German submarine SM UC 53 sunk several merchant ships in August according to the Kriegsnachrichten of the Chef des Admiralstabes der Marine dated Berlin 18 August 1917

German submarines UC 16-79©Warshipsresearch.blogspot.com

An item reported that the German submarine SM UC 53 commanding officer Kapitänleutnant Albrech had torpedoed and sunk in August 5 sailing vessels loaded with sulfur and phosphate.(1)

Note

1. Ordered on 12 January 1916, launched by Germaniawerft, Kiel, Germany with yard number 269 on 27 February 1917, commissioned on 5 April 1917 and scuttled at Pola [nowadays Pula, Croatia] on 28 October 1918.

Source

Bundesarchiv RM-40-622