'Salamander I' was a British unrealised operation by the Special Operations Executive to use a four-man party, led by R. Ulstein, to attack shipping in the Nordgulen and FlorÝ area of German-occupied Norway using four 'sleeping beauty' motorised submersible canoes (September 1944).
More formally designated as the Motorised Submersible Canoe, the 'sleeping beauty' was built by the Special Operations Executive as a one-man underwater vehicle to undertake clandestine reconnaissance missions or attacks on German vessels.
The Motorised Submersible Canoe was designed by Major Hugh Reeves baed on an idea of Lieutenant Colonel 'Blondie' Hasler for an 'underwater glider' and developed at Aston House to Hasler’s specification. Built of mild steel, the canoe was 12 ft 8 in (3.86 m) long with a beam of 2 ft 3 in (0.69 m), used a 5-hp electric motor powered by four 6-volt batteries, had a top speed of 4.4 kt, and could travel between 34.5 and 46 miles (56 and 74 km) at a cruising speed of 3.1 kt. Its maximum operating depth was 50 ft (15 m).
The canoe was designed to carry up to 3.5 lb (1.6 kg) of explosives in the form of nine limpet mines, and could be dropped near its target by a heavy bomber. Fore and central trimming tanks within the hull could be flooded to sink the craft underwater, or have compressed air blown into them to surface the craft. The pilot controlled the craft by means of a joystick connected to the rudder and diving planes, breathed through a Siebe Gorman Salvus Mk II Amphibian rebreather or Dunlop Underwater Swimming Breathing Apparatus, and had to come close to the surface to establish his position. The canoe could also be paddled or moved by raising the mast and setting a sail. Although the canoe was designed to accommodate only one 'pilot' frogman, a post-war model was attempted with a two-man crew. Different configurations were tried on the canoe, these including the positions of the hydroplanes; these were positioned aft, but sometimes moved forward during experimental work. The high-pressure air tanks could afford four blows for surfacing from 40 ft (12.2 m) or up to 20 blows for surfacing from 15 ft (4.6 m).
At the end of 1943 the canoe was known as the Assault Warfare Sub Committee' and was trialled in the Queen Mary Reservoir in Surrey, in which it was compared with the 'Chariot' manned torpedo and Welman mini-submarine. The canoe was found to be small enough for as many as 15 to be be carried in a larger submarine’s torpedo storage compartment), light, easy to navigate, simple to operate, and quick to build. However, the canoe was very difficult to control.
The usual method of operations for the canoe was 'porpoising' in quick rises to the surface to check bearings, then shallow diving. This manoeuvre required the pilot to put the bow of the canoe to the water’s surface and watch the reflection of it underneath the surface, and just when the bow was about to meet with its reflected image the Sleeping Beauty would be put into a dive so that the pilot’s head would come out of the water and he was able to see his direction.
The 'pilot' could leave the canoe to swim and plant limpet mines as an alternative to piloting the canoe directly to the target.
The 'Salamander I' operation was cancelled as a result of objections by the Special Intelligence Service that it would threaten the security of its station near FlorÝ.