All three Thames Class submarines served in the Second World War and, although misemployed in the North Sea and, Mediterranean, were certainly successful, but no more so than other British submarines of the period that cost half as much to build and operate. Oddly, these submarines were never used with the surface fleet, as was intended, and perhaps the highlight of their war career was the vital cargo mission to Malta in September 1941 by Clyde, carrying no less than 1200 tons of desperately needed stores.
Thames was lost on active service off the coast of Norway on 23rd September, 1940. Although the cause was unconfirmed, it is likely that she was mined. The Severn and Clyde were taken out of service whilst on duty in the Far East - in April 1945 and October 1945 respectively.
