High Quality Content by WIKIPEDIA articles! The British Rail Class 508 electric multiple units ("EMUs") were built by BREL at York works in 1979-80. They were the fourth variety of BR`s then-standard 1972 design for suburban EMUs, eventually encompassing 755 vehicles and five classes (313/314/315/507/508). They have mostly worked on the Merseyrail network since 1983, and continue to do so, now refurbished by Alstom`s Eastleigh Works.