Dive Bomber Comparison

[Juha]

I disagree, what is your source? Now the planes of for ex X Fliegerkorps, which attacked RN ships in 39 and 41 belonged to LW so LW's anti-shipping units attacked already in late 39 against RN. Kriegsmarine tried to monopolice torpedo but as I wrote that wasn't only anti-shipping weapon. 40-41 many LW units operated against ships around UK etc.

Juha

 

[JoeB]

Also the basic distinction between hitting a ship and hitting a bridge or tank or bunker is false. If you can't hit a ship, you can't hit a bunker. The fact that the ship is moving is a relatively small part of this issue, getting the bomb to fall where you want it to (correcting for eg wind) to the degree of hitting a ship size target, that's the big part of the issue. LW divebombers were pretty accurate, therefore acceptably effective from German POV, distressingly effective from British and French POV, even off Norway and latter stages of the Battle of France.

The prime of Japanese divebomber pilots could also hit small (er than a ship) stationary targets on land quite well compared to others, as they sometimes demostrated in the early months of the war. Mainly good divebombing was a single skill set, not mainly a different skill set between ship and other point target attack.

But, some targets like well dug in gun emplacements were quite difficult for even divebombers to neutralize, as was also demonstrated by good divebombers of various countries. An example which comes to mind is the USN divebombers at Casablanca in November 1942. The same SBD unit, VS-41, had pretty good (not best ever type results like the Type 99's in Ceylon area anti-ship attacks, but still pretty good) results v French ships, moving and stationary, but just couldn't get bombs to fall within the actual emplacements of the El Hank battery, which is what it would take to destroy such a position. The battery suffered limited personnel casualties, little material damage, in a few days of attacks. Photo's show the area of the battery covered with craters (from USN ships' shell as well as bombs), mostly close, but not close enough. Such a target might be more productively plastered by a larger number of medium or heavy level bombers and get some direct hits by law of large numbers, though a much bigger number of bombs, assuming you had such forces. Or, perhaps the absolute best divebomber units could have gotten direct hits on those gun pits, but again the issue arises of producing, and *reproducing* this level of performance during a war. Divebombers often suffered heavy crew losses which needed to be replaced; and in USN case and other cases, an air arm was often expanding at an enormous pace to meet the needs of the war for good (not absolute best) divebomber units.

Joe

 

[renrich]

One of the factors which helped the LW divebombers, (and the Japanese also) against British ships was that the British shipborne AA was not very effective.

 

[davebender]

Something definately went wrong at Bari during December 1943. I believe the RN was responsible for the defense of that port.

 

[RCAFson]

Something definately went wrong at Bari during December 1943. I believe the RN was responsible for the defense of that port.

I've read various accounts of the Bari disaster, and none of them mention that any RN warships were in the port, except for a depot ship. The lack of a fighter defence seems to be the primary lapse in Allied defence planning.

 

[Shortround6]

I am not sure what the Bari raid has to do with dive bombing.

Was dive bombing actually used in the raid or is this brought up because the Ju-88A-4s used in the raid were capable of dive bombing?

Bari was headquarters for the US 15th Air Force but defense of the port was in the hands of the British army.

I am not sure what the defense of Bari with shore guns has to do with the RN pitiful ship mounted AA defense in the beginning of the war.

 

[parsifal]

Bari is more a red herring than that. It was a disaster, to be sure, and full credit to the high standards of Luftwaffe planning that went into it. But the damage that arose was because of the target ships expploding, full of ammunition as they were, and not the inherent lethality of the aircraft attacking them. The attack force was well led, and the raid well executed, but it was very lucky just the same

 

[davebender]

defense of the port was in the hands of the British army

Does that include coast defense guns and AA guns surrounding the harbor, protective minefields, PT boats and minesweepers operating in the shipping channel, radar systems located in the port area and operating on harbor craft like PT boats etc?

 

[Shortround6]

Does that include coast defense guns and AA guns surrounding the harbor, protective minefields, PT boats and minesweepers operating in the shipping channel, radar systems located in the port area and operating on harbor craft like PT boats etc?

Care to tell us just where you are getting this account from?

It seems widely at variance with this account.

World War II: German Raid on Bari HistoryNet

This from top of page two.

British army Captain A.B. Jenks, who was responsible for the port's defense, knew that preparations for an attack were woefully inadequate.

As for the PT boats (in British service MTBs) try this account:

BBC - WW2 People's War - Bari Raid, 2nd December 1943

Care to detail the coast defense guns for us?

The Italians had surrendered almost 3 months before, German Naval strength in the Adriatic was hardly up to gun bombardment raids.

 

[renrich]

Although Bari may not be a good example of the poor results obtained by RN ship's AA, it is well known that the RN suffered from very poor director fire from AA. The best example my be the Repulse and POW where the Japanese VBs and VTs were almost immune, although the IJN in the raid on Ceylon and the sinking of two CAs and a CV suffered little from AA.

 

[Shortround6]

There is no doubt that the RN suffered from a lack of AA capability for most of the war.

Not enough big AA guns, Director control not good enough and light AA almost non-existent at times.
A pair of quadruple .5 MGs as the only AA guns for a Destroyer?

Lack of guns and director control has little to do with Bari as Renrich has said although it does help to explain some of the success early dive bombers had against the Royal Navy. A good bit of the Ssuccess is due to the crews of the dive bombers but better AA would have caused both more misses and a higher attrition rate among the dive bombers.

 

[RCAFson]

Although Bari may not be a good example of the poor results obtained by RN ship's AA, it is well known that the RN suffered from very poor director fire from AA. The best example my be the Repulse and POW where the Japanese VBs and VTs were almost immune, although the IJN in the raid on Ceylon and the sinking of two CAs and a CV suffered little from AA.

The RN seemed to do pretty good against PQ-18 where AA shot down over 30 Luftwaffe aircraft out of about 260 sorties flown against it, and during the Malta Convoys.

http://www.ibiblio.org/hyperwar/UN/UK/LondonGazette/39041.pdf

Isolated ships could be overwhelmed, but when a balanced force defended a convoy, for example, they certainly made the Luftwaffe or Italian Airforce pay a stiff price.

 

[RCAFson]

A pair of quadruple .5 MGs as the only AA guns for a Destroyer?

Starting with the Tribal class RN destroyers actually had quite a heavy close range AA armament compared to their contemporaries. In 1939 a typical USN DD only had 4 x .5" MGs, while a Tribal or a J class DD had a quad pom-pom and 2 quad .5".

Tribal class destroyer (1936) - Wikipedia, the free encyclopedia

 

[BombTaxi]

The RN suffered from substandard AA direction equipment for most of the war. The armament itself was relatively heavy, but it needed to be when it was so poorly guided.

And Dave, if the LW 'wasn't responsible' for shipping attacks prior to 1942, who was operating the aircraft that attacked coastal traffic during the Kanalkampf, or that attacked the evacuation fleet during Operation Dynamo, or attacked Mediterranean convoys, or indeed, who controlled the Fw200s that hounded the Atlantic convoys and required the introduction of CAM ships, and ultimately, CVEs?

Furthermore, excluding shipping attacks from your assessment of divebomber effectiveness simply shows a lack of faith in your own argument, as such data will show that skilled crews (Americans late in the war, for example), sink far more ships than rookie crews (IJN late in the war, for example). It will therefore become apparent, as several posters have mentioned, that crew training is what made divebombers accurate, rather than any inherent advantage in the airframe designs themselves.

 

[RCAFson]

The RN suffered from substandard AA direction equipment for most of the war.

OK, then which navy had "standard" or "above standard" AA direction equipment in WW2?

How many of those slow Swordfish did Bismarck shoot down? Was German navy AA above standard?

Was Italian navy AA above standard?

How about the IJN? The RN had AA fire-control radar in 1940, and the IJN never developed AA FC radar. and neither did any other Axis navy, AFAIK.

The USN certainly had massive AA armaments in 1945, and had VT ammo from Jan 1943 onward, but the RN seems to compare well with other Navys in the early war period.

 

[BombTaxi]

OK, then which navy had "standard" or "above standard" AA direction equipment in WW2?

How many of those slow Swordfish did Bismarck shoot down? Was German navy AA above standard?

Was Italian navy AA above standard?

How about the IJN? The RN had AA fire-control radar in 1940, and the IJN never developed AA FC radar. and neither did any other Axis navy, AFAIK.

The USN certainly had massive AA armaments in 1945, and had VT ammo from Jan 1943 onward, but the RN seems to compare well with other Navys in the early war period.

I'm happy to debate this in detail in a more appropriate place, but the short story is that the HACS system used by the RN early in the war was not fully tachymetric, and therefore did not provide accurate firing solutions. In 1937, a Queen Bee drone circled the Home Fleet for two and a half hours, constantly under fire from HACS equipped ships. Not a single hit was scored. The following year, the Admiralty's own Director of Research described HACS as a 'menace to the service'. Air-search radar was experimentally fitted to HMS Rodney and HMS Sheffield for the first time in 1939. The same year, the Germans deployed Seetakt operationally, and the Americans began operational deployment of the XAF air-warning/gunnery set. HACS proved woefully inadequate in the Med, where the strikes that crippled HMS Illustrious and HMS Gloucester, and led to the scuttling of HMS Southampton, were pulled off by small groups of divebombers evading the fighter screen and penetrating the HACS-controlled screen with impunity. It isn't pretty reading, but most of RN's surface-to-air and surface-to-surface fire-control gear was obsolescent or ineffective in 1939, mainly due to Admiralty cost-cutting and a pervasive failure at very high levels to understand the threat posed by aircraft to warships. After all, a department was not set up to study AA gunnery within the RN until 1935

My source for all of the above is Corelli Barnett's Engage The Enemy More Closely: The Royal Navy In The Scond World War, pp.46-49 and passim, and I suggest giving it a read to understand the technological deficit with which the RN and FAA entered WWII.

 

[JoeB]

Ship AA claims v a/c would be a case even more unwise than aerial claims in which to conclude anything from one side's accounts. Also, torpedo bombers from even early in WWII had greater vulnerability to AA than divebombers or level bombers, a tradeoff for their ability to 'punch holes which let in water, not air'.

I agree the basic fact is that all navies underestimated the air threat *in practice* prior to WWII. On the basis of design and potential one could debate whether the USN was ahead of the game in fitting true dual purpose directors and armament to DD's, and had arguably better directors and heavy AA guns. But as a practical matter the USN wasn't particularly ready when the US entered the war, in either heavy AA training or condition of equipment (lots of bad 5" AA ammo/fuzes early on, for example), and wasn't up to speed even in time fuze heavy heavy capability until the 2nd half of 1942. Then, pre-VT heavy AA of any kind had trouble dealing with divebombers, and a lot of kills by ships v. torpedo bombers and divebombers were scored by light AA acting as 'revenge' weapon after the plane dropped its weapon (though, it was hoped the AA could distract their aim before they dropped). And the USN didn't have systematically better light AA fits in 1942 than other navies, started out probably less adequate on the whole than RN, which again had been at war for 2+ years.

However as far as assessing results of divebombers relative to the AA threat, if we consider Med actions of 1941-42 v those in Pacific in 1942, v Allied navies, we're talking roughly similar AA capabilities across the Allies navies, broadly speaking, though again the USN was rapidly coming up to speed from unprepared situation in Dec 41. But in no case in 1941-42 are we talking about cases similar to British and French DD's in 1940, which could just send up a few MG tracers to distract a divebomber pilot; were basically counting on dodging the bomb. There is IOW a more serious problem comparing the effectiveness of divebombers ca 1940 v ca. 1942, even before the very heavy AA armaments of 43-45.

Joe

 

[RCAFson]

I'm happy to debate this in detail in a more appropriate place, but the short story is that the HACS system used by the RN early in the war was not fully tachymetric, and therefore did not provide accurate firing solutions. In 1937, a Queen Bee drone circled the Home Fleet for two and a half hours, constantly under fire from HACS equipped ships. Not a single hit was scored. The following year, the Admiralty's own Director of Research described HACS as a 'menace to the service'. Air-search radar was experimentally fitted to HMS Rodney and HMS Sheffield for the first time in 1939. The same year, the Germans deployed Seetakt operationally, and the Americans began operational deployment of the XAF air-warning/gunnery set. HACS proved woefully inadequate in the Med, where the strikes that crippled HMS Illustrious and HMS Gloucester, and led to the scuttling of HMS Southampton, were pulled off by small groups of divebombers evading the fighter screen and penetrating the HACS-controlled screen with impunity. It isn't pretty reading, but most of RN's surface-to-air and surface-to-surface fire-control gear was obsolescent or ineffective in 1939, mainly due to Admiralty cost-cutting and a pervasive failure at very high levels to understand the threat posed by aircraft to warships. After all, a department was not set up to study AA gunnery within the RN until 1935

My source for all of the above is Corelli Barnett's Engage The Enemy More Closely: The Royal Navy In The Scond World War, pp.46-49 and passim, and I suggest giving it a read to understand the technological deficit with which the RN and FAA entered WWII.

I did a lot of research on RN/RCN AA because a previous thread regarding the Fw200 versus convoys, piqued my interest. I thought it rather interesting that HMCS Prince Robert, an RCN AA cruiser could fend off multiple Luftwaffe guided missile attacks:
http://www.ww2aircraft.net/forum/aviation/fw-200-vs-allied-convoys-25548-3.html#post696173

The RN conducted type 79 radar sea trials in April 1938 and began operational use in Oct 1938 aboard Rodney and the cruiser Sheffield.
Seetakt was a surface search/gunnery radar and had no AA capability. The first USN AA radar, the Mk 4 was developed with RN help, and conducted trials in Sept 1941.
The first RN FC AA radar was type 280 and it went to sea in 1939 aboard the AA cruiser Carlisle. It was based upon the British Army GL radar and featured a ranging panel that could provide range accuracy of +/- 25 yds against aerial and surface targets. This ranging panel was then fitted to most radars, including the type 279 aboard Fiji and most other ships with type 279 or 281 radar. Gloucester and Fiji were sunk by aerial attack in May 1941, but only after they ran out of AA ammo. This ranging panel could feed radar ranges directly to the FC computer.

By Sept 28 1941, 31 RN destroyers, 5 sloops and 20 larger ships had type 285 radar, which was a dedicated AA FC radar. AFAIK, no other navy had operational AA FC radar at that date. By the end of 1941 46 RN ships, larger than destroyers had type 279/280/281 radars, most with surface/AA ranging panels.

The RN used a special low HE capacity shell when shooting at the Queen Bee, yet shot down 6 in one month in early 1936, when they used them, presumably, in a manner more closely emulating actual attack runs. WW2 AA systems always assumed straight line flight and could not "predict" the path of a circling aircraft. By 1940, the RN was also adding the Gyro Rate Unit to the HACS, which converted it to tachymetric operation. IN 1940 the RN began to introduce the Mk IV Pom-Pom director, which was fully tachymetric and included a Gyro Rate Unit. The Pom-pom director and GRU was very similar to the USN Mk51 director which used the Mk14 gyro gun sight.

Sources:
Radar at Sea, Howse
Naval Weapons of WW2, Campell

HACS - Wikipedia, the free encyclopedia
Gyro Rate Unit - Wikipedia, the free encyclopedia
Pom-Pom Director - Wikipedia, the free encyclopedia
HMS Fiji (58) - Wikipedia, the free encyclopedia

 

[Juha]

There have been many arguments on HACS and my 2 cent is that it was rather useless first, especially against dive bombers but it was improved over time, IIRC there was 4 marks and III, III* and IV began to be at the level of best USN and IJN high-angle directors and already Mk II or Mk II* was clearly better than the earlier version and passable against targets which changed their speed or altitude, which had been the worst problem of original HACS. But UK and Japan were unable to produce sufficient numbers of their best high-angle directors so many ships had to try to cope with second rate directors.

Juha

 

[parsifal]

I would just point out that the primary mission for AA is not to shoot down enemy aircraft. That is primarily the responsibility of fighter aircraft. Flaks primary purpose is to throw the attacking aircraft off their aim, and to disrupt attacks. It does this by volume of fire, and by getting gunfire as close to the target as possible, not necessarily hiting it. Damaging an aircraft and forcing it to abort, or alternatively to so buffet the aircraft as to throw it off its aim is as good as shooting the aircraft down.

The numbers of airacraft damaged and forced to abort (either by that damage or simply by scaring the pants out of the attacking aircrew) is estimated to have affected close to 1/3 the bombers attacking Schweinfurt in 1943. There is no reason to suggest that it did not affect other nationalities to any lesser extent. In this regard, one has only to look at such operations as Pedestal to rapidly realize that British seaborne ack ack was eminantly successful in carrying out its primary mission.

Whilst there is no doubt in my mind that US fire control was better designed than its British counterparts, against such an intractable enemy as the japanese this did not count for much. During 1944-5, once Kamikazes started to be used, the USN had a great deal of trouble in breaking up Japanese Kamikaze strikes in the accepted way. A damaged Kamikaze is as dangerous as an undamaged one, and unfortunately for the allies, a damaged Kamikaze is unlikely to abort its mission. Whilst the suicide attacks by the Japanese tended to increase the kill rates of USN flak, it also meant as an attack method it was harder to stop. This was why the USN clamoured for the introduction of the 6" AA gun....so that a single shot had the capability to bring down a Kamikaze with a single hit.

I am unaware that the RN in the Pacific had any more or any less success in its flak defences as the US. This leads me to suspect that for practical purposes in 1945 at least that the British flak was no better and no worse than its USN counterparts, in the context of defeating the Japanese suicide attacks.