Mere mention of the phrase is enough to plunge commuters into despair – but engineers at Sheffield University have come up with a new method of clearing the leaves – which can hundreds of train delays and cancellations each winter.
Autumnal leaf fall costs the rail industry £345million – with wet leaves becoming compacted on tracks under trains, creating a slippery layer which causes a loss of grip for wheels.
Now a solution being tested by Network Rail sees dry ice pellets fired at supersonic speed in a stream of air, freezing the leaves and making them brittle.
The pellets then turn back into gas and blast leaves off the line.
The method is being used by track cleaning teams on trial routes across the country and engineers hope to develop an on-board version which will automatically fire pellets at the track ahead.
Professor Roger Lewis, from Sheffield University, said the invention provides ‘more predictable braking and traction’.
Currently, most rail operators use an on-board system which blasts sand on to tracks to generate traction – but this leaves a damaging residue on lines.