much better chance. I would expect the best strategy would depend on the fuze type. China Lake holds many patents related to proximity fuzes.
China Lake Patents

It turns out that the sight on the A-1 is for use with guns, bombs or rockets (GBR) but it's called a "gun sight". This makes sense since all of these look forward, unlike horizontal bomb sights which look down and forward. There is what amounts to an elevation adjustment that needs to be set depending on which munition is being used.
Mk 20 Mod 4 Gun-Bomb Sight

Does anyone know what sight is used on the A-10 for dive bombing?


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## Brooke (Feb 21, 2019)

tomo pauk said:


> Nobody said that IJN was solely defeated by USN carrier feet. I've just pointed out that in 1942 SBDs sunk perhaps 80% or IJN carriers, 0% was sunk by subs.



For the first half of W.W. II the Navy torpedo had multiple design defects to the point that they did NOT work. In the book "Pig Boats" a mission is described where every shot fired by a sub hits the target ship, but none exploded. They saved one torpedo and returned to base. 
Torpedoes


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## tomo pauk (Feb 21, 2019)

Brooke said:


> For the first half of W.W. II the Navy torpedo had multiple design defects to the point that they did NOT work. In the book "Pig Boats" a mission is described where every shot fired by a sub hits the target ship, but none exploded. They saved one torpedo and returned to base.
> Torpedoes



I'm aware of the whole 'USN torpedo scandal'. Not that it allowed many of Japanese ships a free ride, but endangered many of US servicemen for almost no reward. Even made some skipperes defending for accusations of covardice.
But, be as it was, the US aircraft in general, and SBDs in particular were the ones doing sunking of IJN carriers in 1942.


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## Brooke (Feb 21, 2019)

Yes, exactly. Dive bombers were effective. But not horizontal bombing.
Mk 20 Mod 4 Gun-Bomb Sight


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## BAGTIC (Feb 21, 2019)

BiffF15 said:


> The CEP for the A-10 with iron bombs is probably pretty good due to the death dot (CCIP) or Constantly Computed Impact Point. It's like a red dot sight for aircraft. Dot on, push pickle button, target hit, period dot. As for the Spad, I would think it's a bit better than WW2 iron. The predominate reason is time between WW2 and Vietnam gave room for much improvement in academics, techniques, tactics and procedures. Heck, range rides in the OV-10 would have almost all the BDU-33s falling inside 150' (non-combat dropping understood). The more you drop, the better you get.
> 
> Cheers,
> Biff



Accuracy on a target range bears little relationship to combat accuracy. It is like the relationship between a rifleman's accuracy on a target range and his accuracy while under fire in combat.


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## BAGTIC (Feb 21, 2019)

Brooke said:


> Yes, exactly. Dive bombers were effective. But not horizontal bombing.
> Mk 20 Mod 4 Gun-Bomb Sight



Accuracy is largely dependent on TOF whether bombs, bullets, or shells. Dive bombers should have had improved accuracy because they were releasing bombs at very low levels thereby minimizing target movement between bomb release and bomb impact.


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## BiffF15 (Feb 21, 2019)

BAGTIC said:


> Accuracy on a target range bears little relationship to combat accuracy. It is like the relationship between a rifleman's accuracy on a target range and his accuracy while under fire in combat.



Hence the “non-combat dropping understood “ comment.

Also realize that in today’s environment accuracy is tremendous with guided weapons, and sometimes even more so with the GPS add on (coordinates accuracy dependent of course).

Cheers,
Biff


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## fliger747 (Feb 21, 2019)

An issue with dive bombing against heavily armored ships is release height. Lower the release the better chance of a hit, but against Battleships per se even AP bombs may or may not penetrate deck armor. Tirpitz was stationary yet the initial strikes against her were delivered too low for good armor penetration. A subsequent strike had one 750 kg bomb penetrate to the vitals, but didn't explode. However all of the ships defensive and offensive weaponry are located high in the ship and considerable damage can result even if machinery and main magazines remain safe. The steering was protected by an 80-110 mm armored deck, a potential vulnerability. Turret roofs and the conning tower were thick enough to be proof against carrier aircraft bombs but secondary batteries, ready ammunition, fire control positions etc. not.


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## Milosh (Feb 21, 2019)

What is considered low level release height?


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## fliger747 (Feb 21, 2019)

Below 3000' and less than a 70 deg dive.


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## Freebird (Feb 21, 2019)

stona said:


> The figures for 'real' dive bombing in 1944/5, by Typhoons and Spitfires, were nowhere near as good as this.
> 
> Cheers
> 
> Steve


Any data for Barracuda or Firefly?


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## parsifal (Feb 22, 2019)

Level bombing accuracy was affected by a number of factors including



1) speed of the aircraft

2) altitude that the bombs are dropped

3) strength of defending AA

4) whether the target was moving

5) Pilot experience



Over Korea, RAN Fireflies were equipped with all the weapon systems that in modern times have been seen as largely ineffective…..20mm cannon, freefall bombs and unguided rockets. Yet the aircraft of 817 sqn achieved some of the highest accuracy rates of any squadron sized unit at any time in history. They flew something like eight hundred and something sorties I three months and destroyed over 1500 targets in that time. These successful strikes are based on post war verifications, not claims made at the time. It included the destruction of 6xt-34 tanks. Talking to some of the aircrew in that unit, it seems they employed a number of “tricks” to achieve that great accuracy. The one that comes to mind is that they reduced the speed of the firefly greatly by deploying their flaps whilst airborne. This enable their aircraft to virtually ‘float” over their target areas whilst lobbing ordinance at the ground.

Swordfish used similar low speed attack tactics, which explains to me why stringbags, even when used as level bombers, were able to achieve such outstanding accuracy against enemy shipping

Flak makes low speed attacks very dangerous, but the solution here is to supress the flak before the main attacks actually take place. This is what happened at Bismarck Sea…..essentially the earlier US attacks got nowhere with the Japanese, because they were forced to fly high and fast and their accuracy was affected by the defending ship borne flak. The ten gun terrors of 30 sqn in the later attacks came in low and fast, carrying out their runs on the defenders length wise down the ship, which killed or disabled the defending AA guns in a severe way. The Beaforts and A-20s, mixed in b-25 gunships then came in to more or less decimate the whole convoy.

So, given the right circumstances, level bombing can be deadly enough…….the secret is co-ordination. In Korea, that co-ordination was in the form of the Sea fury FB-11s flying suppression missions, whilst at Bismarck Sea it was the 30 sqn beaufighters.

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## JAG88 (Apr 28, 2019)

fliger747 said:


> An issue with dive bombing against heavily armored ships is release height. Lower the release the better chance of a hit, but against Battleships per se even AP bombs may or may not penetrate deck armor. Tirpitz was stationary yet the initial strikes against her were delivered too low for good armor penetration. A subsequent strike had one 750 kg bomb penetrate to the vitals, but didn't explode. However all of the ships defensive and offensive weaponry are located high in the ship and considerable damage can result even if machinery and main magazines remain safe. The steering was protected by an 80-110 mm armored deck, a potential vulnerability. Turret roofs and the conning tower were thick enough to be proof against carrier aircraft bombs but secondary batteries, ready ammunition, fire control positions etc. not.



Which is why the LW developed their Rocket-assisted bombs 500Kg and up, but they never had the chance to use them on a proper target IIRC.

They got hits on a couple CLs, but no BBs or CVs.


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## fliger747 (Apr 29, 2019)

Before guided bombs, only the dive bombers had a good chance of responding to the maneuvers of an evading ship. Even so it was hard enough to correct a dive laterally that the hit rate wasn't that great compared to a no maneuvering target.


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## Glider (Apr 29, 2019)

JAG88 said:


> Which is why the LW developed their Rocket-assisted bombs 500Kg and up, but they never had the chance to use them on a proper target IIRC.
> 
> They got hits on a couple CLs, but no BBs or CVs.



If we are thinking of the same weapon then the German guided bombs when used were very effective, sinking one modern BB the Roma and damaging at least two more, the Italia and the Warspite. A number of cruisers were also seriously damaged.


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## JAG88 (Apr 29, 2019)

Glider said:


> If we are thinking of the same weapon then the German guided bombs when used were very effective, sinking one modern BB the Roma and damaging at least two more, the Italia and the Warspite. A number of cruisers were also seriously damaged.



No, I am talking about the unguided, solid fuel, rocket-accelerated, armor piercing ones, PC500/1000/1800 RS, these were dive bomber weapons allowing the pilot to dive low and still have the bomb hit with enough speed to penetrate:



























Luftwaffe Resource Center - Drop Ordnance - A Warbirds Resource Group Site

You are thinking about the guided munitions, HS 293 and Fritz X.

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## Glider (Apr 29, 2019)

JAG88 said:


> No, I am talking about the unguided, solid fuel, rocket-accelerated, armor piercing ones, PC500/1000/1800 RS, these were dive bomber weapons allowing the pilot to dive low and still have the bomb hit with enough speed to penetrate:
> 
> View attachment 536515
> 
> ...


Thanks for the information


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## parsifal (Apr 29, 2019)

fliger747 said:


> Before guided bombs, only the dive bombers had a good chance of responding to the maneuvers of an evading ship. Even so it was hard enough to correct a dive laterally that the hit rate wasn't that great compared to a no maneuvering target.




Im sorry but I don't agree. Torpedo bombers, operating with other torpedo bombers could employ anvil tactics and be very effective against shipping,, with comparable loss rates to divebomber attacks. Level bombers, operating at very low level, in concert with aircraft used in flak suppression, such as occurred at bismarck Sea were also very effective. There were many other combinations of these basic mixes in force structure.

Its also worth pointing out that some of the greatest maritime tallies were achieved by sircraft like the Swordfish. In 1941 for example, Malta based Swordfish are estimates to have sunk at least 250000 tons of enemy mercantile tonnage. that sounds like a fairly modest total, until it is realised that the average availability for these attacks were often less than 5 a/c at any one time .

In the Korean war era, some of the most efficient shipping killers were aircraft like the Firefly, which were not a divebomber. they were essentially fighterbombers, optimised for air to surface attacks. The RAN squadrons used in this capacity did not use guided weaponary, they used unguided bombs mostly.

The germans used divbombers, and they were effective, but this effectiveness often masquerades as the only means of sinking ships or carrying out effect air to ground support. Look a little closer and this rapidly is exposed for the myth that it is.


Your second point about "hit rates not being that great" is also able to be unproven. During the attacks by the IJN on HMS Cornwall and Dorsaetshire, the IJN divebomber group involved is known to have achiecved a hit ratio in excess of 80% Thats exceptional, no one has ever come close to beating it before or since, but still there weree many instances of achieving hit rates in excess of 50% If you have well trained crews, relatively unprotected targets, that arent moving too quickly, a lot of hits are likley no matter what the delivery system.

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## fliger747 (Apr 29, 2019)

The point being that many warship targets were well defended, moving rapidly and maneuvering. So the never to be bested comment sort of proves the point. One reads the account of the dive bombers at Midway , one of the most consequential of the war, there were a lot of misses on a relatively large target. They were successful with a small number of hits because of the flammable state of the carriers at the moment of the attack. At Sana Cruise SODAK was hit on #1 turret by a 500 lb AP Bomb, the turret crew wasn't even aware of the hit, though it gouged a barrel on turret two and wounded Captain Gatch. 

But yes, the Dive Bombers in their heyday were quite effective. But the Yamato sisters were largely done in by the torpeckers.


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## Glider (Apr 30, 2019)

The RAF found that the rockets were very effective anti shipping weapons at anything up to light cruiser level. For merchant shipping anything was vulnerable. Dive bombing was basically passé by the end of the war.


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## JAG88 (Apr 30, 2019)

Glider said:


> The RAF found that the rockets were very effective anti shipping weapons at anything up to light cruiser level. For merchant shipping anything was vulnerable. Dive bombing was basically passé by the end of the war.



Only against weakly defended targets, rockets deliver less and dispersed HE, and launched at a shorter range than a dive bomb attack to boot, try that against tougher opposition and they are toast.


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## fliger747 (May 2, 2019)

Yes, USN used rocket attacks against shipping and light warships very effectively! Though not possessed by the Axis, the VT fuze probably spelled the end of the Dive Bomber.


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## RCAFson (May 2, 2019)

JAG88 said:


> Only against weakly defended targets, rockets deliver less and dispersed HE, and launched at a shorter range than a dive bomb attack to boot, try that against tougher opposition and they are toast.



IIRC, rockets used for anti-shipping strikes were fired to strike the water , where they then proceeded UW to strike the ship's hulls below the water line. I know this is how they were used against submarines, and rockets could penetrate a sub's thick pressure hull in this manner.


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## buffnut453 (May 2, 2019)

JAG88 said:


> Only against weakly defended targets, rockets deliver less and dispersed HE, and launched at a shorter range than a dive bomb attack to boot, try that against tougher opposition and they are toast.



I'd like your source for that information. Take a look at the pair of videos available from the IWM: 

SHIP-BUSTERS [Main Title]

In the first, you can see the gun positions on every ship that's been sunk. In the second you see Banff Wing Mosquitos and Beaufighters going in against ships congregated in fjords. And why were the ships there? Because they could mass flak from both the ships and shore batteries against attacking aircraft. 

Undoubtedly, there's propaganda at play but I think the content speaks for itself in contradicting your contention about weakly defended targets.


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## Greyman (May 2, 2019)

RCAFson said:


> IIRC, rockets used for anti-shipping strikes were fired to strike the water , where they then proceeded UW to strike the ship's hulls below the water line. I know this is how they were used against submarines, and rockets could penetrate a sub's thick pressure hull in this manner.



Amusingly the AP head was developed for use against enemy tanks and the SAP head was developed for use against enemy shipping. As it turned out each head was much better suited to attack the other target and their use was completely reversed from what was initially intended.

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## Shortround6 (May 2, 2019)

Things like this spelled the end of the dive bomber.

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## JAG88 (May 3, 2019)

buffnut453 said:


> I'd like your source for that information. Take a look at the pair of videos available from the IWM:
> 
> SHIP-BUSTERS [Main Title]
> 
> ...



The Germans were using magazine-fed 20mm and semi-auto 37mm flak... weak weapons compared to what they could have fielded, try those raids against a quad-mount, water-cooled MG151/20s or an earlier developed 3,7cm M42, or even the Bofors they did have access to.

The ships were in fjords because that is where you load/offload cargo, so of course you protect them and the ships therein.


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## JAG88 (May 3, 2019)

RCAFson said:


> IIRC, rockets used for anti-shipping strikes were fired to strike the water , where they then proceeded UW to strike the ship's hulls below the water line. I know this is how they were used against submarines, and rockets could penetrate a sub's thick pressure hull in this manner.



At the attackers leisure, since subs have little to no flak and it was more sensible to try and dive anyways.

Yes, flak Uboats, remember how they fared?


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## buffnut453 (May 3, 2019)

JAG88 said:


> The Germans were using magazine-fed 20mm and semi-auto 37mm flak... weak weapons compared to what they could have fielded, try those raids against a quad-mount, water-cooled MG151/20s or an earlier developed 3,7cm M42, or even the Bofors they did have access to.
> 
> The ships were in fjords because that is where you load/offload cargo, so of course you protect them and the ships therein.



I'd still like to see sources for your assertions. What's your source for the weapons in use? Even taking your data as correct, the German 37mm flak gun had a faster rate of fire than any comparable weapon on the planet so I'm not sure how that counts as "weak". 

However, German flak ships were much better armed than what you describe as "weak" to include 88mm, multiple 20-40mm and several smaller-calibre weapons. Yet, despite those odds, the Banff Wing still attacked them successfully using rockets and cannon. The pic below shows flak ship _V-1605 Mosel_ under attack by Beaufighters off Lillesand, Norway, 15 October 1944:





Source: Wikipedia


So, again, please provide some sources for your assertions that rocket weapons were ineffective in highly-defended maritime environments.

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## JAG88 (May 3, 2019)

Ill try to be patient...



buffnut453 said:


> I'd still like to see sources for your assertions. What's your source for the weapons in use? Even taking your data as correct, the German 37mm flak gun had a faster rate of fire than any comparable weapon on the planet so I'm not sure how that counts as "weak".
> 
> However, German flak ships were much better armed than what you describe as "weak" to include 88mm, multiple 20-40mm and several smaller-calibre weapons. Yet, despite those odds, the Banff Wing still attacked them successfully using rockets and cannon. The pic below shows flak ship _V-1605 Mosel_ under attack by Beaufighters off Lillesand, Norway, 15 October 1944:
> 
> ...



1. Outpost boats were not "flak ships", were just that, outpost boats (often requisitioned fishing boats), they did have some AA guns, but that did not make them flak ships...

2. You are thinking of the 3,7cm LAND flak, the KM used the Germany 3.7 cm/83 SK C/30 - NavWeaps, HAND-LOADED SEMI-AUTO, RoF about 30rpm, until 1944, when a modified version of the land flak 36 Germany 3.7 cm/69 (1.5") Flak M42 - NavWeaps was introduced.



3. Those Germany 2 cm/65 (0.79") C/30 and C/38 - NavWeaps were all magazine fed (20 roudns) and air cooled, which means reduced fire rates.






4. UK air attacks werent much of an issue until late war, which is why the KM kept their old weapons in use for so long, the threat wasnt there, when the threat increased they issued 40mm and 37mm M42s, but by then they had far more pressing issues than protecting shipping...

5. Word of advice, never use Wikipedia as a source... just dont.


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## buffnut453 (May 3, 2019)

JAG88 said:


> Ill try to be patient...
> 
> 
> 
> ...




One could suggest that you shouldn't be overly selective in your justifications. The replacement for the original Naval 37mm (30 rpm) had a firing rate of 250 rounds per minute. Why are you discounting that from your arguments because the air war against German maritime assets was still very active in 1944 when the newer weapon was introduced.

I'm also struggling with the point you're trying to make about better AAA defences. The Banff Wing flew against the targets that were available. Had better AAA been in place, then perhaps different tactics or weapons might have been employed. Then again, better AAA means a greater chance of shooting down a dive bomber. So are you suggesting that air-dropped torpedoes were the way to go? That would have been really challenging in the fjords of Norway. Just getting the aircraft into a suitable position to drop the weapon would be challenging...and expose the aircraft and crew to all those better AAA guns you're advocating.


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## JAG88 (May 3, 2019)

I am not discounting anything, I am pointing out the weak AA weapons used by the KM and the fact that they introduced better weapons when it was already too late, lacked the resources to field them effectively and had FAR more pressing issues to worry about.

I am not suggesting anything about the wing, that is all you.


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## buffnut453 (May 3, 2019)

I'm simply asking you to justify your original statement. Rockets used were typically AP not HE and better AAA impacts dive bombers as much as it does rocket-firers or torpedo droppers. So, again, what's the source of your statement that rocket-firing aircraft would be "toast"? I'm not trying to be a pain in the proverbial but you're not answering that simple question.


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## JAG88 (May 3, 2019)

LOL!!!!

Even WORSE!

What the hell is going an AP rocket do to a ship besides a clean hole somewhere? And that is those that hit, rockets are VERY inaccurate, if you want hits you need to launch CLOSER than a dive bomber, which makes the launcher EVEN MORE VULNERABLE to flak!

Let me put it his way, how do you think those attacks would have fared against USN flak? Apparently you dont think better flak may have made a difference, try that against the USN then...


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## buffnut453 (May 3, 2019)

They'd have fared probably about as well as the IJN did with every attack method they tried. A few successes but mostly failures. But that has nothing to do with the delivery system. Dive bombers against the USN would be just as vulnerable.

And as to the AP, the switch was made from HE to AP because it was demonstrated on operations that it had a better effect than HE. You can laugh all you like but, at the end of the day, it worked where and when it was needed.


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## JAG88 (May 3, 2019)

So, by your own admission, better flak like the one used by the USN would have been an effective defense against a rocket attack so, why wouldnt a similar improvement in KM flak have the same result?

Because that is the point, KM flak was weak due to outdated equipment and even then did the job until late war, when it no longer could deal with the number of attackers thrown against them, but by then the introduction of new equipment was made moot by lack of resources and personnel, added to the urgent needs of more relevant fronts.

Rocket-armed planes need to get CLOSER to deliver a WEAKER weapon, if you lose 6 out of 12 aircraft in a strike, you would be happy if you got a few rocket hits or a single 250Kg bomb that would obliterate a small ship? Moreover, that dive bomber could use heavier ordnance lethally against a larger ship, rockets?

Better flak would have a field day with any twin-engined aircraft trying to deliver rockets... that only works against weak opposition overwhelmed by numbers.


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## buffnut453 (May 3, 2019)

We're just going to have to agree to disagree. This is going nowhere. "Weak" is relative...and if you get enough weak single ships together, the whole can become pretty strong. That's precisely why the ships were in the fjords in the first place. The terrain made them harder to attack, and they could mutually support each other, plus have the benefit of any shore-based weapons. 

Of course you're not going to attack larger ships with rockets. That's called "weapon to target matching". No point firing a peashooter at a battleship. However, this whole thread has been about the accuracy of dive bombing. Despite their weak defences, how many dive bombers would it take to attack and destroy all the ships shown in the video? Both delivery mechanisms had their time and their place but flak was the enemy of both. Better flak means both delivery platforms are more vulnerable. Indeed, it could be argued that a twin-engine aircraft is more survivable than a single-engine dive bomber. 

Like I said, we'll have to agree to disagree.


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## JAG88 (May 3, 2019)

Of course, now is "weak is relative"...

A 37mm HE shell doesnt care if the aircraft is single or a twin, its going down, the larger and less maneuverable twin simply makes an easier target...

A single dive bomber can destroy a small target with a single hit, your twins need several hits by several aircraft fo make an impression.


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## Reluctant Poster (May 4, 2019)

JAG88 said:


> Ill try to be patient...
> 
> 
> 
> ...


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## JAG88 (May 4, 2019)




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## Glider (May 4, 2019)

JAG88 said:


> Only against weakly defended targets, rockets deliver less and dispersed HE, and launched at a shorter range than a dive bomb attack to boot, try that against tougher opposition and they are toast.


I am afraid that I disagree. A number of the large modern German destroyers were seriously damaged and at least one was sunk using rockets. The German forces had formidable AA defences and they paid a heavy price against the Coastal Command attacks.


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## pbehn (May 4, 2019)

A mosquito squadron would be perfectly happy to leave destroyers afloat and sink all the boats and barges they were trying to protect.


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## JAG88 (May 4, 2019)

Glider said:


> I am afraid that I disagree. A number of the large modern German destroyers were seriously damaged and at least one was sunk using rockets. The German forces had formidable AA defences and they paid a heavy price against the Coastal Command attacks.



How is this "formidable"?




Or this? 20rd magazines, they last less than 3 seconds before change, so usually only 2 barrels fired at a time in order to try to keep fire up. Which is kind of a good thing, otherwise they would overheat as well...







So, NONE of the KM weapons could actually keep fire up due to RoF limitations, magazines or lack of cooling. Counting barrels is a meaningless exercise without context.


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## JAG88 (May 4, 2019)

Glider said:


> I am afraid that I disagree. A number of the large modern German destroyers were seriously damaged and at least one was sunk using rockets. The German forces had formidable AA defences and they paid a heavy price against the Coastal Command attacks.



You mean the one the crew let sink in port after being damaged the day before? That one?


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## Glider (May 4, 2019)

Simple really. The 37mm L83 (a semi automatic weapon) was replaced by the 37mm 69 which was an automatic weapon with a rof of approx. 250 rpm. The early 20mm C/30 had a 20 round magazine but this was prone to jamming and was replaced by a modified version/38 which had a 40 round magazine. A three directional stabilised mount was introduced in 1944 for the 20mm which would have also increased its effectiveness.

I think this addresses both your points. 

The Light aa weapons carried by the German destroyers varied considerably, but were up to 10 x the 37mm and 16 x 20mm. By any standard a very heavy defence.


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## JAG88 (May 4, 2019)

Glider said:


> Simple really. The 37mm L83 (a semi automatic weapon) was replaced by the 37mm 69 which was an automatic weapon with a rof of approx. 250 rpm. The early 20mm C/30 had a 20 round magazine but this was prone to jamming and was replaced by a modified version/38 which had a 40 round magazine. A three directional stabilised mount was introduced in 1944 for the 20mm which would have also increased its effectiveness.
> 
> I think this addresses both your points.
> 
> The Light aa weapons carried by the German destroyers varied considerably, but were up to 10 x the 37mm and 16 x 20mm. By any standard a very heavy defence.



I am sorry, were are getting this BS?

The M42 was introduced in 1944, and not everyone got them, the KM sat at the bottom of the priority pole as far as resources went which is why they started to scrounge Bofors and Oerlikons from wherever they could.

No, there was no 20rd magazine for 20mm flak, ever.

The three-axial stabilized mount was introduced... IN 1934!!! With the 37mm semi-auto, and it wasnt kept in service for the M42 or the Bofors.

You clearly need to read more on this subject, you are lost.


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## buffnut453 (May 5, 2019)

JAG88 said:


> You clearly need to read more on this subject, you are lost.



Then why don't you enlighten us and provide *sources*. You've been asked for them several times but you just keep regurgitating data and opinions.

You clearly have some detailed knowledge on the topic. Why not tone down the arrogance and patronizing demeanour and try educating instead of mocking? Maybe then we can have an adult conversation instead of this rather silly willy-waving. Who knows, maybe you'd learn something too...if you're willing to listen? 

None of us is as smart as all of us.

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## Glider (May 5, 2019)

I will take your points one at a time.



JAG88 said:


> I am sorry, were are getting this BS?


As mentioned by Buff sources are important. I have a number of book at home but they support the information that can be found on line at NavWeaps | Naval Weapons, Naval Technology and Naval Reunions If I could ask where you are getting your information it would be appreciated by myself and no doubt others. 
To put it another way. I have told you where I am getting my BS, can I ask you to tell us where you are getting yours?


> The M42 was introduced in 1944, and not everyone got them, the KM sat at the bottom of the priority pole as far as resources went which is why they started to scrounge Bofors and Oerlikons from wherever they could.


 You are partly correct. The M42 was a later development but it was fairly widely used on U Boats, the Emden, Destroyers and Minesweepers. However there was another 37mm which was developed with the Army known as the 37mm/57 which was used by the Heavy and Light cruisers as well as some torpedo boats. Re the observation about the German use of the Oerlikons and Bofors, as far as the Bofor was concerned they were always in production in Norway under German occupation and the German Navy had first call on that production. So I suspect that knocks a significant hole in that claim of yours that the navy were bottom of the pile.


> No, there was no 20rd magazine for 20mm flak, ever.


 I think you need to make your mind up here. It was your quote that said that the Germans only had a 20 round magazine, supported by your inclusion of a clip showing a German 20mm gun with a 20 round magazine. This supported your argument that the German guns could only fire for 3 seconds and now suddenly your saying that there was never a 20rd magazine. Again if you could sort out your understanding on this point I would appreciate it. My understanding is quite clear as stated in my previous posting, which is supported by the Navweapons site plus other books.



> The three-axial stabilized mount was introduced... IN 1934!!! With the 37mm semi-auto, and it wasn't kept in service for the M42 or the Bofors.


 Correct, but I wasn't saying that. I was saying that the stabilised mount was introduced for the quad 20mm in 1944


> You clearly need to read more on this subject, you are lost.



I beg to differ



> You mean the one the crew let sink in port after being damaged the day before? That one?



A couple of obvious points.
a) No navy 'lets' a modern powerful ship sink in harbour without good reason
b) She wasn't the only ship of that type/class to be severely damaged, but I will let you find the details


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## Reluctant Poster (May 5, 2019)

For those of you who are actually interested in dive bombing the following video illustrates what the US Navy considered to be proper dive bombing:


The following graph shows that increasing the angle above 70 degrees does not result in an appreciable increase in accuracy, at least at reasonable release heights






As for penetration of armored decks the attached graphs show the capabilities of USN AP and SAP bombs.

It should be noted that the US Navy *did not* have amour piercing bombs in the early part of the war. The Commander in Chief, Pacific Fleet report to the Commander in Chief ,United States Fleet states the following:
"86. Effectiveness of aircraft torpedoes and bombs must be increased
(a) A larger torpedo warhead is urgently required. The present strengthened torpedo is a favorable step in the right direction, but the torpedo must be designed for much higher speed drops. In the Midway action the B-26 and TBF planes received their most serious losses from Japanese fighters when they slowed down to limiting torpedo dropping speed.
(b) Had the 1000 lb armor piercing bomb under development been available for dive bombers, fewer of the many ships that were hit would have escaped; and fewer hits would have been needed to destroy the carriers."

The Task Force 16 Action Report from Midway states:
"9. (g) A.P. bombs suitable for our present dive bombers are required. With present 500 and 1000 lb. bombs attack against armored ships does not disable until ship has been knocked to pieces by many more hits than should be necessary."

This report also admonishes:
"9. (i) Dive bombing attacks on DDs are not profitable because of the difficulties of obtaining hits on such a small and highly maneuverable target. Such attacks should not be made if a larger and more valuable target is available."

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## Reluctant Poster (May 5, 2019)

As to the importance of submarines in the Pacific war the following graphs illustrate their dominance










The Us Navy fleet boats did indeed strangle Japan while also destroying a large portion of the IJN.

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## JAG88 (May 5, 2019)

Glider said:


> I will take your points one at a time.
> 
> 
> As mentioned by Buff sources are important. I have a number of book at home but they support the information that can be found on line at NavWeaps | Naval Weapons, Naval Technology and Naval Reunions If I could ask where you are getting your information it would be appreciated by myself and no doubt others.
> ...



LOL! Ok...

The M42 entered service in 1944, there were never enough to go around, AGAIN, the KM always and for good reasons was at the bottom of the resource priority list to the point that even then the LW got most of the Bofors available as even a cursory search would show...

LOL! The KM didnt have "first call" on anything, it was what was left, and even then the LW got the bulk of the weapons.

Please, the Flak 36/37 was a LW gun, beyond some anecdotal use and the fact that the M42 was developed from it, well, it is inconsequential.

20rd? A Typo, it is your ridiculous 40rd magazine, somehow NavWeaps hasnt fixed that mistake in years, one that seems to have originated on a Polish publication, likely a confusion caused by this...






The 20rd magazines came in 2-magazine boxes, 40rds total... there are no pictures of such magazines and with tens of thousands of guns and hundreds of thousands of magazines... where are they? Let me know when you find one...

The stabilized quad is a heavy and LATE mount, used on large ships, how is THAT relevant? How doest THAT fix the RoF issue? The lack of cooling?

LOL! Sure, like I would waste my time looking for data that are unwilling to show yourself... I wonder why...

Z24 sank the day AFTER being damaged, made port and sank at its berth, you are welcome to go ask its crew why they let a DD sink in late 1944...

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## JAG88 (May 5, 2019)

buffnut453 said:


> Then why don't you enlighten us and provide *sources*. You've been asked for them several times but you just keep regurgitating data and opinions.
> 
> You clearly have some detailed knowledge on the topic. Why not tone down the arrogance and patronizing demeanour and try educating instead of mocking? Maybe then we can have an adult conversation instead of this rather silly willy-waving. Who knows, maybe you'd learn something too...if you're willing to listen?
> 
> None of us is as smart as all of us.



Please... if you have any interest on naval issues you can find most of the info readily on NavWeaps, it is not like it is any mystery or obscure data. The annoyed tone is due to someone clearly looking AT THE SAME DATA and deliberately misconstruing the info talking about earlier version of a gun which were never part of the issue as the flak 30 or that somehow, magically, the KM got showered with fully automatic 37mm guns when the Heer was being crushed on a two front war, the LW measuring new figther pilot lives in HOURS and even putting the MG151 and the 20 into service as a desperate measure to try to stop the thousands of Il-2s, Typhoons and P-47s thrown at them?

Context.

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## buffnut453 (May 5, 2019)

JAG88 said:


> Please... if you have any interest on naval issues you can find most of the info readily on NavWeaps, it is not like it is any mystery or obscure data.



It may be very familiar to you but it may not be for others. Instead of snarky patronizing responses (to me), why couldn't you just post the web page and say "Take a look here"?




JAG88 said:


> The annoyed tone is due to someone clearly looking AT THE SAME DATA and deliberately misconstruing the info talking about earlier version of a gun which were never part of the issue as the flak 30 or that somehow, magically, the KM got showered with fully automatic 37mm guns when the Heer was being crushed on a two front war, the LW measuring new figther pilot lives in HOURS and even putting the MG151 and the 20 into service as a desperate measure to try to stop the thousands of Il-2s, Typhoons and P-47s thrown at them?
> 
> Context.



Firstly, you're making an assumption that someone is deliberately misinterpreting information. You freely admitted that some of the info on NavWeaps is incorrect (the 40-round magazine, for example)...so, again, how are the less-expert among us supposed to know what is correct and what isn't when you won't provide sources (NavWeaps excepted, and Glider actually posted that source first)? 

As to context, you've said "counting barrels is meaningless" and yet that's a vital aspect of operational deployment. It's blindingly obvious that a 30-rpm weapon is inferior to a 250-rpm weapon when comparing the 2 side-by side. However, the operational environment is more complex than that. For example, is a single 250-rpm weapon better than 8x30-rpm weapons? By the single metric of rate of fire (ROF), the answer is "yes" but against a squadron of attacking aircraft, I'd rather have 8 slower-firing weapons because they can engage multiple targets simultaneously. 

This all comes back to your definition of "weak" which you seem to base purely on comparisons with other weapons. However, by clustering vessels in fjords, the Germans were able to provide mutual support and, even if the individual weapon ROF is poor, the combined effect against a squadron of attacking aircraft was probably not intrinsically weak. And that's before we consider any shore batteries that would contribute to the defensive AAA fire. The simple fact of putting rounds in the sky will have some deterrent effect on attackers.

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## JAG88 (May 5, 2019)

No one posts sources for EVERY statement they make, in fact, it is seldom done UNLESS is something out of the ordinary, not common knowledge, mentioning NavWeapons falls into that.

When something is patently obvious ceases to be an assumption, talking about an old gun and implying that the "new model", which was the wartime standard, fixed something relevant to the discussion is simply ridiculous and dishonest. Same thing with saying the 37mm C30 was "replaced", it never was, served all the way to the end of the war. Where is his source for that? Nowhere in NavWeaps... saying "NavWeaps" doesnt mean the thinks he makes up are true, in there or even relevant to the discussion. Did you check or were simply blinded by a link that you ultimately ignored?

Want sources? Go check Campbell and Friedman. There, happy? After all, you are not going to check that either, right?

8 vs 1? How about 8 vs 4? Or 20 vs 1? 20 Muskets vs 1 MG 42... How about that?

That is why I talked about context, Glider mentioned they had "formidable AA defenses" as if that ALONE meant something, that was HIS argument, and you come up with this?

The dumb fjord thing again... cargo ships are vehicles, they move stuff from A to B, that is where they are most vulnerable and actually being useful which is why they steam under armed escort. All ports in the war zone had defenses, what an absurd an irrelevant argument. Lets keep all cargo ships in port, there they shall be safe...

The defense is weak because the effects and results obtained for the effort and resources employed are underwhelming, deck space is limited which is why weapon quality is VERY important (go ask the IJN, Yamato went down with 150+ 25mm AA), use better weapons and you get a better return, a better defense for the investment. Replace them with water-cooled twin Bofors, you get a defense as strong as it could be at the time, not a weak one.

The Germans could have easily had a water-cooled version of the M42 developed pre-war, that alone would have done wonders for them.

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## JAG88 (May 5, 2019)

And just so we are clear...

From Friedman:

"An automatic gun to replace the single-shot SKC/30 (which, however, served out the war) was
ordered in 1939; it materialised as the 3.7cm Flak M42, a lengthened (69 calibres overall) version of
the army’s Flak 36. It was fed by a six-round horizontal clip (ammunition strip), firing 160 to 180
rnds/min. Both the single Flak LM42 and twin Flak LM42 had conventional pointer-trainer control by
hand wheels. There was no associated director. Initially few were mounted, but in 1944 an AA
improvement programme was set up. Smaller units and submarines were to be given Flak M42;
battleships and cruisers were to have the follow-on Flak M43. It never went into production.

Battleships and cruisers were rearmed with single 40mm Bofors under the designation Flak 28.
The programme was Project Barbara. The first ships fitted were the heavy cruisers Admiral Hipper
and Prinz Eugen. The ‘pocket battleships’ were also rearmed. Other guns were planned for light
cruisers. During 1945 rearmament extended to many smaller ships. The small scale of anti-aircraft
upgrade, compared to other navies at the same time, is striking evidence of how little experience the
wartime German navy had of air attack. In addition to 4cm guns, the Germans added 20mm guns on a
substantial scale."

From Koop:

"In November 1944 it was decided to upgrade the ships’ anti-aircraft battery in a gradual
programme, by, for example, filting two additional 3.7cm twins at the level of No 2 gun forward of
the bridge, two more twins replacing the singles amidships and three further twins replacing No 3
gun; 3.7cm-calibre guns would supplant the 2cm singles aboard destroyers fitted with a 15cm main
armament, and additional light AA mountings would be positioned on the bridge.

As the borders of the Reich became increasingly compressed, the programme could only be
partially completed. Only a few destroyers were re-armed fully in accordance with the plan, and the
additions are described below, though others acquired extra mountings during dockyard refits and
fitted them according to the ‘Barbara’ instructions."


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## buffnut453 (May 5, 2019)

JAG88 said:


> No one posts sources for EVERY statement they make, in fact, it is seldom done UNLESS is something out of the ordinary, not common knowledge, mentioning NavWeapons falls into that.



I wasn't asking for a source for every statement but I did want to know what sources you were using. A great many people (on this forum and others) pass off their own opinion as fact. It would be nice to work out where opinion overcomes fact in your comments.




JAG88 said:


> When something is patently obvious ceases to be an assumption, talking about an old gun and implying that the "new model", which was the wartime standard, fixed something relevant to the discussion is simply ridiculous and dishonest. Same thing with saying the 37mm C30 was "replaced", it never was, served all the way to the end of the war. Where is his source for that? Nowhere in NavWeaps... saying "NavWeaps" doesnt mean the thinks he makes up are true, in there or even relevant to the discussion. Did you check or were simply blinded by a link that you ultimately ignored?



Actually, I didn't ignore it. I went and checked it out. That's what I do when people provide reasonable leads to the sources they're using. Lo and behold, here's a quote from the page on the 3.7cm C30 (bold added by me for emphasis):

_"As this was a manually-loaded, single-shot, semi-automatic weapon with a slow rate of fire, the KM started a development program to produce an automatic loader for it. While a prototype was successfully tested, the developmental contract was cancelled *in late 1943 as the SK C/30 was becoming obsolete and was already being replaced on naval vessels by the 40mm Bofors and the 37mm KM42 and KM43 naval FLAK guns*."_

So I call BS on your commend that the C/30 was never replaced. It may have served throughout the war but we need details on how many were serving, where and when. Certainly in 1943 it was starting to be replaced. Some undoubtedly lingered on but how many? Do you have those statistics to hand? If not, quit berating people about being dishonest when they are simply stating facts from the same sources you are citing. You're making an assumption that all 3.7cm AAA guns were C/30s while others are perhaps assuming that many had been replaced by the later weapons. 




JAG88 said:


> Want sources? Go check Campbell and Friedman. There, happy? After all, you are not going to check that either, right?



Well, I just said that I checked the NavWeaps site. I presume Campbell and Friedman is a book? Perhaps a title to go with the authors might be useful?




JAG88 said:


> 8 vs 1? How about 8 vs 4? Or 20 vs 1? 20 Muskets vs 1 MG 42... How about that?



For pity's sake, I was simply using an example of how ROF isn't the only useful metric in operations. Again, can we have a grown up conversation here? I'm beginning to think that's impossible.




JAG88 said:


> The dumb fjord thing again... cargo ships are vehicles, they move stuff from A to B, that is where they are most vulnerable and actually being useful which is why they steam under armed escort. All ports in the war zone had defenses, what an absurd an irrelevant argument. Lets keep all cargo ships in port, there they shall be safe...



They weren't only in ports. They were also using fjords as protected areas during daylight and moving during the night, leapfrogging down the coast. It is entirely relevant to the discussion because it demonstrates (a) the impact of Allied air attacks, and (b) German efforts to consolidate their AAA defences to protect the ships. But, presumably, you didn't watch the videos I posted because those points were made clear!




JAG88 said:


> The defense is weak because the effects and results obtained for the effort and resources employed are underwhelming, deck space is limited which is why weapon quality is VERY important (go ask the IJN, Yamato went down with 150+ 25mm AA), use better weapons and you get a better return, a better defense for the investment. Replace them with water-cooled twin Bofors, you get a defense as strong as it could be at the time, not a weak one.
> 
> The Germans could have easily had a water-cooled version of the M42 developed pre-war, that alone would have done wonders for them.



Again, "better" does not mean that the existing capability is "weak". Anything can be improved upon. 

As to the Bofors, again from NavWeaps "By July 1941 the Kriegsmarine had 247 guns in service and by March 1942 the Luftwaffe had 615 guns in service." Now I know that 247 is not a large number...but that's in the summer of 1941. How many had been delivered and were in operation in 1943 or 1944? Which ships and which shore installations had them? Again, it would be good to know these details because it may be that many of the vessels in Norway had them. If you have data to the contrary, again please share. 

Clearly, the KM was getting Bofors first and as early as mid-1941 so it's reasonable to assume that a number were still in service in 1943-44...because, as noted in my previous NavWeaps post, "in late 1943 the SK C/30 was being replaced...by the 4cm Bofors."


So, once again, quit the snarky comments; it's getting really old. We all just want to learn so how about contributing to the discussion in a more positive tenor?

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## JAG88 (May 5, 2019)

buffnut453 said:


> I wasn't asking for a source for every statement but I did want to know what sources you were using. A great many people (on this forum and others) pass off their own opinion as fact. It would be nice to work out where opinion overcomes fact in your comments.
> 
> 
> 
> ...



So, AGAIN:

From Friedman's Naval Anti Aircraft Guns and Gunnery:

"An automatic gun to replace the single-shot SKC/30 (*which, however, served out the war*) was
ordered in 1939; it materialised as the 3.7cm Flak M42, a lengthened (69 calibres overall) version of
the army’s Flak 36. It was fed by a six-round horizontal clip (ammunition strip), firing 160 to 180
rnds/min. Both the single Flak LM42 and twin Flak LM42 had conventional pointer-trainer control by
hand wheels. There was no associated director. Initially few were mounted, *but in 1944 an AA
improvement programme was set up*. Smaller units and submarines were to be given Flak M42;
battleships and cruisers were to have the follow-on Flak M43. It never went into production.

*Battleships and cruisers were rearmed with single 40mm Bofors* under the designation Flak 28.
The programme was Project Barbara. The first ships fitted were the heavy cruisers Admiral Hipper
and Prinz Eugen. The ‘pocket battleships’ were also rearmed. Other guns were planned for light
cruisers. *During 1945* rearmament extended to many smaller ships. The small scale of anti-aircraft
upgrade, compared to other navies at the same time, is striking evidence of how* little experience the
wartime German navy had of air attack.* In addition to 4cm guns, the Germans added 20mm guns on a
substantial scale."

From Koop's German Destroyers of WW2:

*"In November 1944* it was decided to upgrade the ships’ anti-aircraft battery in a gradual
programme, by, for example, filting two additional 3.7cm twins at the level of No 2 gun forward of
the bridge, two more twins replacing the singles amidships and three further twins replacing No 3
gun; 3.7cm-calibre guns would supplant the 2cm singles aboard destroyers fitted with a 15cm main
armament, and additional light AA mountings would be positioned on the bridge.

*As the borders of the Reich became increasingly compressed, the programme could only be
partially completed. Only a few destroyers were re-armed fully in accordance with the plan, *and the
additions are described below, though others acquired extra mountings during dockyard refits and
fitted them according to the ‘Barbara’ instructions." 




> For pity's sake, I was simply using an example of how ROF isn't the only useful metric in operations. Again, can we have a grown up conversation here? I'm beginning to think that's impossible because you just want to score points and show how much "smarter" you are than the rest of us (and, yes, the "" are deliberate).



A simplistic example, what did you expect? You and Gilder keep pointing at the number of guns as if that meant anything by itself and then complain when challenged.




> They weren't only in ports. They were also using fjords as protected areas during daylight and moving during the night, leapfrogging down the coast. It is entirely relevant to the discussion because it demonstrates (a) the impact of Allied air attacks, and (b) German efforts to consolidate their AAA defences to protect the ships. But, presumably, you didn't watch the videos I posted because those points were made clear!



As Friedman put it, the KM had suffered little against AA attack so improvements were slow, after all, they were operating coastal convoys for a long time with little air support, right?



> "Again, "better" does not mean that the existing capability is "weak". Anything can be improved upon.
> 
> As to the Bofors, again from NavWeaps "By July 1941 the Kriegsmarine had 247 guns in service and by March 1942 the Luftwaffe had 615 guns in service." Now I know that 247 is not a large number...but that's in the summer of 1941. How many had been delivered and were in operation in 1943 or 1944? Which ships and which shore installations had them? Again, it would be good to know these details because it may be that many of the vessels in Norway had them. If you have data to the contrary, again please share.
> 
> Clearly, the KM was getting Bofors first and as early as mid-1941 so it's reasonable to assume that a number were still in service in 1943-44...because, as noted in my previous NavWeaps post, "in late 1943 the SK C/30 was being replaced...by the 4cm Bofors."



You can see the LW had more guns, right? Who do you think kept getting the bulk of them after Barbarossa? If they had so much access, why werent all the KM ships so rearmed? They must have had PLENTY by 1943? And yet, they couldnt even do so with their DDs even in 1944...

I am pretty sure that was due to having far more urgent needs elsewhere...


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## buffnut453 (May 5, 2019)

JAG88 said:


> You and Gilder keep pointing at the number of guns as if that meant anything by itself and then complain when challenged.



Sheer numbers do mean something, particularly in how the forces are laid down and operate. Conversely, you seem to focus solely on the technical parameters of the weapons. Both were important. My frustration is your unwillingness to accept that the tactical laydown of "poor quality" weapons can have a cumulatively positive effect on the defence of, say, a group of vessels.




JAG88 said:


> You can see the LW had more guns, right? Who do you think kept getting the bulk of them after Barbarossa? If they had so much access, why werent all the KM ships so rearmed? They must have had PLENTY by 1943? And yet, they couldnt even do so with their DDs even in 1944...
> 
> I am pretty sure that was due to having far more urgent needs elsewhere...



Yes, the LW had more guns but that total is dated 8 months after the total provided for the KM so we can't really draw any conclusions about priorities from these 2 data points because we don't know how many guns the KM had at the end of February 1942. 

The KM may not have been getting the guns but what about the Wehrmacht and Luftwaffe forces in Norway? Little old Norway was one of the most heavily occupied countries in Europe, with over 400,000 German soldiers. In addition, there was a large quantity of coastal guns as part of the "Atlantic Wall". Such installations are almost always supported by AAA batteries. I keep mentioning the potential for supporting AAA from land-based batteries but you assiduously ignore that comment and continue to focus solely on the KM. 

In line with my last though, it would be good to know what other AAA assets were available along the coast of Norway that could help provide defensive fire for the convoys. Certainly there were Wurzburg and Freya radars and what's the point of having those if there aren't any guns associated?


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## Glider (May 5, 2019)

What I find interesting is that I am being pretty well slaughtered for following a source that most people agree normally has a high standard of accuracy yet it was JAG88 who posted the following:-
'_No, there was no 20rd magazine for 20mm flak, ever.'_
Something that seems to have been conveniently forgotten.

The German ships were very well armed and by the end of the war the defence was formidable. Z5 for example at the end of the war carried a light aa of 10 x 37mm and 13 x 20mm. *Note* all of the 37mm were of the M42 version. 
I also firmly believe that the 3.7cm/57 was widely deployed in the German Navy, its shields are very distinctive and are often seen in photographs. German Destroyers of WW2 page 157 clearly shows two of these mountings in the bridge wing of a destroyer and the photo was taken in the Summer of 1944

PS - if you can find a source that doesn't consider the quad 20mm to be a serious danger then I would be interested.
PPS - I haven't complained about being challenged, but you seem to have thrown a right strop


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## michael rauls (May 5, 2019)

JAG88 said:


> Please... if you have any interest on naval issues you can find most of the info readily on NavWeaps, it is not like it is any mystery or obscure data. The annoyed tone is due to someone clearly looking AT THE SAME DATA and deliberately misconstruing the info talking about earlier version of a gun which were never part of the issue as the flak 30 or that somehow, magically, the KM got showered with fully automatic 37mm guns when the Heer was being crushed on a two front war, the LW measuring new figther pilot lives in HOURS and even putting the MG151 and the 20 into service as a desperate measure to try to stop the thousands of Il-2s, Typhoons and P-47s thrown at them?
> 
> Context.


For whatever it's worth, the guys you are talking to don't deliberately misconstrue information. Could they misinterpret something? Sure, anyone can but I've been reading there posts long enough to know they don't deliberately misconstrue anything.
Just a friendly suggestion that a more congenial manner might be appropriate.

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## Shortround6 (May 5, 2019)

With ships the quality of the guns is important, this is my opinion.

But based on.

There are only so many _additional_ weapons you can add to a ship due to:

1. limited deck space.
2. top weight, stability concerns.
3. limited crew to man additional weapons.

That said just about all Navies did add additional AA guns and some navies took off surface guns and/or torpedo tubes to compensate. Some navies had more spacious crew quarters to begin with and could jam in more men easier. Some Navies accepted the reduction in sea worthiness (stability) as less of a risk than getting sunk by air attack. Some navies added ballast in the bottom of the ship. Stability may have been preserved but freeboard went down. There was often more to it than just how many guns could be delivered from the factory.

The early German 37mm AA gun was one of those triumphs of gunnery hubris over practical results (my opinion). The rate of fire was too low and the gun weight (and mount weight) was too high for the effect hoped for. It was a large, heavy, but high velocity gun but the extra velocity (less lead needed) didn't make up for the low rate of fire.

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## JAG88 (May 5, 2019)

Glider said:


> What I find interesting is that I am being pretty well slaughtered for following a source that most people agree normally has a high standard of accuracy yet it was JAG88 who posted the following:-
> '_No, there was no 20rd magazine for 20mm flak, ever.'_
> Something that seems to have been conveniently forgotten.
> 
> ...




LOL! I already addressed the 20rd issue, feel free to read it again...

I already provided QUOTES of two different sources regarding the availability of new weapons for the KM, feel free to write to the authors to contest their statements...

You can believe whatever you want.

So, how did your inquiry on the DD "sinking", go?

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## JAG88 (May 5, 2019)

michael rauls said:


> For whatever it's worth, the guys you are talking to don't deliberately misconstrue information. Could they misinterpret something? Sure, anyone can but I've been reading there posts long enough to know they don't deliberately misconstrue anything.
> Just a friendly suggestion that a more congenial manner might be appropriate.



Sorry, but when someone claims a weapon was REPLACED, something known to be false, or claiming a new version of the 20mm flak "fixed" something relevant, well, I call BS.

Just a detail, Z39 in Boston with 2 of those "replaced" guns next to what it seems to be a M42.


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## Glider (May 5, 2019)

JAG88 said:


> LOL! I already addressed the 20rd issue, feel free to read it again...
> 
> I already provided QUOTES of two different sources regarding the availability of new weapons for the KM, feel free to write to the authors to contest their statements...
> 
> ...



You certainly did provide quotes from two different sources and I provided clear photographic evidence contained in a book you have already mentioned and I assume you own, which shows that these vessels were armed with these weapons. Something you find it difficult if not impossible to acknowledge.
It is impossible for you to argue against a photo but I could certainly put up a good case for disagreeing with one of the quotes if I were in a debate with the author. To say the following:-

_The small scale of anti-aircraft upgrade, compared to other navies at the same time, is striking evidence of how* little experience the *_* wartime German navy had of air attack.*

Flies in the face of all the evidence. The huge loss of supplies in the med to air attack. The massive escorts needed to get even a couple of merchant ships from point a to point b, plus the constant attacks launched by no 2 Group on shipping and the formation of strike wings. Then the massive effort needed to produce flak ships, flak barges and other escorts to fend off air attack all say something different.


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## JAG88 (May 5, 2019)

Glider said:


> You certainly did provide quotes from two different sources and I provided clear photographic evidence contained in a book you have already mentioned and I assume you own, which shows that these vessels were armed with these weapons. Something you find it difficult if not impossible to acknowledge.



Lol! Because its irrelevant, let me repeat it for the 3rd time:

"*As the borders of the Reich became increasingly compressed, the programme could only be
partially completed. Only a few destroyers were re-armed fully in accordance with the plan, *and the
additions are described below, though others acquired extra mountings during dockyard refits and
fitted them according to the ‘Barbara’ instructions."

You may have whatever anecdotal evidence you may like, the facts remain unchanged and in no way the picture contradicts that...



> It is impossible for you to argue against a photo but I could certainly put up a good case for disagreeing with one of the quotes if I were in a debate with the author. To say the following:-
> 
> _The small scale of anti-aircraft upgrade, compared to other navies at the same time, is striking evidence of how* little experience the *_* wartime German navy had of air attack.*
> 
> Flies in the face of all the evidence. The huge loss of supplies in the med to air attack. The massive escorts needed to get even a couple of merchant ships from point a to point b, plus the constant attacks launched by no 2 Group on shipping and the formation of strike wings. Then the massive effort needed to produce flak ships, flak barges and other escorts to fend off air attack all say something different.



No, it flies in the face of your wishful thinking which is why its upsets you...

No comments on the photo that proves the "replaced" weapons were still there? No?

Sad...

Lets put it up again, just for kicks.


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## michael rauls (May 5, 2019)

JAG88 said:


> Sorry, but when someone claims a weapon was REPLACED, something known to be false, or claiming a new version of the 20mm flak "fixed" something relevant, well, I call BS.
> 
> Just a detail, Z39 in Boston with 2 of those "replaced" guns next to what it seems to be a M42.
> 
> View attachment 537135


Well I don't know if the equipment in question was replaced but assuming it was maybe it's possible they didn't know or maybe, god forbid you misread something or as is usually the case with these sorts of things the truth lies somewhere in between i.e. perhaps it was replaced in some instances and not others or something along those lines.
Different sources can often show different information. 
Compairing information and sources is more enlightening than hitting each other over the head with them..............Ok I'll bow out now.


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## Shortround6 (May 6, 2019)

The German destroyer Z-39 in the photo above finished the war with a pretty decent light AA suite. 
another photo of the same area.




USS Z-39 (DD-939)/ Ex-German Z-39) showing after 37mm Bofors-type A.A. gun platform, near the after stack. Note these 37mm guns are of two different types. Taken at Boston Navy Yard, August 11, 1945. Courtesy of Robert F. Sumrall. Source: Naval History and Heritage Command, Photo No. NH 75405. 

The shrouded twin mount (and it's sister on the other side of the funnel) were the old manual loaded guns. the guns just forward were the newer automatic guns. 
however there there were a further eight of the new guns mounted. Two twins just forward of the bridge behind A turret and two more twins (one on each side) just behind the aft bank of torpedo tubes. the 20mm AA battery appears to be one twin mount on each bridge wing and two quads back to back above X gun. 
picture from the stern




The main guns were pretty much useless for AA fire. (my opinion) because they were 15cm guns with low rates of fire and for the single mounts low elevation. The twin mount had 47 degrees of elevation but it's elevation speed, traverse and rate of fire may have been lacking. 

I would note that in order to mount this AA battery one 15CM gun has been removed from the after deck house where it pointed forward over the aft torpedo tubes. 

I have no information on when the 15cm was pulled and the extra Flak guns installed. 

Information on the Navy 37mm Flak/42 is a bit sketchy. it is _said_ to be developed from the army 37mm Flak 36/37 but with a bit longer barrel and a higher rate of fire. 
The old Army guns used 6 shot "clips" fed in the side, the Navy gun used a 5 shot (?) clip fed in the top. The fast firing Army 37mm Flak 43 used an 8 shot clip fed in the side. 

I have no idea why the Army and Navy adopted different model guns using different feed systems and different ammo. The navy did use some of the Army 37mm Flak 43s on some ships. 
There may be some dispute about the rate of fire of the 37mm Flak 42. Anthony Williams book says 160-180 rpm not 250rpm. 250rpm is correct for the Army Flak 43. 
Since they used different ammo, used a different feed set up and had different length barrels it is a bit difficult to believe they had identical rates of fire. However 4-5 times the rate of fire over the manually loaded guns is still a very significant improvement. (I have a hard time believing the 30rpm for the manually loaded gun for any length of time or in bad weather)

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## JAG88 (May 6, 2019)

Shortround6 said:


> The German destroyer Z-39 in the photo above finished the war with a pretty decent light AA suite.
> another photo of the same area.
> View attachment 537252
> 
> ...



Probably happened when in 1945 while repairing bomb damage. In any case, it is telling that one of the last DDs to be commissioned (Aug 43) still used the obsolete 37mm semi-auto in spite of all the additions, you use whatever you can get I guess. All that is missing is a Bofors to complete the collection of KM flak types... what a mess, would have certainly been better off with a M42 or Bofors-only AA suite.

The 37mm makes more sense on a PaK38 mount than on a ship...

Actually, the few photos I have seen of the M42 are with what appear to be 8 shot clips.
















These ones show 8 as well, no round chambered yet maybe?

Would make sense if they are using the same ammo as the flak 43, not the same loading system but if 8 rounds have been decided to be manageable...

There is a nice mess around 37mm KM flak, sometimes even mixing it with 30mm guns, to me the "souped up flak 36" version makes plenty of sense, likely it would have been forced on the KM on logistical grounds, besides, if they wanted to use a 37mm round other than the LW's, well, they already had a very good one, true, it appeared to be an AT round more than a flak one but, still, it was theirs and already in production, no need to set up a new production line.

But its nazi Germany, so who knows, maybe they did introduce a completely new gun and shell just as everything crumbled around them, crazier shit happened. Maybe someday someone will find the definitive documents in some box with Russian markings on it.

What is the reference for that claim?


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## Shortround6 (May 6, 2019)

I believe the 37mm Flak 42 used a round all it's own.
see :ANTI

2nd photograph.

Judging ammo capacity/size of clips gets tricky as these top hopper feed guns can usually take two clips at a time. Some people claim the 40mm Bofors can take one clip, 2 loose rounds and then a 2nd clip but I would like to see that one  

but




shows 7 rounds above the receiver/gun housing. I would guess that there is one more in the feed way or ready to go in the feed way that is out of sight.
I have no idea what is going on here or how it would work.




except to note again the bottom visible round does not appear to be in a position to go into the chamber.

Or try this video, about 1:10


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## DerAdlerIstGelandet (May 6, 2019)

JAG88 said:


> I am sorry, were are getting this BS?
> 
> The M42 was introduced in 1944, and not everyone got them, the KM sat at the bottom of the priority pole as far as resources went which is why they started to scrounge Bofors and Oerlikons from wherever they could.
> 
> ...



I think you need to tone it down and knock it off with the snide insults, comments and arrogance. They will not be tolerated any minute longer.

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## Glider (May 6, 2019)

The facts seem to be similar to most navies. Some shops received the full rebuild of which F5 was an example. Most received what was available such as Z39 which clearly had a significant number of the latest weapons but kept some of the old guns.
My understanding that the old weapons were replaced was wrong but to pretend that the new weapons were rare was equally incorrect. The photo in the destroyers I mentioned shows two modern twin 37 on each side of the bridge, and was dated summer 44. In fact almost any late war photo of a German Destroyer or larger will have such weapons as the shields are distinctive.
The Royal Navy were similar there was the official equipment but in reality it was a combination of availability and space to put them.

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## JAG88 (May 6, 2019)

Shortround6 said:


> I believe the 37mm Flak 42 used a round all it's own.
> see :ANTI
> 
> 2nd photograph.



Thx! That is, simply, crazy. Did T. Williams get the shell's details?

There is very little difference between that one and the already in use Flak 36 ammo... what would be the point? Raeder...



> Judging ammo capacity/size of clips gets tricky as these top hopper feed guns can usually take two clips at a time. Some people claim the 40mm Bofors can take one clip, 2 loose rounds and then a 2nd clip but I would like to see that one



Yeah, I thought of that, but since the Flak 43 used 8-clips made sense they would use something similar on the KM version but, if you are crazy enough to forbid GEMA from providing the latest radar to the LW, this is peanuts.


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## JAG88 (May 6, 2019)

Shortround6 said:


> I believe the 37mm Flak 42 used a round all it's own.
> see :ANTI



I just noticed that is the shell from the PaK 36... wtf! So it ends up being the other way around? What was the point of creating the 37x263mm for the Flak 18 if you already had a pretty similar 37mm shell?

Germans...


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## Greyman (May 6, 2019)

Shortround6 said:


> I have no idea what is going on here or how it would work.



The 40-mm Bofors could essentially fire continuously, the 4-round clips are for the benefit of the men trying to handle them.

As long as there was room in the loader to start feeding another clip in you could do so -- the gun will keep banging away.

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## Greyman (May 6, 2019)

Quick photo edit to illustrate:


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## Shortround6 (May 6, 2019)

JAG88 said:


> Yeah, I thought of that, but since the Flak 43 used 8-clips made sense they would use something similar on the KM version but, if you are crazy enough to forbid GEMA from providing the latest radar to the LW, this is peanuts.



different clips?





Ammo and "clip" for the Flak 43

The Flak 42 might (?) use a clip more like the Bofors?

BTW, drawing of Bofors gun.




It looks like 2 rounds are hidden inside the gun housing depending on position of the breech block and feed mechanism. 

I am beginning to suspect that a bunch of sources are full of baloney and the German Navy Flak 37 mm 42 was some sort of unlicensed bofors gun, and not developed from the Fak 36 at all. I could be totally wrong but the Flak 42 appears to use a Bofors type feed, it does not use short recoil like the early Army guns or gas like the M43.


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## Shortround6 (May 6, 2019)

Greyman said:


> Quick photo edit to illustrate:



Thank you, I was not sure of how many rounds were hidden out of sight inside the gun housing.


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## JAG88 (May 6, 2019)

Shortround6 said:


> different clips?
> 
> Ammo and "clip" for the Flak 43
> 
> The Flak 42 might (?) use a clip more like the Bofors?.



Oh sure, both clips are quite different, I was thinking along the lines of manageable weight for the ammo loaders, after all those have to be a compromise between weight and how fast the gun goes through the clip so the loaders dont tire too quickly.



> I am beginning to suspect that a bunch of sources are full of baloney and the German Navy Flak 37 mm 42 was some sort of unlicensed bofors gun, and not developed from the Fak 36 at all. I could be totally wrong but the Flak 42 appears to use a Bofors type feed, it does not use short recoil like the early Army guns or gas like the M43.



I wouldnt be surprised and I am with you on the Bofors feed, but why a different shell then? Why not simply adapt it to either existing 37mm flak shell? Why use a 37mm round going OUT of production?

Maybe prevent their ammo supply/suppliers from being stolen by the Heer/LW!?!?! Now it makes "sense"...


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## Barrett (May 9, 2019)

LONG ago when writing my first book (Dauntless Dive Bomber, 1976) I found a 4th Marine Air Wing study of relative accuracy between SBDs and F4Us in CentPac low-threat environments. IIRC the difference between them was surprisingly little, somewhat favoring Dauntlesses as you'd expect. Apparently the specifics were edited out, more's the pity...

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## michael rauls (May 9, 2019)

I would have expected a substantial difference in accuracy. Live and learn I guess............And great book by the way👍


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## Ascent (May 10, 2019)

I think the rocket accuracy needs to be looked at in perspective. Yes, against armoured vehicles in Normandy they normally didn't hit, but a panther is about 22ft long. An R boat, a not unusual escort for coastal convoys, was about 135ft long. A destroyer is what? 400-500ft long? The merchant vessels must have been a similar size. It was not unusual for 50% or better hit rates from rocket attacks.


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## Greyman (May 10, 2019)

Interestingly (and somewhat maddeningly), in May '45 the ORS found that Mosquito salvo accuracy vs. shipping could have gone up from 55% to 80% had the sight harmonisation been 14 mils lower.


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## Glider (May 10, 2019)

I am afraid that I cannot remember the accuracy but I did read of a Beaufighter unit who set the 20mm harmonisation at 800 yards and when the shells started hitting the ship in line with the sights then they would salvo the rockets


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## yulzari (May 11, 2019)

Glider said:


> I am afraid that I cannot remember the accuracy but I did read of a Beaufighter unit who set the 20mm harmonisation at 800 yards and when the shells started hitting the ship in line with the sights then they would salvo the rockets


Being set together in the base of the fuselage I was under the impression that Beaufighter Hispanos were aligned not harmonised. i.e. set to fire straight ahead not to converge. Possibly the reference is to the sights such that the fire and sight setting matched at 800 yards so when the sight and fire were together the range was 800 yards and the RPs fit to fire. Above 800 yards the Hispano fire would be below the sight and closer above. Or maybe the .303s in the wings were harmonised to meet at 800 yards like the 2x.303s in a Hurricane IID?


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## Glider (May 11, 2019)

yulzari said:


> Being set together in the base of the fuselage I was under the impression that Beaufighter Hispanos were aligned not harmonised. i.e. set to fire straight ahead not to converge. Possibly the reference is to the sights such that the fire and sight setting matched at 800 yards so when the sight and fire were together the range was 800 yards and the RPs fit to fire. Above 800 yards the Hispano fire would be below the sight and closer above. Or maybe the .303s in the wings were harmonised to meet at 800 yards like the 2x.303s in a Hurricane IID?


The first part of your post is what I was trying to say. Rocket armed Beaufighters didn't carry the LMG.


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## Greyman (May 11, 2019)

By far most of the calories burned figuring out a proper harmonisation is done in the vertical sense, not merely where the bullet streams cross (if at all).

I by no means have exhaustive data on the subject, but standard 1945 Coastal Command RP harmonisation vs. surface targets was for:

_" ... a firing range of 600 yards in a 12.5 degree dive with an airspeed of 285 knots. The top of the freeboard of the ship should be taken as a point of aim for the cannon at the start of the run-in, and if the rockets are fired at 600 yards the centre of the salvo should hit 50 ft. short."_

I've seen 1944 harmonisations that call for level-flight attacks at 250 mph IAS.


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## Ascent (May 12, 2019)

This has inspired me to reread 'A separate little war' about the Banff strike wing.

It mentions two boats and talking about armament it says "Both carried two 105mm guns, one 37mm anti-aircraft gun, one quadruple mounted 20mm anti-aircraft gun, four twin mounted 20mm anti-aircraft guns and four rocket dischargers."

Even with a relatively low rate of fire that's a lot of lead being thrown in the air.


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## Ascent (May 13, 2019)

Another quote from 'A separate little war', describing how they attacked. This is attributed to Squadron leader Bill Clayton-Graham.

"Normally when making an attack on shipping, the dive at 45 degrees was started at 2,000 feet, opening up with machine guns as sighters at about 1,500 to 1,000 feet. Hopefully the cannons were to knock out the enemies guns, bridge and so forth, and we then fired the rocket projectiles at about 500 feet. These were set to form a pattern spread on impact, so that if aimed correctly about half hit the target above the waterline, the other four undershooting slightly to hit below the waterline. The main danger in this sort of strike was the possibility of flying into your target. Being in a dive with a closing speed of 300mph, you had to pull out very smartly."

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## Glider (May 13, 2019)

Ascent said:


> This has inspired me to reread 'A separate little war' about the Banff strike wing.
> 
> It mentions two boats and talking about armament it says "Both carried two 105mm guns, one 37mm anti-aircraft gun, one quadruple mounted 20mm anti-aircraft gun, four twin mounted 20mm anti-aircraft guns and four rocket dischargers."
> 
> Even with a relatively low rate of fire that's a lot of lead being thrown in the air.



Like the RN the Kriegsmarine used trawlers or vessels built using the design of a trawler for a number of duties and these were called Vorpostenboot. The weapons they were equipped with varied considerably and in the Coastal Forces book (Gordon Williamson) they illustrate one and its equipped with 3 x quad 20mm, 2 x single 20mm and what looks like an 88mm. They carried a serious amount of firepower and vastly more than an RN Trawler


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## elbmc1969 (Sep 28, 2021)

vikingBerserker said:


> For level bombing by both the Navy and Air Corps, practice bombs were dropped on the USS Utah, they were normally US Navy Mark VII water fillable bombers weighted to 50lb bombs after being filled with water which could be colored to track the aircraft or squadron that made hits. The Utah had double layers of timber placed on top of her deck to prevent damage from them. I'm not sure how they handled Dive Bombers
> 
> Here is a view of her front:
> 
> ...


OK, what altitude were they dropping from, was the _Utah_ anchored or in motion, and did anyone notice that none of the level bombers could hit anything?


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## elbmc1969 (Sep 28, 2021)

stona said:


> For bombing angles from 50-90 degrees, up to a release height of about 5,000 feet the accuracy was not markedly different.
> 
> I've attached this diagram, a poor picture taken with my phone as I'm not at home but happen to have my copy of 'America's Pursuit of Precision Bombing' with me! It is just about legible.
> 
> View attachment 472590


At 5,000 feet, it's a CEP difference of about 150 ft, or the difference between a 200 ft. diameter circle and a 500 ft. diameter circle. That means areas of 31,416 and 196,350 square feet, respectively. Remember, that's the area in which *50%* of the bombs will fall: you've increased the area 6-fold.

The Wasp had an over length of 741 ft. and an overall beam of 81 ft. We'll call it a total area of 60,000 square feet. Its length exceeds the diameter of the 50% circle, but nominally we can estimate that 60% of the bombs dropped from a 90-degree dive will hit (5,000 ft.), while perhaps 18% of the bombs dropped in a 50-degree dive will hit.

That's an immense difference.

This ignores the differences in ability to track a maneuvering ship and of the difficulty that very-high angle dive bombers present to anti-aircraft gunner.


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## elbmc1969 (Sep 28, 2021)

Peter Gunn said:


> Correct, there was a radio control station on another ship that was able to manipulate the engines and rudder, I'm not sure if she shipped a crew standing out of harbor and then they left via small craft and returned to take her back in after the exercise was over, or if she was remote controlled for the entire exercise.
> 
> From Wiki (FWIW):
> "On 7 April, _Utah_ left Norfolk for sea trials to train her engine room crew and to test the radio-control equipment. The ship could be controlled at varying rates of speed and changes of course: maneuvers that a ship would conduct in battle. Her electric motors, operated by signals from the controlling ship, opened and closed throttle valves, moved her steering gear, and regulated the supply of oil to her boilers. In addition, a Sperry gyro pilot kept the ship on course."


The _Idaho_ was similarly equipped for the 1921 bombing tests (inaccurately known as the "Billy Mitchell" tests.


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