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Thursday 25 Jul 2013

Groundbreaking factory train to cut years off Great Western electrification

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National

A factory on rails – the first of its kind to be used on Britain’s railways – will slash years off the time it will take to electrify the Great Western main line.

With 235 route miles to electrify from Maidenhead in the east to Swansea in the west - and many thousands of trains to keep running while the work is done - Network Rail is working with German manufacturer Windhoff to build the High Output Plant system (HOPS) train to do the job.

This 23-vehicle train, in effect several trains in one, will work its way west, building the railway electrical infrastructure as it goes.

Project director for Network Rail, Western and Wales, Robbie Burns, said: “Electrifying the Great Western is a big challenge but the benefits for passengers and the wider economy will be equally huge. Electric trains are more reliable, cleaner, accelerate faster and use less energy. Their fuel cost is 45 % lower than diesel trains, and they are also cheaper to maintain.

“But electrifying such a long stretch of line in such a short timeframe, 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 in the UK and we are looking forward to starting next year.”

Operating six nights a week, the £40m HOPS will do its work after dark, with adjacent lines open for business at speed – if not maximum speed – aiming to 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. And there’s 17,000 piles to be sunk before Swansea.

Electrifying the Great Western using the HOPS will be a much more efficient process than methods used in this country in the past, with work able to be carried out while trains are still running.

Without it, the work would need to be undertaken at weekends, with disruptive line closures. It is intended to have electric trains running to Swansea by 2018.

How it works:
With several consists in one train, the HOPS will leave the purpose-built depot in Swindon and split up to head to different parts of the line at its 60mph top speed. It carries enough supplies and equipment to avoid having to bring anything to the trackside on lorries and staff can be picked up at stations en-route.

The different consists are:

- A piling rig, with two MPVs with Movax vibro piling heads, which literally vibrate the steel piles into the soil, 2 pile carrying wagons, and finally a Fambo hydraulic percussion hammer MPV for tougher ground.

- An excavation and concrete batching consist. This will feature an Hitachi excavator plus a Kniele concrete unit which will mix concrete from onboard aggregate, cement and water tanks.

- A structures consist, which will erect the Series One masts, portal booms and twin track cantilevers. It is intended to carry 30 masts for erection, per night.

- Ancillary conductor consist, which will install the earthing wires, return wires and small parts such as registration arms and other equipment.

- The contact and catenary consist, which will string up the remaining wires, under tension. Another unit install other articles such as contenary wires under low bridges, neutral sections and record information such as height and stagger.

Each consist will include two MPVs with full driving cabs, powered by MTU power packs, which can be driven at 60mph off-site. On site driving cabs will allow the train to be driven very slowly in possessions, such as when installing contact wire.

Where it will be
The HOPS will be maintained and restocked at the High Output Operating Base (HOOB) near Swindon. A further distribution site in the town will act as a stockpile for materials, which will be delivered to the HOOB when needed.

Around 200 people will work on the HOPS project overall, employed by operator Amey, and recruited from along the route of the line.

It is intended that many will train on the equipment they are installing, before being ‘left behind’ to work as maintenance staff on the overhead, leaving the railway a legacy of highly-skilled railway electrical engineers.