The British Rail Class 507 is a type of electric multiple unit (EMU) passenger train built by British Rail Engineering Limited at Holgate Road carriage works in two batches from 1978 to 1980. They were the second variety of British Rail's standard 1972 design for suburban EMUs derived from PEP stock, which eventually encompassed 755 vehicles over five classes (313, 314, 315, 507 and 508). They have worked on the Merseyrail network from new and continue to do so, having been refurbished by Alstom's Eastleigh Works. The Class 507 units are all now or more years old. History With the Class 502 units life-expired, unable to cope with the demands of the new Link tunnel and approaching 40years old, by 1977 a replacement was sought. Owing to the success of the Class 313 fleet on suburban services from King's Cross, four sets were temporarily transferred to Merseyside and based at Hall Road TMD. Sets 313013/063 were used for clearance trials on the Southport, Ormskirk and Kirkby-Garston lines. The results showed that a similar type of stock would be suitable for the Merseyrail Northern Line. Initially, 47 sets were ordered (507001-507047) but cost issues forced this number to be reduced to 38 units, then 30 by early 1978 when the first sets were under construction. Ultimately, 33 units were built between September 1978 and October 1979. The first set was delivered to Birkenhead North depot during September 1978, with the first test run taking place on 9 October 1978. On 25 October 1978, a Royal Special involving units 507001 and 507002 conveyed The Queen and several other VIPs on a special service between Moorfields and Kirkby. Following the journey, she declared the new-look Merseyrail network officially open. The first passenger working occurred on 1 November 1978, with unit 507001 working the 07:39 Southport-Liverpool Central with a commemorative headboard. It worked between Liverpool and Southport for the remainder of the day, while unit 507002 operated between Liverpool and Ormskirk. Further Class 507 units steadily entered service and the Class 502 was, in turn, withdrawn. By mid-1980, Northern Line services were entirely in the hands of the Class 507 and all of the sets were in service by October 1980. A host of new liveries appeared following sectorisation of British Rail. Following privatisation, the Class 507 units were used interchangeably between both the Northern Line and the Wirral Line, working a further four