Recalibration: renovation A73 tunnels with new two-phase approach

The renovation of the Roertunnel and Tunnel Swalmen on the A73 is being carried out by contractor combination Croonwolter&dros - Ballast Nedam using a two-phase approach. This is a new instrument in the transition to a vital infrastructure sector launched by Rijkswaterstaat together with market parties in 2020. Meanwhile, the first phase containing the Preliminary and Final Design (VO & DO) has been completed and the parties are starting the second phase (Execution Design (UO) and realisation). During a review moment, the combination Croonwolter&dros - Ballast Nedam and Rijkswaterstaat shared several evaluation points to pass on to future two-phase projects.

The renewal and renovation of the two A73 tunnels is one of the first projects implemented using the two-phase approach. This approach includes a phase (phase 1) between the contract award and final execution. In phase 1, Croonwolter&dros and Ballast Nedam work with Rijkswaterstaat on the design and implementation planning, and risks are identified in advance. The aim is to achieve a stable execution without many surprises during the execution period (phase 2). This approach is an experiment by Rijkswaterstaat to reduce uncertainties during execution and to achieve a better and fair distribution of risks. And thus to a healthier construction sector.

Content first, contract form second

Based on various propositions, experiences and conclusions, the learning experiences from this two-phase approach were discussed interactively with each other with the aim of passing them on as tools for future projects. Led by Maarten Neelis, Director Market Transition at Rijkswaterstaat, one of the things that emerged was that all parties agreed that the two-phase approach achieved better risk allocation and management. And that an open and transparent attitude from both sides (contractor and client) is an important factor in this.

'Very proud'

Michèle Blom, Director-General at Rijkswaterstaat: "Technology, environment and directors all cover substantive issues that you need to understand well before deciding which contract form to choose. That doesn't work the other way around. I am very proud to have signed the first recalibration document of a two-phase approach and hope it will not be the last."

Lessons learned

Several learning points emerged during the first phase. For instance, the importance of dependency within the two-phase approach was highlighted, as it creates the right tension in the time-quality-money triangle. This ensures earlier and better management of risks and more stable implementation.

Sander Lefevre, Ballast Nedam board member: "I strongly support the instrument applied here: the two-phase approach. It's not about who carries which risk, but rather about deepening those risks and having the same understanding of them together. A project like the renovation of the A73 tunnels is complex enough as it is, making it all the more important how best to approach it with all interests in mind. This milestone and mutual cooperation give me a lot of confidence for the future."

Eugene de Roodt, Statutory Director at Croonwolter&dros fully agrees and adds: "We believe in working together. The big V&R task we have together requires many more employees than we have in the infrastructure market and especially the engineering market. This success is going to help enormously in getting young people excited about the infra market."

It is not about who carries what risk, but rather about deepening those risks and having the same understanding of them together
Sander Lefevre Board member Ballast Nedam

About the A73 project

For Limburg, the A73 forms a crucial north-south connection between Venlo and the A2 at Echt-Susteren. Since 2008, this motorway includes two tunnels in the Roermond area: the Roertunnel (2,400 m) and Tunnel Swalmen (400 m). Over 50,000 vehicles use these every day. Commissioned by Rijkswaterstaat, Ballast Nedam and Croonwolter&dros carry out the replacement and renovation of both tunnels in 2023 and 2024. The two parties will also be jointly responsible for maintenance of the tunnels for the next five years.

During the replacement and renovation of the tunnel technical installations of both tunnels, extra attention will be paid to system integration. This will be achieved on the basis of the national tunnel standard, so that the tunnels meet the latest standards of the Directorate-General for Public Works and Water Management around standardisation and safety. Within the project, ten of more than 50 technical systems will be replaced, including ventilation, lighting, video and audio. Also, where possible, the profile-free clearance height will be increased to 4.70 metres so that in time there will no longer be any height restrictions at the A73 tunnels. In addition, both tunnels will receive light-coloured asphalt. The white crushed stone in the asphalt reflects the lighting in the tunnel and that of the cars. This reduces the need for strong lighting in the tunnels and saves energy.

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