The construction of the Stad Sea Tunnel aims to change the way ships traverse one of the most demanding areas of the Norwegian coast. Designed to increase safety and reduce delays caused by bad weather, the infrastructure will allow vessels to pass directly across a peninsula.
is preparing to proceed with work at the narrowest point of the Stad peninsula, between Moldefjord and Kjødepollen, in the Vanylvsfjord. The start of work is scheduled for the beginning of 2027, after several years of planning, public tenders and discussions about costs.
The project is officially presented as the world’s first full-scale tunnel built specifically for ships. The passage will be 1.7 kilometers into the rock and have a total length of about 2.2 kilometers when the entrance areas are included.
Alternative to one of the most dangerous maritime areas
The objective of this sea tunnel is to avoid passage through the Stadhavet Sea, considered by the Norwegian Coastal Administration to be one of the sections most exposed to weather conditions and most difficult to navigate along the country’s entire coast.
During periods of bad weather, some vessels are forced to reduce speed, change route or wait until they are able to continue. The situation affects cargo ships, fishing boats and passenger transport, reducing the regularity of maritime connections.
The Norwegian Government explains that the characteristics of the sea around the peninsula increase travel times and the risk of accidents. The tunnel should reduce waits, make schedules more predictable and improve safety conditions for vessels traveling along the coast.
Dimensions allow the passage of large ships
The structure will be 50 meters high from base to ceiling and 36 meters wide. Between the water surface and the highest point inland there will be 33 meters of free space.
These dimensions will allow the passage of vessels with dimensions similar to those used on the Hurtigruten and Kystruten coastal routes. The infrastructure was not designed just for small boats, thus distinguishing it from the old tunnels built for canals and inland waterways.
The work is expected to require the removal of approximately three million cubic meters of rock. The excavation will be carried out using conventional methods, using drilling and explosives, according to the technical documentation made available to potential contractors.
Costs reached 8.6 billion crowns, around 775.7 million euros
The Norwegian Parliament had approved construction in 2021, initially with a much lower cost margin. The Government proposed to suspend the project in October 2025, after the proposals presented by competitors exceeded the planned budget.
After further negotiations, the Norwegian Coastal Administration presented an updated estimate. The maximum cost margin rose to 8.588 billion Norwegian kroner, approximately 774.6 million euros, while the project management value was calculated at approximately 8 billion kroner, equivalent to 721.6 million euros, at the current exchange rate.
The agreement reached within the framework of the revised State Budget also allocated 150 million crowns, around 13.5 million euros, for the continuation of work, completion of the tender and construction preparation. The Storting, the Norwegian Parliament, also authorized an increase in the cost margin, previously set at 5.385 billion crowns, approximately 485.7 million euros.
Three groups competed for the construction
The evaluation of the proposals submitted for the main contract has already been completed. The three final competitors were the Norwegian company AF Gruppen, the French company Eiffage Génie Civil and the consortium formed by Skanska and Vassbakk & Stol. After the chosen company is announced, there will be a period for the presentation of any complaints. Only then can the contract be signed and the actual preparation of the construction site begin.
“We are ready to begin the necessary processes to facilitate the start of construction in early 2027,” said Einar Vik Arset, director general of the Norwegian Coastal Administration. In addition to the main contract, contracts are planned to demolish buildings located nearby and install new water pipes on both sides of the future passage. The entity estimates that construction work could last approximately five years.
If the schedule is met, the Stad Sea Tunnel could be completed around 2032. The infrastructure should create a safer and more regular route for passenger ships, fishing vessels and freight transports that currently depend on conditions offshore Stadhavet.
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