U-156 was
launched on 17 April 1917 and
commissioned on 22 August 1917 under the experienced U-boat ace Konrad Gansser, who commanded her until June 1918, following which Richard Feldt took command until the U-156 was lost in September 1918. On 17 January 1918,
U-156 entered isolated Naos Bay in the Spanish Canary Islands. She was scheduled to meet with sister
U-157 and a small Spanish flagged merchant vessel in an attempt to transit prohibited materials past the British blockade to Germany. The British learned of the meeting through decoded signals and ambushed the
U-156 in a failed attempt to sink her. The British submarine actually hit the
U-156 with a torpedo but the torpedo had failed to explode. On 15 June 1918,
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. On 8 July 1918
U-156 stopped and scuttled the Norwegian owned
Manx King at , which was traveling between New York and Rio de Janeiro. Captain
Rasmus Emil Halvorsen and her crew were rescued from the lifeboats after 27 hours by DS
Anchites of Liverpool, England. A mine laid by
U-156 is often credited with the loss of the cruiser
USS San Diego on 19 July 1918, ten miles southeast of
Fire Island, New York. On 21 July 1918
U-156 opened fire on a beach and marsh within the boundaries of the American town of
Orleans, Massachusetts, and several nearby merchant vessels. The bombardment of the beach may have been a case of overshooting the targeted maritime vessels. In the end,
U-156 severely damaged a tugboat and sank four barges.
HS-1L flying boats and
R-9 seaplanes were dispatched from the Chatham Naval Air Station and bombed the enemy raider with bombs that failed to explode, through either mechanical failure or lack of experience on their bombardiers.
U-156 returned fire with her deck guns in an unsuccessful attempt to down the aircraft. It was the first time in history that American aviators engaged an enemy vessel in the western Atlantic. The
Attack on Orleans was the only
Central Powers raid mounted against the United States
mainland during
World War I and the first time the Continental United States was shelled by a foreign power's artillery since the
Siege of Fort Texas in 1846.
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 ton schooner
Nelson A. (4 August) to the 766 GRT
Dornfontein (2 August).
U-156 was credited with the sinking of the tanker
Luz Blanca, just off the headlands of Halifax on August 5/1918. On 20 August,
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. On 21 August,
U-156 was about to attack some fishing boats off
Nova Scotia when
HMCS Hochelaga which escorted 4 ships intervened. However,
Hochelaga 's skipper, Lieutenant R.D. Legate, ordered his ship to turn around towards the ships escorted, instead of attacking the submarine. Back in port he was arrested, court marshaled and dishonorable discharged from the navy. ==Fate==