The French connection

The BPL route features some impressive structures, including viaducts over rivers and bridges over railways and roads, including motorways. When design changes called for one river bridge to be moved 10m to one side, the line was adjusted for 14km east and west to compensate for the shift - ample demonstration that a high-speed line is more than just its component parts.

Eiffage developed a standard design for most of its bridges, allowing for component construction off-site and quicker assembly on-site. For the first time, it used cut-and-cover tunnels made from three-piece pre-cast concrete arches which halves the cost compared with casting concrete in situ (they have been used on French roads before but not railways). Further innovation came with other cut-and-cover tunnels (sometimes called green tunnels) built using steel sheet-pile walls rather than diaphragm walls.

The decision to use asphalt resulted from the problems Eiffage has seen on France’s eastern HSL (LGV Est). It also has some construction advantages, in that lorries can be driven on it (heavy steel plates are laid to provide turning areas so the lorries do not damage the trackbed) but it also saves on ballast, with a top layer of 32cm rather than 35cm.

On this layer runs a MATISA track-laying machine operated by Eiffage subsidiary Wittfeld to lay the two tracks. The machine has run at up to 2.2km per day, although 1.5km per day is more usual. It works to an alignment tolerance of 10mm left and right of the track’s design route with the machine laying sleepers, threading rails into position and then pushing into place the clips that secure the rails to the sleepers.

The machine carries a stock of monoblock sleepers to an SNCF design (Eiffage even considered building its own sleeper factory at one point) and a stock of rails. They are temporarily bolted together to form 900m lengths which are then dragged out in front of the machine. Once the rails are lying to the left and right, the machine slowly moves forward until it runs out of rails, at which point another long string is pulled forward. Their temporary fishplate joints will be removed, the rail containing the holes cut away and then two lengths joined using flash-butt welding
and appropriately stressed. The machine returns to base every night to be loaded
with more materials.

The stones which form the line’s ballast are noticeably larger than those used in Britain. This allows the ballast to cope with the forces of fast running. It’s also laid in a precise shape that has two distinct raised sections on either side of a lower central trough. This ensures that when the sleepers are laid they are correctly supported to spread the loads imposed through the rails. The trough prevents any sleepers being supported merely at their centre.

HSLs demand tight tolerances. At a recent Institution of Mechanical Engineers conference, HS2 Rail Systems Engineering Director Mark Howard talked about track geometry tolerances of 1mm. He also noted the importance of the user (passenger and maintainer) and the need to put people at the heart of HS2’s design. This is all reflected in the work Eiffage has under way in France.

Eiffage subsidiaries have completed power and cabling works with two major sub-stations along the route drawing electricity from the French national grid. The subsidiaries have also co-ordinated signalling installation by Ansaldo and overhead line equipment (OLE) erection by Colas Rail (OLE installation is one of the few rail disciplines that Eiffage does not encompass). This catenary is to SNCF’s V350 design. Masts are erected during trackbed construction before ballast, sleepers and rails, which, initially, looks like a road flanked by masts and blue and yellow signal marker boards. On some of the link lines to SNCF’s classic network, even the signals have been installed before the tracks!

Meanwhile, Eiffage’s maintenance base is collating the information it needs to keep the line in good condition. The site is already busy, not least because it doubles as a base for the track laying machine. It will be from here that maintenance is planned, stock levels monitored and efficiency analysed to further improve maintenance. Track staff will be based here (25 for signalling, electrification and telecoms and a production team of 15, including works train drivers and control centre staff).

Software will also be used - the Maximo system has been selected to monitor the state of the line. Eiffage believes that this, combined with ArcGis mapping, is sufficient. It uses BIM (building information management) and plans to use BIM on HS2, learning from its experience on BPL.

The track was also designed with maintenance in mind, and frequent wide spaces have been created alongside the tracks in which equipment can be placed. These spaces are the equivalent of a maintenance lay-by on a road, although the French call them ‘platforms’. The importance of including them is one of the lessons Eiffage learnt from its joint venture on the Perpignan-Figueras HSL between France and Spain (which also includes the 8km Perthus tunnel under the Pyrenees).

The company believes it can bring this maintenance experience to HS2 because, although it understands that HS2 plans to do its own maintenance, whole-life costs are improved if maintenance is considered during the design phase.

Watching a high-speed railway being built is an impressive sight and it’s abundantly clear that Eiffage has the necessary skills and experience. That’s why it is now looking towards HS2 and the opportunities that line presents. Indeed, the BPL line will open in 2017 - around the time construction work should start on HS2. That there could be a seamless transfer of skilled people has not escaped Eiffage’s notice.

It has joined Carillion and Kier in a joint venture to bid for HS2 construction contracts. The consortium has been completing pre-qualification questionnaires (PQQs) with bidding for real contracts expected to follow over the next year or so. As Michel Oléo says: “We have experience of high-speed lines. We have experience of being free to innovate and of working with different partners. I hope HS2 recognises this in our PQQ.”

The three partners bring different experience. Kier and Carillion have extensive UK experience. Kier delivered the civil engineering needed for High Speed 1 around King’s Cross, including eight bridges and viaducts, tunnels and earthworks. It had to cope with the operational railways around it - including Network Rail and London Underground’s Piccadilly Line - as well as the Grand Union Canal.

More recently, the company is closely involved with Crossrail, London’s major east-west rail building project. Kier has taken on contract C435 for Farringdon station, which will deliver two ticket halls at either end of two platform tunnels. The western hall will be shared with Farringdon’s Thameslink services while the eastern hall will provide access to Underground services at Barbican.

Two further Crossrail joint venture contracts highlight Kier’s expertise; C300 and C410 for the Western Running Tunnels and for all station tunnels and sprayed tunnel linings in Bond Street and Tottenham Court Road stations, plus access shaft contracts at Liverpool Street and Whitechapel stations.

Meanwhile, Carillion is Network Rail’s largest contractor as well as being one of the major players on the UK Highway programme. Its most significant current rail project involves carrying out major modifications to the GW mainline at Old Oak Common (a significant HS2 hub) and West London, for Crossrail.

Carillion is proud of its environmental and sustainability record on both rural and urban projects throughout the UK. This included the East London Line project, key to the success of the 2012 Games.

The trio - Carillion, Eiffage and Kier - announced their joint venture last June with their chief executives welcoming the chance to work together. Their combined expertise covers the disciplines needed by HS2, with its mix of long tunnels, open country construction, links to existing rail lines and the need to keep local communities content, not only during construction but also afterwards, when trains are running.

France is an acknowledged leader and pioneer of high-speed rail travel. Few countries can bring its depth of experience to bear in the field and even fewer European countries have this ability. Britain already benefits from French know-how with High Speed 1 running from London to the Channel Tunnel. It uses TVM signalling and track and OLE designs to French standards and performs with delays which are measured in just seconds.

A joint venture of Carillion, Eiffage and Kier is exceptionally well placed to combine French experience with British knowledge to build High Speed 2 and so radically transform the capacity and connectivity of Britain’s rail network.

• This feature was published in the HS2 supplement of RAIL 789 (December 9 2015)