Rolls-Royce Hawk

Hawk
Preserved Rolls-Royce Hawk
Type	Liquid-cooled inline piston engine
Manufacturer	Rolls-Royce Limited
First run	1914
Major applications	SSZ class blimp
Number built	205

The Rolls-Royce Hawk was a British aero engine designed by Rolls-Royce in 1915. Derived from one bank of six cylinders of the Rolls-Royce Eagle, it produced 75 horsepower at 1,370 rpm. Power was progressively increased to 91 hp by February 1916, and 105 hp by October 1918.^[1]

After Rolls-Royce made the prototypes, the Hawk was manufactured under licence by Brazil Straker in Bristol between 1915 and 1918. During this period 204 engines were built, and the Hawk earned a reputation for high reliability.

Many engines of this type were used to power the

coastal patrol airships of which 76 were built.

Applications

• Avro 504F
• Farman MF.7
• Royal Aircraft Factory B.E.2
• SS class blimp
  (1 example)
• SSP class blimp
• SSZ class blimp
• SST class blimp

Post war one engine (serial number 332) was fitted into a specially built hull and launched on Windermere in 1922 with the name Canfly. With a flywheel added it was directly connected to the boat's propeller without a gearbox. Capable of reaching speeds of 26 knots (30 mph; 48 km/h) Canfly was used as the official's boat at several world speed record attempts during the 1920s and 1930s. The boat and engine are now displayed in a working but non-operational state at the Windermere Jetty museum.^[2]

Specifications (Hawk I)

Data from Lumsden^[3]

General characteristics

• Type: 6-cylinder liquid-cooled
  inline
  aircraft piston engine
• Bore: 4 in (101.6 mm)
• Stroke: 6 in (152.4 mm)
• Displacement: 452.3 in³ (7.41 L)
• Length: 46.85 in (1190 mm)
• Width: 23.5 in (597 mm)
• Height: 35.5 in (902 mm)
• Dry weight
  : 387 lb (175.5 kg)

Components

• Overhead camshaft
• Fuel system: Twin Claudel-Hobson FZR carburettors
• Fuel type: Petrol
• Cooling system: Liquid-cooled

Performance

• Power output: 75
  hp
  (56 kW) at 1,350 rpm
• Compression ratio: 5.1:1
• Power-to-weight ratio: 0.2 hp/lb (0.3 kW/kg)

See also

• Rolls-Royce aircraft piston engines

Comparable engines

• Mercedes D.II

Related lists

• List of aircraft engines

References

Notes

1. ^ Pugh 2001, p.78.
2. ^ "Canfly". Windermere Jetty: Museum of Boats, Steam and Stories. 2019. Retrieved 30 April 2019.
3. ^ Lumsden 2003, p.187.

Bibliography

• Flight 7 May 1954
• British Airships
• Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003.
  ISBN 1-85310-294-6
  .
• Pugh, Peter. The Magic of a Name – The Rolls-Royce Story: The First 40 Years. Duxford, Cambridge: Icon Books, 2001.
  ISBN 1-84046-151-9
  .
• Taulbut, Derek S. Eagle – Henry Royce’s First Aero Engine, Rolls-Royce Heritage Trust, 2011.
  ISBN 978-1-872922-40-9
  .

External links

Wikimedia Commons has media related to Rolls-Royce Hawk.

• RR-Hawk at Shuttleworth Collection in the UK^{[permanent dead link]}
• RR-Hawk at USAF museum