The Norwegian Coastal Administration (NCA) wishes dialogue with the market regarding the planned invitations to tender for the design and construct contract for the construction of Stad ship tunnel.
The NCA intends to announce the competition at the end of 2021. The aim is then to sign a contract at the end of 2022, with the start of construction of Stad ship tunnel in Spring 2023.
− This progression means a slightly delayed start up, and thereby a slightly later opening of the ship tunnel than was previously outlined. The start-up phase of projects of this dimension defines the subsequent process. It is extremely important to ensure a correct start for this extensive project, which means that we have an extremely thorough process for this procurement, project manager Terje Andreassen says.
Stad ship tunnel is primarily what is known as a fairway project, and it will be the world’s first full-scale ship tunnel. Parts/elements of the construction of the ship tunnel are methods that is known to the industry. The challenge here is that there are few, if any, comparable projects where all these elements are brought together.
− To put it very simply, this is more like a big, long mutain hall than a tunnel. The upper part of the ship tunnel will be driven through in the same way that ordinary tunnels are constructed. Then the bottom will be blasted out, layer by layer. In mining this is known as bench blasting. This is very extensive work that will be done to make the tunnel safe and navigable. That is to say, establishing structures and rockfall protection that are similar to the solutions for quay and jetty construction, explains Andreassen.
And we are talking about huge quantities of excavated material. The tunnel will be 1.7 kilometres long.
− In total, we are talking about around three million cubic metres of solid rock. That corresponds to about eight million tonnes of excavated material. About two-thirds will be large boulders from blasting. The rest will be smaller material from ordinary tunnelling, explains Andreassen.