Nash & Thomson

Nash & Thompson was a British engineering firm that specialised in the production of hydraulically operated gun turrets for aircraft. The company was also an important manufacturer of hydraulic-powered radar scanners, used on radar systems such as H2S and AI Mark VIII.

History
Nash & Thompson was established in 1929 at Kingston upon Thames by business partners Archibald Frazer-Nash and E. Grattan Thompson and registered as a limited company in 1936. The company was formed to develop the turrets that Frazer-Nash had originated at his automotive firm, Frazer Nash, and the designs were consequently numbered in a series prefixed with "FN".

The company's major competition in the UK was from Boulton & Paul, which had licensed the designs of the French company S.A.M.M. (Societe d'Application des Machines Motrices). While the FN turrets used hydraulic power produced by the aircraft's engine, the BP designs used individual hydraulic pumps for each turret supplied from the aircraft's 24 volt electrical system.

Products
Nash & Thompson built a wide range of turrets for aircraft. All were powered hydraulically and carried 0.303 inch (7.7 mm) Vickers K or Browning machine guns, except where noted. Many were built by Parnall Aircraft which took over their patents, patent rights, designs and contracts in 1935.


 * FN-1 – "lobster back" partially enclosed turret for Hawker Demon
 * FN-4A – four gun rear turret
 * FN-5 – two gun nose turret on Avro Manchester, Short Stirling and Vickers Wellington
 * FN-5A – two gun nose turret on Avro Lancaster
 * FN-7 – two gun dorsal turret on Blackburn Botha, Manchester, Short Sunderland, Stirling
 * FN-9 – two gun retractable "dustbin" ventral turret on Wellington, rarely fitted.
 * FN-10 – two gun tail turret on early-model Wellington and Armstrong Whitworth Whitley
 * FN-11 – two gun retractable nose turret in Sunderland
 * FN-13 – four gun tail turret in Sunderland
 * FN-16 – single Vickers 'K' gun front turret in Whitley
 * FN-17 – two gun retractable "dustbin" ventral turret on Whitley, rarely used
 * FN-20 – four gun tail turret on Lancaster, Wellington, Stirling and Whitley
 * FN-21A – two gun retractable "dustbin" ventral turret on Manchester, rarely used
 * FN-25 – two-gun retractable "dustbin" ventral turret for the Wellington I based on the FN-17
 * FN-50 – two gun dorsal turret ("Centre Gun Turret") on Lancaster, late-model Stirling
 * FN-51 – two gun dorsal turret on early-model Handley Page Halifax
 * FN-54 – two gun rearward firing chin turret on Bristol Blenheim Mk.IV and Bristol Beaufort
 * FN-64 – two gun ventral turret ("Under Gun Turret") on Lancaster with periscopic sight, rarely fitted
 * FN-77 – retractable ventral turret fitted with Leigh Light for the Wellington and Warwick based on the FN-25
 * FN-82 – two gun (0.5 inch (12.7 mm) Browning) tail turret on late-model Lancaster
 * FN-120 – four gun tail turret; refinement of the FN-20 weighing 40 lb less; used on late-model Lancaster and Wellington
 * FN-121 – four gun tail turret on late-model Lancaster fitted with Village Inn gun-laying radar; also used without AGLR on Wellington and Warwick
 * FN-150 – an improved two gun dorsal turret, based on the FN-50, and fitted to many Lancasters