The Welman submarine was a Second World War one-man British midget submarine developed by the Special Operations Executive. It only saw action once and was not particularly successful. Designed by the Commanding Officer of SOE's Inter Services Research Bureau (ISRB), Lt Col. John Dolphin, as a method of delivering a large explosive charge below an enemy ship, the Welman was a submersible craft in length (including explosive charge), weighing about . Unlike the "Chariot" human torpedo, the operator was enclosed within the craft, and did not need to wear diving gear. The Welman could transport a time-fused explosive charge of Torpex, which was intended to be magnetically attached to a target's hull. Vision was through armoured glass segments in the small conning tower, and no periscope was fitted. Following trials in the Queen Mary Reservoir near Staines towards the end of 1942, the Welman was put into production, the production being contracted out to Morris Motors Limited's requisitioned factory at Oxford. Despite the craft's inability to cut a way through anti-submarine nets (which both X class submarines and Chariot manned torpedoes could do) and the poor visibility available to the crewman, 150 production examples were ordered in February 1943. Production was halted in October 1943 when operational research showed the concept suffered from too many disadvantages, by which time some 100 examples had been produced (precise numbers are unknown). In early 1943 the Royal Navy establishment on board the submarine depot ship HMS Titania was expanded to carry out sea trials of the Welman. Training courses for operators were located at Fort Blockhouse in Gosport. Trainees were drawn from the Royal Navy, the Royal Navy Reserve, and other Special Forces groups which included the Special Boat Section of the Commandos. HMS Titania was relocated to Loch a' Chàirn Bhàin, south of Cape Wrath, in the north west of Scotland, which became a secret training base for all mini submarine operations.