THE ARRIVAL of autumn has seen Network Rail’s annual battle with the leaf-fall season commence – as the infrastructure operator works hard to keep the rails clean from the challenges created by mulch.
Its dedicated fleet of Railhead Treatment Trains and Multi-Purpose Vehicles were being positioned and tested around the country from early September in preparation for the season, which lasts until mid-December.
A huge amount of planning goes into scheduling and operating the trains, which have become an essential tool in protecting the safety of the railway. Each year the autumn railhead treatment circuits cover more than a million miles between October and December, with the entire network being treated 50-plus times.
Traction is provided by various freight operating companies from a number of RHTT hubs located around the country. Colas Rail Freight, DB Cargo, Direct Rail Services, Freightliner and GB Railfreight all provide locomotives to top-and-tail RHTT services.
Decaying leaves settle on the rails and through the passage of trains and autumnal wet weather, they get ground onto the railhead, forming mulch and creating a thin, black layer on top of the rail.
The mulch on the railhead can create hazardous conditions for trains, similar to the effects of black ice on the roads, making it difficult for braking trains to stop and creating wheelslip for trains trying to accelerate when travelling over affected sections of line. It can also cause detection issues for signalling equipment.
The RHTTs are fitted with high-pressure water jets that blast away any built-up contaminants from the railhead to improve adhesion. They also apply an adhesion modifier to the rails, which is made up from a mixture of suspension gel, sand, and steel or iron shot. The MPVs perform a similar job but have a smaller capacity and range than the larger RHTTs.
The Network Rail fleet totals 29 RHTTs and 32 MPVs, which are deployed around the country, operating intens
