Naval battle during the Second World War
The Battle of the Bay of Biscay or Operation Bernau, was a naval action that took place on 28 December 1943 during the Second World War during the Atlantic campaign. The engagement took place between two light cruisers of the Royal Navy and a force of destroyers and torpedo boats of the that had sailed to rendezvous with a blockade-runner and escort it to port. The British operation was part of the Allied Operation Stonewall to intercept German blockade-runners off the west coast of France. In the confused action that followed the cruisers and sank the torpedo boats , and the destroyer .
Background.
Allied blockade of Germany.
From the start of the war on 3 September 1939, the Allies proclaimed a blockade of Germany to prevent the import of goods. Germany had no rubber, oil, tin and tungsten. Until Operation Barbarossa the German invasion of the Soviet Union, it evaded the blockade via the Trans-Siberian Railway. After the supply route was closed at the start of Barbarossa and after the Japanese entry into the war, German and Italian ships were stranded in Japan and Japanese-occupied Singapore. The ships were used as blockade-runners, sailing to ports in occupied France after mid-1940, when Germany had taken control of the European coast from Norway to the French–Spanish border. From April 1941 to May 1942, 32 ships tried to reach France and 14 succeeded. In 1941 and 1942, German and Italian ships brought in of commodities and exported to Japan. From August 1942 to April 1943 fifteen ships tried to run the blockade and four got through.
Blockade-running.
After sailing from Japan, through the Pacific and the Indian Ocean to the Cape of Good Hope, blockade-runners kept radio silence and passed rearranging points at planned times. When a ship was due, U-boats and aircraft were barred from attacking merchant ships in a lane in the mid-Atlantic, to the north-east from a line level with the Canary Islands, east of the Azores and then east to Bordeaux. Escorts were laid on through the Bay of Biscay and the ships received occasional support further out from U-boats. After the cargo has been discharged, the ship was re-fitted for the next journey.
More accommodation was built for crew and passengers, decks were reinforced, guns and ammunition stores were installed. A minimum of four scuttling charges of up to were placed in the bottom of the hull and armed when the ship sailed with 7–9-minute fuzes; the crew kept their belongings ready in case they abandoned the ship. The vessel went into dry dock to have the hull cleaned to increase its speed and the ship underwent sea trials, sometimes incorporating the delivery of goods to Bassens or to another Biscay port. When ready to sail, the ship waited in the Gironde for an escort of minesweepers. Early in the war, the sailing schedule was little different from a peacetime commercial service.
Ultra.
The defeat of the German U-boat offensive in the Battle of the Atlantic in 1943 was followed by the last attempt by the Germans to pass blockade-runners through the Bay of Biscay to and from the Japanese empire. From May 1943 decrypts of Japanese diplomatic wireless traffic revealed to the Allies that the losses of the 1942–1943 season had not deterred the Axis from making another attempt in the autumn. Seven merchant ships were to sail from Europe carrying of exports and that the Germans were building special U-boats to import of goods from Japan in 1943. In July and August, photographic reconnaissance and agent reports from the French Atlantic ports that sailings for the far East were being prepared and by 6 September it was clear that seven ships were close to sailing.
On 4 October, after the blockade-runner "Kulmerland" had been hit by Allied bombers, a signal from the Japanese Ambassador in Berlin showed the Allies that the export programme had been cut to because of the bombing. On 18 July the British and Portuguese reached a basing agreement for the Azores, which came into force on 8 October and which had the potential to deter the Axis from trying to run the blockade. On 23 October, the Germans introduced new W/T methods for signalling between U-boats and blockade-runners in the Bay of Biscay and in early November "Dresden", thought to be a blockade-runner, struck a mine. The British thought that five ships were preparing to leave the Bay and that four ships were preparing to return from the Far East. Later in November, another decrypt from the Japanese Ambassador revealed that the German export programme had been reduced again, to . US Navy patrols in the South Atlantic were increased.
Prelude.
1943–1944 season.
U-boats were used to transport small amounts of commodities in 1943 while bigger transport submarines were built but by winter German industry would need several shiploads of rubber and other cargoes. Despite the risks several ships would have to be despatched from Japan. There were five motor vessels in Japan and it was thought that if they left at fairly frequent intervals, the Allies might be distracted by the hunt for one and let another slip through their blockades. The ships would be on their own on the voyage but the run through the Bay of Biscay could be assisted by surface ships and aircraft. The five ships would carry of rubber and other goods and sail at intervals that would allow the Biscay escort forces to meet one about out from Bordeaux, escort it to port and then sail to meet the next one. The best time for the attempts to run the blockade would be midwinter 1943–1944.
 ( GRT, code-name , Kapitän Paul Hellmann) of the Hamburg America Line (HAPAG) with of rubber, of tin and of tungsten, sailed from Kobe on 2 October, disguised as the British ship "Prome", rounding the Cape of Good Hope on 15 November. "Osorno" was followed by the refrigerated cargo ship (reefer) (2,729 GRT, code-name , Kapitan Piatek) of the Robert M. Sloman Jr. line of Hamburg, carrying of tungsten; a year's worth of consumption in the German war economy. sailed third on 4 October 1943 from Yokohama; and departed later in the month. Allied spies reported the arrival of the first three ships at Saigon (now Ho Chi Minh City), raising the alarm.
In late December 1943 a "Kriegsmarine" destroyer flotilla, reinforced by six large s, was ordered to the Bay of Biscay to escort the blockade runners "Osorno" and "Alsterufer", which were carrying vital cargo from Japan (Operation Bernau). "Osorno" reached the Gironde on 26 December but struck a wreck in the estuary. She was beached and subsequently unloaded offshore. "Alsterufer", carrying tungsten ("Wolfram") and rubber, was en route to Europe.
27 December.
 Franz Kohlauf sailed from Brest on the morning of 27 December with the torpedo boats , , and . The 8th Destroyer Flotilla ( Hans Erdmenger) put out from the Gironde with destroyers , , and , accompanied by two torpedo boats, ( Wirich von Gartzen) and . By 04:00 the next day the 4th Flotilla was due south of Cape Clear, the 8th Flotilla standing to the south, ready to meet "Alsterufer". Just after noon the torpedo boats turned east, astern of the northernmost destroyers, taking station on their port side.
Plymouth Command.
The Admiralty were also aware of the impending arrival of "Alsterufer" through the decryption of German Enigma messages at Bletchley Park and ordered the nearest ships in the area to intercept "Alsterufer". The closest ship was the light cruiser , which sailed from the Azores on 24 December; it was joined by . had been ordered from Gibraltar, steamed past Lisbon and HMNZS "Gambia" was in the Western Atlantic.
The German flotillas did not know that during the previous afternoon a B-24 Liberator bomber of 311 (Czechoslovak) Squadron had attacked and set "Alsterufer" on fire. Abandoned by her crew, the ship was finished off by Liberators of 86 Squadron. This released the "Glasgow" and "Enterprise", who were about south-west of the German flotilla and were steaming eastwards along the 45th Parallel.
Battle.
Allied aircraft had already reported the position of the German ships around 13:00 on 28 December. About the same time a German Focke-Wulf Fw 200 Condor sighted and attacked both cruisers but was deterred by anti-aircraft fire. The German aircrew immediately turned north-east, reporting the position of the British cruisers more than half an hour later to Erdmenger. Captain Charles Clark on "Glasgow", assuming that he had been reported, turned north-east, working around the position of the German ships to intercept them. The sea was becoming rougher and the wind had increased to , making sailing difficult for the destroyers and torpedo boats.
"Glasgow" sighted the destroyers at 13:32 at a range of . The cruisers attacked at full speed and altered course to cut the German ships off from their base. "Glasgow" opened fire with its 6-inch 'A' and 'B' turrets using her Type 273 radar for ranging and "Enterprise" opened fire a few minutes later. The two leading German destroyers were not hit as shells missed by . "Z23" launched six torpedoes, three from each bank of tubes, when the range was down to but missed. Both destroyers commenced firing with their 15 cm guns and the fall of shot was over on Glasgow's port quarter. At about 14:05, a German shell hit "Glasgow", exploding in 'A' boiler room, killing two members of the port pom-pom crew and wounding six others; "Enterprise" was straddled by near misses.
By 14:18 all of the German ships had engaged; the 4th Torpedo Boat Flotilla attempted several torpedo attacks but was frustrated by the heavy seas. "Z32" and "Z37" turned towards the cruisers, closed to , launching six and four torpedoes respectively. "Glasgow" to make an emergency turn to port as the track of one torpedo passed about from the port quarter and two more near the port side. "Enterprise" had separated from "Glasgow" and acted independently. After the torpedo attack, the destroyers laid smoke and retired towards the flotilla. The German ships were in line, "Z32" followed by "Z24", "Z37", "T23", "T27", "T26", "T22", "T25", "Z27" and "Z25"; "Z32" and "Z37" were off to port during their torpedo attack.
The German force split and "Glasgow" reversed course at 14:35 to chase the northerly group of destroyers; "Enterprise" had already altered course to the west to head them off. The Germans launched another torpedo attack but shortly after "Z27" had fired, it received a shell hit from "Enterprise" in the boiler room, passing through an oil bunker which caused a huge fire. Clouds of steam gushed from the forward funnel as its speed fell off. After being hit, "Z27" fired a salvo of four torpedoes but all missed.
"Glasgow" concentrated on "T25", which received hits near the aft torpedo tubes, the "Flakvierling" and the 3.7 cm flak platforms, which killed or wounded their crews. Another shell demolished the mast and the funnel. "T25" was reduced to a sitting duck and requested "T22" to take off her crew. "Glasgow" changed aim to "T26", which was quickly bracketed by near misses. "T22" had both cruisers on its port side, fired a full spread of torpedoes and gunfire. The torpedoes missed and as "T22" turned to starboard towards "T25", it was bracketed by near misses. "T22" abandoned the rescue attempt after suffering another hit and made smoke, fired her guns and withdrew to the south-west. "T26" was still under fire and was soon severely hit in the boiler room and as "T22" made smoke to screen it, "T26" signalled that she was sinking; "T22" turned away northwards.
The cruisers reversed course, soon catching "T26". "Enterprise" was ordered to sink it and "Glasgow" turned north again to search for damaged vessels, particularly "T25". "Glasgow" soon came across "Z27", drifting and silent. Closing to point-blank range, "Glasgow" hit the destroyer's magazines. A large explosion killed Erdmenger, his staff and the captain. "Enterprise" finished off "T26" with a torpedo and then attacked "T25", whose bridge and upper deck and aft superstructure were wrecked. "Enterprise" closed to , firing guns and firing a torpedo; "T25" was abandoned soon after, burning and sinking.
The cruisers converged and seeing no sign of the German squadron and after having sunk three ships for only minor damage, headed for Plymouth. The ships arrived on the evening of 29 December, low