Nash &amp; ThompsonNash &amp; Thompson Nash & Thompson Nash & Thompson was a British engineering firm that developed and produced hydraulically operated gun turrets for aircraft. As part of Parnall Aircraft it was also an important manufacturer of hydraulic-powered radar scanners used on radar systems such as H2S and AI Mark VIII. Nash & Thompson also designed the hydraulically-powered turret traversing systems that were used in British Cruiser tanks from the A9 - the first tank with a powered turret traverse - through to the Cromwell. History. Nash & Thompson was established in 1929 at Kingston upon Thames by business partners Archibald Goodman Frazer Nash and Esmonde Grattan Thompson  Nash & Thompson developed the hydraulic gun turrets that Frazer-Nash invented and his designs were consequently numbered in a series prefixed with "FN". Parnall Aircraft. In May 1935 they formed Parnall Aircraft taking over George Parnall & Company and Hendy Aircraft Company. Thompson was appointed managing director and Frazer Nash technical director. 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). 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 with which they merged in 1935. Nash & Thompson Nash & Thompson was a British engineering firm that developed and produced hydraulically operated gun turrets for aircraft. As part of Parnall Aircraft it was also an important manufacturer of hydraulic-powered radar scanners used on radar systems such as H2S and AI Mark VIII. Nash & Thompson also