Leaves On the Line
No, we mean Leaves On the Line. It’s no joke, but we’re on the case.
You wouldn’t think the humble leaf could cause so much trouble. 50 million leaves fall onto our train tracks every autumn. When mixed with rain and squashed by train wheels, they form a slippery layer on the rails like black ice. Our drivers need more time to stop and start the trains as the wheels have less grip on the tracks. We prepare in advance for autumn and here are just a few of the things we do in preparation.
Times are changing
We're making some small changes to our timetable this autumn to keep trains running on time.
Some morning trains will leave a few minutes earlier. Evening trains will leave London at the same time as usual, but some will arrive at stations along their route a few minutes later.
The timetable changes affect both weekday and weekend services.
On days when we expect the weather to be at its worst, our Off-Peak* metro services will call less frequently at some stations.
These timetable changes give us the extra time we need to drive the trains safely.
*The amended timetable affects Monday-Friday Off-Peak metro services towards London. Some morning Peak services leaving London are also affected.
We're on the case
- Clearing hundreds of miles of trackside vegetation throughout the year
- Running special leaf-busting trains throughout autumn that clean the rails using water jets and apply a sand-based gel to help trains grip the rails
- Adding a few minutes to journey times to give drivers more time to stop and start
- Putting an amended timetable in place at some stations on days when the weather is forecast to be at its worst
The science bit
The once lush trees of spring and summer slowly fade, through shades of yellow and orange, to brown, before their leaves fall gracefully to the ground. Winds carry them towards the railway line, where the rush of air from passing trains pulls them directly onto the tracks, where they are crushed to a pulp. Around 50 million leaves fall onto our train tracks every autumn.
Leaves are made up of around 80% water, with the rest made up of a complex combination of other substances including pectin, cellulose, and a type of fatty acid that, when compressed, have a lubricating effect. When this happens on train tracks, its essentially like coating them with Teflon, and the steel wheels struggle to grip the steel tracks. Braking distance can more than double, with trains taking up to 1000 metres to stop.
The wet mulch also messes with the electrical signals used to keep track of where all the trains are on the network. This combination of issues leads to a potentially dangerous situation, so to be on the safe side, we need to move slowly and occasionally miss out the odd station along the route to make up time. We know that this can be frustrating but we have teams working around the clock using specialist machines to clean the railhead (the top of the rails). It’s an arduous task, but trust us, we’re on it and working hard to minimise disruptions to your journeys.