Another try - this one fits better ...
On January 12, 1950 the submarine HMS Truculent was returning to Sheerness, having completed trials after a refit at Chatham. In addition to her normal crew, she was carrying an additional 18 dockyard workers.
HMS Truculent was travelling through the Thames Estuary when she collided with the Swedish oil tanker, the Divina, and sank to the bottom of the river.