Armstrong Siddeley Double Mamba Engine 

The Armstrong Siddeley Python was an early British turboprop engine designed and built by the British Armstrong Siddeley company.

Armstrong Siddeley had produced a successful range of low and mid power radial engines prior to World War II including the 5 cylinder Genet in 88 and 110HP versions, the 5 cylinder 165HP Mongoose, the 7 cylinder 235HP Lynx and Cheetah Engines, and the double row Leopard, Jaguar and Panther.

While all of the Armstrong Siddeley radial engines were named after "big cats" their post war jet engines were named after "snakes" and included the Viper engine developed for the GAF Jindervik, and the Double Mamba turboprop engine used in the Fairey Gannet anti submarine aircraft.

The Armstrong Siddeley company was formed in 1919 and was a British manufacturer of luxury cars and later, aircraft engines. In 1935 J D Siddeley was bought out by the Hawker Aircraft Company to form Hawker Siddeley and in 1960 the aircraft engine division was merged with Bristol Aero Engines to form Bristol Siddeley, which was taken over by Rolls Royce in 1966.
 

The Double Mamba was an  engine design of around 3,000–4,000 hp (2,500–3,000 kW). It was used mostly on theFairey Gannet anti-submarine, naval carrier based aircraft developed for the Royal Navy, 36 Fairey Gannets also saw service on HMAS Melbourne with the Royal Australian Navy.

The Double Mamba (also known as the Twin Mamba) was a development of the Armstrong Siddeley Mamba with two Mambas driving  two  "4 blade" contra-rotating propellors through a combining gearbox.

 Engine starting was by cartridge, however, forced air restart was achieved in flight. One engine could be shut down in flight to conserve fuel.

The Museum's Double Mamba is from a RAN Fairey Gannet similar to the Museum's example XG789.
 

  Engine Specifications