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Piling rig: The Hops system will enter service next year
Network Rail has unveiled its ‘factory on wheels’ train, which it said will dramatically reduce the cost of electrifying stretches of track, including the Great Western main line.
The 23-vehicle High Output Plant System (Hops), built by German manufacturer Windhoff, will move forward at a rate of 1,500m per nightshift, inserting piles and erecting steel masts, wires and cables in one movement. Hops has a steel safety wall attached to its side, so it can be used while adjacent railway lines remain open.
Hops will enter service next year on the Great Western main line to electrify 235 miles of track between Maidenhead and Swansea.
Robbie Burns, project director for Network Rail, Western and Wales, said: “Electrifying such a long stretch of line, while also making sure passengers can still take trains to where they want to go, is a challenge we need new technology to meet.
“The factory train will allow us to work overnight, when the network is less busy, and will also mean we can keep trains running. It’s a step change in the way we work.”
Operating six nights a week, the £40 million Hops will sink up to 30 piles per shift. This equates to the usual length of one stretch of conductor wire – between 1,200 and 1,500m. Around 17,000 piles will need to be sunk before reaching Swansea.
Hops will effectively be several trains in one. It will comprise a piling rig with Movax vibro piling heads, which will be used to vibrate the steel piles into the soil. It will also comprise two pile-carrying wagons, and a Fambo hydraulic percussion hammer for tough ground.
An excavation and concrete batching unit will feature a Hitachi excavator plus a Kniele concrete unit which will mix concrete from onboard aggregate, cement and water tanks. Another unit will erect the masts, portal booms and twin-track cantilevers.
An ancillary conductor train will install the earthing wires, return wires and small parts such as registration arms and other equipment. The contact and catenary equipment will string up the remaining wires, under tension.
Another unit will install other articles such as wires under low bridges, neutral sections and record information such as height and stagger.
The Hops train will be maintained and restocked at a base near Swindon. A further distribution site in the town will act as a stockpile for materials, which will be delivered when needed. Around 200 people will work on the Hops project overall, employed by operator Amey.