Somerville's Aggressiveness at Ceylon

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glenn239
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Re: Somerville's Aggressiveness at Ceylon

Post by glenn239 » 07 Feb 2010 18:03

In the first week of April the IJN found and sank well over 100,000 tons of shipping in the Bay of Bengal. All my requirement needs is for them to put prize crews aboard about 1/3 of these ships rather than sink them. The shipping problem is now solved.
The point is that there was no ‘shipping problem’ insurmountable in 1942. Yes, the Japanese were short of shipping during the war, but in 1942 they had enough to conduct major operations throughout the year. As stated, the IJA mobilized over 700,000 tons late in 1942 to fight at Lae/Solomons. This type of effort was more than adequate for the requirements in the Indian Ocean.
I am afraid I rather lost track of your argument about logistics and I am not sure where you thought the supplyline was leading. However, I will assume you may have been talking about Ceylon
The summary is that the Japanese had more than enough resources in 1942 to eject the Royal Navy from the Indian Ocean.

The assumption is that the Japanese have taken Ceylon and other islands around India, and then invaded with a 40,000 man force (or whatever) at the mouth of the Red Sea. They have then established land based airpower and a forward naval base, and have blockaded the Red Sea passage to Europe. The supply line runs from Japan to the Red Sea. The ship sails from Japan loaded with war supplies. It refuels in the NEI. It sails to the Red Sea port and unloads, and then returns to the NEI. It loads with raw materials from the NEI and goes back to Japan. A ship on the Indian Ocean run does double duty; it is a war transport on the outward leg and a civilian supply transport when returning to Japan. It requires no tanker support to function because it refuels at Java.

The fleet logistics are also favorable; the warships are operating near to the NEI, so their fuel situation is much better than if fighting a campaign from Truk or Rabaul.
Of course if they continued this taking of prizes there were several hundred other Allied MS in use in the Indian Ocean so plenty to choose from once they controlled the seas having destroyed Somerville.
I suspect that if the Japanese close the mouth of the Red Sea, that maybe 500,000 tons or even 1,000,000 tons of Allied shipping becomes trapped in Egypt and is scuttled and/or captured and pressed into service. When Egypt falls, it becomes inevitable that the entire Med will go Axis, probably including Gibraltar. It’s a long route, but Germany and Italy now have access to the oil in the NEI. The Italians, for example, would press everything they could lay their hands on into service as tankers to start importing oil. NEI production would be boosted by oil workers exported from Europe.
Of course with respect to the Middle East supplies I am more interested in the IJN stopping that traffic rather than capturing it. My patrol strategy outlined previously should more than adequately do that job by deterring the Allies from risking precious men and tanks until the sealanes were safe.
If the Axis Powers conquer Egypt, then all sorts of really bizarre counter-historical strategies become feasible. What if the Japanese import some '88's and FW-190’s? What if Gibraltar falls and Kido Butai enters the Atlantic Ocean?

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Re: Somerville's Aggressiveness at Ceylon

Post by Rob Stuart » 07 Sep 2012 22:37

Hello everyone,

I’m a little surprised that I’ve not seen this older thread before, since Operation C is the WW2 event of most interest to me. I’m also surprised that the first post in the thread, by Pips, quotes (and in a couple of places, misquotes) an article I wrote which was published in Canadian Military Journal in few years ago, without acknowledging that this was his source. My article is online at http://www.journal.forces.gc.ca/vo7/no4/stuart-eng.asp for anyone who'd care to read it.
That said, it’s an interesting thread and I like to comment on a few of the posts:

Andy H., you commented that
“One of the most glaring omissions from Somervilles OoB was a viable and effective Submarine force, for both aggresive actions and for Fleet recon etc”.

In fact, the Eastern Fleet had six subs: Truant, Trusty, K-XI, K-XIV, K-XV and O-19. Truant was at sea from 23 March to 12 April and was sent after KdB but could not intercept it. Trusty was under repair during Operation C and did not sail until 13 April. K-XI sailed from Colombo on 8 April but this was too late. O-19 sailed on 31 March for the Eight Degree Channel, probably because the British knew from Singint that a Japanese sub (I-4) was to do a patrol there. The other two Dutch submarines were unservicable.

“mcaryf”, commented on 2 Feb 2010 that
“The Ryujo could carry around 50 planes albeit with a relatively poor capacity to get them on deck but it was not even one of the 6 front line carriers whilst still substantially superior to anything the RN could field.”

In fact Ryujo carried 15 Kates and a few Claudes in April 1942. It was superior to Hermes but inferior to Formidable, which had 33 aircraft, and Indomitable, with 47.

You commented in the same post that
“The coastline of Ceylon was much too long for the forces there in April 1942 to defend.”

The six defending brigades did not have to defend the whole coastline. Ceylon was beyond the range of any Japanese air base, so the Japanese had to seize an intact or nearly intact airfield before KdB had to withdraw. There were actually very few airfields on Ceylon and the defenders would have had pretty good prospects for successfully defending these airfields before KdB withdrew. They could then bring up their reserves without interference from the air and at least contain, if not eliminate, the Japanese lodgements.

You also said that
“They might even have found some sort of welcome from the local populace, there was at least one example of Ceylonese troops being executed by the British for mutiny and parts of the Burmese army had recently gone over to the Japanese. This was also a period when tens of thousands of Indian nationalists were being put into prisons by the British.”

In fact precisely three Ceylonese soldiers were executed, and these executions were after the war. The mutiny happened on Cocos island in May 1942 and involved an isolated party of Ceylonese gunners. The moale of Ceylonese forces on Ceylon was probably a different matter altogether. And the big round up of Indian nationalists you refer to happened months later, after Ghandi launched his “Quit India” campaign.

Glenn, you suggested that, apparently after taking Ceylon,
“The way the Japanese make Egypt fall is to seize air bases at the mouth of the Red Sea and establish a full-strength air army there that prevents British supplies moving up the Red Sea.”

This would mean taking Aden, Djibouti, or some such base in this area. These places are 2,000 NM from Colombo, which would be the nearest Japanese base. KdB would have to be used to provide air support, which means that the landing force would have to take an airfield, and get it back into working order, before KdB had to withdraw. Big risk of failure. And how would you get your 100 aircraft there? 2,000 NM is well over even the ferry range of any single-engined aircraft, so you need more carriers to get them there, and any Betty experiencing engine trouble en route is going to be lost. Furthermore, the Japanese supply line to the mouth of the Red Sea would be at least as vulnerable as their supply line to Guadalcanal proved to be, as there would be several Alied air bases within range of your base and the sea route to it would be flanked by Cochin, Addu Atoll, Karachi, Mogadishu, and any other port were the British could station oilers and depot ships.

As well, there is a flaw in your claim that “
The Japanese merchant marine pool that averaged 2.34 million tons of shipping in 1942 managed to import into Japan 19 million tons of materials – about 8 tons of goods per year for every ton of shipping in the pool. A Japanese expedition of say 40,000 men and 100 aircraft into the Middle East to sever the Allied jugular to Eygpt may have required 25 lbs per man per day and 50 tons per plane per month – 240,000 tons of supply per year. At 8 tons of supply per ton of shipping, that’s a train of 30,000 tons of merchant vessels.”
Your figure of “8 tons of supply per ton of shipping” is an average, and much of the 19 million tons of imports were brought in from Korea and other nearby places, with the ships involved making a lot of quick round trips. It is a 12,000 NM round trip from Japan, where the bombs, torpedos, ammo, spare parts, etc, were made, to Aden and back. No Japanese merchant ship is going to be able to make eight round trips a year over such a distance under wartime conitions (eg, delays due to diversions and convoy assembly) – particularly if it’s sunk or damaged or breaks down on one of these runs. So it will take a lot more than 30,000 tons of shipping to sustain your base.

mcaryf, you commented that
“In the first week of April the IJN found and sank well over 100,000 tons of shipping in the Bay of Bengal. All my requirement needs is for them to put prize crews aboard about 1/3 of these ships rather than sink them. The shipping problem is now solved.”

In fact Ozawa sank 20 ships totalling 93,000 tons. Roskill is wrong when he states in his official history that 23 ships of 112, 312 tons were sunk. (see http://propnturret.com/tully/viewtopic. ... pasa#p5381.) Of the 20 ships actually sunk, Harpasa and Van Der Capellen were sunk by Ozawa’saircraft, and Dardanus, Bienville, Selma City, Ganges and Sinkiang were disabled or damaged by air attack before being caught by Ozawa’s ships, which leaves 13 ships of about 58,000 tons as candidates for taking as prizes. But seizing these ships was easier said than done. First of all, they are all close to the coast of India, and most of the victims turned for the coast, screaming for help on the radio, and weren’t going to stop unless disabled. There is no point in seizing a disabled ship 30 miles off the enemy coast but 600 miles from the nearest port you control. Second, from the Japanese point of view this was a bad place to stop to lower boats, row a prize crew over and, presumably, escort a gaggle of slow merchantmen. The Japanese overestimated British air strength in the area and would have considered it too risky to hang about. In fact, Ozawa’s northern group (Kumano, Suzuya and Shirakumo), which had no fighter cover, would likely have been attacked by a flight of Wellingtons based at Calcutta had it stayed in the area longer than it did.

Cheers,

Rob
Last edited by Rob Stuart on 07 Sep 2012 23:43, edited 3 times in total.

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Re: Somerville's Aggressiveness at Ceylon

Post by Rob Stuart » 07 Sep 2012 22:53

(deleted duplicative post accidentally aded)

Rob

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Re: Somerville's Aggressiveness at Ceylon

Post by Carl Schwamberger » 08 Sep 2012 02:33

Rob... thanks for the link to the article.

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Re: Somerville's Aggressiveness at Ceylon

Post by Carl Schwamberger » 08 Sep 2012 02:33

Awfully anoying there is no simple way to delete duplicate & unwanted messages
Last edited by Carl Schwamberger on 08 Sep 2012 15:58, edited 1 time in total.

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Re: Somerville's Aggressiveness at Ceylon

Post by Carl Schwamberger » 08 Sep 2012 02:34

Rob... thanks for the link to the article.

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Re: Somerville's Aggressiveness at Ceylon

Post by glenn239 » 08 Sep 2012 15:49

The six defending brigades did not have to defend the whole coastline. Ceylon was beyond the range of any Japanese air base, so the Japanese had to seize an intact or nearly intact airfield before KdB had to withdraw. There were actually very few airfields on Ceylon.
I haven’t yet read the linked article. Thanks for posting it.

I defer to your superior knowledge with respect to material conditions on Ceylon. Note though that the Japanese will presumably seize Ceylon as the culmination to a series of operations with that end, just like the NEI was taken after a series of operations culminating with the invasion of Java in March 1942. The Maldives would almost certainly be taken in the preliminary operation to establish a seaplane base there, and with naval superiority, smaller landing forces (perhaps regiment or brigade size) could be landed on coastal India in the preliminaries to threaten Allied lines into Burma, the idea being to divert British attention elsewhere. The initial Japanese air base to support Ceylon operations would have to be either on Ceylon or on the coast of India within 200 miles of the landing area for Ceylon.

With respect to the “withdrawal” of Kido Butai, I would advise extreme caution about making handy assumptions along this line. Japanese doctrine in the southern drive was to establish a full forward fleet anchorage (Staring Bay) in Borneo fully capable of supporting the naval resources necessary to maintain dominance in the Java Sea throughout all periods of the southern offensive. The analogous fleet base for a Bay of Bengal offensive is at Andaman Islands only 600 miles from Ceylon, and Japanese carrier divisions could replenish there in sequence, meaning that there is no basis to assume Kido Butai must withdraw at all .

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Re: Somerville's Aggressiveness at Ceylon

Post by glenn239 » 08 Sep 2012 15:50

This would mean taking Aden, Djibouti, or some such base in this area. These places are 2,000 NM from Colombo, which would be the nearest Japanese base. KdB would have to be used to provide air support, which means that the landing force would have to take an airfield, and get it back into working order, before KdB had to withdraw. Big risk of failure.
All of this is true, but the Axis Powers did not operate on the offensive analogous to the Allied Powers, wherein 1944 the Japanese were utterly crushed at the Marianas and then the plodding American command then granted them nearly an entire year (!!!) to fortify Iwo Jima and Okinawa against the next advance. Here, assuming Aden is now the next objective, the British must have been crushed at Ceylon and their defences in the Far East are therefore in a complete shambles. Unless a US counteroffensive in the South Pacific materializes to divert Japanese attention, there is no reason to suppose the British could succeed at Aden when they will have failed at Ceylon under much better relative conditions.

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Re: Somerville's Aggressiveness at Ceylon

Post by glenn239 » 08 Sep 2012 15:54

It is a 12,000 NM round trip from Japan, where the bombs, torpedos, ammo, spare parts, etc, were made...
Quite correct. But ammunition and equipment is only a small part of shipping requirement to a force in Aden that is not engaged in heavy ground combat. Food, fuel and aircraft replacements being the main issue, with the food being not further than Indochina, the (refined) fuel in the NEI, and the aircraft being able to ferry themselves at least as far as Rangoon or Andaman. That is a round trip of only about 4,000 miles, not 12,000.
So it will take a lot more than 30,000 tons of shipping to sustain your base.
That may be true. I look forward to your reading your projection on Japanese shipping requirements to an Aden force of 40,000 men in garrison. I’m assuming that you’re thinking of a British base by which to project an army against Aden, in order to increase shipping requirements. But I do not see where this forward British base is to be supplied from that cannot also be crushed by Japanese naval power. In fact, I cannot see the basis by which the conclusion is reached other than that overwelming Japanese carrier power would decide the issue in the entire Indian Ocean. I'm assuming from this that the Americans must divert Kido Butai into the Pacific to create the conditions for a British counteroffensive?
And how would you get your 100 aircraft there? 2,000 NM is well over even the ferry range of any single-engined aircraft, so you need more carriers to get them there, and any Betty experiencing engine trouble en route is going to be lost....
Single engine aircraft would have to be ferried. Twin engine could stage from Ceylon. Yes, it is true that mechanical failure or navigation could see a plane lost. I would preume as many as 1 in 20 Betty bombers might succumb to attrition enroute.

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Re: Somerville's Aggressiveness at Ceylon

Post by waldzee » 08 Sep 2012 16:07

mcaryf wrote:Hi cstunts

I think you now and the IJN at the time vastly over estimated the US capacity and willingness to mount more than nuisance raids (e.g. Doolittle) in the Pacific in 1942. Even after the IJN's catastrophe at Midway the US did little more than nibble at the edge of the Japanese conquests until well into 1943 and during most of that time the IJN were doing without the availability of 4 front line carriers that they still had in April 1942.

The Japanese attempt to take Midway and the Aleutians made very much less strategic and tactical sense than mounting an attack on Ceylon in particular and the Indian Ocean in general. It could even have served a similar purpose to the IJN's intention for Midway in that it would almost certainly have eventually compelled the US fleet to come to the aid of the RN so the IJN might have been granted their decisive battle but in more favourable circumstances as they would almost certainly have achieved at least a foothold on Ceylon which they did not at Midway.

It is absolutely clear now and must have been reasonably apparent at the time that 1942 was the decisive year for WW2 as the Axis did not have the capacity to sustain a long war. Success or otherwise at Midway had no chance of determining the war. However, success in the Indian Ocean could have opened a world of opportunities for all the Axis partners particularly as the Japanese needed the Germans to knock both the UK and Soviet Union out of the war.

With respect to the ability and willingness of the IJN to operate over enormous distances, I am sure that if they had not attempted the Midway/Aleutians operation, very few of those posting here would have suggested it as a realistic option for them to have even considered.

The Japanese certainly intended to return to the Indian Ocean after Midway and had started to pre-position some minor units but in my view that would already have been too late even if they had won at Midway. Their key opportunity was in April/May 1942. The Indian Ocean option was obviously considered but not selected by the Japanese although it had its proponents such as Admiral Nagano. However, in considering alternate history, there is the possibility that if the Japanese had found Somerville and destroyed his fleet then two things occur. The Japanese would have discovered the lack of real capability of the RN carriers and the US might have been obliged to reinforce the Indian Ocean at the expense of the Pacific. Would, for example, the Doolittle Raid still have taken place on April 18th if Somerville's fleet had been destroyed in the first week of April? The Doolittle Raid was after all just intended as a stunt and its actual strategic consequences unpredicted. These various possibilities could have changed the Japanese decisions with respect to the Indian Ocean. This is why I think a full scale fight between Somerville and Nagumo was one of the most important battles that did not happen in WW2 ranking alongside an earlier German focus on Moscow in 1941.

Regards

Mike
++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Youmay have overlooked a 'small'operation carried out at a place called Guadacanal, Mike :D

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Re: Somerville's Aggressiveness at Ceylon

Post by Carl Schwamberger » 08 Sep 2012 18:55

Interting items in the Stuart article http://www.journal.forces.gc.ca/vo7/no4/stuart-eng.asp

The remark indicating all or most of the Albacore torpedo bombers were radar equipped caught my eye. I'd thought only a minority were carrying this. A second item was the remark of the IJN anticipating a USN raid on the home islands 11-16 March. That raises a lot of questions about the source, what intel the IJN based this on, who took it seriously enough to change the operational schedules... From other sources it appears the IJN was starting to take the USN raids seriously, as more than a anoyance.

Another remark illustrates the accidents of war, describing how the attack of 11 Squadrons Blenheims went in undetected until the bombs dropped among the Japanese ships. Of use to the analyst of tactical details would be the weather/clouds, altitude the Blenheims fkew at & direction of approach, size/location/activity of any CAP,

Another general set of questions concern the night attack Sommerville intended. On the Japanese side I understand the Kito Butai did not keep a CAP aloft at night, th the Japanese fighter pilots were capable of of taking off at night. AAA gunnery effect would depend in part on density of the fleet, did the KB spread out at night, or concentrate the ships closer? On the Brit side there is the question of how the Albacores would attack. I'm skeptical they could assemble in the dark for massed attack in formations. That implies nearly as many axis of attack as there would be bombers arriving, and the attacks spread over some time. Perhaps as much as 40 miniutes? I'm also wondering if the early aircraft arriving over the fleet would take any action to assist the following aircraft. At Taranto the Brits dropped flares to mark and back light the target ships. Did nay of the Albacores carry illumination flares suitable, and was this a tactic the pilots intended?

The final and most difficult question is the number of actual torpedo hits the Brits might be expected to make. A uncertain approach against a large and manuvering fleet at night is going to be somewhat confusing for both sides. If 2/3 of the Albacores reach the enemy fleet then something like 15 torpedos could be launched? How many actual hits will that translate into? ...and in the confusion will any IJN ships collide? That happened more than once in daylight, what are the odds in this situation?

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Re: Somerville's Aggressiveness at Ceylon

Post by Rob Stuart » 08 Sep 2012 22:42

Hi Glenn. I’m happy to be debating Ceylon with you on yet another forum.
Note though that the Japanese will presumably seize Ceylon as the culmination to a series of operations with that end, just like the NEI was taken after a series of operations culminating with the invasion of Java in March 1942. The Maldives would almost certainly be taken in the preliminary operation to establish a seaplane base there, ...
Each of the amphibious “jumps” the Japanese made in taking the NEI was within range of land-based aircraft. Malé, probably the closest Maldivian island, was 1300 NM from Sabang. No Maldivian island had an airfield at the time, so your seaplane bases would have no fighter defence. The northern Maldives were within range of Wellingtons and B-24/LB-30s which could be moved fairly easily to southern India and the sourthern most atoll, Addu Atoll, had a garrison and coast defence guns, so taking it would be like taking Wake. Furthmore, your H6Ks could easily have been destroyed by a couple of hours bombardment by a light cruiser arriving at dawn.
…with naval superiority, smaller landing forces (perhaps regiment or brigade size) could be landed on coastal India in the preliminaries to threaten Allied lines into Burma, the idea being to divert British attention elsewhere.
Won’t work. The British were not going to divert anything from Ceylon to counter a landing up near Burma, because they considered Ceylon far more important. That is why there were six brigades in Ceylon and more fighters on Ceylon than in north-east India.
The initial Japanese air base to support Ceylon operations would have to be either on Ceylon or on the coast of India within 200 miles of the landing area for Ceylon.
While there were a number of airfields in southern India within range of Ceylon, I don’t think any of them were on the coast. As for mounting a preliminary landing to seize a Ceylonese airfield before the main Ceylonese landing, this would be a non-starter. This is because the only two large air bases were at Trincomalee and Colombo, which were too heavily defended to be taken by a regiment or a brigade. The others were inland, too small, or unknown to the Japanese. The Japanese would be able to seize a worthwhile airfield only with their main landing force, either at Trincomalee (the better bet, I think) or Colombo.
With respect to the “withdrawal” of Kido Butai, I would advise extreme caution about making handy assumptions along this line. Japanese doctrine in the southern drive was to establish a full forward fleet anchorage (Staring Bay) in Borneo fully capable of supporting the naval resources necessary to maintain dominance in the Java Sea throughout all periods of the southern offensive. The analogous fleet base for a Bay of Bengal offensive is at Andaman Islands only 600 miles from Ceylon, and Japanese carrier divisions could replenish there in sequence, meaning that there is no basis to assume Kido Butai must withdraw at all.
Okay, I’ll concede that portions of KdB could withdraw to Port Blair (700 NM from Trincomalee, about 900 from Colombo) in turn to replenish. Let’s assume that four CVs were committed. The 1400 NM round trip from Trincomalee would take four days, plus probably two days to replenish, so six days. The two carriers left off Ceylon could easily expend all their bombs during those six days and need to make tracks for Port Blair as soon as the first two returned, so most of the time there would be only two CVs off Ceylon. They would have to stay in range of the beachhead, so the British would have a good idea where they were and Somerville, with Indomitable, Formidable and Illustrious and their 65 torpedo bombers, might have been able to pull off the night torpedo attack he tried to do on 5 April. Even if the British did not risk their carriers, they had four operational submarines at Colombo which would be a definite threat to any force which had to stay more or less put – this is why Wasp was lost in September. All of this goes to show that KdB, whether at full or half strength, could not hang about forever, so a good airfield (probably China Bay) would have to be seized and put back in operation quickly. This would be difficult.

I would also add that Port Blair was within range of Allied aircraft. The US 10th Air Force attacked it (unsuccessfully) on the night of 2-3 April and RAAF Hudsons destroyed a number of H6Ks on 14 and 18 April. I think the Wellingtons at Calcutta could attack Port Blair as well, so it was not an entirely safe anchorage.

Incidentally, Staring Bay was not in Boreno, it was in Celebes, near Kendari. Vis-à-vis Ceylon it was not exactly an advanced base – the transit from Staring Bay to Colombo lasted from 26 March to 5 April, only two days less than did the transit from Hitokappu Bay to Pearl Harbor.

But if we’re talking about an attack on Aden, having half of KdB withdraw for replenishment to Ceylon, a round trip of 4,000 NM (14 days), is out of the question. The half left off Eden would run out of bombs in much less than 14 days. Any 36 Zeros, minus losses, would not be a lot to defend the CarDiv, the beachhead, and the CarDiv's air strikes.
… the Axis Powers did not operate on the offensive analogous to the Allied Powers, wherein 1944 the Japanese were utterly crushed at the Marianas and then the plodding American command then granted them nearly an entire year (!!!) to fortify Iwo Jima and Okinawa against the next advance.

The next major advance after the Marianas was not Iwo Jima, it was the Philippines, attacked only four months later. Far from being plodding, it happened long before the Japanese could replace the air groups on their remaining carriers. (The first two Unryu’s were commissioned before Leyte Gulf but never received air groups and could not deploy for this battle.)
But ammunition and equipment is only a small part of shipping requirement to a force in Aden that is not engaged in heavy ground combat. Food, fuel and aircraft replacements being the main issue, …
What makes you think your ground force in Aden would not be involved in heavy gound combat? Aden is not an island. Rommel’s last attempt to advance was decisvely defeated by 27 July, after which time the British could have deployed an armoured division equipped with tanks better than any the Japanese had, plus infantry, more and better artillery than the Japanese would have, and attack it overland, supported by a lot more than 100 aircraft. In fact, they would very likely get wind of the impending attack well in advance, as was the case for operations MO and MI, in which case they could reinforce the garrison, sow a lot of mines, sink block ships, prepare the fuel stocks and airfield(s) for destruction, etc. And their naval defence could easily have taken a different form than at Midway, where the US went after KdB. What if the RN ignored KdB and went after the 300,000 tons of transports and cargo ships three or four days behind them? The Eastern Fleet could have sortied from Kilindari and come up on the invastion fleet from behind. I don’t accept that the EF would necessarily be destroyed during an invasion of Ceylon, because Somerville and the Admiralty had agreed that preserving the EF was more important than keeping Ceylon in British hands. Somerville kept out of Japanese reach after Operation C and would seek battle only under favourable conditions, so there would still be an Eastern Fleet around to dispute an invasion of Aden. On the other hand, one or more Japanese carriers could have been lost or put out of action off Ceylon.

All in all, taking Aden from Ceylon would be a bit like the US trying to take Brest from Newfoundland with the Germans already in Iceland, Ireland and the UK. It’s a pipedream.

Cheers,

Rob

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Re: Somerville's Aggressiveness at Ceylon

Post by Rob Stuart » 09 Sep 2012 01:43

Hello Carl,

I researched my article for almost two years before completing it. It thinks it’s pretty sound in general, but in the six years since then I’ve learned of some mistakes in it and you’ve fingered one of them right off the bat. You quite right to say that only a minority of the Albacores had ASV. None of Indomitable’s did, it seems, and probably only some of Formidable’s had it, but I don’t know how many.

My statement that “between 11 and 16 March, Shokaku and Zuikaku made an unplanned sortie to search for a US carrier task force thought to be approaching Japan, and they did not rejoin the First Air Fleet at Staring Bay, off Kendari on the island now known as Sulawesi (then Celebes), until 24 March” is not far wrong, albeit the explanation is a bit differnet than I thought it was. The circumstances of CarDiv5’s delay are explained in Osamu Tagaya’s posts in the thread at http://www.j-aircraft.org/smf/index.php?topic=10088.0 and in his recent book Aichi 99 Kanbaku ‘Val’ Units 1937-42.

Regarding the 11 Sqn attack on 9 April, you might want to check out the lengthy exchange earlier this year at http://www.j-aircraft.org/smf/index.php?topic=11931.45. Eugen Pinak suggests in Reply #56 that KdB was not taken by surprise by 11 Sqn, and this is debated, perhaps without being definitely decided, duirng the next 80 or so posts. This thread may well represent the most detailed discussion you’ll find anywhere on this attack.

Your questions about the Alabcore attacked planned for the night of 5-6 April are good ones. A few Indomitable and Formidable aircrew have published memoirs noting that Albacores were ranged, armed and ready to go during the late afternoon, but how many there were or exactly what the plan was is unclear to me. I have Somerville’s report of proceedings (it’s at http://www.naval-history.net/xDKWD-EF19 ... uction.htm) but it does not explain these points. I also have Indomitable’s deck log but it notes only take-offs and landings, and does not refer to aircraft which were ranged but did not take off. We would need the log or reports of Rear Admiral Boyd, the commander of Somerville’s carriers, or the logs or reports of the Commander (Flying) of the two carriers, to learn these details, I suspect – if they still exist.

Somerville reportedly had 45 Albacores, of which four were launched at 1400 on an air search and not back until 1800 – and one of them was shot down and another was damaged. Assuming that a couple of the remaining 41 were unserviceable and that four would carry only flares, there would be 35 torpedo-armed planes at most. It’s terribly hard to say how many hits they might have made. There were three strikes againt the Italian fleet off Crete on 27 March 1941. The first, with four Albacores from Formidable and a few Swordfish from Crete, made no hits. A mid-afternoon strike from Formidable (I don’t know how many Albacores were involved but probably something in the order of six to eight, scored a hit on Vittorio Veneto. The third, by six Albacores and four Swordfish, scored one hit on Pola. Victorious attacked Bismarck with nine Swordfish after dark on 24 May, in weather conditions which were much worse than on 5 April ’42 off Ceylon, and scored one hit. Ark Royal attacked Bismarck after dark on 26 May, in very bad weather which forced the 15 Swordfish to make uncoordinated attacks but they scored two hits. Together these five attacks scored five hits for about 40 drops, or just over 10%. As the weather was quite good on 5 April, I suspect that the Albacorce attack would be reasonably well coordinated and something like four to six hits could reasonably be expected. If there were six hits but none of them hit a carrier, well maybe the damage to its escorts would force KdB to head home without attacking Trincomalee but presumably Coral Sea and Midway would still happen as they did. On the other had, if they scored only two hits, but one was on Zuikaku and the other on Shokaku, damaging but not sinking them, then presumably Coral Sea would be skipped and the US would have had Lexington, Enterprise, Hornet and an undamaged Yorktown at Midway. It's really anyone's guess what might have happened, but one thing I'm fairly confident about is that Somerville would probably escape retribution. The two fleets would have been about 100 miles away when Somerville launched, with Nagumo to his northeast. He could have recovered his aircraft by before midnight and been a further 150 miles to the southwest by first light, making it unlikely that Nagumo would find him before having to leave to RV with his tankers. (Nagumo searched hard for Somerville on the 6th, but to east, precisely the wrong direction.) The unlaunched night attack of 5 April is one of the biggest “what ifs” of the first few months of the war and is one of the things which makes Operation C so interesting.


Rob

Carl Schwamberger
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Re: Somerville's Aggressiveness at Ceylon

Post by Carl Schwamberger » 09 Sep 2012 02:15

Rob... thanks for the attention to my questions. As for which aircraft were equipped with radar: one assumption of mine is a third crew might be a indicator, I've never done any research on this.

March Raid: I was unaware the Enterprise had made another raid in early March. What a busy ship. this was not to many days from the Rabaul raid and the raid on the New Guinea convoy. I'd also thought the only large scale IJN reaction to the US raids was after the home islands attack of April. Here we see the possibility of a decision to abruptly alter other large operations in response. This is worth further investigation for the insight it might provide into the thinking of the IJN leaders.

"..and that four would carry only flares.." hmmm... so you are thinking flares would probablly have been packed along? As for the rest of it; 35 torpedo bombers is 50% more than what I'd understood, and I'd misunderstood a search/strike group of 24 had been sent aloft at or after dusk. A strike group taking off together or in two groups is different from what I'd interpreted from other accounts. 10% - 3 or 4 torpedo hits is a lot more than i'd dare think to this point. The implications... I feel faint & must go elevate my feet. Thanks & later

Rob Stuart
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Re: Somerville's Aggressiveness at Ceylon

Post by Rob Stuart » 09 Sep 2012 14:27

Carl,

My numbers supposed that the search launched at 1400, which actually did find Nagumo, had provided accurate enough info on KdB's position, course and speed to have permitted a strike to be launched at about 1800. Regarding the night search, Somverille's ROP says that "At 1930 a night search with A.S.V. aircraft commenced to cover the section 345 degrees to 030 degrees to a depth of 180 miles. Nothing was located by this search." Since this search covered an arc of only 65 degrees, I would presume that no more than four Albacores were involved, but I won't be able to confirm this until I can see a copy of Formidable's log. Formidable had 21 Albacores, so if KdB had been found during this night search it could have launched a maximum of 17 Albacores. Indomitable had 24 Albacores, minus the one lost and the one damaged during the afternoon search, so 22 to launch, if all were servicable. I'm not sure if 22 could be launched in one range but 20 could for sure, so let's say 20 from Indomitable. That would give us up to 37 to launch, minus four flare-carriers would be 33 with torpedoes. So slightly smaller.

I'm not sure that I understand your comment that "As for which aircraft were equipped with radar: one assumption of mine is a third crew might be a indicator...". The standard Albacore crew was three, whether or not ASV was carried, so if you're thinking that Albalcores with three aircrew had ASV, that was not the case.

Cheers,

Rob

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