Thor (HSK 4) was an auxiliary cruiser of Nazi Germany's Kriegsmarine in World War II, intended for service as a commerce raider. Also known to the Kriegsmarine as ; to the Royal Navy she was Raider E. She was named after the Germanic deity Thor.
Early history
Formerly the cargo ship Santa Cruz, she was built by Deutsche Werft, Hamburg, (DWH) in 1938, and was owned and operated by the Oldenburg Portuguese Line (OPDR), Hamburg. In the winter of 1939–40 the navy requisitioned her and had her converted into an auxiliary warship by DWH. She was commissioned as the commerce raider Thor in March 1940.
First cruise
Thor began its first combat cruise on 6 June 1940, under the command of Captain Otto Kähler. Thor spent 329 days at sea, and sank or captured 12 ships with a combined tonnage of .
Thor stopped her first victim on 1 July, the 9290-ton Dutch cargo ship Kertosono, which was carrying a cargo of petrol, timber, asphalt, and agricultural machinery. Kähler decided to send her under a prize crew to Lorient, France, where she arrived safely 12 days later. At the time, Thor was disguised as a Yugoslavian freighter.
On 7 July Thor encountered Delambre, a 7,030 GRT British freighter. Thor fired several broadsides, the third of which hit Delambre, stopping her dead in the water, after which Thors boarding party scuttled the ship with demolition charges.
Two days later Thor intercepted the Belgian freighter Bruges, which was carrying a cargo of wheat. Bruges was scuttled, and her crew of 44 was taken aboard Thor. On the 14th, Thor stopped another freighter carrying wheat, the British Gracefield, and sank her by demolition charges.
On 16 July Thor attacked the British freighter Wendover without warning, as Wendover was seen to be armed. Wendover was hit by several shells from Thor and set on fire. A boarding party set demolition charges which caused Wendover to capsize, and she was then sunk by gunfire. 36 of the Wendover's crew of 40 survived: two crew including the radio operator were killed in the attack; two more were wounded and died of their injuries while aboard Thor.
The Dutch freighter Tela, en route to the UK, was intercepted on 17 July. Thor fired a shot across her bow; she stopped without sending distress signals. The crew of 33 abandoned ship and were taken aboard Thor, and Tela was sunk by demolition charges.
On 28 July, Thor encountered the British armed merchant cruiser HMS Alcantara, which was armed with eight six-inch (150 mm) main guns. Kähler turned away from Alcantara and tried to outrun her for three hours until he realized Alcantara was faster than Thor. At that point Kähler decided to turn and fight, hoping to inflict enough damage on Alcantara to allow Thor to escape. Thor scored three early hits on Alcantara: one between her bridge and funnel, a second aft, and a third on her waterline that caused flooding in her engine room, forcing Alcantara to reduce speed. Thor turned away from Alcantara and received two hits from her six-inch guns, killing three crew members. Instead of risking further combat, Thor made her escape under cover of a dense smokescreen.
After the battle with Alcantara, Thor repaired her battle damage, cleaned her boilers and changed her disguise. Thor rendezvoused with the supply ship Rekum on 25 August and then returned to Brazilian waters. Two weeks later, on Sept 8, the Yugoslav Federico Glavic was stopped, but allowed to proceed unmolested, as Yugoslavia was neutral at the time. On 26 September Thors float plane discovered the Norwegian whale-oil tanker Kosmos, which was carrying over 17,000 tons of whale oil. The Kosmos would have been a highly valuable prize ship, but the fact that she was short of fuel, slow, and easily recognizable made keeping her as a prize unfeasible. Kähler ordered Kosmos to be sunk by gunfire.
On 8 October Thor caught the 8,715-ton British refrigeration ship Natia. Thor scored a direct hit, which stopped Natia dead in the water, though she continued wireless transmissions. Thor hit Natia seven or eight more times with gunfire, and a torpedo that tore open her side. Another 35 rounds were fired before she sank. 84 of Natia's 85 crew were taken aboard Thor, bringing her total to 368. Most of these prisoners were transferred to the supply ship Rio Grande in mid November.