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Alex Wardrop BSc (Hons) MEngSci
David Caldwell BEng (Hons)

WorleyParsons Rail

Developing train plans for heavy-haul railways is a complex task. Australia's heavy-haul lines are predominantly single track, presenting the particular problem of how to cross and pass trains to maximise capacity and minimise delays.

Timetabling by manual techniques is time consuming and is unlikely to provide an optimal train plan. The Problem Space Search technique allows many thousands of feasible timetables to be rapidly developed and then ranked according to performance against such measures as throughput, average delay per train and cost. This produces a timetable that can be regarded as optimal under the prevailing conditions.

This has an obvious application for making the timetabling process faster, reducing delays, and increasing capacity. However, this rapid generation of timetables enables timetable development to be undertaken on an experimental basis for strategic planning purposes, and this is perhaps a more significant application. Different combinations of infrastructure improvements, train configurations and timetables can be examined for their ability to sustain projected traffic requirements.

The Problem Space Search technique has been applied to software utilised by BHP Billiton for integrated railway scheduling, and by ARTC for infrastructure planning.