Completed in May 1905 as German Harald Horn for H.C. Horn, Schleswig. 1905 transferred to Fruchtdampfer AG, Lübeck. 1908 registered in Russia as Christian for AG für mechanische Holzbearbeitung A.M. Luther, Reval. On 29 Aug, 1917, requisitioned as transport No. 32 by the Russian Imperial Navy and assigned to the Baltic Fleet. Came under Soviet control and was renamed Proletarij by the Glavnogo Upravleniya Vodnogo Transporta (Glavvod) in July 1918. 1924 assigned to the Baltic Office of Sovtorgflot (STF-BGK). 1934 transferred to Severnoje Gosudarstvennoe Morskoe Parokhodstvo (SGMP) and 1939 to Murmanskoe Gosudarstvennoe Morskoe Parokhodstvo (MGMP), Murmansk. On 15 Aug, 1942, requisitioned as transport by the Soviet Navy and assigned to the Northern Fleet.

At 00.15 hours on 5 Dec, 1944, the Proletarij (Master P.G. Izhmyakov) in convoy PK-20 was hit on the port side by one FAT torpedo from U-995 about 15 miles north of Tsyp-Navolok Cape. At 02.03 hours, the ship was probably again hit by a torpedo in grid AC 8579 and sank within 30 seconds in grid AC 8821 after being hit by a coup de grâce at 04.16 hours. The crew of 33, ten gunners and 13 passengers (military personnel) abandoned ship, but many of them drowned or froze to death after their lifeboat capsized upon launch. Others died of exposure after swimming to rafts or another boat before they could be rescued by MO-426 which picked up the survivors including the master, but he and another crew member died of hypothermia. In all, 21 crew members, six gunners and two passengers were lost.