The Rosemount, a steel hulled steamship laden with a cargo of 3100 tons of timber, 276 hp, two boilers, 3044 GRT, built 1905 Northumberland S. B. Co. Ltd. Newcastle, England. Armed with one 12 pounder 8 cwt gun, Operated by Seville & United Kingdom Carrying Co. Ltd. (Owner: J. Cory & Sons Ltd). Cardiff, Wales. Registered in Cardiff, Wales. Commanded up to at least 1915 by Captain S. Cook, who is presumed to still have been in command at the time of this incident.
This vessel in passage from Archangel, Russia, for Sharpness, Gloucestershire, England. via Lerwick was steering a zigzag course when the German submarine U101, Captain Karl Koopmann, was observed approx 5-6 miles away at a position approx 45 miles NE by N of Muckle Flugga, Unst on August 6th 1917. The submarine opened fire at 6.40am, with the Rosemount replying with her own gun, but the submarine was out of range. A smokescreen was laid down by the vessel but the submarine still managed to score hits from 7.45am, and at 8.05am with both vessels exchanging fire, a shell wrecked the bridge of the Rosemount fatally injuring the helmsman, and injuring the Captain. Further hits set the deck cargo on fire, and the order to stop the ship and take to the lifeboats was given at 8.20am, the injured helmsman dying in one of them approx 15 mins later.
Continuing to shell the vessel, the submarine closed in and fired a single torpedo in to her, before approaching the lifeboats and demanding the ship's papers. These, they were told had been destroyed, but a wages book was handed over. The submarine then fired a second torpedo in to the vessel. She was not observed to sink, but it is presumed she did so at or near the given position.
The survivors were picked up by the fishing trawler Scorpion at 6am on August 7th and subsequently landed at Lerwick.