The Motor Rail & Tramcar Co Ltd built petrol and diesel engined locomotives which were mainly narrow gauge. Although the trade name Simplex was used from the early days it was not until 1972 the company was renamed Simplex Mechanical Handling Ltd. In 1987 loco manufacture ceased, business being transferred to Alan Keef Ltd of Ross-on-Wye, who continue to provide spares and have built several locos to Motor Rail designs.