SM UB-16 - Conversion To Minelayer

Conversion To Minelayer

UB-16 and three sister boats, UB-10, UB-12, and UB-17, had all been converted to minelaying submarines by 1918. The conversion involved removing the bow section containing the pair of torpedo tubes from each U-boat and replacing it with a new bow containing four mine chutes capable of carrying two mines each. In the process, the boats were lengthened to 105 feet (32 m), and the displacement increased to 147 metric tons (162 short tons) on the surface, and 161 metric tons (177 short tons) below the surface. Exactly when this conversion was performed on UB-16 is not reported, but UB-12 was at the dockyard from November 1916 to January 1917. The lack of reported successes by UB-16 during this same span makes it a possibility that her conversion was accomplished in a similar timeframe.

On 13 March, UB-16, now under the command of Oblt. Rudolf Stier, was responsible for sinking the 895-ton steamer Lisette near the Shipwash Lightship. One month later, on 13 April, the fishing smack Ruth was boarded and sunk by UB-16; Ruth was the final ship sunk by UB-16.

On 28 April, British forces attempted to block the canal at Zeebrugge and bottle up the vessels of the Flanders Flotilla in the Zeebrugge Raid. In the raid, the British succeeded in sinking two obsolete cruisers, Iphigenia and Intrepid, in the narrowest part of the canal. British admiral Roger Keyes, who had planned the raid, believed that the Flanders Flotilla ships were bottled up for a long period of time. However, the following day, after the Germans had removed two piers, UB-16—under Oblt. Vicco von der Lühe, her newest commander—made the first sortie from Zeebrugge after the raid.