IJN Soryu's and USS Wasp's Durability and Usefulness

According to Nihon Kaigun: http://www.combinedfleet.com/soryu.htm

- 1025-1026 While continuing launch preparations against a sighted enemy carrier, attacked by thirteen enemy dive bombers. Two direct bomb hits are sustained, one on the forward elevator, the other aft the second elevator, setting off furious fires and induced explosions among the armed and fueled aircraft.
- 1029 A 1,000 pound bomb hit amidships abreast the stacks, the bomb or its blast effects apparently penetrating to explode on the lower hangar deck starting fires amid the aircraft returned from the Midway strike. The explosion also damaged the upper section of the boiler rooms and shattered steam lines. With the main supply line shattered, steam to drive the turbines escaped. SORYU's engines abruptly ceased and she lost all propulsion on both sides. Plane-guard destroyer ISOKAZE near-missed off fantail.

This seems to indicate that the engines were taken out by a direct hit. You are right though that she took 3 bomb hits.

That was a 1,000-pound weapon, though. Makes me wonder: if Soryu only took that bomb hit with no refuelling or rearming airplanes on board, how would she be salvaged? The damage does not seem to be fatal in of itself, and only involves loss of propulsion. I think power to the weapons should be around. Towing her, perhaps?
Partly true as the explosion was augmented by the stocks of nearby ordonance, fueled aircraft and so on, so the single bomb did start the crippling, but did not cause it on its own. A single 1000 lbs bomb with a 303 lb (137 kg) explosive warhead (AN-M59) is not enough to both penetrate Soryu's lower hangardeck, which was lightly armored, but still armored. Note the weapon itself did not penetrate the lower hangardeck, so all had to be done by the blast alone. Putting additional explosives to it in the form of stocks of ordonance nearby as well as armed and fueled aircraft, it is entirely possible to cause massive structural damage including breaking bulkheads and decks, armored or not.
 
@McPherson

The KM U-boat arm was a clown club? I thought their legacy was that they fought a commerce war as cost effective as any other offensive of the Nazis, plus they sank capital ships HMS Eagle, HMS Courageous, HMS Barham, HMS Ark Royal, and HMS Royal Oak.
 

McPherson

Banned
@McPherson

The KM U-boat arm was a clown club? I thought their legacy was that they fought a commerce war as cost effective as any other offensive of the Nazis, plus they sank capital ships HMS Eagle, HMS Courageous, HMS Barham, HMS Ark Royal, and HMS Royal Oak.
How many of them died?
What was their loss to kill ratio?
Did they succeed in their objectives?
How many of their defective U-boats killed them without the allies having to do anything at all?

They were a Clown Club. The clown club compared to the Dutch, British and Americans.
 
How many of them died?
What was their loss to kill ratio?
Did they succeed in their objectives?
How many of their defective U-boats killed them without the allies having to do anything at all?

They were a Clown Club. The clown club compared to the Dutch, British and Americans.
The Americans were operating on easy mode against the Japanese while the Germans were on lunatic mode fighting the British, Americans, and Canadians. That the Americans achieved better results is difficult to untangle from the vastly easier combat environment they enjoyed.

As for the Brits, I wouldn't hold them up as any sort of exemplars of submarine ops. In particular, against the Italians they didn't do any better than the Germans did against the Allies. The Italians did a remarkable job getting supplies to Libya by sea and accounted for half the Royal Navy's submarine losses in only three years of combat.
 

McPherson

Banned
The Americans were operating on easy mode against the Japanese while the Germans were on lunatic mode fighting the British, Americans, and Canadians. That the Americans achieved better results is difficult to untangle from the vastly easier combat environment they enjoyed.

As for the Brits, I wouldn't hold them up as any sort of exemplars of submarine ops. In particular, against the Italians they didn't do any better than the Germans did against the Allies. The Italians did a remarkable job getting supplies to Libya by sea and accounted for half the Royal Navy's submarine losses in only three years of combat.
1. The Americans operated in Shallow Seas.
2. Under constant enemy air cover.
3. For two years with defective torpedoes and an incompetent command structure.
4. When they geared up and finally got their act together, they faced a JAPAN who instituted Italian level escort and convoy measures.
5. They won their submarine campaign.

When did the Germans ever do that?

Since the British never faced Japanese ASW when it was effective, I find British assertions that the Japanese in 1944 were "easy" to be spurious and without merit.

DATA 1.

DATA 2.

Work is by Geren Nichols.

Geren Nichols
, former Surgeon (1981-2010)
Answered 1 year ago · Author has 3.7K answers and 4.1M answer views

Off the California coast there is nearly always a thermocline, a point where the temperature below the level drops within feet. Thermoclines are known to reflect sound and can cloak subs below them.
Comment: It is called the Japan Current, the American submariners knew about it and used it against the Japanese. Apparently the Germans NEVER used the Gulf Stream thermocline the same way.
In the Battle of Atlantic it seems that time after time once a surface escort ID’ed on sonar a sub it was nearly as good as dead. Sonar was good enough that U-Boats seldom got away. The Atlantic convoys began to survive when they had few escorts. Subs on the surface were picked off with radar and subs underwater moved slower than the convoy had to attack through the frontal screen of escorts and were often detected with active sonar or ASDIC before coming into range.
This was blue water and open ocean in the Atlantic. The Western Pacific was island archipelago dominated and resembled the Mediterranean as a submarine environment. Survival was much harder.
I have question for people that might know. Is there a dramatic difference in the thermoclines in the Pacific and the Atlantic and could that be an issue? There were multiple issues with the IJN and its technology but were they also fighting in an ocean that hid subs below thermoclines?
There is a difference. Significantly the Pacific thermocline varies more with latitude and with water temperature as to depths. Also the currents shift more and swirl.
In the 1950’s TV series Run Silent, Run Deep the American subs were always hearing pings and yet the destroyers would wander off after a few close depth charges. (Worse than basing opinions on the internet has to be basing them on recalled 60 yo TV programs.)
Hollywood garbage.
The Pacific has much less violent waves than the Atlantic and less mixing in general leading to at least in California a thermocline a a depth easily reached by a sub. If it was an issue should have been an issue in the Mediterranean also.
It was.
 
Okay, and? None of that responds to my assertion that the Japanese were a vastly inferior opponent in ASW than the Allies, an assertion backed up by both links you gave.
 

McPherson

Banned
Okay, and? None of that responds to my assertion that the Japanese were a vastly inferior opponent in ASW than the Allies, an assertion backed up by both links you gave.
The information is time dependent and I included the weather effects and terrain in context to show the Battle of the North Atlantic was nothing like Battle of the North Pacific.

Anyway, YMMV, and should. I just write that British assessments were and are grossly inaccurate.
 
Quick googling says American submarines sank ~5 million tons of shipping while U-boats sank around 14 million tons...I don’t know about the bang-for-buck, but I don’t think it’s fair to say they were a clown club just because they were one arm of the military that lost a war against 3 superpowers.
 

McPherson

Banned
Quick googling says American submarines sank ~5 million tons of shipping while U-boats sank around 14 million tons...I don’t know about the bang-for-buck, but I don’t think it’s fair to say they were a clown club just because they were one arm of the military that lost a war against 3 superpowers.
Complete Data Here.

Summary.

Navy
Rank
Order
Total
sub.
lost
Total ton.
ships sunk
by sub.
Total
number
ships sunk
No. ships
sunk per
sub. lost
Ton. ships
sunk
per
sub. lost
1
USA
52​
5.2M​
1314​
23​
101,923​
2
Britain
75​
1.52M​
697​
9.3​
20,266​
3
Germany
781​
14.5M​
2,828​
3.6​
18,565​
4
Italy
82​
1M​
NA​
NA​
12,195​
5
Japan
127​
.907M​
184​
1.4​
6,923​
6
Russia
109​
402,437​
160​
1.5​
3,692​

The Germans were inefficient and ineffective.

They fought a naval war against the British and Canadians who were losing it, and then add the Americans. Tide turned. Mainly because of the Canadians in the West Atlantic who carried on and taught the Americans how it was to be done. British? How did coastal command and western approaches do before the victory in 1943? NTG.

As for the Pacific, see previous comments. The British were a non factor. The Med, where the RN did most of its sub fighting was "mixed results." The British submarine arm was unable to cut Italian SLOCs, though they did inhibit a good chunk of traffic. Reason? Italians were the best ASW practitioners among the Axis, naval geography and the British misused their boats.
 
Good point. Did that help to do in Taiho?
I cant remember what exactly led to Taiho's destruction- but I do remember that it had something to do with a torpedo hit and a poorly conceived damage control decision that led to gasoline fumes permeating the entire ship.

As to whether systems capable of injecting carbon dioxide into the lines would helped, my guess is that they definitely would not have hurt- at all.

I think the Taiho incident is also indicative that not only were IJN Carriers fragile, but IJN command skills needed to maintain them were also very fragile and difficult to replace. Midway and follow on battles seem to not only have cost the IJN irreplaceable carrier aircrew, but also irreplaceable carrier ship handling know how as well. Then factor in that with IJN already light on construction and damage control to begin with, there was not alot of room for error.
 
I cant remember what exactly led to Taiho's destruction- but I do remember that it had something to do with a torpedo hit and a poorly conceived damage control decision that led to gasoline fumes permeating the entire ship.

As to whether systems capable of injecting carbon dioxide into the lines would helped, my guess is that they definitely would not have hurt- at all.

I think the Taiho incident is also indicative that not only were IJN Carriers fragile, but IJN command skills needed to maintain them were also very fragile and difficult to replace. Midway and follow on battles seem to not only have cost the IJN irreplaceable carrier aircrew, but also irreplaceable carrier ship handling know how as well. Then factor in that with IJN already light on construction and damage control to begin with, there was not alot of room for error.
Aircrew, ship handlers, and mechanics. Those were in desperately short supply as well and a ton of them went down with the First Air Fleet off Midway.
 
Complete Data Here.

Summary.

Navy
Rank
Order
Total
sub.
lost
Total ton.
ships sunk
by sub.
Total
number
ships sunk
No. ships
sunk per
sub. lost
Ton. ships
sunk
per
sub. lost
1
USA
52​
5.2M​
1314​
23​
101,923​
2
Britain
75​
1.52M​
697​
9.3​
20,266​
3
Germany
781​
14.5M​
2,828​
3.6​
18,565​
4
Italy
82​
1M​
NA​
NA​
12,195​
5
Japan
127​
.907M​
184​
1.4​
6,923​
6
Russia
109​
402,437​
160​
1.5​
3,692​

The Germans were inefficient and ineffective.

They fought a naval war against the British and Canadians who were losing it, and then add the Americans. Tide turned. Mainly because of the Canadians in the West Atlantic who carried on and taught the Americans how it was to be done. British? How did coastal command and western approaches do before the victory in 1943? NTG.

As for the Pacific, see previous comments. The British were a non factor. The Med, where the RN did most of its sub fighting was "mixed results." The British submarine arm was unable to cut Italian SLOCs, though they did inhibit a good chunk of traffic. Reason? Italians were the best ASW practitioners among the Axis, naval geography and the British misused their boats.

Numbers do not tell a lot in this discussion. The actual cause of losses is not related to these anyway as the vast majority of submarine losses were vastly dirrering between the different fighting nations.

1. The very high number of German submarines lost includes the ones destroyed in their ports during bombing raids and the boats lost in airstrikes directly on them while the boats were in transit to, or from their ports. (especially in the Gulf of Biscay which was a deathtrap.) No USN boat was lost in such a way, besides a few in the very early part of the war in the SE Asia region, as geography did not allow this sort of thing.
2. Total tonnage sunk by German U-Boote was vastly superior to any other nation's results, mostly due to the fact the Germans fought for almost 6 years and the USN did not. As such false claims of the so called ineffectiveness of the German U-Boote campaign is rubbish and not validated by factual arguments.
3. Total tonnage sunk also is depending on the volume of the various nation's merchant navies and transport fleets, which also is completely negated in this discussion. The worlds largest merchant fleet was the British and this is partly the reason the opposing German score is so high, as there simply were more targets to shoot at, compared to the significantly smaller Japanese merchant and transport fleet, which was almost completely destroyed in WW2, so not much more could have been done by the Allies. As such the USN and other Allies did a great thing here in removing most of the Japanese transport capacity, where the Germans did well in numbers, but were matched by the output of the combined British and US shipbuilding capacity., something Japan did not even approach
4. Convoy doctrine too as different, resulting in Allied convoys being much harder targets to attack, due to the sheer size of most allied convoys and the number of escorting escorts present, where the Japanese (and Italians too) used small convoys with much less escorts in general, making these much easier pickings.
5. The German Navy had also prepared for war long before the fighting started and did use what it had in submarines relatively offensive from start, where the USN was not prepared at all and had to learn a lot the hard way in the early days of the war. In the start the USN submarines were send out on their own on single boat patrols, in a random way, while the German Navy coordinated its U-Boote from the first day in the war on known shipping routes and convoy's and other targets of value, who were known to be there by intelligence.
6. The Dutch submarines in SE Asia were actually the most effective in the short period they were allowed to operate in the region, before Japan siezed their bases in the East Indies. The Dutch had been preparing for war a long time before the fighting actually started and used some more intelligent tactics to deploy their limited military resources by coordinating submarines with air patrols, even using small hunter groups of three boat groups, whenever possible.
 
Um - @McPherson , @HMS Warspite , @I want to learn , @CV12Hornet , this is quite a long way from the OP. By all means have this discussion if you want though.

Meanwhile, bulging Wasp has been mentioned - which is something I've never heard of before, and which is probably a good idea. But how much speed would be lost? She was already quite slow anyway and losing 2 or 3 more knots might relegate her to serving with the battleships as some sort of fighter carrier.
 
Partly true as the explosion was augmented by the stocks of nearby ordonance, fueled aircraft and so on, so the single bomb did start the crippling, but did not cause it on its own. A single 1000 lbs bomb with a 303 lb (137 kg) explosive warhead (AN-M59) is not enough to both penetrate Soryu's lower hangardeck, which was lightly armored, but still armored. Note the weapon itself did not penetrate the lower hangardeck, so all had to be done by the blast alone. Putting additional explosives to it in the form of stocks of ordonance nearby as well as armed and fueled aircraft, it is entirely possible to cause massive structural damage including breaking bulkheads and decks, armored or not.
Good to know. Note that Soryu only had 1 inch of armour over machinery spaces and 2.2 inches over magazines/fuel stores. Still very vulnerable to bombs, rearming and refuelling planes or not.
 
Good to know. Note that Soryu only had 1 inch of armour over machinery spaces and 2.2 inches over magazines/fuel stores. Still very vulnerable to bombs, rearming and refuelling planes or not.
That is true, though that would mean the bomb had to physically pierce the deckarmor in order to do damage directly, where in realtime it already detonnated in the hangar itself, causing a deluge of follow=up explosions of far greater power than the explosives inside that bomb alone could do.
 
Mind you 1" and of deck armor really isn't going to stop any decently sized bomb its moreso to keep the explosion and shrapnel out of the ships vitals.
 
Coming back to the main post; Both Soryu and USS Wasp were comparable in size, capabilities (except speed), strength and weaknesses. So in both cases all would depend on how their respective crews would react on and fight against damage in combat.

In this case the 2nd part of 1942, the USN had made several gains in both training and capabilities with dealing battle damage. The IJN did not treat such a thing at the same level, though had learned about a few things as well by this period in the war (Guadalcanal campaign showed an improved resistance to battle damage on other CV's in the IJN so Soryu would likely have made the same improvements.) Also note the majority of damage dealt by USN aircraft was with divebombers, partly due to the switch from the obsolete TBD to the more advanged TBF, partly due to the still horrible quality of USN torpedoes at this time. Japanese airgroups normally had a more ballanced strike with equal numbers of divebombers and torpedobombers, often coordinating their attacks, where USN practice at the time was still a fragmented attack with every CV doing its own thing with little or no cooperation.

Given the differences I would suppose both USS Wasp and Soryu to be about equal in terms of just the ship itself, but tend to give the IJN a small advantage in air operations, partly due to combat experience, partly due to operational doctrine. So in terms of a direct slug out between the two, I would give Soryu's airgroup the benefit of the doubt in doing the first damage, which USS Wasp still might survive, as the ship itself would have been prepared for battle and trimmed correctly as trained for. USS Wasp's airgroup was relatively untested and not well equipped at the time, with no torpedobombers trained for being operated from this ship, as the ship lacked this type of aircraft originally and even had no magazines internally for torpedoes. The complement of TBF's just were shipped in prior to her OTL last mission, with no torpedoes, meaning these aircraft would use bombs as primary weapons. So the heaviest ship killing potential was for the Japanese in this phase of the war.

Basically all would depend on how damage was countered and how the ship's internal flaw's would play up. In this case USS Wasp was the tougher design, based on the equally designed larger Yorktown, where the narrow hulled Soryu had some designed flaws in her when build, like all IJN CV's at the time. These were primarily in the aviation fuel bunkers and pipelines internally, as well as a protocol in how aircraft operations were conducted, namely arming and fueling in the hangars, where the USN normally did this on the flightdeck. The USS Wasp was therefor in the advantage in this item, though when taking damage from large warheads, like torpedoes the difference as about nullified, as both were seriously vulnerable to shockdamage and had a tendency to loose power when hit by underwater explosions. (Something USS Wasp could not deal out, missing torpedoes for her aircraft in august 1942. )
 
Some things.

The Wasp class has a superior fire main system. It did not fail her until the flooding knocked it out.

The elevators / lifts on the USS Wasp do not descend below the flight deck and bottom below out in a bilge space. One of the reasons Japanese aircraft carriers exploded and blow torched was because these elevator wells acted as natural collection points for gasoline when fuel lines ruptured. The vapors given off resulted in the creation of what we know now as a Fuel / Air / Explosive or FAE detonation event. This killed HIJMS Taiho. HIJMS Shōkaku, HIJMS Akagi and probably did in Jun yo as well. Numerous other Japanese flattops often simply blowtorched because of it.

USS Wasp had superior AAA, and a better air group and fighter director facilities (Pry Fly). She had a better rudder steer and better torpedo defense in her compartmentation than Soryu. What killed her was clearly mishandling and bad luck, not actual performance metrics. She died hard. Soryu went down like a punk. Wasp was tougher than she looked.

And I maintain, if she had been properly bulged (1938-1939) in a refit, after the Japanese LNT walkout, she would have done better on that 15 September 1942 despite those three torpedoes.

Remember, the Wasp made two club runs to Malta as was, and not a scratch. She was able to DODGE and weave. This also showed two things; The Luftwaffe was incompetent as to anti-ship compared to the IJNAS and the KM U-boat arm was also a clown club.
USS Wasp CV-7 had not a very good AA as this was just the eight 5 inch/38 guns mounted in pairs in the four courners, with no realistic backing of reliable medium and light AA, as the four quad 1.1 inch mountings were a nightmare to operate and prone to jamming and the mix of a few 20mm and .50 cal MG's was inaddequate. Wasp needed escorting warships to mount a realistic FLAK against enemy aircraft in the Guadalcanal timeframe.

BTW, Soryu had a heavier but slower rate of fire main heavy AA outfit, but as all IJN CV's and warships in general lacked the backup of medium and light AA with a capability to do damage against large numbers of enemy aircraft. the 25mm weapon used was not the best weapon in general.
 
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