The UK's West Coast Mainline is Europe's busiest railway line with more than 2,000 train movements every day.
The line has, however, suffered years of underinvestment which are now being turned round with a massive modernisation programme.
Track renewal is to be a major part of the works, but contractor Jarvis Rail and infrastructure operator Railtrack realised there was a need to re-lay track at a much faster rate than traditional methods allowed.
The answer for Jarvis was to buy a UK version of the P-811S track renewal train (TRT) from Harsco Technologies, of Columbia, South Carolina, at a cost of £12M.
Affectionately known as Big Red, the TRT is capable of re-laying track at a rate of 400m per hour. The progress made in two weekend possessions can now be completed in a single midweek night possession.
The train needs 12 operators and six support workers. Complete with its sleeper-carrying wagons, made by Wabtec of Doncaster, it is more than 300m long.
Once on site the TRT moves forward pulling out the existing rail fastenings. which are picked up by a magnet and stored on the train.
The train then pushes the rails apart, and cuts them, before scooping up the existing sleepers. The ballast is ploughed aside by two metal prongs and planed smooth with a spreader.
The train has two conveying systems. One transfers the old sleepers back along the train using a moving gantry. They are then stored at the rear of the train, on the now emptying wagons which transported the new sleepers.
The new sleepers are transported forward to the beam wagon by the dedicated sleeper handling gantries. They are then set down two at a time, and pushed into position.
New rails, previously placed alongside the tracks, are picked up, drawn in and pulled on to the newly laid sleepers. The rails are heated to the metal stress free temperature, and located in the rail seats of the new sleepers.
The rails are then firmly clipped into place.
A ballast train follows the TLT and the ballast is regulated and tamped. The tamper, a Plasser & Theurer 9.3x, ensures the track is properly supported by the ballast; essential in extending track life and providing a smoother ride.
A separate clean up operation follows and removes the old rails.
Following trials and staff training at a test track at Leamside near Durham, the TLT went into active service in July. Track renewal records were almost immediately being set - first on the weekend of 8 July with 1,335m of track relaid at Hilmorton, near Rugby, broken again two weeks later at Atherstone with a run of 1,536m.
A spokesman for the Jarvis Railtrack Alliance said: 'The Atherstone section was the first opportunity to work in a more real-world railway environment, since it involved up to 150mm of cant, significant curves and work beneath bridges. It presented new challenges for the machine and the team. The experience being gained every time we use the TRT is invaluable.'
Speeding to Scotland
The West Coast Main Line runs for 1,032km from Euston station in London, to Glasgow Central and Edinburgh Waverley stations in Scotland. The line connects the major cities of Birmingham, Manchester and Liverpool, and is responsible for 5bn passenger kilometres and 5.5bn tonne kilometres each year.
After 150 years of service the line is undergoing a £5.8bn renewal programme. Phase one will allow 200km/h running by 2002. And on completion of phase two, train operator Virgin Rail's new tilting trains will be able to operate at up to 225km/h, slashing journey times and providing a real alternative to the airlines. The West Coast Track Alliance of Railtrack with contractor Jarvis, under the West Coast Route Modernisation Project, is responsible for upgrading the entire plain line track.
Maximum gross trailing weight (with 15 sleeper wagons): 1,574t Overall length (with 15 sleeper wagons): 391.03m Speed: In transit, 97km/h; on site, 0.8 km/h Curve capability: In transit, 80m; in operation, 300m
Sleeper handling gantries
Self powered and running on rails mounted on the edge of the sleeper carrying wagons, (SCWs) and the TRT, they carry sleepers to the TRT in batches of 19. The gantries also remove and stack the old sleepers on the SCWs.
Fastener power wagon
Provides hydraulic, pneumatic and electrical power for the TRT. Track fasteners are removed from the old track below the wagon frame, using the trolley.
Consists of two conveying systems for the transfer of old and new sleepers. It lifts, spreads and supports the running rail by a roller guide system. The rear bogie is carried on a sled, running on the old sleepers.
The old sleepers are picked up and loaded onto a sleeper conveyor.
The ballast is ploughed aside and a smooth bed prepared. New sleepers are transferred from an adjacent sleeper conveyor into position on the formation. Behind, new rails are drawn in and heated, then placed onto the new sleepers, ahead of the rear bogie of this wagon.
Rail fasteners are secured within the confines of the wagon frame.
The ballast shoulder is shifted back onto the sleeper ends by a plough placed at the rear of the wagon.