Type U 151 submarine

Type U 151 U-boats were a class of large, long-range submarines initially constructed during World War I to be merchant submarines and later used by the Kaiserliche Marine (Imperial German Navy).

Background
In addition to the cargo-carrying submarines GS Deutschland and GS Bremen (disappeared on a cargo voyage in 1916 while it was still a merchant submarine), six further large cargo submarines were ordered, originally designed to ship material to and from locations otherwise denied German surface ships, such as the United States.

On 16 December 1916, four under construction in the Reiherstieg and Flensburger Schiffbau yards were taken over by the navy and converted to military specification as Type U 151 U-boats, being designated SMU U-151 to SMU U-154. The remaining two, along with Deutschland, which became SMU U-155, passed into naval control in February 1917, as SMU U-156 and SMU U-157.

All were fitted with two bow torpedo tubes and could carry 18 torpedoes, with the exception of the former Deutschland, which was fitted with six tubes. All were armed with two 15 cm SK L/45 deck guns, and carried a crew of 56. They had a cruising range of around 25000 nmi.

The success of the Type U 151 submarines led to "Project 46", the larger Type U 139 "U-cruisers", designed from the outset as military submarines.

Service
Deutschland made two successful commercial voyages before being commissioned into the Kaiserliche Marine on February 17, 1917, as U-155.

Max Valentiner commanded a Type U 151 U-boat, SMU U-157, and undertook the longest cruise in the war from 27 November 1917 to 15 April 1918, a total of 139 days. High-scoring Waldemar Kophamel also commanded a Type U 151 U-boat, SMU U-151 in late summer and fall of 1917.

List of Type U 151 submarines
Seven Type U 151 submarines were built, of which six were commissioned into the Kaiserliche Marine.


 * SMU U-151
 * SMU U-152
 * SMU U-153
 * SMU U-154, sunk by HMS E35
 * SMU U-155, the former merchant submarine Deutschland
 * SMU U-156, probably lost to a mine in September 1918
 * SMU U-157