The action of 8 May 1941 was a single ship action fought during the Second World War by the British heavy cruiser and the "Kriegsmarine" (German Navy) auxiliary cruiser / (Raider F to the Admiralty). The engagement took place in the Indian Ocean off the Seychelles archipelago, north of Madagascar. "Pinguin" caused slight damage to "Cornwall", before its fire on "Pinguin" caused an explosion and sank it.
A British sailor was killed and about c. 200 of the 222 British and Indian Merchant Navy prisoners on "Pinguin", captured from over thirty merchant vessels, were also killed. Of the crew of 401 men, 323 were killed and 60 were rescued along with 22 of the Merchant Navy prisoners. "Cornwall" returned to Durban for repairs until 10 June.
Background.
HMS "Cornwall".
"Cornwall" (Captain Percival Manwaring) was a heavy cruiser of the "Kent" subclass, built in the mid-1920s. It had a displacement of , carried eight guns in four twin turrets, four anti-aircraft guns in two twin turrets, two four-barrelled 2-pounder pom-pom guns and two machine guns. "Cornwall" had an aircraft catapult, three Supermarine Walrus amphibious aircraft and had a maximum speed of .
"Pinguin".
The auxiliary cruiser "Pinguin" ( Ernst-Felix Krüder), was originally the freighter "Kandelfels", which had been launched in 1936. After conversion to an auxiliary cruiser it became to the . "Pinguin" was armed with six guns, a gun, two anti-aircraft guns, four autocannon, two torpedo tubes, 300 mines and an Arado Ar 196 A-1 floatplane. By 15 January, "Pinguin" ("Raider F" to the British) had captured 14 Norwegian merchant vessels by commerce raiding. It had captured three factory ships and eleven whalers belonging to the same whaling company. The prizes were sent to Occupied France where one was renamed and was used as minelayer for the German raiders in the South Atlantic and the Indian Ocean. In April, "Pinguin" sank three British merchant ships in the Indian Ocean, close to the Equator.
Prelude.
 Cape Guardafui
After sinking "Clan Buchanan" on 28 April, "Pinguin" sailed north-west and on 4 May, fuelled and provisioned "Adjutant", which was sent away to wait at a rendezvous near the Saya de Malha Bank. Just after 5:00 a.m. on 7 May, "Pinguin" intercepted and sank the tanker "British Emperor", which was on passage from Durban to Abadan, about east-south-east of Cape Guardafui. "Emperor" had sent a distress message and "Cornwall", en route to refuel at the Seychelles Islands, intercepted the message when about south of the attack. "Cornwall" altered course to north-north-west and increased speed to . A plan was devised to catch the raider, using the Walrus spotter aircraft carried by "Cornwall" to close the raider's "furthest on" line and then search to cover the largest potential variations of the raiding ship's speed and course.
"Cornwall" increased speed to , heading north between the Seychelles and the Chagos Archipelago. Vice-Admiral Ralph Leatham, the Commander-in-Chief East Indies Station, ordered other ships to participate in the search. was sailing westwards at from Nine Degree Channel towards Socotra, while , which was north of Cape Guardafui, sailed for Eight Degree Channel, making for Colombo. , steaming from the Gulf of Aden, passed Cape Guardafui that morning at , to a position about south-east of the headland. The ship then turned south-west at towards the Equator, about from the African coast. Farther west, the armed merchant cruiser , patrolled from the Equator to a position to the south-west.
On the afternoon of 7 May, the two aircraft on "Cornwall" flew reconnaissance sorties for three hours and then altered course to get on the line of the main "Vignot" search. This was plotted for a mean speed of for an hour after the time of the raider report, assuming that the raider needed an hour to sink "British Emperor" and then depart at full speed until dark. At 9:30 p.m., "Cornwall" turned onto a bearing of east-south-east and slowed to search on this line, before the moon set. At dawn, "Cornwall" sent both aircraft to search an area three knots on either side of the raider's estimated speed and turned east at (steaming away from the raider). At 7:07 a.m. on 8 May, one of the aircraft sighted a ship heading south-west at , about west of "Cornwall" but did not report the sighting until landing at about 8:00 a.m. At 8:25 a.m., "Cornwall" altered course to about west-by-south and increased speed to . The second aircraft was launched again at 10:15 a.m. and at 12:23 p.m. it reported that the unknown ship was steaming at and had hoisted the signal letters of a Norwegian motor-vessel "Tamerlane", which the raider resembled but was not on the list of expected ships.
Battle.
"Cornwall" increased speed to then to . At 1:45 p.m., an aircraft was launched to give the bearing, course and speed of the suspected ship by wireless; the ship became visible from "Cornwall" at 4:07 p.m. The ship began transmitting "raider reports", claiming to be "Tamerlane". Despite orders to heave-to and two warning shots, the ship maintained course and speed for more than an hour, until the range was fewer than yards. At 5:10 p.m., "Cornwall" turned to port and the suspected raider made a larger turn to port, opening fire with five guns just before 5:15 p.m.
Due to mechanical failures, "Cornwall" did not return fire for about two minutes and was frequently straddled by shells fired at a rapid rate, before firing two salvoes from the forward 8-inch turrets. The fore steering gear of "Cornwall" was disabled by a 5.9-inch shell hit and after going out of control for a moment, the after steering gear used. By 5:18 p.m., all of "Cornwall's" guns had opened fire, with the advantage of superior range finders and director fire-control systems, instead of local gun control. A salvo hit "Pinguin", which blew up at 5:26 p.m. and sank north of the Seychelles, about from where it had sunk "British Emperor".
Aftermath.
Analysis.
The commerce-raiding voyage of the "Pinguin" had lasted from 22 June 1940 – 8 May 1941 and the ship sank or captured 28 ships of 136,642 GRT. About 50,000 GRT of shipping was sent to Germany as prizes. "Cornwall" returned to Durban for repairs until 10 June; the tactics of the captain of "Cornwall" in shadowing, attempted to identify and closing with "Pinguin" was criticised by the Admiralty. The crew of "Pinguin" had been skilful in disguising the ship and it was difficult to approach a suspicious, yet unidentified ship. A raider had the tactical advantage in deciding when to open fire, before it was unmasked and investigating ships courted danger if the vessel approached from a direction favourable to a raider's guns and torpedoes. Allied ships were given secret call signs and a system was devised for the investigating ship to refer to the Admiralty by wireless to verify ship identities. The new methods made ship identification much easier but took months to implement and similar events occurred when ships were either allowed to sail on and turned out to be raiders or were intercepted and sprang a surprise on the British warship.
The success against "Pinguin" and other raiders was due to the navy Operational Intelligence Centre (OIC) of the Naval Intelligence Division, at the Admiralty. The OIC tracked raiders, based on the position of the sinking of Allied merchant ships and by collating rare sightings and distress signals. German commerce-raiders kept radio silence, avoided common shipping routes, searched for independently routed vessels and tried to prevent their victims from transmitting wireless messages. From May to November 1941, the Germans lost "Pinguin" and two more commerce raiders but Enigma decrypts by the Government Code and Cypher School (GC&amp;CS) were only involved in one sinking.
German commerce-raiders used the (Home Waters) Enigma settings, known as "Dolphin" to the British, before departing and when returning to Germany. The seven raiders at sea in May 1941 had sailed in 1940 before Enigma intelligence became available to the British. When at sea, Enigma-equipped raiders used the settings if they broke radio silence, which Hut 4 at Bletchley Park never managed to penetrate. "Atlantis", the third raider lost in 1941, was sunk by on 22 November after the British read U-boat signals in the setting, introduced in October 1941, to arrange a re-fuelling rendezvous.
Casualties.
A British sailor, near the stern of "Cornwall", was killed when "Pinguin" opened fire. Among the men on "Pinguin" were 222 British and Indian merchant sailors, captured from over thirty merchant vessels. Of the crew of 401 men, the captain and 322 others were killed and 60 were rescued, along with 22 of the Merchant Navy prisoners.
Footnotes.
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Bibliography.
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