Armstrong Siddeley Heritage Trust
Siddeley Puma
The Puma was the first aero-engine to carry the Siddeley name; it was derived from the failing Beardmore BHP/Galloway Adriatic engine, which the War Office had assumed would give the Royal Flying Corps air superiority. Siddeley-Deasy were asked to take responsibility for getting the engine into volume production. John Siddeley agreed, provided they were allowed to improve the engine.
Improvements to the engine included replacing the cast-iron cylinder heads with aluminium and the steel water jackets with detachable aluminium units. There were further issues with the porosity of aluminium cylinder castings, which were overcome by using sleeve liners that were shrunk and screwed into the head.
Within months, the engine entered full production, with deliveries peaking at 250 units per week. By the end of 1918, 4,288 had been delivered, making it the most numerous British engine of WWI.
Siddeley Puma portside view
Siddeley Puma cylinder block
Siddeley Puma starboard view
Technical Details
6-cylinder water cooled upright in line popet valve piston engine
Bore 5.71 ins. 145 mm
Stroke 7.48 ins. 190 mm
Capacity 1,148 cu. ins. 18.835 litres
Power rating 230hp
B.H.P. 250 at 1400 R.P.M
At maximum permitted revs. 264 at 1500 R.P.M. Compression ratio 4.94:1
Weight 624 lbs
Approximate oil consumption 1.54 gals. per hour
Approximate petrol consumption 17.5 gals. per hour
Direct propeller drive, right-hand tractor
Whilst the engine was fitted to many aircraft, its principal use was with the Airco DH9 bomber, with 4,091 being built.
Siddeley Puma installed in a DH 9
DH 9 in flight credit The Historic Aircraft Colection
Close up of Sideley Puma in a DH 9
The Siddeley Puma engine continued to be produced after the end of World War I; many were exported, and Puma engines were fitted to planes produced by 20 different countries. Many DH9 Puma-engined aircraft were converted for civilian use by commercial airlines such as KLM.
One notable post-war achievement was the first single-engined aircraft to fly to Australia from England, a Puma-engined DH 9, which took off from Hounslow, near London, piloted by Flt Lt Ray Parer and Major John McIntosh. They had intended to take part in the 1919 England to Australia flight, also known as The Great Air Race, but technical issues delayed them. They took off one month after the winning entry, a twin-engined Vickers Vimy, had landed at Darwin; nonetheless, they intended to show that the journey could be completed in a single engined aeroplane.
During the journey, they flew over Mt Vesuvius, where billowing hot air caused them to drop 600ft in a few Seconds. Their machine twice caught fire in Syria, where they had to fight off hostile Arabs. The pair took nearly seven months to complete their journey. Having succeeded against all expectations, they both received a hero’s welcome and were awarded consolation prizes of £500 each.
Theirs had been the first flight to reach Australia in a single-engine aircraft. And, symbolically at least, they also transported the first airfreight from England, a carefully stowed bottle of whisky from the DH9’s sponsor, Scottish distilling baron Peter Dawson, whose initials can be seen on the side of the aeroplane in the attached photos.
Images of the Siddeley Puma installed in the DH 9 that made the historic London to Australia flight, together with a map showing the route and landing locations. For best results, enlarge the map by clicking on it.
Double Puma.
One unusual development of this engine was a Pair of Pumas mounted in tandem, with one unit acting as a tractor engine and the other as a pusher. This engine was developed for the Bristol Braemar I, which was powered by a pair of Pumas; the aircraft didn't enter production.
