Sir David McMurtry
Rank 2017
Dublin-born McMurtry, 77, left Ireland at the age of 18 and traces his interest in engineering to making balsa wood aeroplane kits as a child. He rose from an apprentice machinist and fitter in the late 1950s through the ranks to become assistant chief designer at Rolls-Royce by the early 1970s. He began Wotton-under-Edge engineering group Renishaw with colleague John Deer (qv) in 1973, initially running the business from their homes. It floated 10 years later and now has a market cap of more than £1.84bn. He is listed as either an inventor or co-inventor of 47 Rolls-Royce patents and more than 150 at Renishaw, which has branched out from specialist measuring equipment to a range of other hi-tech wizardry.
   The group's 3D printing technology has been harnessed by numerous manufacturers and is to be used by the Land Rover BAR team led by Sir Ben Ainslie in this year's America's Cup to create metal parts for its yacht. Renishaw is regarded by politicians as one of Britain’s flagship businesses, with Theresa May and Philip Hammond holding a summit last November at its headquarters with McMurtry and other members of his board to discuss the state of the UK economy and the chancellor’s autumn statement. McMurtry's Gloucestershire residence, Swinhay House, once served as a spectacular villain's lair in an episode of the BBC drama Sherlock, but the engineering entrepreneur lives elsewhere, apparently because his wife Terry considers the iconic mansion a bit too flashy.
   Renishaw’s shares have had a strong run over the past year, rising by more than a third. McMurtry's stake is now worth almost £670m while other assets and nearly £54m of dividends since 2012 take him to £738m.