A good number of London Underground lines are automatic operation - however on manually operated London underground lines they have a board similar to the zebra

A good number of London Underground lines are automatic operation - however on manually operated London underground lines they have a board similar to the zebra board at each station - it's at the driver end of the platform and shows their alignment, there is no conductor on the underground, just a driver and occasional plain clothes ticket inspectors. However not all underground platforms on each line are of uniform length - for example Baker Street's subsurface lines have platforms shorter than the trains that run on them.