 English Electric built two trains for the line , designed to resemble the electric trains already in use on the Southern Railway , but on a smaller scale . A 94 ft 6 in ( 28 @.@ 80 m ) four @-@ car train , painted red , was capable of carrying 108 passengers , and had a driver 's cab at each end to avoid the need to turn the train around . A 99 ft 6 in ( 30 @.@ 33 m ) train , painted yellow , was also able to carry 108 passengers , but had two extra driver 's cabs in the centre , allowing it to be split into two separate 49 ft 9 in ( 15 @.@ 16 m ) trains , each capable of carrying 54 passengers . It was envisaged that when the line was busy both trains would be used , but during quiet periods the line could be operated by the two halves of the yellow train . The red train was modified so that it could also be split , reducing its capacity to 102 as the two rows of seats at the centre were replaced by driver 's cabs . 
