The renowned and easy to use TRAX computer programme is back. Author Jeff Geary explores the possibilities of controlling a model railway in prototypical fashion, namely by operating points and signals from a signal-box style lever frame. Making the frame mechanically interlocked, ensures that trains can only be signalled when the correct route is set, and that conflicting routes cannot be set at the same time. This new book also explains the principles of signalling, the different types of signal and their significance, and how a typical track diagram would be signalled. The application of these principles to the model railway is then discussed, showing how the block section method of working can be adapted to control the layout. In easy to follow fashion and with copious illustrations, the construction of signals and lever frames is explained, with details on how to construct a set of mechanical locks and releases to ensure exact workings of a lever frame Also included with the book is a CD containing the third version of the TRAX program. Additional facilities available in TRAX 3 include new track formations such as scissors crossings and transition curves plus extended drawing facilities. New signal types have been added plus lever frames incorporating full locking facilities. Also included in the programme is a scripting facility to develop and test timetabling, and utility programs to make it possible to test locking on the lever frame.