POWERHOUSE COLLECTION

Notes

The Armstrong Siddeley company began aero engine development and production when the Royal Aircraft Factory ceased building production engines from February 1917. In January of that year major F M Green left the Royal Aircraft Factory to join Siddeley-Deasey Motor Car Company as chief aeronautical engineer with the task of redesigning the BHP (Beardmore Halford Pullinger) 6 cylinder aero engine. This engine became the Siddeley Puma and was built in larger numbers than any other of its day. When work on the development of the Puma finished, Green focussed on his radial engine that he had designed while at the Royal Aircraft Factory. This engine became the Siddeley Jaguar. Between the wars work continued on developing a variety of radial aero engines with general success. Between 1939 and 1941 Armstrong Siddeley Motors worked on an Air Ministry contract to build a gas turbine engine that had been suggested by A A Griffiths of the Royal Aeronautical Establishment about 1930. When in 1942 Armstrong Siddeley Motors was given a contract to design and develop their own gas turbine engine they began work on the ASX which ran in 1943 and flew in 1944. Its power to weight ratio was not good and a propeller gearbox was added but the engine was heavy. Without any competition Armstrong Siddeley was given the contract to produce the engine, originally called ASP but renamed Python. The Python entered service in 1953 in the Royal Navy's shipboard fighter, the Wyvern S4. The experience gained with the Python allowed the development of the smaller Mamba engine. The Mamba and Double Mamba axial gas turbine engines were developed by Armstrong Siddeley under the supervision of Mr H T Chapman (director and general manager) and by the Armstrong Siddeley design team led by Mr W F (Bill) Saxton, MBE, (chief engineer), Mr W H Lindsey, MA (deputy chief engineer) and Mr A Thomas, MBE (chief designer, aircraft engines). The Mamba ran on the test bed in April 1946 and first flew on October 14, 1947 in the nose of a modified Lancaster test bed aircraft. A Mamba engine was then supplied to Boulton and Paul for fitting to the Balliol aircraft and another sent to Avro for their Athena aircraft. Civil versions were installed in the Miles Marathon and the prototype Armstrong Whitworth Apollo. The Mamba project design had been completed in late 1945 and the design and development of the Double Mamba began in late 1947 with the prototype of the latter being bench tested early in 1949. As the name implies the Double Mamba was made from two Mamba 2 engines of 1,250 shp side-by-side, attached to a common reduction gearbox. The engines each drove four-bladed propellers which were counter-rotating and co-axial. Although this twinning of turbine units was also tried by Bristol with the Proteus for the Bristol Brabazon Mk2 and Saunders-Roe Princess and proposed by Napier with their Naiad turbine and Allison in the United States, it appears that only the Armstrong Siddeley Double Mamba went into series production. The Mamba engine was available for use in the famous airliner, the Vickers Viscount but this aircraft was ultimately powered by the Rolls Royce Dart and the Mamba, in the form of the Double Mamba saw sterling service in the Fairey Gannet naval reconnaissance aircraft. The final AEW.3 (Airborne Early Warning) version was powered by the Mk. 102 Double Mamba engine of 3,875 shp. Made at the Armstrong Siddeley Motors Limited, Parkside, Coventry, England, a branch of the Hawker Siddeley Group.