Rolling stock on the North South Line(NSL) and the East West Line(EWL), comprimising of the C151, C651, C751B, C151A, C151B and the recently-introduced C151C, share a common numbering system and are hence the easiest to record. All carriages use a 4-digit numbering system, with the first digit representing the carriage type and the subsequent 3 digits representing the trainset number a carriage is part of. Note that as a trianset comprimises of only 3 carriages, a typical 6-car train running on the NSL/EWL will be made up of 2 trainsets, usually with running numbers, except in the rare event that 2 trainsets are cross-coupled, with odd-numbered train carriages paired with even-numbered carriages.
The last 3 digits are also important in determining the type of train. C151s have trainset numbers ranging from 001-132(132 total trainsets, 66 trains), C651s have trainset numbers ranging from 201-238(38 trainsets, 19 trains), C751Bs have trainset numbers ranging from 311-352(42 trainsets, 21 trains), C151As have trainset numbers ranging from 501-570(70 trainsets, 35 trains) and C151Bs have numbers ranging from 601-690(90 trainsets, 45 trains).
Thus, with a sample train carriage identifier of 1201, the first number, 1, represents the carriage type(in this case, a Motor Car, numbered M1), while the last 3 digits, 201, represent the trainset number this carriage is part of. Hence, this carriage is from a Siemens C651 train with the train number 201/202, unless trainset no. 201 has been cross-coupled with another trainset.
Some visual examples can be seen below:
Carriage no. 3132. The first digit 3 represents the carriage identifier(3 being a Driving Trailer, DT), and the last 3 digits, 132, represents the trainset number, thus, this carriage is from a Kawasaki Heavy Industries C151, train no. 131/132. Note that train no. 131/132 is special; it is one of 6 C151s refitted with PMSM motors.
Carraige no. 3131. As above, this carriage is a DT cab, belonging to trainset 131 and part of train no. 131/132.
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North-East Line(NEL)
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C151C
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