SM U-156

SM U-156 was a German Type U 151 U-boat commissioned in 1917 for the Kaiserliche Marine. From 1917 until her disappearance in September 1918 she was part of the U&#8209;Kreuzer Flotilla, and was responsible for sinking 44 ships and damaging 3 others, including a warship. She took part in the Bombardment of Orleans.

Background
The U-156, built by the Atlas Werke in Bremen, was originally one of seven Deutschland class U-boats designed to carry cargo between the United States and Germany in 1916. Five of the submarine freighters were converted into long-range cruiser U-boats (U-kreuzers) equipped with two 105mm deck guns, including the U-156. They were the largest U-boats of World War I.

Service history
U-156 was launched on 17 April 1917 and commissioned on 22 August 1917 under Konrad Gansser, who commanded her until 31 December 1917, following which Richard Feldt took command of her on 1 January 1918.

On 15 June 1918 the U-156 sailed with 77 crew. She passed through the North Sea, negotiated the Northern Passage around the northern end of the British Isles, and out into the Atlantic Ocean where she sailed for Long Island. She then proceeded to New York Harbor, where she had been ordered to lay mines. Records show that she was to lay a field of mines in the shipping lane along the south shore of Long Island, just east of the Fire Island lightship.

A mine laid by the U-156 is often credited with the loss of the cruiser USS San Diego on 19 July 1918, ten miles southeast of Fire Island.

The U-156 had meanwhile headed north to attack the US fishing fleet. She sank 21 fishing boats in the Gulf of Maine area, from Cape Cod to the Bay of Fundy, ranging from the 72 ton schooner Nelson A. (4 August) to the 766 ton Dornfontein (2 August).

On 20 August, the U-156 captured the Canadian trawler Triumph southwest of Canso, Nova Scotia. They manned and armed the vessel, and used it in conjunction with the submarine to capture and sink seven other fishing boats in the Grand Banks area, before eventually scuttling her.

Fate
On 25 September 1918 the U-156 failed to report that she had cleared the Northern Passage around the United Kingdom on her return voyage to Germany and was presumed to have struck a mine of the Northern Barrage minefield.

Rene Bastin, a prisoner on the U-140, claimed to have witnessed the fate of the U-156. He said that he was on the bridge of the U-140 while she was running the Northern Barrage in company with U-100, the U-102, the U-117 and U-156 when he suddenly saw the U-156 blown up. He claimed that she was "blown 500 feet in the air". However, Bastin gave the date of this event as 22 October 1918, which was almost a month after the return to Germany of the U-140, the submarine aboard which he was held captive. Additionally, the U-140 never met up with the U-156 and crossed the Northern Barrage with only the U-117 for company on 17 September.