BP class cars were placed into service between 1910 and 1913. They were in steam hauled surburban service until modified for electric train use.
The class adopted was BP, with numbers 1 - 62. The 'P' indicated 'passageway' or centre aisle down the car with seats to each side.
In 1919 and 1922, the cars were modified for electric traction. This involved replacing the gas lighting with electric light circuits and jumper cable sockets and cable on the underframe for traction control.
Twenty eight cars done in 1919 were reclassed to BPT_ with same numbers. The remaining cars done in 1922 were reclassed as _T__ with new numbers.
Car conversions were as follows:
All BP went to BPT with same numbers except the following cars which were recoded and renumbered directly to T: BP 19 to T 305, BP 28 to T 314, BP 30 to T 316, BP 32 - 62 to T 318 - 348.