The British Submarine Campaign of World War II

It is inevitable that the great deeds of British submariners in the Second World War would be overlooked by most. Their fight was not as critical as that of the German u-boats in the Battle of the Atlantic nor as single-handedly successful as the American submarine campaign in the Pacific, however, it would be wrong to ignore it. The submarines of the Royal Navy played, if not a decisive factor, certainly an extremely significant one in the ultimate victory over the Axis powers, particularly Germany and Italy. The British are mostly known, because of the world wars, as being on the receiving end of submarine warfare rather than the ones waging it and, indeed, Britain would lead the way in anti-submarine warfare particularly during World War II. Nonetheless, while the convoy escorts braving the perilous North Atlantic crossing or the warships chasing down German or Italian battleships got most of the attention, the submarines of the King-Emperor went about their work silently severing the vital arteries that kept the Axis powers functioning and their armies on the advance.

HMS Totem

Great Britain began the war with a fleet of 57 submarines, the exact same number as the Germans. The Royal Navy produced quite a large number of different classes of boats but three would be most prominent; the S, T, and U-class boats of which the most famous is probably the T-class. Like the Italians, who had a very large submarine force, the British opted for reliability rather than innovation. For instance, like the Italians, they stuck to the old-fashioned impact fuse for their torpedoes rather than the more sophisticated magnetic fuses used by the Germans and Americans. This made them less effective but, unlike both Germany and America, Britain did not have to go through a period of having unreliable or totally faulty weapons while the bugs were worked out of this new technology. Rather, the British compensated for the weaker destructive power of the impact fuses (in which the brunt of the explosion is focused away from the target) by having boats that packed a larger punch than those of any other navy. British T-class submarines were built to fire an astonishing 10 torpedoes at a time which, British naval engineers reasoned, would more than make up for the drawbacks of their fuses as well as the less advanced targeting systems of British boats. If ten torpedoes are fired at a single target, one or more will almost have to hit it.

When war broke out in 1939, British boats were deployed to Heligoland to patrol the waters off the southwest coast of Norway for German ships and u-boats. Unfortunately, this proved very dangerous even without the Germans as British submarines sometimes fired on each other, mistaking their submarines for German u-boats. Likewise, even when in their designating hunting areas, British submarines were sometimes attacked by the RAF who mistook them for German u-boats. However, the British subs did finally score their first victories with successful attacks by two S-boats. HMS Sturgeon sank a German ship in November and HMS Salmon sank a German u-boat two weeks later. The British submarines would gain a high reputation for their ability to sink enemy submarines at a time when surface ships were still assumed to be their primary targets. The Royal Navy proved that the best weapon to use against a submarine is another submarine and that fact remains true to this day. By the time the war was over, British submarines would account for the loss of 39 Axis subs.

Admiral Horton, 1940

In January of 1940 the Brits would step up their game with the appointment of Vice Admiral Max Horton to command the Royal Navy submarine force. He was a living legend in the submarine community for his fantastic record of success in the Baltic as a submarine commander in World War I. After Britain sustained her first losses to enemy action, it was Horton who ordered British boats to stay out of the shallower waters where German underwater detection gear was less effective. Horton planned to use submarine planted mines to cut off the supply of raw materials coming out of Scandinavia to Germany, which would likely force Germany to invade Norway. As it happened, the Germans did invade Norway though not for that reason. Unfortunately, due to weather conditions and bureaucratic slowness, the Germans were able to slip past the British boats and land their forces before the Royal Navy could react. Nonetheless, the British subs did get a few powerful blows in. HMS Truant sunk the German cruiser Karlsruhe and HMS Sunfish sank a 7,000-ton freighter followed by another before the day was out.

Unfortunately, even with 17 boats in the vicinity, the big game proved elusive. The prized German warships Gneisenau, Hipper and Scharnhorst all escaped attacked due to poor visibility and radio direction-finding by German shore installations which were able to direct their ships around areas where British submarines were on the prowl. This was a problem that would come up again later. There were other minor successes but the fact remains that the British submarine force had failed to stop the German invasion and the Royal Navy had been forced to rely only on the submarine force because of the effectiveness of the Luftwaffe in keeping the British surface fleet away. Likewise, operations off the North Sea coast during the German invasion of France and the Low Countries proved to be of little effect. Concentrating boats in these confined spaces had proved to be a mistake, due to the effectiveness of shore installations in homing in on their radio transmissions, the risk of “friendly fire” and the constant daylight in northern areas.

HMS Phoenix

Fortunately for Great Britain, much more success was to be found in the waters of the Mediterranean where British submarines would have their biggest impact on the war. The largest threat, obviously, was the powerful Italian navy and the extensive coverage over the Mediterranean by the Italian air force. However, due to the shortage of fuel and their industrial inability to keep up with any significant rate of attrition, the Italian surface navy would be forced to remain on the defensive. The first British submarine success in the Mediterranean was, due to confusion over their status, the sinking of a French sloop. While screening a convoy, the submarine HMS Phoenix spotted the main Italian fleet, leading to a fairly significant engagement, but the Phoenix was then sunk by an Italian torpedo boat on July 16, 1940. On the final day of the month, HMS Oswald was sunk by an Italian destroyer off the coast of Messina. As the Germans had done in the North Sea, Italian shore installations used radio direction-finding to locate the British submarine and the Italian destroyers then moved in for the kill.

Morale fell as British submarine losses continued and though successes did increase when the government in London authorized the use of unrestricted submarine warfare, the latter half of 1940 was fairly disastrous for the Royal Navy boats. While sinking less than 1% of Italian shipping to North Africa, Britain had lost nine submarines, five at the hands of the Italian navy and the rest to air attack or mines. At one point, Britain was reduced to only five operational boats in the Mediterranean. Clearly, something had to be done. Italian shipping losses had been extremely light in 1940, warships were not engaged and overall Italian superiority in the central Mediterranean had been maintained. It was a gloomy time as the British came to grips with the fact that, despite what Allied propaganda had told them, their enemy was a formidable one. However, the British did what they have traditionally done; learned from their mistakes and adapted.

HMS Upright

As with the Germans (or the Japanese for that matter), Italian underwater detection gear was not good. The British knew this and so finally came to appreciate that, other than aircraft, the primary way their boats were being located was by radio direction-finding. The British responded by ordering their subs to maintain radio silence unless communication was absolutely necessary. The British also ultimately adopted the practice of keeping their boats submerged throughout the daylight hours if at all possible, only surfacing at night. This reduced their mobility of course but also made them much less likely to be detected by lookouts on ship or shore or by patrolling Italian aircraft. The Admiralty also sent many more submarines to Malta such as 10 new U-class boats in early 1941. With a greater respect for their enemy, more care given to stealth and increased use of mines, British successes began to pick up. In February of 1941 HMS Upright attacked and sank the Italian cruiser Armando Diaz in a surface attack at night, the biggest victory British submarines had yet had in the Mediterranean.

In March, HMS Rorqual laid a minefield, sent two freighters to the bottom and then sank the Italian submarine Capponi. The same month, another British boat, the P31, made a successful attack on a large freighter using Asdic (sonar) alone, earning the commander the DSO. The following month also saw the beginning of a string of victories for the man who would be the most successful British submarine commander of World War II, Lt. Comm. Malcolm D. Wanklyn of HMS Upholder. He sank a freighter in April off Tunisia and two more on May 1, beginning what would be a very successful career, albeit a short one. Sadly, Wanklyn was killed in action in 1942 by the Italian navy but by that time had managed to sink 21 Axis vessels, earning the Victoria Cross. Because of men like him, things were turning around for the British war under the waves. In the first half of 1941 they managed to sink about 130,000 tons of Axis shipping while losing only two submarines, both to Italian minefields. Still, the rate of success was slow at less than two ships a month and of the shipping interdicted by the Allies, including the movement of Rommel’s Afrika Korps to Libya, less than 5% was lost to British submarines.

HMS Upholder

However, the British were steadily improving and were aided by two significant events; the invasion of the Soviet Union, which meant the redeployment of enemy air forces and the breaking of Axis codes which allowed the British to have up to date information on Italian naval movements. The British also very cleverly took care to move aircraft into the area of Italian convoys before the submarines arrived to make their attack so that the Axis high command would assume the RAF had spotted their ships and not catch on to the fact that their codes had been broken. This allowed for more British submarines successes going forward. In September of 1941 the boats at Malta were organized into the Tenth Submarine Flotilla and the “Fighting Tenth” would prove the most successful British submarine force of the war, though also the one with the highest casualty rate.

Having inside information on when and wear Italian supply convoys would be sailing, the British were able to post their submarines in picket lines in front of the enemy. In so doing, the British boats began to really bite into the Axis war effort, sinking four Italian troopships in a few weeks and badly damaging the new Italian battleship Vittoria Veneto which was attacked by HMS Urge and put out of action for over three months. In the second half of 1941 the British lost six submarines but received 13 new boats and in that time managed to take a significant toll on Axis shipping which was critical to the North African war effort. In the desert, logistics were paramount and when the supplies flowed, Rommel advanced; when they did not, the Italo-German forces fell back. The losses were serious enough to compel the Germans to dispatch some of their own u-boats to the Mediterranean, adding a new and dangerous foe for the British to deal with, proven when the U-81 managed to sink the only British aircraft carrier in the Mediterranean, HMS Ark Royal, in November. Moreover, German and Italian air attacks on Malta proved to be devastating, eventually wiping out the RAF defenders, forcing the withdrawal of many ships and damaging three submarines.

HMS Unbeaten

Nonetheless, the British boats continued to put up a terrific fight with HMS Upholder sinking the Italian submarine St Bon in January of 1942 and HMS Unbeaten sinking the German submarine U-374 not long after. In March the Upholder sent another Italian submarine, the Tricheco, to the bottom off Brindisi. However, the Germans had developed better detection gear and shared this with the Italians to great effect. The Italian torpedo boat Circe took out two British submarines using the new gear. The Italians also made ever greater use of minefields and this, combined with the sinking of the British minesweepers, ultimately made Malta untenable as a naval base. The island was ripe for the picking, however, it was saved by German Field Marshal Rommel who convinced the high command to call off the invasion in favor of his attack into Egypt. At one point only 12 British boats were on hand in the area and the Royal Navy was more stretched than ever with the Empire of Japan now menacing the British Empire in the Far East. Many of the boats previously stationed in Malta had been transferred from Asia, which was now also under attack.

Dogged determination proved effective though and despite the reduction in numbers in April of 1942, British submarines sank 117,000 tons of Axis shipping along with the Italian cruiser Bande Nere (sunk by HMS Urge), a destroyer and six Axis submarines. It amounted to only 6% of the materials being sent to Rommel in North Africa but, due to the withdrawal from Malta, was significantly more than what the RAF had managed to intercept. British submarines were also being used to carry cargo to keep Malta alive as Italian naval forces prevented much of the surface convoys from landing their supplies. To fight back against this, British submarines were dispatched to prowl outside the main anchorages of the Italian fleet, to attack when possible but also to warn the high command of when they were moving out. The result was a fierce fight for control of the Central Mediterranean with wins and losses for both sides. However, the need for Axis air power on the Russian front gave the British some breathing room and soon more and more Royal Navy subs were posted to the Mediterranean with new flotillas organized in Gibraltar and Beirut.

HMS Urge

The British war effort was also aided by the fact that the increasingly critical fuel shortages meant that the main Italian battlefield was forced to stay in port most of the time and this, combined with the determination of British air and naval forces, meant that Malta was able to be built back up and more Axis shipping to North Africa was sunk. In October of 1942, even while preparing for the invasion of French North Africa, British submarines still sank 12 enemy ships and one destroyer. When the Axis powers began moving men and supplies into Tunsia to counter the arrival of the Americans, British submarines accounted for 16 ships lost while the RAF took out even more. Their actions were making it ever more difficult for the Axis forces in North Africa to be maintained much less take offensive action. By 1943 the Gibraltar flotilla moved to Algeria, Allied air power dominated the Mediterranean and the Axis shipping lanes were devastated with British submarines accounting for 33 Axis ships. In early 1943 the subs destroyed more ships at sea than any other force, surpassed only by Allied aircraft whose successes included ships in port.

Axis power was receding in the Mediterranean and the British boats were at the forefront of the naval victory thanks to men like Comm. J. W. Linton of HMS Turbulent who was killed in action after sinking 90,000 tons of enemy shipping and an Italian destroyer. He was posthumously awarded the Victoria Cross. Comm. George Hunt of HMS Ultor sank more Axis ships than any other British submarine commander at 30 for which he earned the DSO with bar twice. Comm. Ben Bryant was similarly decorated for sinking over 20 Axis vessels as well as numerous warships. With the capture of Sicily by the Allies, the naval war was practically over but, while outpaced by the air forces, Allied submarines, mostly British, accounted for roughly half of all Axis naval losses in the Mediterranean.

HMS Tally-ho

Of course, though less extensive, the Royal Navy submarine force also saw plenty of action in the Far East though they were only able to really establish themselves from August 1943 onward. Based out of Ceylon, their primary area of operations was the strategic Malacca Straits. In November HMS Tally-ho sank a small tanker, the first victory of British subs in Asian waters, but a more significant success was the sinking of the Japanese submarine I-34 by HMS Taurus. By 1944 the Royal Navy was getting back up to strength in East Asia and more submarines were dispatched as well. In January of 1944 HMS Tally-ho, commanded expertly by Lt. Comm. L.W.A. Bennington, sank the Japanese cruiser Kuma and, despite operating in only 15 fathoms of water, managed to escape the counter-attack of its escorting destroyer. Toward the end of the war, targets became scarcer and the Japanese were forced to resort to the use of primitive sailing ships not worth the expenditure of a torpedo. So, British boats, like their American counterparts, began making greater use of their deck gun.

East Asian operations were not as extensive but could still be intense. Lt. Comm. Anthony Collet of HMS Tactician saved a downed American pilot from the USS Saratoga despite being under enemy fire from shore batteries on Sabang and with a Japanese torpedo boat bearing down on them. For this act of heroism, Commander Collet was awarded the Legion of Merit from the United States. More British submarines were dispatched to the region and two new flotillas were organized. Their impact was not negligible and by late October 1944 the British subs had sunk 40,000 tons of merchant shipping, almost 100 small craft as well as a cruiser, three submarines and six smaller warships of the Imperial Japanese Navy. Not too bad. The smaller British subs were also able to operate in areas such as the Java Sea which were too shallow for the larger American boats. By March of 1945 all Japanese shipping in the Malacca Straits area had been virtually eliminated.

HMS Trenchant

In the build-up to the planned Allied assault on the Japanese home islands, British submarines at least 150 small craft but still managed to find some major enemy warships to target too. On June 8, 1945 Comm. A.R. Hezlet of HMS Trenchant spotted the Japanese cruiser Ashigara and fired a spread of eight torpedoes at 4,800 yards. Five hit home and the Ashigara went to the bottom. Perhaps the last really significant victory for the British was the attack on the Japanese heavy cruiser Takao at Singapore by the British mini-sub (XE-craft) XE-3 which earned her commander, Lt. Ian Edward Fraser, the Victoria Cross. The British submarines in East Asia performed very well and took a considerable toll on Japanese shipping while losing only three of their own boats in the process. They had also closed the Malacca Straits to Japanese shipping, choking off the supplies going to the Japanese forces confronting the British in Burma.

Overall, the British submarine force made a significant contribution to the defeat of Germany, Italy and Japan. Early on, they suffered some serious losses and learned some hard lessons against the Germans in the North Sea and the Italians in the Mediterranean. However, they adapted and came roaring back, taking a considerable toll on Axis warships and plaguing the supply lines keeping Rommel and his Italo-German forces in the field in North Africa. One of, if not the most decisive factor in the successful British defense of Egypt was Rommel’s lack of sufficient fuel and supplies and the British submarine force played a major part in that. Once the Mediterranean was secure, Britain was able to focus on East Asia where not much had been left by the American submarine campaign (the most successful in history) and yet, there too, the British boats played a significant part in disrupting the Japanese lines of supply and taking out several major enemy warships. The Royal Navy impact on the surface might have been more significant, and they may not get as much attention as some others but the British submarine force earned a record in battle during World War II that they can be proud of, contributing to the tradition that would carry Britain forward to the present day.