The British Rail Class 100 diesel multiple units were built by Gloucester Railway Carriage & Wagon Company Limited from 1956 to 1958 , designed and built in collaboration with the Transport Sales Dept. of T.I. ( Group Services ) Ltd. The British Rail Class 100 diesel multiple units were built by Gloucester Railway Carriage and Wagon Company Limited from 1956 to 1958 , designed and built in collaboration with the Transport Sales Dept. of T.I. ( Group Services ) Ltd.