Yellow Trains

The 'Yellow Trains' or to be more accurate, the various measurement and test trains operated by Network Rail are a regular sight to passengers on all parts of the railway system. Operated by Network Rail on behalf of any number of the various companies charged with maintaining the network, their task is to check, assess and monitor the track, bridges and tunnels on both passenger and freight only lines. Andrew Royale spent many years as a computer technician on a variety of the different test trains and in the course of his travels covered much of the network. His story is both technical and personal, from the purpose of the equipment and how it operates to the trials and tribulations of using it.