Track tokens and train safety.  Creating gaps  for special excursions  within the regular timetable.

Transcript -- Synchronising Crossing Times

The Severn Valley Railway is one of Britain's best known steam railways. Over much of its length, there is only a single track, with passing points at various points along the line. As with any commercial rail operation,  the timetable needs to meet passenger needs and health and safety requirements. The five video tracks in this album follow the work of railway  employees as they monitor and develop the service to suit passenger demand and  ensure safety systems are in place. The material forms part of the course MU120 Open Mathematics.