A Guide to Mechanical Locking Frames

A labor of love from Britain's Signalling Study Group, this book provides a description with illustration of every design of mechanical frame ever used in the UK with details on the manufacturer, user, method of operation, and construction features. Illustrated with both line drawings and black and white photos (Xerox quality). Also includes a general history of the mechanical locking frame and a glossary. The authors also wrote "The Signal Box: A Pictorial History and Guide to Designs" and "The Signal Box Directory," which they recommend to provide a comprehensive history on the relationship between the contractors and railways which together developed the mechanical locking frames. 150 pages.