REGISTER

David Caldwell BE (Hons)

WorleyParsons TMG

This paper discusses the application of computer simulations to optimising the layout of signals operating on the Automatic Block principle. Considerable efficiencies can be achieved in signal design and capacity analysis by methodically applying computer simulation tools. A system for quickly and accurately testing the influence of variables (such as train types, dwell times and speed limits) on track capacity and their interrelation with signal placement is proposed.

The aim of the layout is discussed in the context of either maximising line capacity or optimising the layout to a specific traffic requirement. Application of existing simulation tools is explained and weaknesses are discussed. There is a complex interaction between braking distance, signal spacing and clearance times, particularly under diverse traffic conditions. A method for analysing these interactions quickly and efficiently is suggested. A method of laying out signals for maximum unrestricted line capacity is also discussed.