In message ,
Colin Rosenstiel writes
Standard stock 7 car trains were usually M-T-T-M+CT-T-M or M-T-T-M+T-T-M
once uncoupling was abandoned.
On the Northern line all 7 car trains were driving motor, motor, trailer
with two compressors, driving motor, driving motor, trailer with two
compressors, driving motor.
--
Clive.