"A combined-volume reissue of the IRSE 'green booklets' no. 4. Single line control [2nd ed.] - no. 12. Block instruments - no. 13. Train describers."
Title from cover.
Originally published: Teignmouth : Peter Kay, 2001.
British Railway signalling practice. Signalling instruments. ISBN 0902390236. Published by IRSE in 2005. Publication and catalogue information, links to buy online and reader comments.