Often regarded as a joke, “Leaves on The Line” is now recognised as a serious safety and performance issue, which disrupts rail services during the Autumn – not just here in Britain, but all over Europe and North America.
The scale of the leaf-fall problem and the cost of keeping services running smoothly is huge:
It is impossible to predict exactly when the leaf fall season will start and how long it will last, but the weather can provide a guide to its likely onset and how serious it is likely to be for the railway.
A severe leaf fall season often follows a wet summer. It starts with a hard frost, followed by a high wind and a period of dry weather, which causes large amounts of leaves to fall over a short period of time.
But traditionally, Autumn is the season of mists and mellow weather, which spreads leaf fall over a longer period and reduces the severity of the problem.
How do leaves on the line affect trains?
Think of leaves on rails as black ice on roads and you’ll begin to understand the nature of the problem. We’re not talking about piles of dead leaves, but a hard slippery layer that coats the rails and is very difficult to remove. Briefly, this is what happens:
Consequently, trains have to operate at slower speeds to ensure safety and to reduce the potential for the wheels to slide on the rails when slowing, and spinning when trying to accelerate.
This means that drivers have to brake earlier for stations and signals and move off again more slowly - which causes delays to services.
How do leaves on the line affect trains? Continued
If a train can’t move because its wheels can’t grip the rails, often there is no alternative route, therefore following trains can be delayed or cancelled.
In addition to causing disruption to customers, the damage inflicted on train wheels during sliding and spinning on rails is considerable and means some trains have to be taken out of service for expensive repair. The rails too can be damaged costing many thousands of pounds to repair each year.
So what is the rail industry doing about it?
Network Rail, the body responsible for maintaining the rail network, is working to eliminate or minimise the problem of leaves on the line: