How dry ice could be used to tackle train delays this autumn

Monday, 4th October 2021, 9:01 am

Dry ice is set to be used to clear leaves off railway lines in a bid to tackle train delays.

The leaf-clearing technique, which was developed by University of Sheffield engineers, will be trialled by operator Northern on a passenger train in the coming weeks.

How it works

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Pellets of dry ice will be fired in a stream of air from a passenger train onto rails, making leaves frozen and brittle. 

The dry ice then quickly turns back into gas, causing it to expand and destroy the leaves.

Engineers behind the dry ice system claim their method is significantly more efficient as it can be used by passenger trains which cover greater distances than the limited fleet of cleaning trains.

It also does not leave a residue which can damage rails and train wheels, and can be used on the same stretch of railway more than once a day.

The system has previously been trialled on test tracks and could be rolled out widely by 2023/24.

Currently leaves are cleared by 61 special trains which deploy high-pressure water jets followed by a gel containing sand and steel grains to assist with braking.

‘It will be great for passengers’

Professor Roger Lewis, who is leading the development of the new method, told the PA news agency: “This technology will make a step change in train performance during autumn, improving safety.

“It will provide more predictable braking and traction than current technology, and will help to improve train performance, reduce delays, increase passenger satisfaction and support the use of new technologies to enable greater network utilisation of the UK’s railways.

“It will be great for passengers, but also for all the train operators and Network Rail as well. It will make their lives much easier.”

Why leaves on railway lines are dangerous

Some 10 million trees line Britain’s railway, and thousands of tonnes of leaves fall onto the tracks every autumn.

When trains pass over the leaves it creates a slippery layer, with a similar effect to black ice on roads.

This leads to delays as trains must run at a reduced speed, accelerate slower and brake earlier.

Autumn-related issues cost the railway industry approximately £345 million every year.

A version of this article originally appeared on NationalWorld.com