HM Submarine Trenchant
Trenchant was ordered under the 1941 building programme and laid down on 9 May 1942. Originally called P331 she was renamed Trenchant in February 1943. She was the third vessel to have the name, the first was in 1916.
Trenchant was launched on Wednesday 24 March 1943 by Lady Danby. Following the launch, she moved from the river into the basin at 1550 via the south lock.
Trenchant was completed on 29th January 1944 and left Chatham on 13th February 1944.
Following her workup, she sailed for the Far East on 15 May 1944.
After spending most of July in Trincomialee, she sailed for her first war patrol on 25th July.
In August 1944 with the submarine Terrapin she patrolled the coast of Sumatra on air sea rescue duties. This was for the American bombing attack on oil refineries at Palembang. While on this patrol she attacked and sank by gunfire, a fishing boat and motor launch. On 22 August she was back on rescue duties for a carrier attack on Sabang.
On 5th September Trenchant sailed for the north and east coast of Sumatra. The mission was to land commandoes who would blow up a bridge over the river Podada. The successful landing and attack was made on 12th September. She then moved on to lay mines in Aru Bay on the 16th. Many months later, this minefield claimed two ships of 2800 tons in total. Three days after laying the mines, she rammed and sank two junks. Trenchant then crossed the Malacca Strait to Penang where she carried out a successful torpedo attack sinking U859. Lt Commander Hezlet received the DSO for this attack. During October 1944 Trenchant sailed with two chariots secured to her saddle tanks. These were used on the successful raid in Phuket harbour. Two ships totalling over 10,000 tons were attacked, one sunk and the other damaged beyond repair. On her return to base she sank, by gunfire, a junk.
In early December 1944, Trenchant and Terrapin became the first British submarines to work as a wolf-pack. During this patrol Trenchant sank four junks before both boats joined together for a gun action against a Japanese coastal lookout position.
In February 1945, both boats worked together again. Early into the patrol, Trenchant sank by gunfire, a coaster, three lighters a tug and a junk. On March 4th both boats successfully attacked by gunfire a Japanese Submarine Chaser.
In June 1945 Trenchant attacked and sank the Japanese Cruiser Ashigara. Lt Commander Hezlet latter received a bar to his DSO for this attack. This attack proved to be the last significant sinking of a warship by a British submarine during WWII.
In July Trenchant was ordered back to Fremantle. On the way she managed to sink a motor launch, a tug and a landing barge, all by gunfire.
Following the Japanese surrender Trenchant remained on station until October 1945 when she received orders to return to the UK.
Trenchant continued in service until 1961 when, on 19 September, she returned to Chatham, moving into the basin at 0820. Here she remained until 19 July 1963 when she sailed for the scrap yard at the Gareloch.