Leaves on the Line – the annual autumn nightmare for both train operators and infrastructure maintainers.
They may look innocuous, but they can cause real problems. Light and colourful, they get blown by the wind, or sucked by the draught from a passing train, until they line on the head of the rails themselves. The next train along will then squash them onto the railhead.
This leaves a thin, black deposit – a black line around a centimetre or so wide.
Now add a spot of water – dew or rain will do – and the black turns into something resembling Teflon! Friction between the train’s steel wheel and the track’s steel rail almost disappears. So when a train tries to accelerate, it just spins its wheels. When it tries to stop, it just slides with its wheels locked up.
As a result, performance suffers. Acceleration takes ages, causing delays, and drivers have to anticipate the lack of friction and brake for signals and stations very early, resulting in yet more delays.
And that’s not all. When the sliding train comes off the end of the low-friction black line – perhaps in the station platform where there were no leaves to cause the problem – friction suddenly returns and wears a flat on the otherwise round wheel. That results in an uncomfortable ride, the clonk-clonk sound that can sometimes be heard from a passing train, and damage to the track from the uneven pounding of the flattened wheel.
The train has to be taken out of service so its wheels can go over a wheel lathe and be turned round again.
So, leaves on the line are a BAD THING.
Throughout the year, Network Rail endeavours to control lineside vegetation and keep trees at least seven metres back from the rails, but this isn’t always possible.
The end of October and start of November is, traditionally, the period which sees the most difficult conditions as the trees shed most of their leaves. Network Rail has been preparing and deploying its leaf-blasting trains, which clear the detritus off the rails. Train operators have been making their preparations too.
Rob Cummings, Northern’s seasonal performance improvement manager, said: “We have experienced some issues relating to autumn conditions, but the majority of leaves are still on the trees and so more difficult conditions are likely as we move towards November.
“To keep disruption to a minimum we’re working hard to keep the tracks in the best possible condition. Our trains are fitted with sand blasters which treat the tracks as they move, and Network Rail has leaf busting maintenance trains which blast water and sand onto the tracks to remove leaves and provide more grip for passenger and freight trains.
“We have also introduced special timetables on problematic routes and our drivers also have advanced training to help develop techniques which further reduce the impact of slippery rails.”
In addition, a new state-of-the-art wheel lathe has been installed at Northern’s Neville Hill depot in Leeds in time for autumn. Rob continued: “We’re very excited to have this new technology which has been installed ahead of autumn. One of the biggest risks to our performance during October and November is leaves on the line, but by getting more trains ups and running faster we aim to deliver the very best service for our passengers.”
Northern also works in partnership with Network Rail to keep customer’s moving. This year, 179 track gel applicators have been positioned across the region’s rail network. They spray a special sand-like gel onto the rails to help provide extra grip for train wheels.
Specialist teams will be positioned across the North West to check that the autumn treatment programme is working effectively and provide additional support where necessary.
Phil James, Network Rail’s North West route director, said: “Leaves on the line are a big problem for the railway. It disrupts services and inconveniences passengers and every year, Network Rail and train operators work together to battle against the elements to get passengers and freight to their destinations.
“Even more work has gone into getting prepared for autumn this year because of the challenges posed by the coronavirus pandemic, including how we operate the trains themselves. We are ready to keep people and goods moving across the North West by running a safe and reliable service for our customers.”