Stanley Hall's pocket guide to modern signalling practice has been one of the staple volumes in the railway list for many years. The third edition was produced in both original and revised editions and both are now out of print. Since the publication of the last edition, there has been one major change to the railway signalling infrastructure in use in Britain. The opening of the CTRL from St Pancras to the Channel Tunnel has resulted in the adoption of signalling capable of handling trains operating at speeds in excess of 300kmh. This fully revised fourth edition will have more pages to allow for the additional information on the signalling in use on the CTRL and, for the first time, the book includes colour photographs which will make the book much more visually attractive and accessible to users.