The problem we are addressing
The problem stems from the fact that we are not simply dealing with crispy, wafer thin leaves on the track.
- Leaves fall on and around the track and as the train passes the aerodynamic effect will deposit more leaves on to the track.
- When the train passes over the leaves, the wheels compress them into a paste, with a force of around one gigapascal (30 tonnes a square inch), between the wheel and track.
- The leaves are transformed into a black Teflon-like surface (called a 3rd layer contaminant), that’s bonded to the track surface.
- This super slippery layer reduces grip, meaning trains need to accelerate and brake gently to avoid slipping.
Currently, the antidote is regular treatment, with very high pressure water jets (114 million litres of water annually) and the addition of an adhesion modifiying gel to increase grip.
In areas where this is not available, (rural routes often don't have the resource to run machinery over the tracks every few hours) they are typically cleaned by manual cleaning crews. This is effective but extremely labour intensive costing the industry and wider society around £350 million per year (3)(4).
Each of these treatments is good for about 200 axle passes (5), which on a busy line, equates to around two hours of trains. Given that the cleaning rigs might pass over every six hours at best, you can see there’s a lot of room for improvement.
In many areas the railway industry has innovated and improved provision hugely, especially when you consider how many more passengers it transports around the country since the 1990s. But in the area of clearing the leaves to maintain train times, it continues to struggle to solve the nationwide problem 24/7.
How does it work?
Our technology clears the residue on tracks, returning the surface to a dry, clean and uncontaminated state, enabling the trains to run as if it were summer all year round, leading to increased capacity and closer running trains (working towards RSSB targets).
We now have a full-size working demonstrator that we are testing on rural network tracks in South Wales. The next step is to make the prototype available to busier networks for more thorough testing.
The ultimate deployment is to fit this to every passenger train, enabling train drivers to predict braking distances regardless of the weather or season and for network operators to increase the capacity on the miles of track they own.
The short video below is taken from testing of our PlasmaTrack technology on rail at Long Marsden, UK in 2019.