Sommervilles Chance

Both maps I have of the fleet courses are hard to read, but it looks like the two fleets spent the better part of 24 hours, & possibly more, on the 5th & 6th less than 400 miles from each other. Less than two hundred miles for part of that. The British were repeatedly able to locate the Japanese main force. the Japanese located dozens of scattered cargo ships, sank the two crusiers just 60 miles from Sommervilles 'Fast Group' , and caught the Hermes. Yet their air search never picked up on either of the British battle fleets.

I also note remarks about Sommerville, or the '"British" rehearsing or practicing their night combat the week before the Japanese were expected. What that might have consisted of is not indicated.

And, there are remarks about the British expecting a amphibious force as well. Thinking the Japanese intended to land on Ceylon, or perhaps in India.

 

ASV II is a 1.5 meter set for general search. It was more compact than ASV I but used essentially the same electronics. The aircraft mount was one yagi array antenna (like those on German nightfighters) angled out on each wing near the tip. ASV II had about a 20 to 30 nm search range but was only about 10 degrees in bearing accurate. This could be improved some by lobe switching and by the pilot maneuvering the aircraft off the bearing axis a bit. Basically, it told you something was out there and about where it was.

Later in the war when centimetric and decimetric sets came into use night torpedo aircraft became quite effective. But, in early 1942 this wasn't yet the case.

Carrier night landings take constant practice, even today. The British pre-war did practice night landings on carriers. But, the carriers were also lit up. That helps. In wartime turning on a bunch of bright lights on a carrier is asking for trouble. Once the war began night landings became a rarity simply because of the difficultly involved.

The danger outweighs the benefit I would think. The historical record shows that two carrier strikes will get at most two carriers. Even if everything goes perfectly for Summerville he still loses his carriers and then his fleet when the surviving Japanese carriers strike back as they almost certainly will.
I would think that keeping your forces intact, especially in the face of an immenent Japanese withdrawal from the IO would be a far wiser course of action. This leaves you in control in the long run of the IO.
Two deck loads from the Japanese alone amount to roughly about 12 Zero escorts, 16 dive bombers and, 16 torpedo aircraft minimally with a second strike just as big following them or one much larger strike if the Japanese so choose.
The Japanese have enough float plane scouts that they could easily launch several on the heels of the British attack and follow them home more or less. I'd say the danger here is just too great for the British to risk their forces.

I think given that the US just got into the war living to fight another day is a far better option.

 

Both maps I have of the fleet courses are hard to read, but it looks like the two fleets spent the better part of 24 hours, & possibly more, on the 5th & 6th less than 400 miles from each other. Less than two hundred miles for part of that. The British were repeatedly able to locate the Japanese main force. the Japanese located dozens of scattered cargo ships, sank the two crusiers just 60 miles from Sommervilles 'Fast Group' , and caught the Hermes. Yet their air search never picked up on either of the British battle fleets.

I also note remarks about Sommerville, or the '"British" rehearsing or practicing their night combat the week before the Japanese were expected. What that might have consisted of is not indicated.

And, there are remarks about the British expecting a amphibious force as well. Thinking the Japanese intended to land on Ceylon, or perhaps in India.

Quote:
Originally Posted by T. A. Gardner
I really think whether the British try a strike or try a night action they would come out the losers. Even if they did fairly well in a night action, again, come daybreak everything still afloat is going to the bottom when the Japanese strike aircraft show up. There would be nowhere to run at 18 or so knots for most of the battleships. Those slow R class would just ensure the whole formation got caught.

Sommerville had divided his fleet into a Fast and Slow group. Its not clear to me how far apart they were seperated.

"Lighting up a carrier to allow for any sort of approach would have been virtually like sending up flares."

Would that be necessary where the aircraft posess search radars? In Britian they had a system rigged for transmitters to provide a signal for the ASV I & II to home on. That allowed the ASW patrols to locate airfields when the weather changed on them. Been handy if the Brits had that on their carriers. Susposedly the USN had a radio becon for the aircraft as early as June 1942 although the pilots were not yet well trained with it.

 

It isn't finding the carrier that is the problem. It is the last 15 seconds of flight ending in a controlled crash that are..... Maybe it would be best if they just left the lights off after all...

 

Looking at the slow speed of the Albacore (140 knots - 247kph) they are not going to get back to the carriers before dawn anyway. Nice range tho, 800km loaded.

Refering back to the maps a alternate mission profile would be to run west right after launching the strike. The area the Japanese fleet was in the night of the 5th/6th is fairly close to Celon. The strike could go in at/after dawn and then head north away from the carriers.

Still if the Brits do have a night attack ability that would be better, a much larger chance of suprise, negates part of the antiaircraft fire, makes air interception problematic, and even if not single torpedo connects gives the Japanese something to obsess over for the next few nights...

 

The USN in the first six months of the war was able to make successful night torpedo attacks with he same ASV radar that equipped Summerville's carrier planes. So there is no question that it was quite possible for the British planes to perform the same mission, especially since they had trained for it. Japanese aircraft did not operate at night in April, 1942, so they could not have countered Summerville's planes had they attacked. I think you are short changing the Brits abilities at this stage of the game.

Lighting a carrier's flight deck was done routinely throughout the war by both sides. Although there was some risk involved, it was not so great as to preclude it. If the British had practiced night carrier landings, they also would have provided directional deck lighting that could only be seen by an approaching pilot, as both the Japanese and USN did. If Summerville was contemplating a night torpedo attack, he would also have been aware of the need for a night recovery and would have been prepared to risk it. It should be noted that at the Battle of The Philippine Sea, Spruance not only turned on his carrier deck ligyhts, he ordered every ship in his task force to turn on every light they had, ordered his destroyers to fire starshells and had his carriers illuminate hi spotlights and turn them skyward. This is quite a bit more illumination than simply outlining the flight decks with dim directional lights that only approaching pilots can see.

The historical record showed what??

No such historical record existed in April, 1942, all of the carrier vs. carrier battles were still in the future. In fact, the only records of carrier strikes against fleets which did exist at that time (Taranto and Pearl Harbor), showed that very few planes would exact a heavy toll against ships

If everything had gone perfectly for Summerville, he could expect to take out three or four of the Japanese carriers and escape scot free.

Summerville did not know if Nagumo was just raiding in the Indian Ocean or if his attack presaged a full scale invasion of Ceylon. He therefore had no way of knowing if the Japanese intended to withdraw or stay in the Indian Ocean. As it eventuated the British withdrew their naval forces to the East coast of Africa, leaving the Eastern Indian Ocean wide open to any incursions the Japanese wished to make.

Thank you for that information, but it really doesn't have any relevance to Summerville's decision. If he had decided to attack Nagumo's force, he was well aware that, unless he destroyed all of the Japanese carriers, he was vulnerable to a counter strike. For that reason, he most probably would have remained out of range of any undamaged Japanese carriers.

Not at night they couldn't. And Nagumo's not likely to try to launch float planes while under aerial attack; good way to lose ships.

Nagumo had exactly 24 float planes on his Kongo class battleships and Tone class cruisers. He's going to need a lot more planes than that to do a thorough search for Summerville's force. Nagumo would need to use his carrier planes as well and the Japanese didn't like to do that, especially if they've already lost some carriers. You're overestimating the danger to the British. If their torpedo attack scores and the Japanese are minus some of their carriers, they're more than likely to turn around and head home.

 

The Wasp/North Carolina/O'Brien incident was probably the smaller Type 95, I think that was oxigen powered as well though smaller (21 and not 24') so not a type 93 but still a "long lance". Judging from the damage there the larger Type 93 would have been quite effective if it hit. I think second Guadalcanal is the only instance type 93s were fired against battleships so we don't really have that much data to work with or were any fired at Surigao? There are not that many instances of engagements involving US BBs.

 

I'm not sure this is correct. If we look at Midway a good portion of the US strike never found it's target. Furthermore it came in pretty much uncoordinated. In addition the torpedo planes were completely ineffective there. A night strike might well catch the Japanese by surprise and certainly they will have little to counter the torpedo planes. Indeed they may not even be able to spot the torpedoes. Torpedo attacks are always a crap shoot so it's not certain that a raid like this would be a success but it has a chance.

After the raid it's by no means certain that the Japanese find the British in time to do anything. In particular if major Japanese units are damaged they have to either split their forces or abandon them. They also have to find the British CVs which is going to take some hours after dawn even if they are lucky. If the Japanese don't set their course in the same direction as the British the British can be as much as a couple hundred miles away from the launch point before the Japanese even have a chance of finding them. So it's far from certain that the Japanese would be able to launch a counter strike. If the Japanese don't find them early in the day they then have to consider what happens the next night.

 

What are your recomended sources for carrier ops. All I have are the general historys which only have cryptic remarks like" "Sommerville rehearsed a night attack."

At least the Fast Group was within 400 miles of the Japanese main force for over 24 hours and possiblly under 300 for much of that time Several of the briefs on this I've read note that Sommervilles staff was ignorant of the actual effective range of the Japanese aircraft and considerablly underestimated it. He may have thought he was near or beyond the limits of their strike range during daylight on the 5th & 6th. None of the sources
recomended to me are on the shelf here so I'm not certain of this.

Neither do I have any good evidence for Nagumos take on the British strength. Was he aware of the Brit CV & BB situation.

My best guess is if enough Albacores returned from a stike Sommerville would hang at what he thought a safe range and watch for another opportunity. That decision would place the next round in the hands of the IJN reconissance, which failed to locate the British main force at any time that week.

I've been told breakdowns & Brit action had reduced that to 20 float planes. Probablly not important. Unless the Japanese are able to identify the return direction of the strike group or interrogate a captured aircrew they cant be certain the strike did not come from Ceylon, so some of the reconissance might be directed north to reinspect the airfields there. The best chance for the Japanese is if the Brit strike goes in at or just before dawn & it fails to hit more than one carrier. With four CV left and no night delay to reconissance the odds are highest for locating & hitting the Brit fleet. Also if the British have undersestimated Japanese air strike range they may suffer from supirse when it shows up.

 

No, the torpedoes fired against the Wasp were submarine torpedoes, so not Type 93's. They might have been oxygen fueled, but also might have been another type, I have no information on exactly what mark they were. Type 93's are the only type (24", very long range, oxygen fueled) that are properly called "Long Lances" from what I have read.

I do believe there was another instance besides Second Guadalcanal, where Type 93's were fired against capital ships, but I'm not sure; the raid against Truk comes to mind, but I'll have to check my sources.

My point is that Type 93's never scored against any capital ship and that was what they were designed for. Whether or not they would have been effective is a moot point. My point is that Type 93's were ineffective not just because they never hit a capital ship, but they were ineffective because of the type of launching platform they required; a large destroyer or cruiser. That kind of launching platform was very difficult to get into position against capital ships which weren't normally risked in restricted waters and almost always were guarded by heavy screens of escort ships

 

The type 95 is the "scaled down" oxigen torpedo used in the 21' tubes of japanese submarines it's not that far in performance from the Type 93 and is often called long lance as well, it's the most likely weapon for sinkings like Wasp and Indianapolis. The japanese were the most torpedo oriented navy, when most other combattants sacrificed one bank of torpedoes to get more light AA on the destroyers they chose to remove the X 5' mount as they believed an 8 "fish" salvo was necessary to ensure a hit.
IMO the type 93 performed on average better than most other torpedoes, contrary to allied torpedoes it's capable of engaging at ranges similar to those of cruiser main armaments and was the decisive factor in most japanese surface victories, most pacific surface battles were cruiser affairs so that's were it was used, the big battle planned by the battleship admirals never happered so we will never know it the type 93 would have been effective, it's certainly reasonable to think that a 100+ torpedo salvo against a battleline would have achieved a few hits. That it failed at second Guadalcanal is really an isolated episode and not conclusive as random events dominate naval history in the era of steam.

 

More on the night torpedo attack:

In March 1942 there were no US equipped Catalinas flying operationally with radar. A few British aircraft had been fitted with ASV I or II at that point.

ASV II sets were in critically short supply. While several thousand had been ordered almost none had been delivered due to higher priorites for nightfighter sets, ground sets, radio equipment and, a whole list of other electronics that had higher priority.

We don't know how many Albacore might have been fitted with these sets at the time. We also don't know how many of the available sets worked properly either. I doubt that many of the Albacore had such a set installed at the time. Without better information on this aspect it could very well be that none had radar.
To launch an attack Summerville would have had to approach to about 250 to 300 nm from the Japanese as this is about the practical flying radius of an Albacore. If they were flying without radar this would make a night attack virtually impossible to pull off. The Japanese could move as much as 50 nm between the strike leaving and arriving.
This would put the British well within range of a counter strike if done late in the evening.

On likely casualties: Wayne Hughes, Capt. USN ret. in his book Fleet Tactics analyses the early Pacific carrier battles and demonstrates fairly conclusively that one carrier strike is capable of taking out one carrier in almost every instance where it arrives on target. So, historically, at most we might expect if everything goes perfectly the British damage or sink two Japanese carriers leaving them four.
These then retaliate and sink both British carriers. The British have far too few aircraft to mount an effective CAP. The US learned this lesson quickly themselves. By Eastern Solomons the typical US CAP numbered upwards of 30 to 40 fighters. By the time of the Marianas Turkey Shoot the CAP was well over 100 fighters.

Hughes also discusses torpedo attacks in the Pacific War.
If we assume that the British who are torpedo light (most of their DD present have just 4 torpedoes and a few might have 8) and gun heavy manage to get into a night action one would expect them to form a firing line and keep their destroyers out of the way of the larger ships so they don't accidently get hit.
This is exactly what the US was doing in the early Guadalcanal battles: Forming a long single gun line to maximize firepower. I would expect the British to do likewise.
The problem is that this makes the line a perfect target for torpedoes. The Japanese would have opened such a battle by making a run in with destroyers and launching a massive torpedo salvo. They would not have opened fire normally until the torpedo attack took effect. All the Japanese would need would be a good half dozen hits to thoroughly confuse and cripple the British line. I would also expect them to launch from 10 to 15,000 yards well outside the expected firing distance the British would launch a torpedo attack from.
The US countered this sort of effectiveness by Second Savo (Washington, South Dakota) by adopting smaller more compact formations with fewer ships under a commander's control. These minimized the torpedo target but still allowed efficent radar controlled gunfire to occur.
I would still conclude that Summerville was holding a very weak hand and he knew it.

 

This came up on another forum once and I seam to recall it was somewhere between 1/3 and 1/2. However it was also pointed out that the British had used these to lead formations including other types of planes for night attacks. Of course this was on the internet and I don't know what their sources were.

 

Here's a site with an animated version of what the ASV II scope outputs looked like.

ASV MK II Air to Surface Vessel Radar

Because of its wavelength, ASV II would have become useless for targetting at about 1 nm from the target due to minimum range operation meaning the aircraft would still have to visually identify and close with the target to actually make an attack.

 

For the Japanese, the best discussion of IJN carrier operations and doctrine I've seen recently is "Shattered Sword" by Parshall and Tully. For the US, I like Norman Polmar's "Aircraft Carriers", Friedman's US Aircraft Carrier Design History, and Lisle Rose's "Power At Sea; The Breaking Storm". For the British, The only one I've read recently is Friedman's "British Carrier Aviation".

To be honest, however, in the case of American carrier operations, I generally rely on several unpublished documents, letters, tapes, and notes of conversations in my possession collected from an American pilot who served on US carriers throughout WW II, my father.

I have very little idea of what either side knew for certain about the other. You are probably correct that the British were unaware of the Japanese aircraft range advantage. That, however, seldom proved of much use in actual practice. When Ozawa predicated a battle (Philippine Sea) on that range advantage, hoping to escape attack by Spruances aircraft, it didn't work out.

As for Nagumo's intel on British naval strength in the Indian Ocean, Japanese intel started going downhill at the beginning of the war and by April, 1942, was not very informative. You might want to check Prados' "Combined Ffleet Decoded" to see if there is anything mentioned about what Nagumo knew about the British.

I would expect that would depend on the exact circumstances. I doubt either side would want to stick around in close enough proximity to ignite another battle.

Consider;

Nagumo has just become aware that the British carriers can strike at night when he has no effective defense, so he will want to retire beyond any possible British range. And the British, presuming their strike is successful, have just gotten lucky and delivered a solid blow to the heretofore invincible Japanese navy. Summerville would have to understand he isn't likely to be so lucky twice in a row, and he would probably also want to retire beyond any possibility of Nagumo's reach, much as Spruance did at Midway.

I was going on the number of float planes Nagumo's BB's and CA's could carry when fully equipped (3 for each BB, and 6 for each CA). I assumed that number would have been reduced by operational attrition, but I did not know whether the ships carried any spares, so just mentioned the likely maximums.

Yes, perhaps the Japanese could locate and hit back at Summerville if he makes any of those mistakes. My impression was that during the whole Indian Ocean raid, the British had better intel, and better recconnaisance, on the Japanese than vice versa.

 

Actually, the Type 95 submarine torpedo (in reality designated Type 96) which was in service in 1942, was quite different from the Type 93 cruiser/destroyer torpedo; it was NOT just a "scaled down" Type 93.

The Type 93 was 24" in diameter whereas the Type 96 was 21" in diameter. The Type 93 used 100 % pure oxygen; the Type 96 used 36 % oxygen because pure oxygen caused problems on startup and precluded the use of lubricants to slow corrosion which caused irregular functioning in submarine torpedoes.

The range/speed performance of the Type 93 (with a 1,080 lbs. warhead) was 43,700 yards at 36-38 knots, 35,000 yards at 40-42 knots, and 21,900 yards at 48-50 knots.

The range/speed performance of the Type 96 submarine torpedo (with a 1,213 lb warhead) was very different at 4,900 yards at 48-50 knots.

The Japanese also had an electric submarine torpedo (Type 92) in quantity
production in 1942.

See:Japan Torpedoes of World War II

The name "long Lance" was allegedly applied to the Type 93 cruiser/destroyer torpedo by Samuel Eliot Morison after his experience in the Solomons campaign. It is never properly applied to any other Japanese torpedo. The Type 93 must have been a disappointment to the Japanese (see:Were the Best Good Enough?). And it's tremendous range was actually far more than optimal in the South Pacific. The Type 93 was not only difficult to manufacture in quantity, it was dangerous to the ships that carried it. The Japanese would have been far better off to develop a reliable, but more ordinary torpedo and put the savings is resources and topside weight into effective AA defenses.

 

I don't think that is correct. ASE- and ASV- equipped Catalinas began arriving at Pearl Harbor on April 1, 1942. The British had ASV-equipped Catalinas before Pearl Harbor. ASV may have been in short supply until the US began manufacturing the British-designed radar in January, 1942, but after that, the planes began being equipped a the factories before delivery.

I think it's a safe bet that enough of the British planes had radar to guide an attack force to the Japanese fleet. Summerville wasn't stupid; he knew radar was necessary to find a fleet before it could be attacked. He also was aware of the Albacores range, speed, and the necessity of staying far enough away to allow his strike aircraft to be rcovered and get out of range of a Japanese daylight strike. Any Japanese counter strike the next day would first have to locate the retiring British fleet; that would take at least a couple of hours. A strike launch would take another couple of hours; with good planning and a little luck, Summerville could have been well outside effective range of any Japanese counterstrike the next day.

Summerville had 45 Albacore torpedo aircraft; what they can sink or damage depends on their skill, training and luck, but it would certainly NOT be beyond the realm of possibility for them to sink or badly damage three carriers. If that happened, Nagumo isn't very likely to contemplate a counter-strike the next day becuse if he tries and misses, his force cod then be hit by another night torpedo attack against which he has absolutely no defense.

Captain Hughes anaylses of carrier strikes and counter-strikes was based on US carrier doctrine which, at that time, was predicated on conventional DAYLIGHT strikes between two hostile carrier forces. When one carrier force is capable of striking the other at night, when it has no defensive capability, Captain Hughes analyses really doesn't apply. The size of Summerville's potential CAP is really irrelevant if the Japanese can't find his fleet or if he retires beyond the range of the Japanese aircraft.

I assume you are now exploring the possibility of a night surface battle?

The RN and the USN had quite different experience in April, 1942. The RN, at that point, had 30 months of experience in night surface battles. Their gunnery ships and DD's had practiced night surface actions, and their light forces had worked for some time with British heavy units (unlike US DD's in the Solomons); they are not at all likely to assume the same formations that the USN would later, around Guadalcanal.

The British are far more likely to allow their DD's to act independently in screening the British heavy units. With radar, the British cruisers and BB's aren't likely to "accidently hit" their own destroyers and will maneuver to avoid torpedo attacks (which they had experienced in actions with German ships). The British DD's (and cruisers which also carried torpedoes) will use them to force the Japanese screening forces to keep their distance. Don't forget, both sides will have to etach (and escort) their carriers; since the Japanese have far more carriers to escort than the British, there will be fewer Japanese DD's and cruisers in any surface battle.

Probably not. I've already shown why the Nagumo will be short of destroyers (he has only 2 heavy, and one light cruiser, and the light crusier does not carry Type 93's) in any surface battle. he might try to bluff Summerville with a cruiser/DD charge, but it's not going to get anywhere close to the British gun line. The Japanese, if they launch torpedoes at all, will be forced to launch at extreme range and will be unlikely to get many hits at all. Unless Summerville makes a very grievous mistake by not maneuvering his gun line, or using his screening ships as you suggest, the Japanese torpedoes aren't really going to be a big factor barring fantastic luck on Nagumo's part. Remember, the Japanese were never able to tag a capital ship with a Type 93, and for good reason associated with the launching platform.

That's not why there were only two BB's on the American side at Second Guadalcanal. Washington and South Dakota were the only two heavy US ships that were fast enough to get there in time. And a compact formation would only make it more likely that Japanese torpedoes would fid their mark. Willis Lee's formation was very spread out out and his ships maneuvered practically independent ly of each other. His destroyers were far ahead of his heavy ships and he used them as true screening vessels like the British would.

Summerville's hand was not that weak when compared to Nagumo's force although he did have some negatives. But then, so did Nagumo.

 

This from the 'Canadian Military Journal' written by Rob Stuart. I'm not familar with that publication so I'll leave it to others to judge for themselves the quality of its content.

http://www.journal.forces.gc.ca/au-ns/index-eng.asp

And here is a link to the artical the paragraph below is drawn from.

http://www.journal.forces.gc.ca/vo7/no4/stuart-eng.asp

"Somerville thought the Japanese aircraft would probably attack in moonlight – there was a full moon on 1 April – and arrive back over their carriers at dawn, at approximately 0600 hours. To accomplish this, Nagumo would have to reach his launch point by about 0200 hours. Somerville decided to ambush him. If his radar-equipped force found radar-deficient Nagumo during the night, he could launch a torpedo aircraft strike with a fair prospect of inflicting damage. Until last light on 31 March, he kept well to the west, out of range of Nagumo’s search aircraft, and then headed straight for the anticipated Japanese launch point, which he reached at 0230 hours."

This outlines Somervilles thinking. Further along in the text it indicates he was acting fairly aggresively on the 5th & 6th April when the Japanese did arrive. Stuart states that the British force A, the fast fleet group, was less than 200 miles from Nagumos fleet. From this artical & others remarks it appears to me the the British had trouble sorting out the exact Japanese location from multiple incomplete and contradictory air recon reports. That sounds bad, but it is a level better than the Japanese who failed to locate the Brit fleet at all.

Two points for research come to mind. 1. What sort of night naval air ops did the British conduct in the Med or Atlantic agaisnt the Italians & Germans? Were there any? 2. What sort of training had the fleet air arm conducted during the preceding year?

 

The carrier attack on Taranto was conducted entirely at night. There may have been other British carrier attacks at night, but I'm not that familiar with RN operations in the Med or Atlantic.

 

Duh! I used to know that. Anoying to relearn stuff I knew thirty years ago. They used flares? I recall moonlight was a concern but can recall if it was actually made use of.