Expert in immersed tunnel construction

Tunnel Engineering Consultants, or TEC for short, may not be a familiar name in the Netherlands, but it has gained international fame with projects such as the Øresund link, the Hongkong-Zhuhai-Macau bridge-tunnel combination in China and the Fehmarnbelt Tunnel. A conversation with Hans de Wit, Managing Director of TECs about the consultancy's expertise  for tunnel construction and specialized in (immersed) tunnels. And that without its own personnel.

TEC was established in the late 1980s as a permanent joint venture between the leading international engineering firms Royal HaskoningDHV and Witteveen + Bos. The two organizations decided to pool their knowledge particularly in large underground projects, especially abroad. "The reason for setting up TEC is to combine the knowledge, expertise and experience to be able to take on large (immersed) tunnel projects together," explains De Wit. "By the way, our first project was in the Netherlands, the Noordtunnel in the A15 under the North River, which was completed in 1992. In the mid-1990s, our expertise was also in demand abroad. The Øresund connection between Denmark and Sweden was our first really big foreign project."

World player in immersed tunnel projects

The Dutch joint venture is rightfully a world player in immersed tunnel projects. De Wit gives some examples: "We are now actively involved in the Fehmarnbelt Tunnel, an almost 20km long tunnel connection between Germany and Denmark to be completed in 2026, in which we have also shaped the safety concept together with our partners Ramboll and Arup in this project. For this kind of long tunnel, customization is required and there are no guidelines or codes yet, which are directly applicable. An interesting project for us as specialists to flesh out. We also contributed to the Busan Geoje connection in South Korea and the 32-kilometer bridge-tunnel connection between Hong Kong, Zhuhai and Macao in China, 6 kilometers of which were constructed as an immersed tunnel. The longest immersed tunnel in the world. In addition, we are involved or have recently been involved in tunnels in Brazil, the Middle East, Mexico and Scandinavia."

TEC is currently closely involved in the Blankenburg connection as a designer for the construction consortium (Image: ©Rijkswaterstaat)

For some years now, TEC has been somewhat more active again in its own country. "We are currently closely involved in the Blankenburg connection as a designer for the construction consortium, for which we are realizing the integral design of the two tunnels, respectively a land tunnel (Holland Tunnel) and an immersion tunnel under the Scheur (Maas Delta Tunnel). The renovation of the Eerste Heinenoordtunnel and the program to tackle road tunnels around Amsterdam is also within our scope, but on the client's side. In addition to upgrading the installations, we are also involved in the civil engineering condition assessment of the tunnels, including tunnel safety."

TEC may be less known as a "name" in the Netherlands, its supporters all the more. "As TEC, by the way, we don't have our own staff. We fly each project with specialists from our two parent organizations," De Wit concludes.