Letter: Cleaner buses

THE council's motives behind the tram plan were to update Edinburgh's public transport by providing new, modern, efficient hardware. Electric trams were seen to be fast and attractive with less pollution.

Electric tram motors use no power when stationary and they work very efficiently at low speeds.

However, trams have to pick up power from overhead wires under which they have to be aligned exactly, requiring fixed tracks. These are expensive, as Edinburgh has found to its unending cost.

Bus design has changed radically since the council adopted the tram plan. Hybrid buses now operating successfully in London, Leeds and Manchester have electric motors which, like trams, do not use power while the bus is stationary and are efficient at low speeds.

These buses do not have a diesel engine and are about a quarter as big as the engines in existing Edinburgh buses.

That small engine drives a generator which charges onboard batteries, which power the motors. Although such buses have many of the advantages of trams, they do not collect their power from an overhead wire and so do not have to run on fixed tracks.

Moreover, hybrid buses may be used on any route at any time, a flexibility that enables them to be rerouted whenever a street has to be closed.

They can replace existing buses one bus at a time.

It would be perverse for the council not to consider the option of using hybrid buses - now being made by a number of comopanies including Alexander Dennis in Falkirk .

BARRY HUTTON

Main Road

Easter Pencaitland