Concrete Evidence

In the recent Melbourne heatwave, track buckling was one of the many problems that contributed to problems on the network. Buckling is an issue with modern continuous welded rail (CWR) as it lacks expansion gaps. The traditional method of trail construction was to use lengths of rail joined with fishplates. These could be left slightly loose one one side so that the rail could expand and contract a little bit in response to the prevailing conditions. The correct way to lay CWR is to stress (stretch) it to its length at the hottest expected temperature and then fix it to the sleepers, preventing it from contracting. However, this requires heavy concrete sleepers firmly fixed in the road bed, wooden sleepers wont take the strain. So with that in mind, its good to see that maintenance work at Pascoe Vale Station has been done with an eye to the future. No wait, that would be what happens in some city with competently-run public transport.

Posted by Ian Donaldson