Rolls-Royce Thrust Measuring Rig
Encyclopedia
The Rolls-Royce Thrust Measuring Rig (TMR) was a pioneering vertical take-off and landing aircraft developed by Rolls-Royce
Rolls-Royce Limited
Rolls-Royce Limited was a renowned British car and, from 1914 on, aero-engine manufacturing company founded by Charles Stewart Rolls and Henry Royce on 15 March 1906 as the result of a partnership formed in 1904....
in the 1950s. The TMR used two Nene
Rolls-Royce Nene
|-See also:-References:NotesBibliography* Bridgman, L, Jane's fighting aircraft of World War II. Crescent. ISBN 0-517-67964-7-External links:* *...
turbojet engines mounted back-to-back horizontally within a steel framework, raised upon four legs with castors for wheels. The TMR had no lifting surfaces (wings, blades, etc.) and was understandably nickname
Nickname
A nickname is "a usually familiar or humorous but sometimes pointed or cruel name given to a person or place, as a supposedly appropriate replacement for or addition to the proper name.", or a name similar in origin and pronunciation from the original name....
d the Flying Bedstead
Flying bedstead
The Flying Bedstead was a nickname given to two completely different experimental vertical take-off and landing aircraft, both receiving the nickname because each comprised a skeletal platform raised on four legs that resembled a bedstead....
.
Design and development
The man largely responsible for the development of the TMR was Dr Alan Arnold GriffithAlan Arnold Griffith
Alan Arnold Griffith was an English engineer, who, among many other contributions, is best known for his work on stress and fracture in metals that is now known as metal fatigue, as well as being one of the first to develop a strong theoretical basis for the jet engine.-Early work:A. A...
who had worked on gas turbine
Gas turbine
A gas turbine, also called a combustion turbine, is a type of internal combustion engine. It has an upstream rotating compressor coupled to a downstream turbine, and a combustion chamber in-between....
design at the Royal Aircraft Establishment
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...
in the 1920s and was a pioneer of jet lift technology. Griffith was employed by Rolls-Royce in 1939.
Two Thrust Measuring Rigs were built with the first taking to the air on 3 July 1953 at Hucknall Aerodrome
Hucknall Airfield
Formerly RAF Hucknall, Hucknall Airfield is located north northwest of Nottingham, Nottinghamshire, England.Hucknall has been in continuous use as an airfield since 1916. Formerly RAF Hucknall, it featured in the film The One That Got Away...
, Nottinghamshire
Nottinghamshire
Nottinghamshire is a county in the East Midlands of England, bordering South Yorkshire to the north-west, Lincolnshire to the east, Leicestershire to the south, and Derbyshire to the west...
, England, though it remained tethered to the ground while airborne. The first free flight by the TMR was made on 3 August 1954 with R.T. Shepherd, Rolls-Royce's chief test pilot, at the controls. The TMR had only marginal excess power and flying was tricky due to this, combined with the slow throttle response of the engines, and a considerably degree of anticipation in the use of engine power was required in order to prevent overshooting of desired altitude, and to ensure a gentle touchdown when landing.
As the TMR possessed no inherent stability
Flight dynamics
Flight dynamics is the science of air vehicle orientation and control in three dimensions. The three critical flight dynamics parameters are the angles of rotation in three dimensions about the vehicle's center of mass, known as pitch, roll and yaw .Aerospace engineers develop control systems for...
, it incorporated an automatic stabiliser system.
The output of the jets
Jet engine
A jet engine is a reaction engine that discharges a fast moving jet to generate thrust by jet propulsion and in accordance with Newton's laws of motion. This broad definition of jet engines includes turbojets, turbofans, rockets, ramjets, pulse jets...
was directed towards the centre of the rig with one jetpipe discharging downwards through a central nozzle while the other jet discharged downwards through two smaller nozzles on either side. Four outrigger arms extended out from the rig, one on either side and one each at the front and rear, through which compressed air
Compressed air
Compressed air is air which is kept under a certain pressure, usually greater than that of the atmosphere. In Europe, 10 percent of all electricity used by industry is used to produce compressed air, amounting to 80 terawatt hours consumption per year....
was released for control in roll
Flight dynamics
Flight dynamics is the science of air vehicle orientation and control in three dimensions. The three critical flight dynamics parameters are the angles of rotation in three dimensions about the vehicle's center of mass, known as pitch, roll and yaw .Aerospace engineers develop control systems for...
, pitch
Flight dynamics
Flight dynamics is the science of air vehicle orientation and control in three dimensions. The three critical flight dynamics parameters are the angles of rotation in three dimensions about the vehicle's center of mass, known as pitch, roll and yaw .Aerospace engineers develop control systems for...
and yaw
Flight dynamics
Flight dynamics is the science of air vehicle orientation and control in three dimensions. The three critical flight dynamics parameters are the angles of rotation in three dimensions about the vehicle's center of mass, known as pitch, roll and yaw .Aerospace engineers develop control systems for...
when in flight. The purpose of the rig was, as the name suggests, to test turbojet engines for lifting purposes and to develop techniques for controlling such an aircraft.
Following successful trials of the TMR, Rolls-Royce began development of the Rolls-Royce RB.108 direct-lift turbojet, five of which were used to power the first true British VTOL aircraft, the Short SC.1
Short SC.1
|-See also:-Bibliography:* Barnes, C.H. with revisions by Derek N. James. Shorts Aircraft since 1900. London: Putnam, 1989 . ISBN 0-85177-819-4.*Illingworth J. K. B. and Chinn H.W. . London: HMSO, 1969. Retrieved: 11 December 2007....
.
Aircraft on display
The second Thrust Measuring Rig (SerialUnited Kingdom military aircraft serials
In the United Kingdom to identify individual aircraft, all military aircraft are allocated and display a unique serial number. A unified serial number system, maintained by the Air Ministry , and its successor the Ministry of Defence , is used for aircraft operated by the Royal Air Force , Fleet...
XK426) was destroyed in 1957 but the first (Serial XJ314) is preserved and on public display at the Science Museum
Science Museum (London)
The Science Museum is one of the three major museums on Exhibition Road, South Kensington, London in the Royal Borough of Kensington and Chelsea. It is part of the National Museum of Science and Industry. The museum is a major London tourist attraction....
in London, England.
Specifications (Thrust Measuring Rig)
External links
- Pictures of the Thrust Measuring Rig (with text in Russian)
- A Science Museum picture of XJ314
- http://www.scienceandsociety.co.uk/results.asp?txtkeys1=Flying+Bedstead Flying Bedstead’ after its (Low Fuel) accident, Hucknall, Nottinghamshire, 1957. With Air Commodore Larsen
- Pathe News - Flying Bedstead