View source for Rolls-Royce Hawk

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{{Use dmy dates|date=August 2017}}
{{Use British English|date=August 2017}}
{|{{Infobox Aircraft Begin
 |name = Hawk
 |image =Rolls-Royce Hawk duxford.JPG 
 |caption = Preserved Rolls-Royce Hawk
}}{{Infobox Aircraft Engine
 |type=Liquid-cooled [[inline engine (aviation)|inline piston engine]]
 |manufacturer=[[Rolls-Royce Limited]]
 |national origin=
 |first run=1914
 |major applications=[[SSZ class blimp]]
 |number built = 205 
 |program cost = 
 |unit cost = 
 |developed from = 
 |developed into = 
 |variants with their own articles =
}}
|}

The '''Rolls-Royce Hawk''' was a British [[aircraft engine|aero engine]] designed by [[Rolls-Royce Limited|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&nbsp;hp by February 1916, and 105&nbsp;hp by October 1918.<ref>Pugh 2001, p.78.</ref>

After Rolls-Royce made the prototypes, the Hawk was manufactured under licence by [[Straker-Squire|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 [[SSZ class blimp|SSZ class]] coastal patrol airships of which 76 were built.

==Applications==
*[[Avro 504|Avro 504F]]
*[[Farman MF.7]]
*[[Royal Aircraft Factory B.E.2]]
*[[Sage Type 3]]
*[[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 {{convert|26|knots|mph km/h|0}} ''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 of Boats, Steam and Stories|Windermere Jetty museum]].<ref>{{cite web |url=https://windermerejetty.org/items/canfly/ |title=Canfly |publisher=Windermere Jetty: Museum of Boats, Steam and Stories |date=2019 |accessdate=30 April 2019}}</ref>

==Specifications (Hawk I)==
{{pistonspecs
|<!-- If you do not understand how to use this template, please ask at [[Wikipedia talk:WikiProject Aircraft]] -->
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|ref=''Lumsden''<ref>Lumsden 2003, p.187.</ref>
|type=6-cylinder liquid-cooled [[Inline engine (aviation)|inline]] aircraft piston engine
|bore=4 in (101.6 mm)
|stroke=6 in (152.4 mm)
|displacement=452.3 in<sup>3</sup> (7.41 L)
|length=46.85 in (1190 mm)
|diameter=
|width=23.5 in (597 mm)
|height=35.5 in (902 mm)
|weight=387 lb (175.5 kg)
|valvetrain= OHC – [[Overhead camshaft]]
|supercharger=
|turbocharger=
|fuelsystem=Twin [[Claudel-Hobson]] FZR carburettors 
|fueltype= Petrol
|oilsystem=
|coolingsystem=Liquid-cooled
|power= 75 [[horse-power|hp]] (56 kW) at 1,350 rpm
|specpower=
|compression=5.1:1
|fuelcon=
|specfuelcon=
|oilcon=
|power/weight=0.2 hp/lb (0.3 kW/kg)
}}

==See also==
{{aircontent
<!-- other related articles that have not already linked: -->
|see also=
*[[Rolls-Royce aircraft piston engines]]
<!-- designs which were developed into or from this aircraft: -->
|related=

<!-- aircraft that are of similar role, era, and capability this design: -->
|similar aircraft=

<!-- relevant lists that this aircraft appears in: -->
|lists=
*[[List of aircraft engines]]

<!-- For aircraft engine articles.  Engines that are of similar to this design: -->
|similar engines=
*[[Mercedes D.II]]
<!-- See [[WP:Air/PC]] for more explanation of these fields. -->
}}

==References==

===Notes===
{{reflist}}

===Bibliography===
{{refbegin}}
*''Flight'' 7 May 1954
*[https://web.archive.org/web/20110713031618/http://infomotions.com/etexts/gutenberg/dirs/etext96/bappf10.htm 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}}.
{{refend}}

== External links ==
{{commons category}}
* [http://www.johnbass.co.uk/cm/displayimage.php?album=1&pos=75 RR-Hawk at Shuttleworth Collection in the UK]{{dead link|date=March 2018 |bot=InternetArchiveBot |fix-attempted=yes }}
* [https://web.archive.org/web/20130404155102/http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=856 RR-Hawk at USAF museum]

{{RRaeroengines}}

[[Category:Rolls-Royce aircraft piston engines|Hawk]]
[[Category:1910s aircraft piston engines]]
[[Category:Airship engines]]