Rn vs IJN

[Shortround6]

SV Goodall, the RN's chief designer states that the 18in MkXII used a 440lb warhead:

It very well could be my mistake.
"Naval Weapons of World War II" by Campbell says explosive charge of 388lbs and I changed it warhead weight.
Now your says 440lbs explosive weight.

The later Mark XV torpedo started with 388lb of TNT and later 432.5lbs of Torpex for carrier aircraft and 545lbs of Torpex for land based planes. The Mark XV is supposed to have weighed 1801lbs but is was stronger and held more air.

The Mark XII gained weight also, like 2.5lbs more shale oil and another 10lbs of air (air pressure went from 1600psi to 1900psi). Not stated but certainly possible that the MK XII got a heavier war head between 1937 and 1941?
Or the 388lb charge was contained in a 440lb warhead (casing and firing pistol/s?) and that is a source of confusion.
Some versions of the Mk XII got the "air-tail" similar to the Mk XV but no weights given.


I would note that the Japanese must have been very clever indeed to fit 867lb charges into under 2000lb torpedoes.

 

[Shortround6]

and definitely a D3A over a Skua

well that is rather a no-brainer.
When the IJN placed the order for the D3A1 Blackburn only had 4 planes left to complete on the order.
The Skua was sinking German ships before the D3A1 was undertaken carrier trials.

1-2 years can make a big difference. Especially for aircraft like the Skua where there were no improved versions ever built.

 

[RCAFson]

It very well could be my mistake.
"Naval Weapons of World War II" by Campbell says explosive charge of 388lbs and I changed it warhead weight.
Now your says 440lbs explosive weight.

The later Mark XV torpedo started with 388lb of TNT and later 432.5lbs of Torpex for carrier aircraft and 545lbs of Torpex for land based planes. The Mark XV is supposed to have weighed 1801lbs but is was stronger and held more air.

The Mark XII gained weight also, like 2.5lbs more shale oil and another 10lbs of air (air pressure went from 1600psi to 1900psi). Not stated but certainly possible that the MK XII got a heavier war head between 1937 and 1941?
Or the 388lb charge was contained in a 440lb warhead (casing and firing pistol/s?) and that is a source of confusion.
Some versions of the Mk XII got the "air-tail" similar to the Mk XV but no weights given.


I would note that the Japanese must have been very clever indeed to fit 867lb charges into under 2000lb torpedoes.

I don't know whose mistake it is, and 388lb is oft stated, but by 1940 the FAA MkXII was fitted with a 440lb TNT warhead.

When the KGV class was being designed the RN built a full scale model (Job 74) of the amidships section and it was tested against an 18in torpedo warhead with 440lbs of TNT. Friedman in British Carrier Aviation, P156n states that the WW2 MkXII used a 440lb TNT warhead against Bismarck:

4) - The aerial torpedo warhead was
440lbs of TNT, compared with
750 or even 1000 for a ship or
submarine launched torpedo. In 1940-
41 British aerial torpedoes failed to sink
the French battleships Dunkerque an
Strasbourg and the German Bismarck, in
each case inflicting severe (and tacti-
cally crippling) but not fatal damage
On the other hand, they did sink three
Italian battleships at Taranto in Novem-
ber 1940.

 

[Shortround6]

I don't know whose mistake it is, and 388lb is oft stated, but by 1940 the FAA MkXII was fitted with a 440lb TNT warhead.

Again, we may be quoting different things. Or people of the time quoted different things.

Explosive weight is not warhead weight anymore than a 500lb bomb contains 500lbs of explosives.
Or that the quoted 88lb warhead for a Sparrow missile actual contains 88lbs of explosives.

Unfortunately warhead weight and explosive weight are sometimes used interchangeably some people.

 

[ThomasP]

In my notes I have the Mk XII weighing in at 1620 lbs (388 lbs TNT filler) and 1665 lbs (432.5 lbs Torpex filler), in both cases weight is with the MAT (Mk III?) tail attached.

 

[RCAFson]

In my notes I have the Mk XII weighing in at 1620 lbs (388 lbs TNT filler) and 1665 lbs (432.5 lbs Torpex filler), in both cases weight is with the MAT (Mk III?) tail attached.

Again, we may be quoting different things. Or people of the time quoted different things.

Explosive weight is not warhead weight anymore than a 500lb bomb contains 500lbs of explosives.
Or that the quoted 88lb warhead for a Sparrow missile actual contains 88lbs of explosives.

Unfortunately warhead weight and explosive weight are sometimes used interchangeably some people.

Goodall, Friedman and the Job 74 trials clearly state an 18in aerial torpedo warhead fitted with 440lb of TNT. Goodall and the Job 74 trials needed to know the exact amount of TNT fitted, and weren't concerned about the total weight of the warhead, including it's casing.

IIRC, Torpex is not as dense as TNT.

 

[Wild_Bill_Kelso]

well that is rather a no-brainer.
When the IJN placed the order for the D3A1 Blackburn only had 4 planes left to complete on the order.
The Skua was sinking German ships before the D3A1 was undertaken carrier trials.

1-2 years can make a big difference. Especially for aircraft like the Skua where there were no improved versions ever built.

Timing is a bitch. What is the real mystery here is how they went from the Skua and the (already old) Swordfish, to basically just the Swordfish and it's somewhat flawed near clone, the Albacore.

 

[ThomasP]

Torpex is more dense than TNT, with sg of 1.72 vs 1.65 respectively.

 

[WARSPITER]

Torpex allowed British and US torpedoes to have 50% more explosive power without adding a large amount of weight.

By comparison, to add around 20% more explosive power using TNT would have required a warhead around seven to eight times
the original weight - in other words a massive increase in the torpedo size and weight.

Artillery shells had a similar problem. Large TNT charge simply turned the casing to powder as it went off which wasn't what was
required. One fix would be to use expensive alloys for the casing which was also time consuming. Ammonium nitrate decreased the power
of the explosion but ensured the casing of the shell broke into large pieces that flew off in all directions (shrapnel) - job done.

Torpex was better than straight TNT as TNT isn't as efficient. RDX was a lot more sensitive but when mixed with TNT the two combined
to make a more powerful detonation. Aluminium powder was also added to increase heat generation giving overall better pressure
which equals a better shock wave against the target.

Basically a 700lb torpedo warhead gave the same destructive power as a 1000+ lb TNT warhead.

 

[swampyankee]

The really shocking thing about the US torpedo debacle isn't so much that they had the problems to begin with, but that even in the face of the loss of scores of ships and submarines and thousands of lives of US servicemen, they could not recognize let alone fix the problems. That is the part which deserves a second look with respect to modern times, because it's a theme with US procurement which haunts us periodically.

The really shocking thing about the US torpedo debacle isn't so much that they had the problems to begin with, but that even in the face of the loss of scores of ships and submarines and thousands of lives of US servicemen, they could not recognize let alone fix the problems. That is the part which deserves a second look with respect to modern times, because it's a theme with US procurement which haunts us periodically.

Bureaucrats -- a category which includes people in uniform -- and managers, which includes people with titles like "commandant," will frequently ignore data they don't like, up to and including attacks on the people reporting the data. The reaction of the USN, including more people than just those at Newport, to field reports of torpedo problems was an egregious example of a bureaucratic group ignoring data. It's not unique, and not even the worst incident of it in US history

 

[MIflyer]

I suspect the root cause was the USN's general deprecation of the value of the torpedo

The root cause was that after the War to End All Wars the USN decided that private industry would not have a reason to continue producing torpedoes, since they had no commercial applications and since there was not going to be any wars any more, no one would build them. So they decided to take over all torpedo development and production themselves in order to ensure their supply. Given that there were no wars to force the unruly imposition of reality, the USN torpedo factory rapidly became a treasured self-licking ice cream cone. The Rhode Island Congressional delegation intervened in the event of any attempt to make improvements or weed out the deadwood, including preventing any other location being established to produce torpedoes, even as war threatened. Thus, the main priority became preserving government civilian jobs there and funds that should have been spent on proper testing were seen as a threat to paychecks. When the horrific results of this approach became apparent soon after 7 Dec 1941 the response from Goat Island was deny, deny, deny, and accuse others. Adm Lockwood had run the factory, was in charge of US subs based in Australia, and KNEW there was nothing wrong with his torps; it was the idiot sub skippers at fault. Finally, after one sub fired its entire complement of torpedoes at a very large Japanese whaling factory ship, without sinking it, the sub's captain walked into the Admiral's office at Pearl Harbor and literally screamed in outrage. After that even Lockwood had to admit that he'd had enough reports that maybe there was some kind of a problem with US torpedoes.

And this whole shameful, treasonous, disgusting story apparently proved to be so attractive to some people that 30 years later it was repeated almost exactly in a program called The Space Shuttle, except that it went on for another 20 years after it was found to be a massive mistake.

 

[MIflyer]

The TBD actually turns out to be worse than the Swordfish in most respects, if you really look at them.

How much enemy fighter operation did the Swordfish ever face? Not much. At Coral Sea, when they put a few F4F's down on the deck with the TBD's they not only got some hits but did not lose a single torpedo bomber.

The RN carrier Glorious had Swordfish when its captain ordered a bombing attack on Norwegian shore installations occupied by the Germans. The squadron replied that was a suicde mission, such slow biplanes against the AAA. The carrier capatin was so infuriated that he requested that teh ship proceed back to Scapa Flow so a court martial board could be convened ASAP. The Glorious departed, with no air patrols and only a single destroyer for escort. Both RN ships were sunk by the German battlecruisers Scharnhorst and Gneisenau, with heavy loss of life. If the Glorious had TBD's they could have done high altitude level bombing attacks with a pretty good chance of survival.

 

[Wild_Bill_Kelso]

The root cause was that after the War to End All Wars the USN decided that private industry would not have a reason to continue producing torpedoes, since they had no commercial applications and since there was not going to be any wars any more, no one would build them. So they decided to take over all torpedo development and production themselves in order to ensure their supply. Given that there were no wars to force the unruly imposition of reality, the USN torpedo factory rapidly became a treasured self-licking ice cream cone. The Rhode Island Congressional delegation intervened in the event of any attempt to make improvements or weed out the deadwood, including preventing any other location being established to produce torpedoes, even as war threatened. Thus, the main priority became preserving government civilian jobs there and funds that should have been spent on proper testing were seen as a threat to paychecks. When the horrific results of this approach became apparent soon after 7 Dec 1941 the response from Goat Island was deny, deny, deny, and accuse others. Adm Lockwood had run the factory, was in charge of US subs based in Australia, and KNEW there was nothing wrong with his torps; it was the idiot sub skippers at fault. Finally, after one sub fired its entire complement of torpedoes at a very large Japanese whaling factory ship, without sinking it, the sub's captain walked into the Admiral's office at Pearl Harbor and literally screamed in outrage. After that even Lockwood had to admit that he'd had enough reports that maybe there was some kind of a problem with US torpedoes.

And this whole shameful, treasonous, disgusting story apparently proved to be so attractive to some people that 30 years later it was repeated almost exactly in a program called The Space Shuttle, except that it went on for another 20 years after it was found to be a massive mistake.

I lol'd at "Self Licking Icecream Cone"

I agree with most of the post though.

As far as the Space Shuttle, we may have blown two of them up but that's not unusual for 20th Century space launches. I don't really see how the shuttle program even comes close to comparison as a debacle. The torpedo thing could have cost us the war, it certainly led to at least hundreds if not thousands of our own people dying, aside from being a grift and a waste of money.

 

[Wild_Bill_Kelso]

How much enemy fighter operation did the Swordfish ever face? Not much.

I'd say that would be because they used them almost exclusively at night. Swordfish did operate in an environment where enemy fighters were around (i.e., the Mediterranean, and at least potentially, Indian Ocean or Pacific), and not being able to use them during the day was a severe limitation, as was the very short range. Add very limited and poor fighter protection options, and a small carrying capacity for aircraft by the RN carriers, and FAA has fairly weak capabilities. It's impressive that they did as much with it as they did.

The ability to carry radar so early compared to other types was an advantage for the Swordfish, allowing them to conduct effective night attacks and maybe even more important, bad weather attacks. But TBF Avengers had this capability by late 1942.

I'd say the inability to survive encounters with enemy fighters, the slow speed increasing both vulnerability to interception by fighters and targeting by AAA, as well as increasing (doubling or tripling in some cases) the length of time to conduct a strike over a given distance, which was very limited anyway with this type, were all fairly telling disadvantages. Not so much in 1940, and maybe still competitive, all things considered, in early 1942, but by late 1942 this is not viable. But the poor FAA pilots still had to fly them.

At Coral Sea, when they put a few F4F's down on the deck with the TBD's they not only got some hits but did not lose a single torpedo bomber.

That is a fair point, though I would argue they got lucky. Coral Sea was really the first ever major naval carrier battle. TBD was extremely vulnerable both to fighters and AAA, and the Wildcats themselves were pretty vulnerable when flying down low. Specific circumstances in this battle contributed to the (somewhat limited) US success. The USN made serious mistakes too though.

At Coral Sea, the CAP defense for the Shōhō on May 7 for example was very limited - four A6M and two A5M, with all the other fighters being loaded and fueled. Seven Japanese fighters, who had to be split into defending high (dive bomber) and low (torpedo) approaches, were contending with 18 Wildcats escorting 53 SBDs, and 22 TBDs. That greatly improved the odds for the USN strike planes.

In many subsequent engagements in the Pacific however there were much larger numbers of enemy fighters available to intercept strikes. And the TBD did not have a good record subsequent to Coral Sea. It is fortunate that it was quickly replaced by the TBF / TBM.

The RN carrier Glorious had Swordfish when its captain ordered a bombing attack on Norwegian shore installations occupied by the Germans. The squadron replied that was a suicde mission, such slow biplanes against the AAA. The carrier capatin was so infuriated that he requested that teh ship proceed back to Scapa Flow so a court martial board could be convened ASAP. The Glorious departed, with no air patrols and only a single destroyer for escort. Both RN ships were sunk by the German battlecruisers Scharnhorst and Gneisenau, with heavy loss of life. If the Glorious had TBD's they could have done high altitude level bombing attacks with a pretty good chance of survival.

I doubt that. IIRC TBD had a slower cruise speed than a Swordfish as well as inferior range. It wasn't particularly well protected and probably inferior in maneuverability. Swordfish was also stressed for dive bombing which may have been a better option for that raid, which would have had little chance of success regardless IMO. Certainly level bombing (in this case without even a norden sight) had a poor accuracy rate historically during the war.

 

[Wild_Bill_Kelso]

One point about the TBF, which was certainly better in most respects than a Swordfish - it was very, very big. Swordfish wasn't that small either - 45' 6" wingspan, 35' 8" length, 12' height. But an Avenger is considerably bigger - 54' wingspan and 40' length, 16' height. So it's like 15% larger. Same ratio larger than a Stuka or say, a Hellcat.

Vulnerability to AA depends on a lot of factors. Speed was important, and a TBF could theoretically get up to 275 mph, and cruised at 215 mph (partly because it could carry ordinance internally, inside a bomb bay), while a Swordfish puttered along at a stately 143 mph carrying ordinance. But size mattered too. The bigger the target the easier to spot and the easier to hit, to some extent. I always saw that as an issue with the design.

And for that reason, (size and speed), I think for a lot of targets, if it was a high threat environment such as anything protected by German AAA, and it wasn't a torpedo run, they were probably better off using fighter-bombers where available, than the big 'light bombers' like the TBF. This is basically what the USN did to a large extent later in the war, using F6 and F4U fighters to do a lot of strikes vs land targets, unless the target was relatively lightly defended.

 

[Thumpalumpacus]

I lol'd at "Self Licking Icecream Cone"

I agree with most of the post though.

As far as the Space Shuttle, we may have blown two of them up but that's not unusual for 20th Century space launches. I don't really see how the shuttle program even comes close to comparison as a debacle. The torpedo thing could have cost us the war, it certainly led to at least hundreds if not thousands of our own people dying, aside from being a grift and a waste of money.

The engineers at Morton Thiokol knew for years that the O-rings on the SRBs were a dangerous potential failure spot, but NASA didn't want a redesign as that would ground the fleet for 18 months. Additionally, at least one engineer at M-T advised on the morning of the Challenger's launch that it be scrubbed due to the weather rendering the O-rings brittle and likely to fail. He was ignored in part from M-T's leadership, and partly due to NASA pressure.

While the 7 astronauts lost don't compare to the hundreds estimated lost due to shitty Mk 14s, in terms of both money and institutional stupidity the loss was the equal of the torpedo imbroglio.

I can't speak to how bureaucracy may have affected the loss of Columbia regarding the heat tiles. I seem to remember some finger-pointing, but hopefully someone else will pipe up on that disaster and if it too is another case of bureaucracy killing crews or not.

<off to google this for a refresher>

 

[RCAFson]

How much enemy fighter operation did the Swordfish ever face? Not much. At Coral Sea, when they put a few F4F's down on the deck with the TBD's they not only got some hits but did not lose a single torpedo bomber.

The RN carrier Glorious had Swordfish when its captain ordered a bombing attack on Norwegian shore installations occupied by the Germans. The squadron replied that was a suicde mission, such slow biplanes against the AAA. The carrier capatin was so infuriated that he requested that teh ship proceed back to Scapa Flow so a court martial board could be convened ASAP. The Glorious departed, with no air patrols and only a single destroyer for escort. Both RN ships were sunk by the German battlecruisers Scharnhorst and Gneisenau, with heavy loss of life. If the Glorious had TBD's they could have done high altitude level bombing attacks with a pretty good chance of survival.

Lt Commander Heath, the flight ops officer, was to be court martialed for being reluctant to order a Swordfish DB attack against an airfield, and an ill defined road which didn't appear on Glorious' maps. He considered that the potential strike force, 5 Swordfish with 3 Gloster SGs as escort, was insufficient for the task at hand, especially given the vague intel. The Swordfish Sqn CO and flight crews were quite prepared to undertake the operation. Heath was quite prepared to order an attack on the airfield alone.

In fact Heath had been returned to Scapa Flow a week earlier and when Glorious was sunk she was returning to Scapa to refuel (with a load of RAF fighters onboard), and, time permitting to allow for the CM of Heath. Captain Doyly Hughes was granted permission to proceed independently to Scapa Flow with only two destroyers as escorts.

Glorious could not operate TBDs as her flight deck length and max speed was insufficient to allow TBDs to safely TO with a useful war load.

BTW, the Swordfish was capable of aimed level bombing, as the navigator had provision for a vertical bomb sight.

 

[swampyankee]

The root cause was that after the War to End All Wars the USN decided that private industry would not have a reason to continue producing torpedoes, since they had no commercial applications and since there was not going to be any wars any more, no one would build them. So they decided to take over all torpedo development and production themselves in order to ensure their supply. Given that there were no wars to force the unruly imposition of reality, the USN torpedo factory rapidly became a treasured self-licking ice cream cone. The Rhode Island Congressional delegation intervened in the event of any attempt to make improvements or weed out the deadwood, including preventing any other location being established to produce torpedoes, even as war threatened. Thus, the main priority became preserving government civilian jobs there and funds that should have been spent on proper testing were seen as a threat to paychecks. When the horrific results of this approach became apparent soon after 7 Dec 1941 the response from Goat Island was deny, deny, deny, and accuse others. Adm Lockwood had run the factory, was in charge of US subs based in Australia, and KNEW there was nothing wrong with his torps; it was the idiot sub skippers at fault. Finally, after one sub fired its entire complement of torpedoes at a very large Japanese whaling factory ship, without sinking it, the sub's captain walked into the Admiral's office at Pearl Harbor and literally screamed in outrage. After that even Lockwood had to admit that he'd had enough reports that maybe there was some kind of a problem with US torpedoes.

And this whole shameful, treasonous, disgusting story apparently proved to be so attractive to some people that 30 years later it was repeated almost exactly in a program called The Space Shuttle, except that it went on for another 20 years after it was found to be a massive mistake.

Again, the same issues did not occur with naval shipyards or with places like Watervliet and Springfield arsenals and the Naval Gun Factory. I suspect that the exact same issues with the Mk14 would have happened regardless of whether they were produced by a USN facility or a private contractor. Sweetheart deals between military bureaucrats and private contractors have been known to exist.

The problem was a bureaucracy, one that happened to include USN line officers, ignored or actively suppressed information they didn't like. Yes, the USN torpedo factory may have stonewalled, but its managers, which included USN officers, were not held accountable as much or because of personal relationships, not because of ownership. How many managers at Newport were ring knockers?

 

[Shortround6]

I'd say that would be because they used them almost exclusively at night. Swordfish did operate in an environment where enemy fighters were around (i.e., the Mediterranean, and at least potentially, Indian Ocean or Pacific), and not being able to use them during the day was a severe limitation, as was the very short range. Add very limited and poor fighter protection options, and a small carrying capacity for aircraft by the RN carriers, and FAA has fairly weak capabilities. It's impressive that they did as much with it as they did.

A lot of this true. However The Japanese carriers launched very few (any?) long range torpedo strikes, as in much over 200-240nm?
Swordfish book range was 452NM with torpedo, B5N2 range with Torpedo was 528NM? Range as a recon plane was 1075NM?
Swordfish actually had better defensive armament, as in crappy beats none out the front and bad beats truly crappy out the back. A Lewis gun in 1942 Japanese yype 92 was a Lewis gun.
British were putting Vickers K guns on Swordfish.

Granted the B5M2 cruised around 25-35kts faster than the Swordfish.

The ability to carry radar so early compared to other types was an advantage for the Swordfish, allowing them to conduct effective night attacks and maybe even more important, bad weather attacks. But TBF Avengers had this capability by late 1942.

We are not really comparing the Swordfish to the Avenger here. And even with radar the TBF didn't have a working torpedo until well into 1943.

I'd say the inability to survive encounters with enemy fighters, the slow speed increasing both vulnerability to interception by fighters and targeting by AAA, as well as increasing (doubling or tripling in some cases) the length of time to conduct a strike over a given distance, which was very limited anyway with this type, were all fairly telling disadvantages. Not so much in 1940, and maybe still competitive, all things considered, in early 1942, but by late 1942 this is not viable.

Again lets compare the actual performance of the B5N2 to the Swordfish.
The B5N2 was not 2 times faster over distance with a torpedo. It may have been 33% faster which is good advantage but not resulting in the Swordfish taking 2 to 3 times to conduct a strike. Talking 1942- early 43 here. The B6N didn't show up until mid 1943 and that was the version with the Mamoru engine which was not really suitable for operations.

In many subsequent engagements in the Pacific however there were much larger numbers of enemy fighters available to intercept strikes. And the TBD did not have a good record subsequent to Coral Sea. It is fortunate that it was quickly replaced by the TBF / TBM.

The B5N suffered rather similar losses at the Battle of the Eastern Solomons. None the 1942 Japanese attack aircraft were very survivable in the face of decent (sufficient numbers) of fighters.
I would note that the TBD is sort of a red herring. They only built 129-130 of them (fewer than Skuas) and by Dec 1941 there were only about 100 left due to attrition. They had been out of production for over two years and there were never going to be any more. The replacement by the TBF was part of plan that had started in 1939.

A bit like the Buffalo which engaged in two combats in US colors, the total record of the TBD was several raids on Japanese Islands that had no aircraft and the Battle of the Coral Sea and the Battle of Midway. Not a large number of battles to draw conclusions from. given the defective torpedoes and the crappy US tactics (not enough escort fighters for even TBFs) the TBD gets a lot of blame for things that were not it's fault. It was obsolete, there is no question.

 

[Admiral Beez]

How much enemy fighter operation did the Swordfish ever face? Not much.

Thankfully so, as the Swordfish was shot down in droves when encountering enemy fighters.

11 February 1942, during the attempt to torpedo the German battleships, Scharnhorst, Gneisenau and Prinz Eugen, all six Swordfish were shot down by German fighters.

5 April 1942, Nagumo's force launched 36 fighters for the strike on Colombo. All six Swordfish of 788 NAS were shot down by Japanese fighters.