Armstrong Siddeley Snarler

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ASSn.1 Snarler
Country of origin United Kingdom
Manufacturer Armstrong Siddeley
Liquid-fuel engine
Propellant Liquid oxygen (LOX) / methanol/water
Pumps Centrifugal, mechanically driven by external shaft drive from other engine.
Performance
Thrust 2,000 lbf (8.9 kN) [1]
Propellant capacity LOX 75 imperial gallons (340 L),
water-methanol 120 imperial gallons (550 L)

The Armstrong Siddeley ASSn. Snarler was a small rocket engine used for mixed-power experiments with an early turbojet engine[2][3] and was the first British liquid-fuelled rocket engine to fly[4] Unlike other British rocket engine projects that used hydrogen peroxide as an oxidiser, Armstrong Siddeley's used liquid oxygen. The rocket engine is described as having a dry weight of 215 lbf (960 N) thrust of 2,000 lbf (8.9 kN) and a specific fuel consumption of 20 (lb/h)/lbf thrust.[4] Work began in 1947 and the final configuration was first tested on 29 March 1950.[5]

The prototype of the Hawker P.1040 Sea Hawk, VP 401, had a Snarler rocket of 2,000 lbf thrust added in its tail. The Rolls-Royce Nene turbojet, of 5,200 lbf thrust, had a split tailpipe which exhausted either side of the fuselage. The combination was termed the Hawker P.1072.[5][6] This gave approximately[7] 50% greater thrust, although with twenty times the fuel consumption.[4] It was first used in flight on 20 November 1950, by Hawker's test pilot Trevor "Wimpy" Wade.[3] Half a dozen flights were made using the rocket motor before a minor explosion damaged the aircraft. Although methanol was used in the P.1072, jet fuel could be used for the Snarler. It was decided that reheat was a more practical proposition for boosting jet thrust than rockets.

An unusual feature of the engine was that the fuel/oxidiser pump was externally driven, by a drive from the gearbox of the P.1072's turbojet engine.[8] This feature continued into the first versions of the subsequent Screamer engine, but was later replaced with a turbine-driven turbopump.

Variants[edit]

ASSn.1 Snarler
The prototype and test engines, (given the Ministry of Supply designation ASSn.).

References[edit]

  1. ^ "United Kingdom Aerospace and Weapons Projects: Rocket Engines". Skomer. Archived from the original on 2008-04-22. 
  2. ^ S. Allen (7 Dec 1951). "Rockets for Aircraft Propulsion". The Aeroplane. 
  3. ^ a b "Snarler" (PDF). Flight: 92–93. 25 July 1952. 
  4. ^ a b c "Aero engines 1954" (PDF). Flight: 447–448 (Armstrong Siddeley Snarler ASSn.1). 6 August 1954.  (includes external line drawing)
  5. ^ a b "Armstrong Siddeley Snarler" (PDF). Flight: 176–180. 6 August 1954. 
  6. ^ "The Quest for Power..." (PDF). Flight: 444 (P.1072 Armstrong Siddeley Snarler ASSn.1). 6 August 1954. Transferring liquid oxygen from a B.O.C. spherical tanker to the Hawker P.1072 in which the Sn rocket was tested. The gas is exhausting through the lower vents and rapidly evaporating.  (P.1072 being fuelled)
  7. ^ Although the Nene's thrust, as for any turbojet, fell with increasing altitude the Snarler's remained constant.
  8. ^ "Armstrong Siddeley Screamer" (PDF). Flight: 160–164. 27 July 1956.  (not publicly known at the time of Flight, 1954)