Infrabel is putting the finishing touches to its Diabolo project

Infrabel, the manager of the Belgian railway infrastructure, is currently putting the finishing touches to Diabolo – the new direct rail link to and from Brussels Airport. With four months before the rail link goes into service, Luc Lallemand, Infrabel’s CEO, exclusively tells Global Railway Review the most important achievements and strategic priorities of the prestigious Diabolo project.

Strategic railway link in the centre of Europe

Thanks to Diabolo, Brussels Airport will be directly connected with the major axes of the Belgian network and also with several European cities, via the international axes Frankfurt–Liège–Brussels–Paris and Amster – dam–Brussels–Paris.

After the completion of the Belgian highspeed network in 2009, which is now in service and which covers the Belgian territory from border to border (in the direction of France, Germany and the Netherlands and in the direction of Great Britain through the Eurotunnel) Belgium once again has strategically positioned itself at the centre of Europe.

Diabolo is an underground railway connection between the Brussels-National- Airport station (in the airport itself) and the new double railway line Schaerbeek–Mechelen (L25N) along the central reservation of the E19 motorway, which will also contribute to improving congestion to and from the capital.

This northern railway access on the Antwerp–Mechelen–Brussels axis marks the next important milestone in improving access to and from Brussels Airport by rail – after the eastern railway access was created on the Liège–Limburg–Leuven axis with the Nossegem curve (December 2005).

An essential aspect of Infrabel’s strategy

Diabolo (€540 million) and the previously constructed Nossegem railway curve tie in with Infrabel’s phased strategy to progressively increase Belgian rail capacity with carefully chosen investments, while also significantly improving access to the national airport.

As a consequence, Infrabel also invested in the four-track line on the strategic railway axis Brussels–Leuven and the railway curve of Leuven. Both of these railway infrastructure projects were already made available to railway operators at the end of 2006 by Infrabel to put into service.

Thanks to these key infrastructure projects, Brussels Airport is now connected to the national and European networks enabling it to further develop into one of the most accessible airports by rail in Europe and worldwide.

A Belgian first and a best practice of PPP

Diabolo marks a first for the Belgian railways because it is the first public-private partnership to be completed. The financial closing and awarding of the building contract took place on 28 September 2007 and marked a milestone in Infrabel’s young history (the company was founded on 01/01/05).

The private partner contributes +/- €290 million in the construction of the underground railway link through the intermediary of Northern Diabolo NV. Infrabel will invest +/- €250 million in the implementation of the overground railway line along the central reservation of the E19.

The project company, Northern Diabolo NV, is a special purpose entity consisting of the investors, HSH Nordbank AG and International Public Partnership GP Ltd (= a company of the former Babcock & Brown Group). The construction parts of the project were contracted to THV DIALINK consortium, which consists of CEI-De Meyer, MBG, Wayss & Freytag, VINCI Construction Grands Projets and Smet Tunnelling.

The Diabolo PPP is a good example of best practice for other public-private partnerships in Belgium and in Europe. The PPP which was concluded for the Liefkenshoek railway link (+/- €690 million) in Antwerp’s port is Infrabel’s second successful public-private partnership.

Railway works and tests are the last steps prior to being put into service

The most important construction works on the new Line 25N and on Diabolo were completed at the end of 2010. Recently, TUC RAIL, Infrabel’s railway technology consultancy, also completed the connection towards Brussels. They did this by building a 90m-long viaduct from the E19 motorway towards the rail yard in Schaerbeek.

In accordance with a phased planning schedule, Infrabel has been working on the roadbed along the 11km-long central reservation of the E19 motorway as well as in the tunnels bored under Brussels Airport’s runways.

The railway itself uses continuous welded rails, which are manufactured in Infrabel’s workshop in Schaerbeek (the largest rail workshop in Belgium) according to the ISO-9001 standard. The catenary system has been installed along the entire route and signalling works have been carried out.

These works have now been completed so that the new railway infrastructure can be tested from early 2012 onwards. After the required homologation by the independent safety bodies Belgorail and DVIS, Infrabel can then put Diabolo into service on 10 June 2012 so that railway operators can use it for national and international railway traffic.

Tunnel shafts bored under the Brussels Airport site

The most spectacular element of the Diabolo project undoubtedly was the computer and laser-operated boring of two tunnel shafts. Two boring shields (Danté and Niña) of the German company Herrenknecht were used for this from April until September 2009.

Both tunnels were bored separately using a 66m-long boring machine, proceeding with assistance from a high-pressurised water shield (‘Hydro Mix shield’) over a distance of 1.07km. The boring of the two shafts was conducted 16.5m below ground, that is to say, below the main taxi and runways at Brussels Airport, so that the actual flight operations were never hampered during the construction works.

Infrabel connected the tunnels to a new underground rail and switching complex at Pier A. This complex will be part of the refurbished Brussels National Airport station, which will have three extended (425m-long) platforms, which were designed by Eurostation, the SNCB Holding’s consultancy for station projects.

The connection with the new railway line along the E19’s central reservation was realised with two underground branch lines and an access slope. The total length of the new underground railway connections is 2.7km direction Brussels and 2.4km direction Antwerp, since the latter has a shorter ramp.

Schaerbeek–Mechelen railway line and other linked projects

In the summer of 2007, Infrabel started the preparatory works for the construction of the new L25N railway line. After the excavation of the former Witte Kinderbos – which was given a new lease of life elsewhere in Vilvoorde through renewed woodland planting – the roadbed for the future railway line was laid along the central reservation of the E19 motorway, after which the works on the railway line could commence.

With a view to better access and increased safety, Infrabel has adapted seven bridges along the route. In Zemst, the railway departs from the central reservation via a new 150m-long bridge across the motorway to connect with the existing railway line in the direction of Mechelen.

Elsewhere Infrabel is building a bypass to be completed by the end of 2015 to increase capacity on the strategic link between Brussels and Antwerp. At the back of Mechelen station, Infrabel is also planning to build two additional tracks and two new platforms, which tie in with the Mechelen Station Surroundings Master Plan.

The rail bypass is also vital for the Regional Express Network or RER (horizon 2020) which will contribute to significantly improving mobility in and around Brussels. An important link in this frame is the future railway link Watermael–Schuman–Josaphat. This railway tunnel east of Brussels ensures that the European quarter will be directly connected to Brussels Airport by the end of 2015.

Safety: Infrabel’s absolute priority

In accordance with its strategy, Infrabel will automatically install the ETCS European signalling system (Level 1) on the new railway infrastructure of Diabolo and of Line 25N. This system means trains brake automatically and continuously when the train looks likely to go through a red signal or if a train does not comply with the maximum allowed speed on the railways. The tunnels and the overground railway line will also be fitted with the digital communication network GSM-R.

In terms of safety, the Diabolo rail tunnel will be equipped with safeguards such as a fire detection system (including cameras), an evacuation system (including a smoke and heat removal system) and extinguisher pipes. There will also be access routes and shafts for the emergency services, transverse connections and so on. Infrabel will also provide extinguisher and intervention vehicles for the fire and emergency services as well as a central command post in the airport.

Diabolo: a multifunctional infrastructure

The Diabolo project corresponds with Infrabel’s following three strategic priorities:

● Optimised safety due to the imple menta – tion of ETCS and a host of safety measures along the entire route

● A phased improvement of the regularity of train traffic by commissioning new railway infrastructure

● A progressive expansion of the capacity of the network tying in with the realisation of the other infrastructure projects.

Diabolo is also part of the ‘Air Rail’ strategy to improve the intermodal connection between air and rail traffic and thus significantly im proves mobility in the long run and in function of the customers.

Finally, Diabolo will also have a massive impact on the development of Belgium’s national airport as one of the most important economic industrial hubs of Belgium.

About the author

Luc Lallemand has been CEO of Infrabel and Chairman of the Management Committee since October 2004. Mr. Lalleman has a Bachelor seamanship and certificate of officer of long trade navigation and is also a Commercial Engineer. He has worked in various organisations including, among others, Financial Advisor with the Department Treasury of the SNCB (1991–1995), Budget Advisor and Principal Private Secretary with the Minister of Transport (1995–1999), Deputy Principal Private Secretary with the cabinet of the Vice Prime Minister (1999–2002) and Chief Financial Officer with SNCB (2002–2004). Mr. Lallemand also holds the position as Director with bPost, Vinçotte, RFF, RATP DEV (Paris) and is Chairman of the Board of Directors with TUC RAIL.