SMS Vulkan was a U-boat salvage tug in the Kaiserliche Marine laid down in 1907 and commissioned 1908. The ship displaced 1595 tons and had a top speed of 12 knots. The famous U-boat ace Max Valentiner served as salvage officer on Vulkan in early 1911. On 17 January 1911, he and the crew saved all 30 men from U-3 by getting them out of the torpedo tube after it was sunk near Kiel harbour in Heikendorfer Bay because of an unclosed valve in the ventilation shaft. Amongst the saved crew was Otto Weddigen, the later commander of U-9 and Paul Clarrendorf, the commander of U-boot-Abnahme-Kommando in Kiel which enlisted u-boat crews.