“Leaves on the line” is a term often repeated in the British media to the point of ridicule in the late Autumn and early winter, as passengers face disruption due to train services being delayed, subject to last-minute alterations or even cancelled.
“The leaf-fall months pose a major problem for the UK rail network, and Network Rail takes the problem of low railhead adhesion, caused by leaves which have fallen from lineside trees, very seriously. Network Rail tasks one of its divisions, the National Delivery Service, with overseeing the contracting out of trains which can help improve railhead conditions throughout the autumn, specifically in known “black spots” for poor adhesion.
For years, there has been a fight against the slippery rail conditions present at this time of year, termed the “Railhead Treatment Trains” (RHTTs). These trains are deployed across the country, tasked with both cleaning the railhead of greasy leaf mulch with high-pressure water jets and the laying of “Sandite”, a composite material of sand and aluminium in the form of an adhesive paste, applied to the rail to aid traction.
RHTTs primarily come in two forms – two-car Multi Purpose Vehicles (MPVs), lightweight multiple units also used by Network Rail in the summer for weedkilling duties, and the loco-hauled sky-blue modular FEA flat wagons, carrying large tanks and spraying equipment, which were first introduced by Network Rail for the 2005 leaf-fall season.
Chiltern Railways also use a converted three-car first generation diesel multiple unit to cover some of their running lines. For the autumn 2011 season, a pair of Network Rail’s 97/3 locomotives (specially converted from Class 37s, with the addition of the new ERTMS in-cab signalling system) were provided for use on the Crewe-based Welsh diagram, where their once immaculate yellow liveries was then obliterated by a brown film of sandite and general railhead dirt.
The loco-hauled RHTT sets, which present the most interest to rail enthusiasts, are currently operated by two freight operating companies – German-owned DB Schenker (formerly EWS) and Carlisle-based Direct Rail Services (DRS), and bring loco-hauled trains to many parts of the rail network which rarely see anything other than multiple units, such as the rural branch line from Oxenholme to Windermere, in the Lake District.
The fleet of FEA wagons is based and maintained through the year at Network Rail’s depot at York Holgate, the city’s former carriage works complex, and they are dispatched in multiples of two or three to the various out-stations for the autumn season in September. The wagons are fitted with through wiring for the multiple-working systems of various locos. This is particularly useful as all but the Inverness-based circuit (which employs a single Class 67) are operated in top ‘n’ tail mode.
Under the current contracts, DRS operate a total of six RHTT circuits – two based at Carlisle Kingmoor (one covering Cumbria and North Lancashire and the other covering the North East) and four based in the sidings at Stowmarket, covering many of the routes in East Anglia. The Class 66-hauled LNW circuit from Carlisle, consisting of three wagons, is one of the longest circuits, taking over 20 hours to cover all of its booked routes.
DRS have employed two pairs of 57s and three pairs of Class 37s on their RHTT trains in the season which has just finished. Some of the most popular RHTT trains with photographers have been the two York-based circuits, which employ pairs of veteran Class 20 locomotives, carrying a range of heritage liveries.
The normal crewing arrangements for the RHTT workings consists of a single driver, accompanied by the operator of the sandite and jetting equipment, an employee of JSD Rail, contractors who also work with Network Rail during the weedkilling season. The operator carries a large hand-held remote control, from which he is able to adjust the settings of the various modules onboard the wagon or MPV.
The water sent jetting down onto the rails is at an incredibly powerful pressure – at over 20,000psi, it is able to easily clear the railhead of any grime or leaf mulch. The jetting can take place at speeds of up to 60mph, but cannot be done when the train is stationary, as the highly-pressurised water would cause serious damage to the rails themselves! Laying sandite paste, however, can only be done at a maximum of 40mph.
Each RHTT season finishes in December, with a phased withdrawal of the various circuits around the country, depending on reported railhead conditions and the weather – there is little point continuing to run the circuits if all of the leaves have already decanted from the trees! The locomotives and their FEA wagons return, in convoy, from their outposts. The wagons will then spend nine months undergoing preparation for their next intensive season, while the locomotives return to their home depot. The National Delivery Service now turns its attention to their next major logistical operation – the deployment of snowploughs across the railways of Britain.