This configuration, apart from being well-suited to multi-fuel use, also had the advantages of being of simple design with a low parts count, had low bearing loads, and possessed good cold-starting characteristics. Some technical assistance was provided to Leyland by Rolls-Royce, who by that time was a parent to the Napier aero-engine company, Napier itself remained a subsidiary of English Electric. Both Tilling-Stevens and Leyland produced single-cylinder prototype engines for the tank engine project and by 1959 the resulting complete engine design had become the Leyland 60, or L60, with the first engine running that same year.
