Pobjoy Airmotors and Aircraft was a

British British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories and Crown Dependencies. * British national identity, the characteristics of British people and culture ...

manufacturer of small

aircraft engine An aircraft engine, often referred to as an aero engine, is the power component of an aircraft propulsion system. Aircraft using power components are referred to as powered flight. Most aircraft engines are either piston engines or gas turbin ...

s. The company was purchased by

Short Brothers Short Brothers plc, usually referred to as Shorts or Short, is an aerospace company based in Belfast, Northern Ireland. Shorts was founded in 1908 in London, and was the first company in the world to make production aeroplanes. It was particu ...

shortly before the start of

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

, production continuing until the end of the war.

History

Douglas Rudolf Pobjoy started in the engine business working with

Roy Fedden Sir Alfred Hubert Roy Fedden MBE, FRAeS (6 June 1885 – 21 November 1973) was an engineer who designed most of Bristol Engine Company's successful piston aircraft engine designs. Early life Fedden was born in the Bristol area to fairly weal ...

Cosmos Engineering Cosmos Engineering was a company that manufactured aero-engines in a factory in Fishponds, Bristol during World War I. Sir Roy Fedden, the company's principal designer, developed the 14-cylinder radial Mercury engine during this period. The com ...

just after the end of

World War I World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...

. Cosmos went bankrupt shortly after the war, and its assets were picked up by the

Bristol Aeroplane Company The Bristol Aeroplane Company, originally the British and Colonial Aeroplane Company, was both one of the first and one of the most important British aviation companies, designing and manufacturing both airframes and aircraft engines. Notable ...

, where Fedden would go on to produce a line of extremely successful engines. Pobjoy also spent time in the RAF as an education officer. Here he met Flt. Lt.

Nicholas Comper Nicholas Comper (29 April 1897 – 17 June 1939) was an England, English aviator and aircraft designer, whose most notable success was the 1930s Comper Swift monoplane racer. Early life Nicholas Comper was born in Lambeth, London, England, the ...

who went on to design the

Comper Swift The Comper C.L.A.7 Swift is a British single-seat sporting aircraft designed and produced by the Comper Aircraft Company. It was the company’s first aircraft. The Swift was designed shortly after Nicholas Comper’s departure from the Royal A ...

, that would later fly from London to Australia in 9 days 2 hours. Pobjoy partnered with

Parnall Parnall was a British aircraft manufacturer that evolved from a wood-working company before the First World War to a significant designer of military and civil aircraft into the 1940s. It was based in the west of England and was originally known ...

to develop an engine for the Swift. Although they felt that a cast-block inline engine like the ones being produced by Cirrus and

de Havilland The de Havilland Aircraft Company Limited (pronounced , ) was a British aviation manufacturer established in late 1920 by Geoffrey de Havilland at Stag Lane Aerodrome Edgware on the outskirts of North London. Operations were later moved to ...

would always be less expensive, they nevertheless selected the

radial Radial is a geometric term of location which may refer to: Mathematics and Direction * Vector (geometric), a line * Radius, adjective form of * Radial distance (geometry), a directional coordinate in a polar coordinate system * Radial set * A ...

layout for their design, feeling that the cost would be more than offset by the lighter weight and higher performance his designs would offer. Douglas Pobjoy later took over the design, and started a company of his own to produce it at Hooton Park in the Wirral. The Parnall/Pobjoy design, the 7-cylinder 67 hp

Pobjoy P The Pobjoy P was a British seven-cylinder, air-cooled, aircraft engine designed by Douglas Rudolf Pobjoy and built by Pobjoy Airmotors. It became the progenitor of the Pobjoy R/ Niagara/Cataract A cataract is a cloudy area in the lens (an ...

, received its 50-hour type rating in 1928. This was followed in 1929 by the 75/80 hp

Pobjoy R The Pobjoy R is a British seven-cylinder air-cooled radial aircraft engine designed and built by Pobjoy Airmotors. Introduced in 1926, it was a popular engine for ultralight and small aircraft in the 1930s. A notable feature of the Pobjoy R was ...

, that became very successful, notably on the

General Aircraft Monospar The General Aircraft Monospar was a family of touring and utility aircraft designed and built by the United Kingdom, British aviation company General Aircraft Ltd (GAL). Development In 1929, the Monospar Company Ltd was formed to pursue new t ...

. Later designs included the 85/90 hp

Pobjoy Cataract A cataract is a cloudy area in the lens of the eye that leads to a decrease in vision of the eye. Cataracts often develop slowly and can affect one or both eyes. Symptoms may include faded colours, blurry or double vision, halos around light, ...

, replacing the Pobjoy R, and the 130 hp

Pobjoy Niagara The Pobjoy Niagara is a British seven-cylinder, air-cooled, radial, aero-engine first produced in 1934. The design ran at higher speeds than conventional engines, and used reduction gearing to lower the speed of the propeller. This led to a notic ...

of 1934. The Niagara was used on a number of designs by Shorts designers, notably the

Short Scion Senior The Short S.22 Scion Senior was a 1930s United Kingdom, British four-engined nine-passenger floatplane built by Short Brothers. Design and development The Scion Senior was developed as an enlarged version of the Short Scion, Scion light transpo ...

and the original half-scale prototype for the

Short Stirling The Short Stirling was a British four-engined heavy bomber of the Second World War. It has the distinction of being the first four-engined bomber to be introduced into service with the Royal Air Force (RAF) during the war (the earlier Handley ...

, the S.31. The Niagara's compact size and excellent performance led to it being used on the General Aircraft GAL.38 and Airspeed AS.39 extremely long-endurance slow-flying "Fleet Shadower" prototypes produced to Air Ministry specification S.23/27"Lumsden (2003) where they maximized airflow over the wings. In 1934, Pobjoy Airmotors moved its plant to

Rochester, Kent Rochester ( ) is a town in the unitary authority of Medway, in Kent, England. It is at the lowest bridging point of the River Medway, about east-southeast of London. The town forms a conurbation with neighbouring towns Chatham, Kent, Chatham, ...

, to be closer to its largest customer, Shorts. The move, and the ongoing effects of the

Great Depression The Great Depression was a severe global economic downturn from 1929 to 1939. The period was characterized by high rates of unemployment and poverty, drastic reductions in industrial production and international trade, and widespread bank and ...

, drove the company into financial difficulty, and it was eventually bought outright by Shorts. The company was made public in 1935. Douglas Pobjoy then moved on to designing de-icing equipment for high-altitude flights. During the Second World War, Pobjoy ran a section of Rotol Airscrews of Gloucester, England, and was responsible for the design and development of an airborne generator, intended for use on the Short Shetland flying boat. The unit consisted of a flat-six sleeve-valve air-cooled petrol engine driving the generator. This was installed inboard on the aircraft, and due to the incorrect closure of the cooling ducts the engine overheated and the resulting fire destroyed the prototype Shetland. It seems that the project was abandoned at this stage. After the war Pobjoy designed a new tractor. On 4 July 1948, he was returning from a sales trip to

Helsinki Helsinki () is the Capital city, capital and most populous List of cities and towns in Finland, city in Finland. It is on the shore of the Gulf of Finland and is the seat of southern Finland's Uusimaa region. About people live in the municipali ...

when the

Scandinavian Airlines The Scandinavian Airlines System (SAS), commonly known as Scandinavian Airlines, is the national airline of Denmark, Norway, and Sweden. It is part of SAS Group and is headquartered in Solna, Sweden. Including its subsidiaries SAS Link and ...

Douglas DC-6 The Douglas DC-6 is a piston-powered airliner and cargo aircraft built by the Douglas Aircraft Company from 1946 to 1958. Originally intended as a military transport near the end of World War II, Douglas reworked it after the war to compete ...

in which he was flying was involved in the

1948 Northwood mid-air collision The 1948 Northwood mid-air collision took place on 4 July at 15:03 when a Douglas DC-6 of Scandinavian Airlines System (SAS) and an Avro York, Avro York C.1 of the Royal Air Force (RAF) mid-air collision, collided in mid-air over Northwood, Lon ...

. All 38 passengers in both aircraft were killed.Lumsden (2003), p.178.

Aircraft

* Pobjoy Pirate

Engine designs

(1928) :7-cylinder radial, air-cooled, geared, 2,480 cc, 67 hp (50 kW) *

(1933) :7-cylinder radial, air-cooled, geared, 2,835 cc, 85 hp (63 kW) * Pobjoy Cataract I-III (1934-6) :7-cylinder radial, air-cooled, geared, 2,835 cc, three marks with take-off powers from 80-98 hp (60-73 kW) * Pobjoy Cascade (1934) :7-cylinder radial, air-cooled, direct drive version of Cataract I, 2,835 cc, take-off power 70 hp (52 kW) * Pobjoy Niagara I-IV (1936-7) :7-cylinder radial, air-cooled, geared, cowled, 2,835 cc, four marks with take-off powers from 84-98 hp (63-73 kW) * Pobjoy Niagara V (1937) :7-cylinder radial, air-cooled, geared, cowled, 3,138 cc, take-off power 142 hp (106 kW)

Notes

References

* Jane's Fighting Aircraft of World War II. 1946 * Lumsden, Alec. 2003. British Piston Engines and their Aircraft. Airlife Publishing. . {{Pobjoy aeroengines Defunct aircraft engine manufacturers of the United Kingdom

History

Aircraft

Engine designs

See also

Notes

References