Freeze on the line: Ice pellets blast leaves off tracks
IT is a phrase guaranteed to chill the hearts of commuters – ‘leaves on the line’.
But now experts believe they have come up with a solution to the problem which causes huge train delays each year.
Autumnal leaf-fall costs the rail industry £ 45million and affects millions of passengers. Wet leaves are compacted on tracks under the weight of trains, creating a slippery layer which causes a loss of grip – like black ice on roads.
A solution being tested by Network Rail this autumn 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, developed by Sheffield University engineers, is being used by track cleaning teams on trial routes across the country.
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’.
Passengers endured almost 6,500 hours of delays caused by leaves in 2018/19 – up 78 per cent from ,650 hours in 2009/10, figures show. 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.