british rail class 158 "express sprinter" is a type of diesel multiple unit (dmu) train. they were built for british rail between 1989 and 1992 by brel at their derby works. they were built to replace old dmus and locomotive-hauled passenger trains. class 159 trains are almost the same as class 158s. they work many non-electrified services such as exeter st david's to london waterloo. they were among the last new trains in the uk to be built with the old toilet system which emptied directly onto the track. brel also built 20 carriages to 1m gauge for export to thailand in 1990/1.