WILLIAM BARTER uses experience from HS2 to show how the techniques of timetable planning support development of a major project, and how timetabling practices need to evolve to reflect high-speed operations
In a major project, it is never too soon to start timetable planning. A ‘development timetable’ tests the capability of intended infrastructure to deliver the proposed service. Drafting a timetable allows operating costs for the business case to be quantified – energy and rolling stock maintenance deriving from vehicle-miles, and crew costs from train-hours, as well as confirming the fleet size need to run the service.
But how to compile a timetable for a railway that does not yet exist?
SIMULATION
Computer simulation establishes the inputs to the timetable, and tests potential operation of that timetable.
The building blocks of any timetable are the Sectional Running Times (SRTs) between adjacent ‘timing points’ (essentially, stations and junctions), reflecting the rolling stock capabilities combined with the route speed limits and gradients, as well as whether the train is starting from, stopping at or passing each timing point. Raw simulation output is turned into SRTs by adding a robustness marg…
