BYLINE: Ad van den Dool

Strukton Railinfra bv

Strukton Railinfra faces the challenge of laying 140 km of track and installing 220 km of overhead wires on the Betuwe Route in one year.

After a selection process involving nine prequalified contracting consortia from various European countries, the contract for the trackwork and 25 kV electrification was awarded inSeptember 2003 to Strukton Railinfra, in alliance with German overhead electrification firm Fahrleitungsbau GmbH. Detailed engineering design is underway, and construction will start in June 2004.

Strukton Railinfra has already carried out an extensive risk analysis with the group’s engineering consultancy T&E. Much of the detailed engineering has still to take place, and not all the details of the materials are known at this stage, but it is important to start the process if construction is to begin on schedule.

Logistics challenge

In terms of technology, the project is not particularly complex, and Strukton Railinfra has opted for conventional construction methods. The NS-90 sleepers will be laid with gantry cranes, as used on the Sliedrecht - Gorinchem section. This should minimise the risk of disruption, while maintaining the greatest degree of flexibility.

However, the limited timescale means that the contractors will have to make relentless progress. According to Project Manager Geert Datema, ’everything will depend on the logistics operation, and any disruption will impact on the entire chain. We have therefore put all our suppliers on alert.’

Most materials will be delivered by barge or lorry, as the railway parallels the Waal and Maas rivers and the A15 motorway. Each day 2400 sleepers will arrive in 20 loads. The route will need about 250000 in total, which is more than the combined annual production of the two factories in the Netherlands able to make these sleepers (Spanbeton and Meteoor). Another 80 loads (2000 tonnes) of ballast per day will be needed for the trackbed, or 170000 tonnes for the whole route. A Robel self-unloading train will bring in the 360m long rails.

The number of supply depots will be kept deliberately low, to minimise the nuisance for local residents, and the worksite will move along the line as construction progresses.

An important logistics base will be located at the so-called Central Exchange Point at Valburg, where freight trains will be sorted after 2006. This facility is currently being built by Strukton Railinfra and is scheduled for completion in April 2004. During the construction phase, it will be the main depot for distribution of 260000 tonnes of top ballast.

Prefabrication and co-ordination

Logistics is more than just a smart way of transporting building materials. The use of labour and equipment will be especially critical in achieving qualitative and quantitative objectives. One decision has been that construction of the overhead electrification will be synchronised precisely with that of the track. Separate assembly teams have been set up for each stage of the process, undertaking repetitive tasks, in order to achieve a high rate of work.

The Betuwe Route is the first line in the Netherlands to be built for 25 kV 50Hz. However, there are several places where it will intersect other lines, notably the crossings with the ’s-Hertogenbosch - Utrecht and Arnhem - Nijmegen routes. As a result four different electrification systems will be required: B5 (25 kV moveable), B8 (25 kV fixed), B4 (1·5 kV DC ready for conversion to 25 kV) and B1 (1·5 kV DC traditional).

Strukton Railinfra has already built up its experience with 25 kV during the electrification of the 40 km Harbour line south of Rotterdam, which forms the western end of the Betuwe Route.

A complicating factor, flagged up by Senior Development Engineer Arie Flantua, is that noise screens have been built on the open track along 60% of the main line. ’The screens are already in place and the overhead electrification masts will be installed behind them. This means that our staff will have a limited view of each other and of the work, from the track or from behind the screens. This is far from ideal, and will require changes to the working methods, not to mention good communications.’

Wherever possible, OLE components will be prefabricated by the suppliers or at the various construction sites. For example, tensioning wheels will be preassembled on the masts to speed installation. The dimensions of the arms on each mast are being calculated separately, and they will arrive from the supplier fully-assembled. And the cable suppliers have agreed to modify their reels to carry more wire than usual, which will cut down on the number of reel changes needed.

Key to the installation of the catenary and contact wires will be the use of the Gemma wiring train. This will be closely followed by a 30m long ’platform train’ borrowed from Strukton Railinfra’s Belgian operation. These wagons have a built-in power supply for small tools, which will enable the wiring teams to achieve a very high production rate.