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Frequently asked questions about Stad ship tunnel

Do you have questions about Stad ship tunnel? Here we have gathered some of the frequently asked questions, as well as answers. Click on the question, then the answer pops up.

Why build a ship tunnel?

The Stad sea is the most exposed and most dangerous area along the coast of Norway. A ship tunnel will reduce the risk of incidents and accidents, making the voyage safer for both passengers and freight, as well as securing traffic regularity. It will also strengthen industrial and commercial activities in the region.

What will the total costs be for the project?

Calculations show that ship tunnel will have an estimated cost of approximately NOK 3 billion.

When will the tunnel open?

Optimistically, if the building process starts in 2021/2022 the ship tunnel could open i 2026. However, before the ship tunnel can be built, a number of prerequisites must be met, such as a decision from the Parliament, as well as financing and permits for construction in place. 

Is this the first ship tunnel in the world? Why hasn't a ship tunnel already been constructed?

Stad ship tunnel will be the world's first full scale ship tunnel. There are no other tunnels made for ships, only for smaller boats – narrow boats and barges. Those are located in Great Britain and France.

It is diffucult to say why a ship tunnel has not already been built. One reason might be that there has not been enough political will to do it. Also, the environmental effects of reducing fuel/pollution are more of a key topic now than it was before.

How will traffic be regulated? Will there be traffic lights?

Yes, we are going to follow the usual standard with red and white signal lights to show when it is safe to pass through the ship tunnel. Passing vessels will most likely get slot times from a Vessel Traffic Service (VTS) centre – which would work in a simular way to slot times for aviation traffic.

How will the tunnel cope with changes in the tide?

There is a small difference in tide level between the two fjords that will be connected by the tunnel. The current in the canal (the tunnel) will at most be up to 2 knots. In other words – the tide will not cause any problems for the vessels.

Will some ships have priority?

Yes. Commercial traffic will be given priority - especially passenger traffic. But leisure boats and other vessels can also use the tunnel.

How much will it cost to sail through the tunnel?

Use of the tunnel will be free of charge. However, compulsory pilotage, regulated by the Pilot Act, would be applicable for vessels over 70 meters using the fairway through Stad ship tunnel. Compulsory pilotage would be applicable for vessels over 70 meters. It is possible that compulsory pilotage may be replaced with a Pilot Exemption Certificate (PEC).

Will it be possible for people to walk in the tunnel?

No. On each side, there will be a 3.5 meter wide fended lead structure, but this is mostly to prevent the bridge wing from touching the tunnel walls. In addition, this structure may be used in the event of an evacuation, and thus have the status of emergency exit.

What will the distance be between passing vessels?

For safety purposes the distance between passing vessels will probably be around 400 meters. As a general rule, this  is regarded as the minimum distance for safe travel. With this distance, we will be able to allow five ships to pass through every hour.

Can leisure boats use the tunnel around the clock?

No. This issue is still undergoing planning. Most likely leisure boats will be granted specific slot times, for example during the morning and evening. Another alternative would be to add them to the convoy of passing vessels.

What will the speed limit be through the tunnel?

A decision on final speed limitation for both fjords and in the tunnel will be made at a later date, as part of the revision of the Maritime Traffic Act. Through the tunnel, it will likely be eight knots for speed boats, which equals a  ten minute voyage through the tunnel. Other boats would most likely have to hold five knots.

How much clearance will the boats have to either side?

Passing vessels could be up to 21.5 meters wide, and would then have a clearance of 2.5 meters on each side. This has undergone testing in a model tank, where the aim, among other things, was to investigate the best speed to maneuver efficiently and safely through the tunnel. Entry / approach has also been tested in a simulator.

Which safety measures will be in place to protect the ships' side hull in the tunnel?

The tunnel will have fendering that have been dimensioned for the largest vessels that may pass through.

How many buildings must be removed in order to build the tunnel?

Estimates made in connection with the technical preliminary study, show that four houses and some barns, sheds and boathouses have to be demolished to initiate the construction process. The NCA has had meetings with each of the landowners who may be affected, and there is a good dialogue between the homeowners and the Norwegian Coastal Administration and the municipality on this issue.

How will the construction of the tunnel progress?

The structure will be more simular to that of a large and long mountain hall than a tunnel, and we plan to engage highly experienced engineers to carry out construction. In Norway, there is plenty of experience and great expertise in this type of work. The upper part of the ship tunnel will be run the same way as conventional road tunnels. After that, the construction will work downwards, layer by layer. This method is called pallet blasting.

How much rock mass will be removed during construction?

Overall, we are talking about approximately three million cubic meters of rock. This is equal to around eight million tons of pulp. Around two thirds of this will be bigger blocks from blasting. The rest is smaller scaled mass that you get from regular tunneling.

How will the rock mass be removed?

The rock mass will be transported out of the tunnel by vehicles in a traditional manner. Furthermore, the rock mass will be transported on large barges to other locations for final disposal. There might also be a need to establish a service tunnel next to the main tunnel.

A final solution in terms of driving method and logistics will probably be clarified in cooperation with the contractor.

What will the tunnel mass be used for?

The extracted rock mass will be used in the neighboring municipalities to establish new land areas and expand existing areas for business purposes. Which municipalities and areas have not yet been decided. Sections of the masses may be deposited in a regulated deposit at sea.

How will you prevent water from entering during construction?

During the construction period, "thresholds" will most likely be in place at both ends of the tunnel – higher than kote -12. This will enable dry tunnel operations to be carried out below sea level for most of the tunnel.

How do you ensure that ships steer directly into the tunnel entrances?

At both ends there will be around 160 meters long, diagonal leading constructions for entering. There will also be safety zones outside the openings free of other vessels in case the vessel needs to go astern (reverse its position).  In addition, there will be an area dedicated as the 'point of no return' for vessels going into the tunnel.