First published in 1972, this reference work on L.M.S. Signals is still held in high regard by all railway historians today and remains the definitive book on the subject. Up to that time, few books of this type had ever been produced, yet it set the scene for what would become the now expected detailed work on specific examples of railway history. Only 800 copies of the original book were produced and it has never been reprinted. Those few copies that do come on the market today command a high price, not just because of rarity value, but because of the expertise clearly demonstrated in its compilation.38 years later, and long overdue, this is the very first paperback reprint of the original edition. With only a few minor corrections, the book remains 99% as per the original. It will be welcomed by those with an interest in signalling as well as anyone who appreciated a comprehensive and detailed railway work.