Car No. E50249 was the mysterious oddity which kept a generation of rail enthusiasts, especially those in East Anglia, puzzled. Built to Diagram 548 in 1959, it was thus identical to the 51471 - 51494 batch but built under a different Lot Number; 30505 (51471 etc. were Lot No. 30503). E50249 was always quoted as being part of a 4-car unit, but no 4-car Cravens units existed. So in this respect as well as its unique Lot No., it was in effect a one-off. The "4-car" designation was thought to have come about as 50249 was built as a replacement for the DMBS of a 4-car Metro-Cammell unit withdrawn with accident damage. Metro-Cammell car E50173 was withdrawn and scrapped (in October 1957 when still almost new) following a serious accident at Hexham, but that was two years before 50249 was built and in any event 50173 did not have a van whereas 50249 did. To add to the mystery, 50249 sat bang in the middle (in respect of its number) of a very large batch of various types of Metro-Cammell cars built two years earlier. The logical answer to that puzzle is Cravens 50249 being built to replace a Metro-Cammell car which bore the same number. The problem with this theory is that no record appears to exist of a Metro-Cammell car bearing the number 50249. When new, 50249 is known to have worked briefly in the Darlington area but coupled to what exactly isn't known. Very soon, 50249 was transferred to East Anglia where it rasped and rattled around for the rest of its life. Perhaps one day somebody will be able to finally clear up the mystery of this Cravens oddity