XE class submarine

XE4 in Sydney Harbour, 1945
Class overview
Operators:	Royal Navy
Preceded by:	X class
General characteristics
Displacement:	30.25 tons surfaced 33.5 tons submerged
Length:	53.25 ft (16.23 m)
Beam:	5.75 ft (1.75 m)
Draught:	5.3 ft (1.60 m)
Propulsion:	Single shaft One Gardner 4-cyl diesel engine 42 hp (31.3 KW) @1800 rpm One Keith Blackman electric motor 30 hp (22.3 KW) @1650 rpm
Speed:	6.5 knots (12.0 km/h) surfaced 5.5 knots (10.1 km/h) submerged
Range:	500 nm (926 km) surfaced 82 nm (152 km) @ 2 kts submerged
Test depth:	300 ft (90 m)
Complement:	4–5
Armament:	Two × 4,400 lb detachable explosive charges

Six XE-class midget submarines (HMS XE1 to XE6) were built for the Royal Navy during 1944. They were an improved version of the X Class midgets used in the attack on the German battleship Tirpitz.

They carried a crew of four, typically a lieutenant in command, with a sub-lieutenant as deputy, an engine room artificer in charge of the mechanical side and a seaman or leading-seaman. At least one of them was qualified as a diver.

In addition to the two side charges (each of which contained two tons of amatol explosive), they carried around six 20-pound limpet mines which were attached to the target by the diver.

They and their depot ship HMS Bonaventure arrived at Labuan in July 1945. Four of them managed to see action before the war ended.

These operations, carried out in July 1945, were intended to cut the undersea telephone cables connecting Singapore, Saigon, Hong Kong and Tokyo. The intention was to oblige the Japanese to use radio and render themselves open to message interception.

Operation Sabre was directed at the Hong Kong to Saigon telephone cable, and carried out by XE4, which was towed to within 40 miles (64 km) of the Mekong Delta by the submarine HMS Spearhead, where she looked for the two telephone cables by using a towed grapnel. She eventually snagged the first cable, and managed to haul it about 10 feet (3.0 m) off the seabed. XE4's diver, Sub-Lieutenant K.M. Briggs, used the net/cable cutter to sever it. The second cable was soon found as well, and was severed by the second diver, Sub-Lieutenant A. Bergius. Two divers were carried due to the operating rule that a diver should not spend more than 20 minutes in depths over 33 feet (10 m) and no more than 10 minutes over 40 feet (12 m). XE4 and Spearhead returned to Labuan on 3 August 1945.