SM UB-4 - Service Career

Service Career

The submarine was commissioned into the German Imperial Navy as SM UB-4 on 23 March under the command of Oberleutnant zur See Karl Gross, a 29-year-old first-time U-boat commander. UB-4 soon joined the other UB I boats then comprising the Flanders Flotilla (German: U-boote des Marinekorps U-Flotille Flandern), which had been organized on 29 March. When UB-4 joined the flotilla, Germany was in the midst of its first submarine offensive, begun in February. During this campaign, enemy vessels in the German-defined war zone (German: Kriegsgebiet), which encompassed all waters around the United Kingdom (including the English Channel), were to be sunk. Vessels of neutral countries were not to be attacked unless they definitively could be identified as enemy vessels operating under a false flag.

UB-4 kicked off operations for the new flotilla when she departed on her first patrol on 9 April. The following day, she sank the first ship credited to the Flanders Flotilla. The 5,940-ton British-flagged Harpalyce, which had been chartered by the American Commission for Relief in Belgium, was headed for Norfolk, Virginia, United States, in ballast after delivering relief supplies to Rotterdam. UB-4 came upon the steamer between Harwich and the Hook of Holland and pulled to within about 100 yards (91 m). Despite the fact that the ship had a pass of safe-conduct from Germany, was marked with the words "Belgian Relief" on her side, and was flying a white flag with the same wording, Gross torpedoed the vessel without warning. Harpalyce sank in about five minutes, which allowed no time to launch any of the lifeboats. The Dutch steamers Elisabeth and Constance, and the American steamer Ruby picked up survivors. Herbert Hoover, head of the relief committee, reported that his organization's charter of the ship ended after delivery of the cargo in Rotterdam, but expressed disbelief that the ship could have been the victim of a torpedo attack, given the "distinct assurance" that ships engaged in the relief effort "would not be molested". Harpalyce's master and 14 others from the 44-man crew died in the attack. Harpalyce was the largest ship sunk by UB-4 during her career.

UB-4's followed up the sinking of Harpalyce by sinking the Greek ship Ellispontos, a steamer of 2,989 gross register tons (GRT). Ellispontos was en route to Montevideo from Amsterdam when sunk by Gross and UB-4 on 17 April. Although German U-boats sank over 100,000 tons of shipping in each of May and June, UB-4 did not contribute to those totals. She did add one ship to the 98,000-ton tally for July when she sank the Belgian ship Princesse Marie Jose and her load of coal on 29 July. The 1,954-ton steamer had sailed from Dunston and was headed to Bordeaux when sunk 1.5 nautical miles (2.8 km) from the Shipwash Lightship off Harwich.