Roy Fedden
Encyclopedia
Sir Alfred Hubert Roy Fedden MBE
(6 June 1885 - 21 November 1973) was an engineer
who designed most of Bristol Engine Company's successful aircraft engine
designs.
area to fairly wealthy and influential parents. Fedden's family was the first in the area to own a car, an interesting parallel with Harry Ricardo
's. This early influence almost certainly led to his future career. Fedden attended Clifton College
, but did not do well scholastically and was known primarily for sports. After graduation, he declined to enter the Army, the "normal route" (one route, a route if you weren't very bright i.e. you hadn't made into the Sixth) for some students at Clifton, and announced he would apprentice as an engineer.
to hire him, and the design was produced as the successful Shamrock. He remained at Brazil Straker over the following years, and he was particularly influential in convincing company management to take on the repair of various aircraft engines when World War I
started. The company's role soon expanded to producing Rolls-Royce Hawk
and Falcon engines, as well as major parts of the famous Rolls-Royce Eagle. Henry Royce
offered Fedden a senior position with his company, but Fedden declined.
In 1915, Fedden started the design of his own aero engine, along with his draughtsman
Leonard Butler. The two were inseparable for the next twenty years, and most of their designs were stamped "FB" to indicate the shared credit. They designed two engines during World War I: the 14-cylinder radial
Mercury, notable for the cylinders being arranged helically instead of in two rows, and the larger, more conventional single row nine-cylinder Jupiter design of about 400 hp.
, where work on the designs continued. Both were ready for testing in 1918, but there seemed to be little interest at first. In September, however, a Mercury was experimentally fitted to a Bristol Scout
, and it dramatically improved performance, easily beating the competing Sunbeam Arab
. Bristol then decided to try the Jupiter in their new Badger design, finding that it too completely outperformed the competing ABC Dragonfly
. Production of both designs for Bristol was to start immediately, but the war ended only days later and the contract was cancelled.
With the ending of the war, Cosmos had no production designs, and their repair work was quickly dwindling. The company was soon insolvent. Convinced of the quality of the Cosmos designs, the Air Ministry "made it be known" that they would be rather happy if the company were purchased by Bristol
, which eventually took place in 1920. Sir George White later noted that they acquired Mercury design and seven engines, all the assets of Cosmos, along with Fedden and his design team, all for just £15,000. Even then most sources suggest they only did so after being forced to by the Air Ministry
, which is perhaps not surprising given the fragile economy of the era.
Bristol soon found a role for the larger design, which entered production at Bristol's new engine plant in Filton as the Bristol Jupiter
. The Jupiter became a commercial success and was widely used around the world, resulting in Fedden becoming one of the most highly paid engineers in Europe
.
By the late 1920s, the Jupiter design was no longer competitive, and Fedden and Butler started work on a pair of new designs. Both would use a supercharger
to provide boost even at ground level, at that time a new-fangled idea, and thereby deliver similar power as the Jupiter's from a much smaller engine. Re-using their earlier name, this design emerged as the Bristol Mercury
, while a more powerful design at the same size as the original Jupiter became the Bristol Pegasus.
wrote a series of seminal papers at the RAE
claiming that the poppet valve
system was already operating at its peak capability, and that any future engines would have to use sleeve valve
s instead. Fedden and Butler immediately turned to such a design, adapting the Mercury to become the Bristol Aquila
, and the Pegasus as the Bristol Perseus
. However, both of these engines quickly found themselves at the "low end" of the power spectrum as ever-larger aircraft designs demanded ever-larger engines to power them.
To solve this problem, the two designs were quickly adapted to two-row configurations, resulting in the Bristol Taurus
and the superb Bristol Hercules
. Not one to rest on his laurels, Fedden then started adapting the Hercules into a two-row 18-cylinder design as the Bristol Centaurus
.
The Taurus was in service when World War II
started in 1939, but the Hercules was still in testing. Work on the Centaurus was suspended while the final problems with Hercules production was worked out. The entire Bristol sleeve-valve range would see widespread service throughout the war on a wide variety of designs. They were so successful that the Air Ministry
forced a reluctant Bristol to help with the high-power Napier Sabre
project that had bogged down due to problems with their sleeves.
With Hercules production in full swing in 1941, Fedden returned to the Centaurus. Production was able to start in 1942, but at the time there were few aircraft that could be adapted to a 2,500 hp engine. Newer designs intended to mount engines of this size appeared near the end of the war, notably certain versions of the Hawker Tempest
, taking over from the Sabre in that design.
For his role in creating some of the most successful aircraft engines of the era, Fedden was knight
ed in 1942.
The stress of wartime production needs had taken its toll on Leonard Butler, who left the company to recuperate. Although Fedden had created a long line of hugely successful engines for Bristol, he had fought constantly with management over funding priorities. Without Butler's influence it seems Fedden "had enough", and shortly after being knighted, he left Bristol to take up a variety of positions within the Government. For much of the remainder of the war, he travelled in the United States
with another Bristol employee, Ian Duncan, to study their production line techniques in order to improve their own.
On his return, Duncan and Fedden set up Roy Fedden Ltd. in 1945. Their first product was a small horizontally-opposed aero engine intended to be installed within the wings of twin-engine aircraft. The Fedden O-325 saw no use. He then turned to a new turboprop
design which also found little interest. Finally they decided to design their own car, powered by a three-cylinder air-cooled radial, but they found it had serious handling problems and tended to flip over when being cornered hard. This was largely due to the desire to maximise interior space coupled with the inherent difficulty of packaging a three-cylinder radial in a car chassis, which led to the engine being mounted above the rear axle, giving the car an undesirably high centre of gravity. Work started on a replacement chassis, but the rest of the company's engineers lost interest and left, and soon the company had to be dissolved.
After this, Fedden worked for a time consulting with George Dowty
, but soon retired and spent his time teaching at the College of Aeronautics at Cranfield University
.
Fedden was childless. He has sometimes been mistakenly described as the father of a prominent British artist called Mary Fedden
. He was in fact her uncle.
Flight articles
Order of the British Empire
The Most Excellent Order of the British Empire is an order of chivalry established on 4 June 1917 by George V of the United Kingdom. The Order comprises five classes in civil and military divisions...
(6 June 1885 - 21 November 1973) was an engineer
Engineer
An engineer is a professional practitioner of engineering, concerned with applying scientific knowledge, mathematics and ingenuity to develop solutions for technical problems. Engineers design materials, structures, machines and systems while considering the limitations imposed by practicality,...
who designed most of Bristol Engine Company's successful aircraft engine
Aircraft engine
An aircraft engine is the component of the propulsion system for an aircraft that generates mechanical power. Aircraft engines are almost always either lightweight piston engines or gas turbines...
designs.
Early life
Fedden was born in the BristolBristol
Bristol is a city, unitary authority area and ceremonial county in South West England, with an estimated population of 433,100 for the unitary authority in 2009, and a surrounding Larger Urban Zone with an estimated 1,070,000 residents in 2007...
area to fairly wealthy and influential parents. Fedden's family was the first in the area to own a car, an interesting parallel with Harry Ricardo
Harry Ricardo
Sir Harry Ricardo was one of the foremost engine designers and researchers in the early years of the development of the internal combustion engine....
's. This early influence almost certainly led to his future career. Fedden attended Clifton College
Clifton College
Clifton College is a co-educational independent school in Clifton, Bristol, England, founded in 1862. In its early years it was notable for emphasising science in the curriculum, and for being less concerned with social elitism, e.g. by admitting day-boys on equal terms and providing a dedicated...
, but did not do well scholastically and was known primarily for sports. After graduation, he declined to enter the Army, the "normal route" (one route, a route if you weren't very bright i.e. you hadn't made into the Sixth) for some students at Clifton, and announced he would apprentice as an engineer.
Apprenticeship
His apprenticeship was completed in 1906, and he immediately designed a complete car. He managed to convince the local firm of Brazil StrakerStraker-Squire
Straker-Squire was a British automobile manufacturer based in Bristol, and later Edmonton in North London....
to hire him, and the design was produced as the successful Shamrock. He remained at Brazil Straker over the following years, and he was particularly influential in convincing company management to take on the repair of various aircraft engines when World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
started. The company's role soon expanded to producing Rolls-Royce Hawk
Rolls-Royce Hawk
|-See also:-Bibliography:*Flight 7 May 1954**Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6....
and Falcon engines, as well as major parts of the famous Rolls-Royce Eagle. Henry Royce
Henry Royce
Sir Frederick Henry Royce, 1st Baronet, OBE was a pioneering car manufacturer, who with Charles Stewart Rolls founded the Rolls-Royce company.-Early life:...
offered Fedden a senior position with his company, but Fedden declined.
In 1915, Fedden started the design of his own aero engine, along with his draughtsman
Technical drawing
Technical drawing, also known as drafting or draughting, is the act and discipline of composing plans that visually communicate how something functions or has to be constructed.Drafting is the language of industry....
Leonard Butler. The two were inseparable for the next twenty years, and most of their designs were stamped "FB" to indicate the shared credit. They designed two engines during World War I: the 14-cylinder radial
Radial engine
The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders point outward from a central crankshaft like the spokes on a wheel...
Mercury, notable for the cylinders being arranged helically instead of in two rows, and the larger, more conventional single row nine-cylinder Jupiter design of about 400 hp.
Cosmos Engineering and the Jupiter
During this period the aviation portions of Brazil Straker were purchased by Cosmos EngineeringCosmos 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...
, where work on the designs continued. Both were ready for testing in 1918, but there seemed to be little interest at first. In September, however, a Mercury was experimentally fitted to a Bristol Scout
Bristol Scout
The Bristol Scout was a simple, single seat, rotary-engined biplane originally intended as a civilian racing aircraft. Like other similar fast, light aircraft of the period - it was acquired by the RNAS and the RFC as a "scout", or fast reconnaissance type...
, and it dramatically improved performance, easily beating the competing Sunbeam Arab
Sunbeam Arab
|-See also:-Bibliography:* Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6.* Brew, Alec. Sunbeam Aero-Engines. Airlife Publishing. Shrewsbury. ISBN 1 84037 023 8...
. Bristol then decided to try the Jupiter in their new Badger design, finding that it too completely outperformed the competing ABC Dragonfly
ABC Dragonfly
-Bibliography:* Bruce, J.M. "Sopwith Snipe...:...the RAF's First Fighter. . " Air Enthusiast International Volume 6 Number 6, June 1974. Bromley, UK: Fine Scroll....
. Production of both designs for Bristol was to start immediately, but the war ended only days later and the contract was cancelled.
With the ending of the war, Cosmos had no production designs, and their repair work was quickly dwindling. The company was soon insolvent. Convinced of the quality of the Cosmos designs, the Air Ministry "made it be known" that they would be rather happy if the company were purchased by Bristol
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 aero engines...
, which eventually took place in 1920. Sir George White later noted that they acquired Mercury design and seven engines, all the assets of Cosmos, along with Fedden and his design team, all for just £15,000. Even then most sources suggest they only did so after being forced to by the Air Ministry
Air Ministry
The Air Ministry was a department of the British Government with the responsibility of managing the affairs of the Royal Air Force, that existed from 1918 to 1964...
, which is perhaps not surprising given the fragile economy of the era.
Bristol soon found a role for the larger design, which entered production at Bristol's new engine plant in Filton as the Bristol Jupiter
Bristol Jupiter
The Bristol Jupiter was a British nine-cylinder single-row piston radial engine built by the Bristol Aeroplane Company. Originally designed late in World War I and known as the Cosmos Jupiter, a lengthy series of upgrades and developments turned it into one of the finest engines of its era.The...
. The Jupiter became a commercial success and was widely used around the world, resulting in Fedden becoming one of the most highly paid engineers in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
.
By the late 1920s, the Jupiter design was no longer competitive, and Fedden and Butler started work on a pair of new designs. Both would use a supercharger
Supercharger
A supercharger is an air compressor used for forced induction of an internal combustion engine.The greater mass flow-rate provides more oxygen to support combustion than would be available in a naturally aspirated engine, which allows more fuel to be burned and more work to be done per cycle,...
to provide boost even at ground level, at that time a new-fangled idea, and thereby deliver similar power as the Jupiter's from a much smaller engine. Re-using their earlier name, this design emerged as the Bristol Mercury
Bristol Mercury
|-See also:-Bibliography:* Bridgman, L, Jane's fighting aircraft of World War II. Crescent. ISBN 0-517-67964-7* Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9...
, while a more powerful design at the same size as the original Jupiter became the Bristol Pegasus.
Development of sleeve valve engines
In 1925 and 1926, Harry RicardoHarry Ricardo
Sir Harry Ricardo was one of the foremost engine designers and researchers in the early years of the development of the internal combustion engine....
wrote a series of seminal papers at the RAE
Royal Aircraft Establishment
The Royal Aircraft Establishment , was a British research establishment, known by several different names during its history, that eventually came under the aegis of the UK Ministry of Defence , before finally losing its identity in mergers with other institutions.The first site was at Farnborough...
claiming that the poppet valve
Poppet valve
A poppet valve is a valve consisting of a hole, usually round or oval, and a tapered plug, usually a disk shape on the end of a shaft also called a valve stem. The shaft guides the plug portion by sliding through a valve guide...
system was already operating at its peak capability, and that any future engines would have to use sleeve valve
Sleeve valve
The sleeve valve is a type of valve mechanism for piston engines, distinct from the usual poppet valve. Sleeve-valve engines saw use in a number of pre-World War II luxury cars and in USA in the Willys-Knight car and light truck...
s instead. Fedden and Butler immediately turned to such a design, adapting the Mercury to become the Bristol Aquila
Bristol Aquila
|-See also:-Bibliography:*Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9...
, and the Pegasus as the Bristol Perseus
Bristol Perseus
|-See also:-Bibliography:* Bridgman, L, Jane's Fighting Aircraft of World War II. Crescent . ISBN 0-517-67964-7* Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9...
. However, both of these engines quickly found themselves at the "low end" of the power spectrum as ever-larger aircraft designs demanded ever-larger engines to power them.
To solve this problem, the two designs were quickly adapted to two-row configurations, resulting in the Bristol Taurus
Bristol Taurus
|-See also:-Bibliography:*Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9...
and the superb Bristol Hercules
Bristol Hercules
|-See also:-Bibliography:*Gunston, B. Classic World War II Aircraft Cutaways. Osprey. ISBN 1-85532-526-8*Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9...
. Not one to rest on his laurels, Fedden then started adapting the Hercules into a two-row 18-cylinder design as the Bristol Centaurus
Bristol Centaurus
|-See also:-Bibliography:*Bridgman, L, Jane's Fighting Aircraft of World War II. Crescent. ISBN 0-517-67964-7*Gunston, Bill. Development of Piston Aero Engines. Cambridge, England. Patrick Stephens Limited, 2006. ISBN 0-7509-4478-1...
.
The Taurus was in service when World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
started in 1939, but the Hercules was still in testing. Work on the Centaurus was suspended while the final problems with Hercules production was worked out. The entire Bristol sleeve-valve range would see widespread service throughout the war on a wide variety of designs. They were so successful that the Air Ministry
Air Ministry
The Air Ministry was a department of the British Government with the responsibility of managing the affairs of the Royal Air Force, that existed from 1918 to 1964...
forced a reluctant Bristol to help with the high-power Napier Sabre
Napier Sabre
The Napier Sabre was a British H-24-cylinder, liquid cooled, sleeve valve, piston aero engine, designed by Major Frank Halford and built by Napier & Son during WWII...
project that had bogged down due to problems with their sleeves.
With Hercules production in full swing in 1941, Fedden returned to the Centaurus. Production was able to start in 1942, but at the time there were few aircraft that could be adapted to a 2,500 hp engine. Newer designs intended to mount engines of this size appeared near the end of the war, notably certain versions of the Hawker Tempest
Hawker Tempest
The Hawker Tempest was a British fighter aircraft primarily used by the Royal Air Force in the Second World War. The Tempest was an improved derivative of the Hawker Typhoon, and one of the most powerful fighter aircraft used during the war....
, taking over from the Sabre in that design.
For his role in creating some of the most successful aircraft engines of the era, Fedden was knight
Knight
A knight was a member of a class of lower nobility in the High Middle Ages.By the Late Middle Ages, the rank had become associated with the ideals of chivalry, a code of conduct for the perfect courtly Christian warrior....
ed in 1942.
The stress of wartime production needs had taken its toll on Leonard Butler, who left the company to recuperate. Although Fedden had created a long line of hugely successful engines for Bristol, he had fought constantly with management over funding priorities. Without Butler's influence it seems Fedden "had enough", and shortly after being knighted, he left Bristol to take up a variety of positions within the Government. For much of the remainder of the war, he travelled in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
with another Bristol employee, Ian Duncan, to study their production line techniques in order to improve their own.
On his return, Duncan and Fedden set up Roy Fedden Ltd. in 1945. Their first product was a small horizontally-opposed aero engine intended to be installed within the wings of twin-engine aircraft. The Fedden O-325 saw no use. He then turned to a new turboprop
Turboprop
A turboprop engine is a type of turbine engine which drives an aircraft propeller using a reduction gear.The gas turbine is designed specifically for this application, with almost all of its output being used to drive the propeller...
design which also found little interest. Finally they decided to design their own car, powered by a three-cylinder air-cooled radial, but they found it had serious handling problems and tended to flip over when being cornered hard. This was largely due to the desire to maximise interior space coupled with the inherent difficulty of packaging a three-cylinder radial in a car chassis, which led to the engine being mounted above the rear axle, giving the car an undesirably high centre of gravity. Work started on a replacement chassis, but the rest of the company's engineers lost interest and left, and soon the company had to be dissolved.
After this, Fedden worked for a time consulting with George Dowty
George Dowty
-Early life:Dowty was born in Pershore, Worcestershire in 1901. He was sent to the Royal Grammar School Worcester after losing his right eye at the age of 12 playing around making a firework....
, but soon retired and spent his time teaching at the College of Aeronautics at Cranfield University
Cranfield University
Cranfield University is a British postgraduate university based on two campuses, with a research-oriented focus. The main campus is at Cranfield, Bedfordshire and the second is the Defence Academy of the United Kingdom based at Shrivenham, Oxfordshire. The main campus is unique in the United...
.
Fedden was childless. He has sometimes been mistakenly described as the father of a prominent British artist called Mary Fedden
Mary Fedden
Mary Fedden OBE, is a British artist. Fedden is represented by Portland Gallery, London.-Early years:Sometimes mistakenly described as the daughter of Roy Fedden , Mary Fedden studied at the Slade School of Fine Arts, London from 1932 to 1936...
. He was in fact her uncle.
External links
Flight articles