The British Rail Class 142 is a class of Pacer diesel multiple units used in the United Kingdom. 96 units were built by BREL in Derby between 1985 and 1987. They were a development of the earlier Class 141 which were introduced in 1984.They were initially built for use on rural branch lines. However, as of April 2015 they are mainly used on busy commuter routes in the major cities in the north of England, with some also in use on local services around Cardiff.