Beardmore-Halford-Pullinger (BHP) were a series of aircraft engines used in production between 1916 and 1918. The engines were used on many notable First World War aircraft, such as the Airco DH.4, DH.9, Airco DH.10 Amiens, de Havilland DH.15 and Avro 529 aircraft.
The name is derived from the three elements of:
- Sir William Beardmore of William Beardmore and Company: Responsible for funding and providing original engines from his production company, which manufactured aero engines used in many aircraft prior to 1916 such as the 120 hp, 160 hp and Beardmore Tornado (diesel). They also manufactured aircraft and airships, such as the Beardmore W.B.III, and R23X class airship. The company types were modified into the B.H.P. engines.
- Major Frank Halford: Responsible for proposing modifications to the engines originally taken from Beardmore designs. Brevet Capt. Halford worked for the Air Inspection Directorate (AID) at Farnborough. He would later design the first turbo charged racing car engine, the Halford Special, all the engines made by de Havilland including jets and rockets, and several engines for Napier, including the Sabre.
- Thomas Pullinger: Halford's proposals were made a working proposition by engineer and managing director of the Arrol-Johnston car factory T C Pullinger. Arrol-Johnston had manufactured the Austro - Daimler as the 160 hp Beardmore aero-engine. Arrol-Johnston's works was at Heathhall in Dumfries and continued development and production of aero engines such as the B.H.P. The B.H.P. was handed over to the Siddeley Motor Company and their version which had further improvements became well known as The Puma. Galloway Engineering was a subsidiary of Arrol-Johnston. Pullinger continued production of the B.H.P. post-war as the Galloway Adriatic.
The BHP engines
The first BHP engine was a modified Beardmore 120 hp, itself a licensed copy of the Austro-Daimler straight six petrol engine. Changes made for the BHP included twin carburettors and dual ignition. These increased its output to 160 hp.
Halford and Pullinger then designed a completely new engine which delivered 230 hp. A new company, the Galloway Engineering Co. Ltd. was set up in Dumfries to continue development and production of the engine. It was sold as the Adriatic.
The engine was also licensed to Siddeley-Deasy, to be built at their Parkside works. John Siddeley himself worked on the engine and would later, after additions to the watercooling system, release an improved 240 hp version as the Siddeley Puma.
Motor Co. Ltd. Coventry, Siddeley-Deasy and the Arrol Johnston factory were eventually called upon to assist production as Galloway Engineering could not produce enough units per week, after which they were left with just making the steel engine blocks.
- Galloway BHP Atlantic. Two cylinder blocks from the Galloway BHP were combined on a single crank shaft to create the V12 configuration Atlantic, delivering 500 hp.
- Galloway BHP Pacific. The Pacific was an Atlantic fitted with Puma cylinder blocks.
- Airdisco Nimbus.
- "The De Havilland D.H.9", Flight, Iliffe and Sons Ltd, p. 386b, 6 April 1956, retrieved 8 March 2011
- Spooner, Stanley, ed. (4 March 1926). "The A.D.C "Nimbus" Engine" (PDF). Flight: 122. Retrieved 8 March 2011.
- "The B.H.P. Aero Engine", Flight, p. 88, 3 February 1921, retrieved 8 March 2011
- page 120, The Aeroplane, 2 February 1921
- Douglas R. Taylor, Boxkite to Jet: The Remarkable Career of Frank B. Halford, Rolls-Royce Heritage Trust, 1999.