Harman Patil (Editor)

Armstrong Siddeley Double Mamba

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Armstrong Siddeley Double Mamba

The Armstrong Siddeley Double Mamba is a turboprop engine design developed in the late 1940s of around 3,000–4,000 hp (2,500–3,000 kW). It was used mostly on the Fairey Gannet anti-submarine aircraft developed for the Fleet Air Arm of the Royal Navy.

Contents

Design and development

The Double Mamba (rarely known as the Twin Mamba) was a development of the Armstrong Siddeley Mamba with two Mambas driving contra-rotating propellers through a combining gearbox.

Engine starting was by cartridge, however, forced air restart was achieved in flight. One engine could be shut down in flight to conserve fuel.

Variants and applications

The Ministry of Supply designation system for these engines reflects the obvious linkage to their Mamba lineage:
AS = Armstrong Siddeley
M = Mamba
D = Double
num = model

The Double Mamba engine was also proposed for the Westland Westminster, a 30-seat helicopter that was later built as a prototype powered by a pair of Napier Eland E220 turboshaft engines.

Engines on display

Preserved Double Mamba engines are on public display at the:

  • Australian National Aviation Museum
  • Deutsches Museum Flugwerft Schleissheim
  • Gatwick Aviation Museum
  • Imperial War Museum Duxford
  • Midland Air Museum
  • Queensland Air Museum
  • Specifications (ASMD.3)

    Data from Flight

    General characteristics

  • Type: Turboprop engine
  • Length: 102.25 in (2,597 mm)
  • Diameter: 52.8 in (1,341 mm)
  • Dry weight: 2,170 lb (984 kg)
  • Components

  • Compressor: 10 stage axial (x2)
  • Combustors: Six combustion chambers (x2)
  • Performance

  • Maximum power output: 2,960 eshp (2,207 kW)
  • Overall pressure ratio: 5.35:1
  • Air mass flow: 18.5 lb/sec (8.4 kg/s) per single Mamba unit
  • Specific fuel consumption: 1.71 lb/(lbf·h)
  • Power-to-weight ratio: 1.36 eshp/lb
  • References

    Armstrong Siddeley Double Mamba Wikipedia