The Japanese Sweep Into the Indian Ocean
Naval Warfare
Outside
The Pacific
The Japanese Sweep into the Indian Ocean.
By
M. J. Bourne
Naval Warfare Outside the Pacific:
The Japanese Sweep into the Indian Ocean
Copyright M J Bourne 1995
2nd Edition published 1997 by
Vandering Publications
1 Lindal St,
Barrow-in-Furness
Cumbria
LA14 1AY
3rd Edition published 2010 by
Vandering Publications
29 Dumfries St,
Barrow-in-Furness
Cumbria
LA14 2DA
All rights reserved.
No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying or otherwise, without prior permission in writing from the copyright holder.
Introduction.
In order to minimise the confusion that naturally would arise from operating a multinational alliance, the Allies in World War II divided the globe up into "areas of responsibility", in each of which one of them would have the main responsibility for the conduct of the war. The Pacific Ocean was assigned to the Americans, and as Japan was adjacent to the Pacific it followed that most of the naval clashes were contests between the USA and Japan. There was occasional assistance for the Americans, particularly at the start of the war, from small numbers of British and Dutch vessels. As soon as the defeat of Germany became inevitable, the British organised a Pacific fleet that supported the US in the final battles around Japan itself. Apart from these notable exceptions, it was the US Navy that carried out the lion's share of the fighting against the Japanese Navy. The resultant battles, carrier against carrier, are justly famous - Coral Sea; Midway; Leyte Gulf; but before all these there was a brief interlude. In April 1942, the Japanese sent a task force into the Indian Ocean, an area for which the British were responsible.
The Japanese sweep into the Indian Ocean resulted in the only fleet sized clash between the Japanese Imperial Navy and Britain's Royal Navy that occurred throughout the entire war. A few Australian and Dutch units were present, but no American forces were involved at all. It was a fascinating clash between two divergent traditions and theories of war at sea, both of which were perfectly valid in their own circumstances. Both strategically and tactically the result appeared to be clearly decisive, and yet curiously it turned out not to be so, for the victors did not capitalise on their successes. The main result was a reappraisal of policy in the area by the losers.
This is the story of what happened.
The Strategic Situation.
By the spring of 1942 Japanese imperial ambitions in the Pacific had been exceeded beyond all expectations, far ahead of schedule and with minimal casualties. The European colonial powers were preoccupied with war at home. T heir policy of defending their far Eastern possessions with large forces using mostly obsolete equipment had proven to be disastrously inadequate. The American air force had been effectively eliminated by surprise attacks on the Philippines. The American fleet had been similarly disabled at Pearl Harbour. Only luck had saved the aircraft-carriers, which had been out of harbour when the attack came. It was these carriers that were ultimately to claim the credit for stemming the seemingly irresistible tide of the Japanese advances, which soon overran the Philippines, Malaya, and Dutch East Indies.
In 1942 however, although the benefits and advantages of naval aviation were recognised by all the combatants, most authorities still saw the battleship as the main naval strike weapon - not (as it was to prove) merely extra defensive firepower for carrier task forces, or provider of heavy support for amphibious landings. All of the American Pacific fleet battleships had been destroyed or immobilised at Pearl Harbour. Both of Britain’s immediately available capital units (Prince of Wales and Repulse of the ill-starred Force Z) had been sunk attempting to defend Singapore. To conventional strategic thought the Japanese had the run of the western Pacific, helped by their interior lines of communication. Even to those who foresaw the domination of the aircraft-carrier the situation still seemed grave, for the Japanese had six big fleet carriers to the Americans four, and they also had several smaller escort carriers as well. It must have seemed that nothing could stop this Oriental blitzkrieg.
Japanese superiority was so absolute in the Pacific that threats to adjacent areas became a real possibility. With the fall of Singapore on February 15th 1942, and Rangoon on March 28th, the British, in particular, became alarmed at the prospect of a descent upon the "Jewel of the Empire", the sub--continent of India itself. The perceived threat was to the island of Ceylon (modern day Sri Lanka). A substantial Japanese fleet based there would dominate the whole of the Indian Ocean, effectively severing the sea routes to India, Australia and the valuable Middle Eastern oilfields.
For their part, the Japanese were rather at a loose end as to what to do with their premier strike force. An invasion of Hawaii had been rejected due to the distance. Consultations with the Germans had been made with regard to a tentative link up between the Africa Korps and a Japanese force invading through the Middle East via Ceylon and south India. This plan, which epitomised British fears, was eventually vetoed by Hitler. The only remaining option was to push south onto Australia, a move that was to eventually lead to the strategic check at the battle of the Coral Sea. Before they moved though, the Japanese decided to sweep into the Indian Ocean to dispose of the remaining British Commonwealth naval presence. On the way, air strikes could be made on Port Moresby and Darwin in north Australia in support of Japanese efforts in New Guinea.
The British had of course drawn up contingency plans for the possibility of conflict with Japan. The original scheme called for the assembling of a powerful fleet in the Indian Ocean and western Pacific, cooperating with the Americans in the Eastern Pacific. This force was naturally to have had battleships as its main strike element, no less than seven in fact, but war with Germany and Italy had forced major units to be widely dispersed, and it was estimated that assembling the originally conceived fleet would take nearly nine months. The need was far too pressing for that.
Accordingly, every possible resource was scraped together to defend Ceylon. The garrison of the island was strengthened until by the end of March it was the equivalent of two whole divisions, even though it was appreciated that a Japanese invasion of India was altogether more likely via Burma and Assam. The anti-aircraft defences of the island were upgraded and reorganised. Radar was earmarked for installation at the Ceylon airbases, and no less than six extra squadrons of fighters were flown in to provide air cover. Finally an Eastern Fleet was formed, under the command of Admiral Sir James Somerville, and based on the excellent natural harbour at Trincomalee and a secret base under construction at the Addu Atol.
It was an impressive build-up in such a short period of time, especially considering the desperate demands of other theatres of operation, and underlined the importance Britain placed on retaining control of the area. These measures seemed to be vindicated when Intelligence reported that the Japanese were preparing to send a fleet into the Indian Ocean on or about the 1st of April, 1942.
At this time the Eastern fleet was slowly assembling as ships became available. The battleship Warspite had just arrived at Trincomalee from Freemantle. Waiting for her was the aircraft-carrier Hermes, two cruisers and a destroyer. At Colombo was another aircraft-carrier, Formidable, together with five cruisers and six destroyers. The 3rd Battle Squadron, the carrier Indomitable and eight destroyers were at the Addu Atoll.
Eastern Fleet Order of Battle.
Force "A" (or fast division).
Aircraft-carriers.
Indomitable (Indomitable class).
Formidable (Illustrious class).
Battleship.
Warspite (Queen Elizabeth class).
Cruisers.
Dorsetshire (Norfolk class).
Cornwall (Kent class).
Emerald (Emerald class).
Enterprise (Emerald class).
Destroyers.
Hotspur (Gallant class).
Foxhound (Echo class).
Napier (Jackal class) Royal Australian Navy}.
Nestor (Jackal class) Royal Australian Navy}.
Paladin (Onslow class).
Panther (Onslow class).
Force "B" (or slow division).
Aircraft-carrier.
Hermes (Hermes class).
Battleships.
Ramillies
Resolution
Revenge
Royal Sovereign (all “R” class).
Cruisers.
Caledon (Caledon class).
Dragon (Danae class).
Heemskerck (Heemskerck class) {Royal Netherlands Navy}.
Destroyers.
Arrow (Acasta class).
Decoy (Diamond class).
Fortune (Echo class).
Griffin (Gallant class).
Isaac Sweers (Sweers class) { Royal Netherlands Navy}.
Norman (Jackal class) { Royal Australian Navy}.
Scout (Tenedos class).
Vampire (Whirlwind class) { Royal Australian Navy}.
At Colombo.
Destroyer.
Tenedos (Tenedos class) {under repair}.
In addition there were nine sloops in the area, namely Falmouth, Shoreham, Hindustan, Indus, Jumna, Sutlej, Clive, Cornwallis and Lawrence. All but the first two were Royal Indian Navy vessels. There were also five "Flower" class corvettes on patrol duties—Aster, Hollyhock, Marguerite, Tulip and Verbena. Finally there were three submarines - Truant, Trusty and a Dutch boat, probably K.14. Trusty was unfit to sail and confined to Colombo. The location of the other two is unknown, but they were to have no bearing on the action.
On paper this concentration all seems most impressive, but close examination soon begins to show serious deficiencies. The principal weakness of the Eastern fleet was its ad-hoc nature. The sixteen destroyers alone were of twelve different classes. The ships had never operated together before. The captains were unused to each other and the admirals had no first hand knowledge of the capabilities of their commands.
Nor did the actual vessels themselves inspire a great deal of confidence. Of the five battleships, the four "R" class types (making up the third battle squadron) had all been built before the First World War. They were slow, very short-ranged and, being designed before the advent of effective air power, had little deck armour, making them very vulnerable to dive-bomber attacks. The fifth battleship, Warspite, was also a veteran of the 1914-1918 conflict, but at least she had since been extensively modernised.
Of the aircraft-carriers, Hermes was Britain's first serious entry into the field of naval aviation. She too was old, slow and poorly armed. Moreover her aircraft carrying capacity was a mere eighteen.
The remaining two carriers, Indomitable and Formidable, were powerful front-line units comparable in size to any carrier then existent. However, their design philosophy was very different. The British, whose main opponents were obviously destined to be the Germans and the Italians, had less need of long-range strike aircraft in the relatively less expansive Atlantic and Mediterranean waters. What they did need were aircraft carrying vessels that could protect convoys against air attack. This was regarded as vital to the safeguarding of the sea routes on which the British Empire ultimately depended. Essentially these ships were of a size, speed and range similar to contemporary American and Japanese designs, but optimised to protect against air attack. As such, they carried large numbers of high-altitude heavy anti-aircraft guns and had armoured decks capable of withstanding bomb hits without putting the ships flight operations completely out of action. These desirable features had a price however. Indomitable could only carry a modest forty-five aircraft, and Formidable a mere thirty-three. They and their sister ships were to prove their worth in the desperate convoy battles in the Atlantic and the Mediterranean, but they were simply not designed for the classic carrier-to-carrier duel of the type that was to so characterise naval operations in the Pacific theatre.
Of the smaller ships, only one of the cruisers, Dorsetshire, carried radar. Both of the big cruisers were considerably smaller and less powerful than their Japanese opposite numbers, mainly because they had been built under treaty limitations that every other maritime nation had simply ignored. All of the six-inch gun armed light cruisers had been constructed under the emergency war plan of the First World War. Many of the destroyers were also very old, and most were also much smaller than their Japanese counterparts. The "Scout" class in particular were little better than destroyer-escorts.
But the most serious deficiency was in the quantity and quality of the aircraft deployed. The principal fighter was the Hawker Hurricane, a sturdy if somewhat stolid bomber interceptor that had in fact been the mainstay of the Royal Air Force during the Battle of Britain, in spite of all the attention given to the much better known Supermarine Spitfire. By April 1942 the early versions of the Hurricane were becoming obsolete and as practically all the actual machines deployed to Ceylon were mark Is’, it is hardly surprising that they were to find themselves easily outmanoeuvred by the Japanese Zero fighter—especially at low altitudes. Serviceability was a problem too. The Hurricanes had been rushed in from the Middle East and their engines were still equipped with desert air filters, which meant they were quite useless until tropical filters could be fitted instead.
The other main fighter aircraft employed was the Fairey Fulmar, a purpose-built naval plane used on both the carriers and from Ceylon's air bases. Fulmars were durable, and like most British carrier aircraft very versatile. However, they had no other advantages. Big, heavy and slow, they were no match for the Japanese Zero.
The best fighter deployed was the Martlet, the British name for the American Grumman F4F Wildcat. An almost ideal carrier-borne fighter, the Wildcat was small, light and extremely easy to maintain, making it very reliable. It was also a good fighting machine, being heavily armed, very manoeuvrable and possessing an excellent range. Unfortunately there was only one squadron of them available.
The principal strike plane used was the Fairey Albacore, a three seat utility biplane designed as a maid-of-all-work for the Royal Navy's Fleet Air Arm. It served as a mine-layer, a torpedo-bomber, a reconnaissance plane and even as a submarine hunter. It was both much slower and had far less range than either of it's counterparts in the US and Japanese navies, although the main weapon, the 18 inch torpedo, was superior to contemporary American designs.
Poor though the performance of the Albacore was, it still exceeded that of the other main strike plane, the Fairey Swordfish. "Stringbags" (as they were affectionately known) were the Albacore's predecessor as the main British naval bomber. They were fabric covered biplanes which when fully armed had a range of only 540 miles and a top speed of only 88 mph! It would be quite impossible to force either of these aircraft through contemporary Japanese carrier air defences. The British did have one advantage though. Their crews were much better trained in night flying, and had far more experience of it too. Therefore a night attack against a Japanese force which had neither radar or night fighters might be quite
effective.
Fairey Albacores in formation. Photo courtesy of the Fleet Air Arm Museum.
The RAF could contribute only a single squadron of land-based level bombers. These sixteen Blenheims were fair strike planes and the aircrews were all pre-war regular air force. However, they had no experience in anti-shipping operations, and level bombing had long since been proven to be relatively ineffective against mobile maritime targets. The only reconnaissance planes available were seven Catalinas, for which only six crews could be found.
Japanese Forces for the Indian Ocean Sweep, April 1942.
The Japanese forces, under the overall command of Vice-Admiral Kondo, were in stark contrast to the hurriedly scraped together British Eastern Fleet. The main carrier strike force was the famous "Kido Butai", the force that had carried out the attack on Pearl Harbour (with the exception of the aircraft-carrier Kaga, which had been detached to Japan for servicing). "Kido Butai" was then the most powerful naval strike force in the world. Its’ component ships were modern and well-armed. Their crews were experienced, highly-trained, and had known nothing but victory.
Like Somerville, Kondo divided his ships into two groups. A raiding force under Vice-Admiral Ozawa was ordered to sweep into the Bay of Bengal, with the intention of disrupting the rich commercial traffic there. The second force, under Vice-Admiral Naguma, was to cover the actions of the raiding force by launching air attacks on British bases in Ceylon, and if possible the British Eastern fleet as well. It was well equipped to do so. Each of the five big aircraft carriers was equipped with two squadrons of Zero’s, some 120 machines in total. Each also carried two smaller squadrons of the “Val” dive-bomber and the “Kate” torpedo-bomber, except for the larger Akagi, which carried three of each, making a grand total of 100 of each type.