 The railway never had a timetable , and operated according to demand . Whenever one station had a sufficient number of passengers the driver signalled to the other station that he was about to depart , and the trains from both stations would set off simultaneously , passing at the halfway crossing loop . The journey took approximately five minutes . Outside of times of peak demand the full @-@ length trains were generally not used , and the trains used split into their two @-@ car sections . There was no depot : trains were stabled in the lower section of the tunnel . 
