Testing has begun in Germany of a new “factory train” that will reduce the cost of electrifying Britain’s main lines.
German firm Windhoff is constructing the High Output Plant System (HOPS) for Network Rail. When electrification of the Great Western main line begins on 14 January, it will carry the equipment, materials and personnel required for each work session direct to site, travelling at 60mph on lines which are open to trains as normal.
This eliminates the complexities of planning and managing access by road and rail for each worksite along the 270 miles of route.
Normally railways are closed to maintain safety during engineering works, causing disruption to passengers and incurring compensation payments to train operators. For the HOPS, Windhoff and Network Rail devised a barrier system enabling scheduled trains to pass on the track adjacent to the one that is temporarily closed for electrification works.
Some of the vehicles require a demountable physical barrier, which can be positioned on the right or left side as required. Electronic and mechanical locks will prevent on-board machinery swinging outside the safety envelope or twisting masts or piles so that they momentarily overhang on the wrong side.
Time spent getting equipment and supplies into place and, later, clearing the worksite is a major inefficiency for Network Rail which the new system will reduce.
The HOPS, operated by Amey, will enable engineering works on week-nights, instead of the usual focus on weekends and bank holidays. It is expected to halve, at least, the time required to electrify from London to Bristol, Oxford and Newbury, followed by Cardiff and Swansea.
Robbie Burns, Network Rail’s regional director of infrastructure projects, predicted the HOPS would install 1200 to 1500 metres of electrification equipment each night.
He said: “You can see how much more efficient we’re going to be when we’re getting five times 1500 metres during the week, and still running trains past the worksite.”
He was speaking during a visit to the German test site in July to see the HOPS’ first completed modules. These will carry the equipment and materials for the first stage of the process – installing piles or concrete foundations for the masts from which the overhead electricity cables will be suspended.
Typically Movax vibratory pile drivers will install the piles. In some areas – of shale, for example – a hydraulic percussion hammer will complete the task.
For locations requiring concrete mast foundations, the HOPS will carry raw ingredients and mix them on the spot, eliminating previous difficulties with concrete beginning to cure prematurely.
These initial modules are due to arrive in Britain in October. After further testing and training, they will move in December to the High Output Operations Base in Swindon. The HOOB will maintain the HOPS and restock and configure the modules for the next night’s work.
Other modules, now under construction, will speed up erection of steelwork and cables. Pairs of cables will be strung out simultaneously, with the overhead ones installed at the correct tension (rather than being tensioned in a later process). The final module will facilitate testing.