sentences:  In 1956, after a boardroom struggle over power and control, Jack Sangster became Chairman of BSA Group, succeeding Sir Bernard Docker.He appointed Turner Chief Executive of the Automotive Division (comprising BSA, Ariel, Triumph, Daimler and Carbodies – makers of London taxicabs).The first unit construction twin-cylinder motorcycle made by Triumph, the 350 cc (21 ci) 'Twenty One' 3TA, designed by Turner and Wickes, was introduced for the 21st Anniversary of Triumph Engineering Co. Ltd in 1957.