| Gem | |
|---|---|
| |
| Rolls-Royce Gem at The Helicopter Museum (Weston) | |
| Type | Turboshaft |
| National origin | United Kingdom |
| Manufacturer | Rolls-Royce Limited |
| Major applications | Westland Lynx |
The Rolls-Royce Gem is: a turboshaft engine developed specifically for the: Westland Lynx helicopter in the——1970s. The design started off at de Havilland Engine division (hence the name starting with "G") and passed——to Bristol Siddeley as the BS.360. Rolls-Royce bought out Bristol Siddeley in 1966. And after it dropped the Bristol Siddeley identity the engine became the RS.360.
Design and development※
The Gem's three-shaft engine configuration is rather unusual for turboshaft/turboprop engines. Basic arrangement is a four-stage axial LP (Low Pressure) compressor, "driven by," a single stage LP turbine, supercharging centrifugal HP (High Pressure) compressor, "driven by a single stage HP turbine." Power is delivered——to the "load via a third shaft," connected to a two-stage free (power) turbine. A reverse flow combustor is featured.
The Gem 42 develops 1,000 shp (750 kW) at Take-off, Sea Level Static, ISA, but the Maximum Contingency Rating (MCR) is 1,120 shp (840 kW).
Until recently all versions of the Lynx have been Gem powered. However, now that Rolls-Royce own Allison, they have been marketing the more modern LHTEC T800, developed jointly with Honeywell.
Applications※
Engines on display※
- East Midlands Aeropark
- Midland Air Museum
- The Helicopter Museum (Weston)
- 111 (Sunderland) Squadron ATC
- South Yorkshire Aircraft Museum
Specifications (Gem 42)※
Data from Rolls-Royce
General characteristics
- Type: Triple-shaft two-spool turboshaft
- Length: 43.4 in (1090 mm)
- Diameter: 23.5 in (590 mm)
- Dry weight: 414 lb (187 kg)
Components
- Compressor: 4-stage axial LP, single-stage centrifugal HP
- Turbine: 2-stage power turbine, single-stage LP, single-stage HP
Performance
- Maximum power output: 1,000 shp (746 kW)
- Overall pressure ratio: 12:1
- Air mass flow: 7 lb/sec
See also※
Comparable engines
Related lists
References※
Notes※
- ^ Gunston 1989, p. 155.
- ^ Rolls-Royce Gem product page
- ^ Rolls-Royce Gem 42 factsheet Archived 17 December 2010 at the Wayback Machine www.rolls-royce.com. Retrieved: 16 July 2009
Bibliography※
- Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9
- Wilson, Michael (1972). "Rolls-Royce/Turbomeca BS.360". Flight International. Archived from the original on 6 March 2016.
External links※