Some of us (see end of article if not you) are familiar with Classes 150, 153, 158 and 159,
but what happened to the missing numbers?
Our good friend 150002 was used as a testbed for various feature and was classified as
class 154 for the purpose.
42 2 car units of
class 155 were built by British Leyland, but 35 of them were later converted to class 153, making 70 of them. The remain 7 still operate in Yorkshire
114
class 156 units were built, and they can be found is Scotland and the North and East of England
21 units of
class 157 - called Strathclyde Sprinters - were planned but never got off the drawing board
Class 152 was another planned-but-didn't happen - a conversion plan from class 156 2 car trains to class 152 single carriage multiple units in the same way that 155s became 153s.
So what about the remaining number -
class 151 was a class 150 rival. According to something I read, after testing it entered schedule passenger serice on
6th February 1986.
From Wikipedia:
Development of the Class 151 commenced during 1983 in response to a specification issued by
BR▸ calling for a new generation of
DMU▸ with which to equip its fleet. Both Metro Cammell and British Rail Engineering Limited (
BREL▸ ) were selected to produce prototypes of their design submissions. Accordingly, a pair of 3-car units were constructed, which entered trial service with BR during 1985. If it had emerged successful, the Class 151 would have likely become the basis of Sprinter family of DMUs that were produced during the 1980s. However, following a competitive evaluation against the rival Class 150, the type did not secure a production contract, having lost out to its BREL-built rival. Both units were withdrawn during 1989 and, despite multiple vendors planning to restore them for service, they were ultimately scrapped.
Want to see more?
http://www.traintesting.com/Class151.htm* Other numbers
Class 150 - local diesel units 2 cars used across the country including South West
Class 153 - single carriage trains, no longer in use in South West but were here until quite recently
Class 158 - regional and longer distance units - 2 and 3 car, end doors, corridor throughout, aircon
Class 159 - South West[ern] [trains/railway] 3 car units - minor conversion from class 158.