LGV Rhin Rhône - branche est
int-trou-int  

English version

Spotlight on railway equipment

Throughout the works period, the Eastern branch of the Rhine-Rhone high-speed line will boost the local economy in a number of very different ways.

Following the completion of civil engineering operations, work on the eastern branch of the Rhine-Rhone high-speed line has now entered the railway equipment phase. More than 700 people are currently working on site each day.

To operate trains at high speeds, it is necessary to have track on which they can run, power to drive them, a signalling system to control traffic and a telecommunications systems to transmit information. Installing the railway equipment (track, overhead lines, signalling and telecommunications systems, electrical power supply installations and technical buildings), from the time the first cable arteries are laid to the moment when the overhead power line is energised, represents the final stage in the build-up to tests (Spring 2011) and line commissioning (11 December 2011).

Track and overhead line

Track laying is the final operation in the construction of a high-speed line. It is an operation where precision is vital, since maximum tolerances are in the region of just 5mm!

Track laying

For linear structures such as railway lines, the standard practice is to deliver the different parts to the site in the following order:

  • Temporary track: track has to be laid on a temporary basis to bring in the wagons delivering the rails for the final track. This first track consists of recycled rails and timber sleepers.
  • Concrete sleepers: sleepers, which have an average life of 50 years, are designed to bear the weight of the track. They must be perfectly held in place by means of high quality ballast. After all, a high-speed train running at 320 km/h weighs as much as a Boeing 747 on take-off.
  • Rails: these may be as much as 400 m in length and are welded together. For each track, rails have to be placed on the ground and sleepers positioned on the track subgrade. The rails are then lifted on to the sleepers and secured with resilient metal fasteners or 'spring clips'.
  • Ballast: 5,000 tonnes of ballast are brought in by train each day and poured into the gaps between the sleepers on either side of the rail. The ballast used for a high-speed line is harder and more robust than that of conventional lines. It will be replaced at 25-year intervals.

Since 29 June 2009 (laying of the first rail), the contractors have been busy laying the final track for the line. The process involves 10 key steps:

1) Physically staking out the subgrade.
2) Construction of a temporary track using 18m panels (18m-long rails secured to timber sleepers).
3) Bringing the continuous welded rails (CWR) and placing them alongside the temporary track (Track 1) and on the subgrade where the second track will be laid
4) Delivery of ballast to the temporary track
5) Removal of the temporary track panels and installation of reinforced concrete sleepers by means of special gantries and positioning of the CWR on these sleepers.
6) Preparing a ballast sub-layer on the bed of the second track
7) Laying and adjusting the sleepers on the second track and positioning the CWR on these sleepers
8) Clearance of ballast to enable track lifting operations
9) Installations of points & crossings (switches)
10) De-stressing the CWR
11) Supplementary levelling
12) Finishing operations

Track laying in figures:

  • 1.350 million tonnes of ballast
  • 600 km of rails
  • 550,000 sleepers
  • 380 km of OHL contact wire
  • 63 sets of points & crossings