German submarine U-135 (1941)

German submarine U-135 was a Type VIIC U-boat of the Nazi German Kriegsmarine during World War II.

She was laid down at the Vulkan-Vegesackerwerft in Bremen on 16 September 1940 as 'werk' 14, launched on 12 June 1941 and commissioned on 16 August with Oberleutnant Friederich - Hermann Praetorius in command.

U-135 began her service career in training with the 5th U-boat Flotilla, before moving on to the 7th flotilla for operations.

Operational career
The boat sank three ships totalling and damaged a fourth of 4,762 GRT.

1st and 2nd patrols
The submarine's first patrol began with her departure from Kiel on 24 December 1941. Her route took her across the North Sea and into the Atlantic Ocean via the passage between the Orkney and Shetland Islands. As part of wolfpack 'Ziethen', she sank the Gandia on 22 January 1942 420 mi east of Cape Race, (Newfoundland). She arrived at St. Nazaire in occupied France on the 31st.

Her second foray was northeast of Iceland, but she returned to another port, Brest, on 3 April 1942.

3rd and 4th patrols
Her third sortie was her longest, at 71 days. Having departed Brest on 26 April 1942, she sank the Fort Qu Appelle on 17 May north of Bermuda. She also sank the Pleasantville on 8 June northwest of Bermuda before returning to St. Nazaire on 5 June.

U-135 discovered and shadowed convoy ON 122 during her fourth patrol, and was able to remain on patrol following heavy damage received when attacked with depth charges and Hedgehog by HNoMS Potentilla and HMS Viscount. The boat was later attacked by a Czech-crewed Vickers Wellington aircraft of No. 311 Squadron RAF on 3 October 1942 in the Bay of Biscay. Only minor damage was sustained, but one man was killed and another died of his wounds.

5th and 6th patrols
Her fifth sortie took her across the Atlantic, almost to the coast of Newfoundland.

U-135's sixth patrol was toward Greenland; she was attacked by a British B-24 Liberator of 120 Squadron northeast of Ireland on 8 February 1943. Some damage was repaired, but the boat was forced to return to Lorient on 10 March when further leaks were discovered.

7th patrol and loss
For her last patrol, she left Lorient on 7 June 1943. Northeast of the West Indies, she attacked and damaged the Twickenham on the 15th. She then moved to the east Atlantic where she was attacked by the sloop HMS Rochester, the corvettes HMS Migonette and Balsam and a US PBY Catalina flying boat of VP-92. U-135 was sunk east of the Canary Islands on 15 July. Five men died, there were 41 survivors.