Editing Rolls-Royce Merlin (section)

===Derby===
[[File:Osmaston Rolls-Royce.jpg|thumb|alt=Image of a red brick building with a central front door, the words Rolls-Royce Limited appear above the door in white letters|The [[Marble Hall, Derby|Marble Hall]] at the Rolls-Royce factory, Nightingale Road, [[Derby]] (photo 2005)]]
The existing Rolls-Royce facilities at [[Osmaston, Derby]] were not suitable for mass engine production although the [[Area|floor space]] had been increased by some 25% between 1935 and 1939; Hives planned to build the first two or three hundred engines there until engineering teething troubles had been resolved. To fund this expansion, the [[Air Ministry]] had provided a total of £1,927,000 by December 1939.<ref>[http://discovery.nationalarchives.gov.uk/details/r/C9003607 War Cabinet-Supply and Production: Fourth Report by the Air Ministry, Appendix V, sheet 3.] {{webarchive|url=https://web.archive.org/web/20160308203419/http://discovery.nationalarchives.gov.uk/details/r/C9003607 |date=8 March 2016 }} National Archives.gov.uk. Retrieved: 8 March 2016.</ref>{{#tag:ref|The Crewe works in fact had been leased to Rolls-Royce by the government.<ref>Harvey-Bailey 1995, p. 12.</ref>|group=nb}}  Having a workforce that consisted mainly of design engineers and highly skilled men, the Derby factory carried out the majority of development work on the Merlin, with flight testing carried out at nearby [[Hucknall Airfield|RAF Hucknall]]. All the Merlin-engined aircraft taking part in the [[Battle of Britain]] had their engines assembled in the Derby factory. Total Merlin production at Derby was 32,377.<ref name="Gunston2006190">Gunston 2006, p. 190.</ref> The original factory closed in March 2008, but the company maintains a presence in Derby.<ref>[http://news.bbc.co.uk/1/hi/england/derbyshire/7321327.stm Derby factory closure] {{webarchive|url=https://web.archive.org/web/20080403035424/http://news.bbc.co.uk/1/hi/england/derbyshire/7321327.stm |date=3 April 2008 }} news.bbc.co.uk. Retrieved: 24 August 2009</ref>