199511 – Wardrop – Train Performance and Train Modelling as an Aide to Signal Design

TMG International Pty Ltd, in association with the State Rail Authority of NSW, has progressively developed a family of related railway operational models to serve the analytical needs of railway planners and operators. These models currently cover the areas of:
i) train performance and signal system simulation (MTRAIN);
ii) timetable development and train flow modelling (CAPTURE/PROVING); and
iii) train and motive power scheduling (TRNSYS).

As demand and opportunity permit they will be expanded to cover asset management, electric traction supply modelling and train crew scheduling. However the three core models (above) are operational, proven in service and widespread in use.

The three PC-based computer models were all developed to address planning and operational issues identified in Australian railways. A characteristic of the state railways (ie the State Rail Authority of NSW, the Public Transport Corporation of Victoria, Queensland Rail, TransAdelaide and Australian National Railways in South Australia and Westrail [Western Australia]) in mainland Australia is that they all have to perform the multiple roles of serving suburban passengers, long distance passengers, bulk freight and general freight. There are differences in the scale of operation between operators but they all carry out this multi-purpose role over common railway infrastructure.

In particular, the NSW railways experience challenging operating circumstances. Currently the CityRail suburban passenger business unit operates roughly 2500 weekday trains over a 800 route kilometre/1600 track kilometre territory carrying approximately 240 million passengers annually. By way of contrast the Countrylink long distance passenger business unit currently operates roughly 50 daily trains over a 3250 route kilometre network with prospects of an additional 980 route kilometres. The Freight Rail business unit plus the independent National Rail Corporation handle well over 60 million tonnes of freight annually over roughly 7000 route kilometres.

The operating conditions are various and arduous. Ruling grades in the passenger and freight network are 1:30–33 with 1:40 quite common (refer to curve and gradient diagram for Illawarra Line between Sydney and Helensburgh). Multiple tracks (up to six tracks abreast) over substantial distances exist in metropolitan Sydney and Newcastle to separate all-stops and limited-stops trains. Minimum peak period headways fall to 3 minutes for manually driven trains observing six aspect signals supported by mechanical train stops. Maximum rural headways under train orders may be measured in days. Maximum permitted speeds are moderate (suburban passenger trains may run up to 115–130 km/h, long distance passenger trains may run up to 145–160 km/h and freight trains may run up to 80–115 km/h) however severe gradients and restrictive curvature limit point-to-point speeds. Freight train lengths and trailing loads typically lie between 400–1600 metres and 1500–8400 tonnes.

This railway thus presents a wide range of operating conditions. It also presents many opportunities for modelling and simulation to be used in planning and operational analysis.