Rn vs IJN

ThomasP said:

Also, although the Air Ministry dropped the torpedo carrying requirement for the heavy bombers, any of the big 3 could have been easily modified to carry a couple of torpedoes internally.

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Highly unlikely for the Stirling. Its bomb bay was long (42ft) and shallow but divided longitudinally into 3 by heavy beams, leaving channels only 19 inches wide. They managed to squeeze in mines which were about 17 inches wide but an 18 inch torpedo is probably a step too far. It certainly wouldn't accommodate the torpedo MAT fitting used later in the war to aid dropping at higher speeds and altitudes without modification of the bomb bay doors, something that had to happen with both Hampden and Wellington when they became torpedo droppers.

SaparotRob said:

Okay, I'm a B-17 fanboy. Might the RAF have considered the B-17C/D for purchase? There is no Lend-Lease. The Flying Fortress Mk I did not impress in its European debut with the British but we're talking different operating conditions. B-17s were in the Philippines and Hawaii at this time, I think. While there is no urgency to buy ANYTHING they can get and no BPC, the B-17 does seem to be a better performer than these British bombers.
On a bit of a thread jack, might North American Aviation develop the P.509 on their own?

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Without wishing to be unkind. The B17C as first delivered to the RAF was totally unfit for combat use, why on earth would we want it. Most people agree that the B17E was the first combat capable version and that was only just entering service at the end of 1941. If we wanted it, its very likely that the USA wouldn't have let us buy any as so many were needed for the USAAF

EwenS said:

Highly unlikely for the Stirling. Its bomb bay was long (42ft) and shallow but divided longitudinally into 3 by heavy beams, leaving channels only 19 inches wide. They managed to squeeze in mines which were about 17 inches wide but an 18 inch torpedo is probably a step too far. It certainly wouldn't accommodate the torpedo MAT fitting used later in the war to aid dropping at higher speeds and altitudes without modification of the bomb bay doors, something that had to happen with both Hampden and Wellington when they became torpedo droppers.

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The concept of putting torpedo's in a four engine bomber is just the height of foolishness, unless they were unescorted merchantman. Anti shipping strikes against defended targets was always a high risk occupation. Even the Coastal Command Strike wings, probably the most dangerous and effective units of this type anywhere, armed with the most best aircraft and weapons often had serious losses.
A four engine bomber would be simply shot out of the sky.

Glider said:

The concept of putting torpedo's in a four engine bomber is just the height of foolishness, unless they were unescorted merchantman. Anti shipping strikes against defended targets was always a high risk occupation. Even the Coastal Command Strike wings, probably the most dangerous and effective units of this type anywhere, armed with the most best aircraft and weapons often had serious losses.
A four engine bomber would be simply shot out of the sky.

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B-17s were skip bombing in 1942.

Glider said:

The concept of putting torpedo's in a four engine bomber is just the height of foolishness, unless they were unescorted merchantman. Anti shipping strikes against defended targets was always a high risk occupation. Even the Coastal Command Strike wings, probably the most dangerous and effective units of this type anywhere, armed with the most best aircraft and weapons often had serious losses.
A four engine bomber would be simply shot out of the sky.

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As noted by Greg the first skip bombing missions flown by the USAAC used B17s, although I don't believe they attacked warships.

Greg Boeser said:

B-17s were skip bombing in 1942.

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And when did they stop, my guess 1942?

Wild_Bill_Kelso said:

I am not sure I believe that you need such big bombs to damage refineries.

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Size matters. From the USSBS

Reluctant Poster said:

As noted by Greg the first skip bombing missions flown by the USAAC used B17s, although I don't believe they attacked warships.

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The first skip bombing mission was flown the night of 23 October, 1942.
The two bombers involved targetted what they believed to be a destroyer and light cruiser, scoring direct hits. The targets were actually a pair of subchasers that were damaged and required two months of repairs.

Glider said:

And when did they stop, my guess 1942?

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Once the B-25s and A-20s were modified, so early '43.

Reluctant Poster said:

Size matters. From the USSBS

View attachment 735539
View attachment 735542

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I have previously posted on this subject

Glider said:

The concept of putting torpedo's in a four engine bomber is just the height of foolishness, unless they were unescorted merchantman

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Now the Italians did well with Trimotors and Torpedoes. Why not one more engine?

marathag said:

Now the Italians did well with Trimotors and Torpedoes. Why not one more engine?

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Two answers to that.
1. If they had had more powerful engines they could have made do with just 2 engines like similar sized British & US aircraft !
2. They did add a 4th engine. See the Piaggio P.108. It never became operational in the TB role.

marathag said:

Now the Italians did well with Trimotors and Torpedoes. Why not one more engine?

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Did they do well?. My understanding is that they often were forced to drop their loads beyond effective range. Germany had hideous losses in their He111 torpedo bombers off Russia when attacking the Artic convoys. Condor bombers stopped attacking merchant vessels if they were escorted
As I said earlier, anti shipping raids are always very dangerous, with even the RAF strike wings sometimes taking a lot of casualties. To use a four engine bomber in such a role, is simply asking for trouble

Wild_Bill_Kelso said:

Pensacola, aside from looking badass in that photo, turned out to be a tough ship. At the battle of Tassafronga she survived a torpedo hit (which detonated all the 8" ammo in one of her turrets) through heroic damage control efforts by her crew, but also a strong structure... Her guns destroyed coastal defenses in the Marshal islands and the Kuriles, and later Chichi Jima and Haha Jima. She took but shook off several shore gun hits at Iwo Jima and survived the war.

Salt Lake City (Pensacola class) fought in the battle of Cape Esperance where her radar detected the enemy fleet (along with Helena) and then spotted them via optics. Her gunfire, along with Helena, San Francisco, and the destroyers Farenholt and Laffey then sunk the CA Aoba, the Fubaki, then duked it out with the IJN heavy cruiser Kunugasa, both sides taking hits and SLC taking a hit to her boiler which slowed her down some. CL Boise (Brooklyn class CL) was hit by Kinugasa and severely damaged, losing two turrets.

View attachment 733910
Japanese CA Maya

At the Battle of the Komandorski Islands near Alaska, Salt Lake City led a small USN force (with the CL Richmond and four destroyers) that was trying to attack some IJN invasion transports but ended up in a long range gun duel with Japaneses heavy cruisers Nachi, and Maya, and the CL's Tama, Abukuma at 20,000 yards. One of SLC's seaplanes was hit and caught fire, and was jetissoned. Rudder was blown off by more 8" hits and forward compartments were flooded, eventually leaving her dead in the water, but she managed to shoot back accurately and to hit and damage Nachi and Maya, taking out one of Maya's gun turrets. The US Destroyers then covered SLC by a smoke screen and her crew got the boilers working again. The Japanese ships thinking they were being bombed by Allied aircraft, withdrew.

She then conducted bombardments Tarawa, in the Caroline islands,and later Wake with the Pensacola. Her final bombardment missions were at Iwo Jima, also with Pensacola.

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The Aoba was NOT sunk At Cape Esperance. The Furutaka was the heavy cruiser that sank. The Furutaka was a prime example of the dangers of the "Long Lance" torpedoes as they were hit with a resultant tremendous fire. Also note that she was the oldest 8" cruiser in the world with only 6-8" guns compared to Salt Lake City's 10. The Battle of Cape Esperance pitted the 3 oldest 8" cruisers totaling 18 8" guns against 2 newer and bigger 8" cruisers totaling 19 8" guns and 2 newer and bigger 6" cruisers totaling 30 6" guns. Hardly a fair fight. As usual the USN had poor fire distribution and concentrated initially on Aoba followed by Furutaka. Furutaka was hit by all the USN cruisers as well as a torpedo from a destroyer.
The Japanese seemed only willing to risk their oldest cruisers and battle cruisers at Guadalcanal. I guess they were saving the others for the decisive battle that never came.

Reluctant Poster said:

The Battle of Cape Esperance pitted the 3 oldest 8" cruisers totaling 18 8" guns against 2 newer and bigger 8" cruisers totaling 19 8" guns and 2 newer and bigger 6" cruisers totaling 30 6" guns. Hardly a fair fight.

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... until one considers that American cruisers (Atlantas excepted) didn't carry torpedoes, and the torpedoes the American ships shot were remarkably inferior to any model of Japanese fish. That went quite a ways to making it a fair fight.

Cape Esperance also highlights the use of SG radar which allowed the USN force to fire first and fire accurately.

The effect of the heavy cruiser fire was equalled by the higher rate of fire from the light cruisers. The IJN started
the war with around 20 light cruisers and built five more while the USN used a total of 45. The six inch guns had a
good rate of fire and could match the weight of shot per minute of eight inch guns. Aoba suffered around 40 hits
from both types in a short space of time with the IJN force reacting by turning away and running to open the
range.

In 1943 at Empress Augusta Bay the use of radar allowed Admiral Merrill to keep his cruisers close to the limit of the
Japanese torpedo range while still firing at targets. USN destroyers also used radar to close and fire torpedoes.

Japanese attempts to use star shell were countered by smoke which didn't affect the use of radar.
USN ships numbered four light cruisers and eight destroyers against two heavy IJN cruisers, two light cruisers, and
six destroyers.

The USN force had one cruiser and two destroyers damaged while the IJN lost one light cruiser, one destroyer and
had one heavy cruiser plus one light cruiser damaged with two destroyers heavily damaged. Japanese losses the next
day were also incurred by aircraft from Rabaul with 25 planes out of 100 lost.

The USN fire was not as accurate as they would have liked but would improve as radar techniques developed. The
IJN night fighting ability was not able to keep up.

Earlier that year in Blackett Strait to the west of New Georgia Merrill had used radar to view and target two Japanese
destroyers which were hit one after the other and sunk. The effect of radar in both battles allowed the USN ships to
start hitting their targets before the enemy knew they were there whilst being able to change course quickly which
gave no time for the IJN ships to get into position to use torpedoes.

Thumpalumpacus said:

... until one considers that American cruisers (Atlantas excepted) didn't carry torpedoes, and the torpedoes the American ships shot were remarkably inferior to any model of Japanese fish. That went quite a ways to making it a fair fight.

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I am a heretic and I believe that the USN was correct not to put torpedoes on large cruisers. The heavy cruiser mounted Type 93s did more harm than good. In actuality they only sunk 2 allied ships outright (INN Java and DeReyter) and contributed to the sinking of two American heavy cruisers (USS Vincennes and Quincy). In addition they slightly damaged the USS Chicago. Those are the only 5 enemy ships they actually hit in the entire war. On the other side of the ledger they were instrumental in the loss of IJN heavy cruisers Mikuma, Furutaka and Chokai and of course Mogami infamously sunk a Japanese minesweeper, 3 transports and 1 hospital ship.

There are only two battles where the heavy cruisers actually hit enemy ships: Java Sea and Savo Island. At Java Sea they unequivocally sank 2 light cruisers. One was the INN Java which was basically a WWI German light cruiser and should not have been in the line of battle. The DeRuyter was better, being almost the equivalent of an HMS Arethusa. Neither of these ships could be considered first rate cruisers. I would posit that the shell damage to the HMS Exeter was more important to overall events than the loss of both of the Dutch ships.

As for Savo Island there were 3 ships struck by type 93 torpedoes fired from heavy cruisers. The most important of these were the 2 fired by Kako that struck the USS Chicago, one of which was a dud. While these caused minimal damage the effect they had was pivotal as the Chicago went into full panic mode and failed totally in its duty to warn the other ships and barely fired back before heading in the opposite direction from the battle.
This is the best possible place to be hit with a torpedo. The fighting efficiency of the ship was not impaired in anyway.




Savo Island was a gun duel with the torpedoes not playing a pivotal role. All the cruisers that were lost were damaged beyond salvation before any torpedoes hit. The torpedoes hastened the same inevitable loss as befell Astoria. The Vincennes, Astoria and Quincy all had uncontrollable fires with no means to combat them as the fire fighting mains were all destroyed.

From Vincennes damage report
"19. Just as the enemy searchlights were trained on VINCENNES at 0155, the main battery was directed to train out and fire. A minute later the first enemy salvo struck, hitting the bridge, the carpenter shop, the hangar, battle II and the antenna trunk. Fires were started in the carpenter shop and the airplanes in the hangar. From this time on the enemy was hitting continuously until he ceased firing at 0215.

20. Course was changed to the left and speed increased; however, at no time was it greater than 19.5 knots. About a minute later, direct hits were received on sky aft and sky forward, blowing the after director overboard. Attempts to extinguish fires failed as all fire main risers had been ruptured. Further hits started fires in the movie locker and the cane fender stowage in the after end of the searchlight platform. The fire in the cane fenders was very intense and could not be extinguished. About 0200, attempts were made to evade enemy fire by turning hard right. While in this turn, one torpedo hit (possibly two) was received probably from the submarine which was reported fired on by gun No. 1. No. 1 fireroom was put out of action at this time. While in this turn, the left side range finder hoods of turrets I and II were struck.

21. About 0205, when beginning to make a left turn, steering control was lost in the pilot house. Control was shifted to the after steering station. About this time all steam power was lost due to blowers either being destroyed or drawing smoke and flames from the fires amidships into the firerooms. Diesels were started and they supplied power to turrets I and III. They were still able to fire in local control. Numerous hits during the early part of the action put out most of the guns of the secondary battery.

22. About 0209 turret II was struck on the face plate by an 8" shell which penetrated without exploding and set exposed powder on fire. Another projectile hit the barbette of turret No. I on the starboard side and jammed the turret in train. At this time all turrets and secondary battery except turret III and gun No. 1 were out of action, and all power had been lost.

23. At this time, while still under heavy fire from the enemy, the ship began to list appreciably to port. The crew was about to abandon ship when all at once the enemy extinguished searchlights and ceased firing. During the next fifteen minutes the list increased rapidly and it appeared that there was no possibility of saving the ship. The Commanding Officer then gave orders to abandon ship. About 0250 VINCENNES capsized to port and went down by the head in 500 fathoms of water."

The torpedoes that struck were as follows:
Chicago: 2 torpedoes (1 was a dud) from Kako
Vincennes: 1 torpedo from Choika, 1 torpedo from light cruiser Yubari
Quincy: 1 torpedo from Aoba, 2 -21" torpedoes from light cruiser Tenryu

During the attack on the northern group the Chokai launched 4 torpedoes at 9,500 yards. 3 minutes later she opened fire. The torpedoes arrive at the Vincennes 5 minutes after the gun battle had begun. At this point uncontrollable fires were raging and extensive damage to the Vincennes had been done by Kako's gunfire. There are debates on how many torpedoes hit with one certain and 1 or 2 more which may have actually been shell hits below the water line. I'm inclined to believe that two or three torpedoes hitting out of 4 is a highly unlikely event.

The torpedoes which struck Quincy (1 Type 93 and 2 21 in) were launched well after the gunfire commenced and at a range of only 3,000 yards. An additional Type 93 stuck the Vincennes 15 minutes after that battle started and it was fired from a range of only 2,400 yards.

The battle of Savo Island was decided by the 8" guns of the Japanese heavy cruisers not their torpedoes.

Over 80% of the type 93 hits in WWII were launched from destroyers and there is where the real value lies.

I happen to agree with you. Torpedo's are a short range weapon and large cruisers over say 8,000 tons are not the place for them. There is an argument that lighter cruisers which are more likely to get involved in a short range often night time battle with destroyers and the like could use them. But larger cruisers rely on staying at longer ranges and using their guns. Its one reason why the vast majority of battleships in WW2 didn't have torpedo's. The effective range of the guns began to vastly outranged the effective range of the torpedo compared to WW1.
The weight and space they took up was more effectively allocated to more AA guns and their directors.

I would apply the same argument regarding the carriage of floatplanes on cruisers and battleships. They often seem to be more trouble than they are worth.

If you look at it through the lens of Kantai Kessen doctrine, their putting torpedoes makes sense.

So far as their tradeoffs of utility vs hazard, that the DDs got more hits strikes me as luck of the draw, rather than inherent advantage of ships themselves. But the Japanese had already decided to accept the hazards -- and those same hazards were present on the DDs. Neither the Japanese nor the Americans had any foreknowledge of how things would shake out, either in getting or taking hits.

In hindsight, you're indeed correct that the torpedoes didn't pull their own weight due to circumstances -- but that doesn't mean the Japanese CAs were not more powerful. It just means that the circumstances of war meant that those advantages weren't really leveraged. It's a subtle but distinct difference that is easily obscured by hindsight.

As noted by Thumpalumpacus the Fitting of torpedoes to Japanese cruisers suited the Japanese doctrine of getting as many torpedoes as possible to the main climatic battle.
They did not anticipate a high percentage of hits or even deceive hits. They were anticipating whittling down the Americans before the climatic battle.
Unfortunately the the Americans lost their copy of the script in the mail and did not show up on the stage at the planned for times/locations.
Instead of the hoped for massive, climatic, decisive battle the fighting devolved to close range small unit night fights.
Maybe the mass torpedo attack would not have worked, I don't know, but longish attacks from small numbers of ships against small numbers of ships that were maneuvering more freely didn't really work as shown by others.
Please note that the US script with 8in cruisers firing at long range in daylight with float planes acting as spotters to help correct the long range fire also got lost in mail and not received by the Japanese. The US never planned on getting near torpedo range (US torpedoes) with their 8in cruisers. And we see how that worked out

As for the rest of the World, it seems like only the Italian Zara class (4 ships) gave up on torpedoes and the rest of worlds cruisers fitted between 4 and 12.
Reasons varied due to roles and intended areas of operations.

I agree with a lot of the above but the only observation I have is that during the war I understand that the British 8in cruisers lost their torpedo's to give the weight to AA guns, directors and Radars.

On a different tack, I recognise that the thread is about the IJN and the RN but had war broken out the land airforces would have been involved. Here the Japanese Airforce would have been in serious trouble. I have emptied my office of all its books for redecoration and come across a book on the Japanese Airforce and was very surprised to see that a good number of the fighter units were operating the Ki27 into late 42 and even early 1943.

Had RAF bombers been able to operate in any numbers, attacking even Wellingtons with the Ki27 and its 2 x LMG, against the standard quad .303 turret would have been a tall order