Around were requisitioned, principally from the Swynnerton and Cotes estates.
Sir Alexander Gibb & Partners, Consultant Engineers to the
Ministry of Supply, were appointed to supervise construction. Plans were drawn up by A.P.I.Cotterell & Son, Chartered Engineers, on behalf of Gibb. The
Royal Arsenal,
Woolwich, as the long-established principal Royal Ordnance Factory, designed the various processes and layout of buildings. The Engineer-in-Chief, appointed to oversee the construction was
Wilfrid Cracroft Ash. Site work was divided into areas under divisional superintendents who were directly responsible to Ash. ROF Swynnerton, being a 'filling' factory was the most dangerous of the various types of munitions factories; bomb and shell-casings were filled with highly combustible explosive materials. It was planned that the factory should provide at least some production while construction continued. Swynnerton became operational in stages, from the middle of 1940. The factory was completed in two years, a task which, in peace-time, would have taken five years. It consisted of over 1,700 small buildings, each surrounded by earth banks to contain accidental blasts; if one building was destroyed the adjacent buildings would be unaffected. Five large boiler-houses were built strategically around the perimeter of the site so that, if one or two were bombed, production could still be maintained. Roadways between buildings were of smooth, grit-free asphalt and were called ‘cleanways’ because they had to be kept clean at all times, to avoid any possibility of sparks. In addition to the factory itself, seven residential hostels were built, along with houses and flats, for munitions workers and almost 500 families of specialist staff. ==Railway connections==