Tram risks

The budget process for the City of Edinburgh is accompanied by deep scepticism from Audit Scotland about the city’s ability to make the savings necessary to provide a balanced budget. Risks to the budget include the possibility of operating losses from the trams, for which no provision has been made.

A casual visit to the tram tracks on the corner of North St David Street and York Place highlighted a major issue that might add considerably to those woes.

When metal wheels run on metal tracks the interface between the flange of the wheel and the rail contact surfaces wears.

Under normal use the wear is gradual and the rails, with minor reshaping by grinding, should last in excess of 20 years.

This process is called “side wear”, in rail parlance. Unfortunately, the wear in the area I inspected shows the rails have worn by 7mm in the past eight months, which is substantial, given the timescale and relatively mild winter so far.

The City of Edinburgh Council was all too aware of these issues when it designed the project as I and others told them. There could be other similar areas at the corners of South St David Street and Princes Street; and the old Haymarket Yard onto the platform outside Haymarket Station.

These particular corners are near their design minimum radius and on a steep gradient; the trams have to dump sand onto the rails to create friction on the interface during wet and icy conditions, which has resulted in excessive wear and the certainty that renewals will be required, at considerable cost, within the next few years and that these locations would have to be closed for several months while works are undertaken.

I do hope the council makes provision for a very large sum of money to cope with this inevitability within the relatively near future.

John Carson

Kirkliston Road

South Queensferry