This moving platform has rooms below sea level

The company, located in Haddal near Olstinvik, began crushing stone in 1954. Since then, a lot has happened, including an exciting development in the offshore part of the group. More are likely to happen in the coming years.

Ulstein Betong Marine’s Managing Director, Asbjørn Tronstad, says the mobile dock products they are developing now have solutions adapted to zero-emission transport at sea. The beginning of the zero-emission development was a dock with a charging tower delivered to Aker Brygge in 2021, in connection with the electrification of shuttle traffic in the Oslofjord Basin.

– We are working on solutions for a proposal for the cruise dock in Stranda regarding the Geirangerfjord becoming zero-emissions from 2026. We are also working on a concept that involves fully charged batteries stored in containers in rooms below the docks, which can replace empty batteries in boats Express and ferries. It will follow the same principle as the replaceable batteries in Nio electric cars. We are involved in a pilot project for autonomous ferry movement on the Hareid-Sulesund ferry route, in which Sintef is also involved. It’s all about testing different concepts to get to zero emissions, says Tronstad.

The company is also involved in a project with Havkraft surfers aiming to find solutions that can create green energy with floating docks as a starting point.

– We work with floating docks for the fishing industry, where we developed a floating dock for the shark fishing fleet. This floating dock has boxes for storing fishing gear below deck, facilitating the daily life of coastal fishermen.

Solutions for the Geiranger Strait

In the Geiranger Fjord, there is talk, among other things, of charging docks for electric boats that will be able to transport tourists between cruise ships and the pier in Stranda. But they are also considering the ability to offer extensive berth to cruise ships. The Geiranger Fjord is included in the UNESCO World Heritage List, and it has been decided that cruise ships will not be able to enter the fjord with fossil fuels from 2026. For modern cruise ships, the most advanced technology on the market today is LNG, that is, liquefied natural gas. For LNG, the closest solution seems to be a short-lived goal: adding a dock in Stranda, with more tourists transported in emission-free boats. Today there is no pier for tourist boats in Stranda.

– The Stranda Port Authority has started a project in cooperation with NTNU to look into possible solutions. Most solutions involve floating docks, Tronstad says.

While traditional piers are built on site with large structures, the special thing about piers from Ulstein Betong Marine is that they can be moved.

– A shipping company that is growing, for example, could sell the dock it is expanding into and replace it with a new, larger floating dock. Floating docks can also be linked together, so you can have as much docking facility as you want, says Tone Jøssang Hovdenakk, marketing manager at Marina Solutions, which is partly owned by Ulstein Betong Marine and is the sales force for the docks. They also organize the final stage from berth to final berth.

It is towed into place by sea

Everything is built in dry docks at Hadal and hauled by sea by tow ships to site. Not only are docks produced this way, but also feeding rafts for the aquaculture industry are built this way, with increasingly sophisticated underwater chambers.

– 80% of our sales are to feed fleets. But we are strongly committed to growth in the field of dock production and have recently built a new dock specially adapted for the production of floating docks. “We have a lot of faith in charging docks, whether it comes to regular charging, changing batteries or ‘boosting’ batteries from the charging dock in case there is a power shortage,” says Tronstad.

The first feeder catamaran was produced in 1988. To date they have produced 50 to 60 berths and more than 100 feeder catamarans. In 2021, the company’s turnover reached NOK 120 million. Tronstad says last year was difficult due to the situation on the commodity market. But this year, the company has budgeted NOK 140 million in terms of sales volume. It is approximately half the turnover of the group, which is also engaged in, among other things, the production of ready-mixed concrete, crusher plants and the construction of concrete foundations for buildings. Ulstein Betong Marine is a subsidiary of the parent company Ulstein Betongindustri.

The flows are very stable

The largest piers weigh 1,100-1,200 tons. The largest feed fleets weigh about 2,100 tons. The immediate question here is how these ships float, and whether there is a danger of them sinking. Engineers at Moldskreid in Ålesund, now taken over by Norconsult, are responsible for engineering.

“They have three very experienced engineers designing for us,” says Tronstad, a civil engineer with a background in the oil industry in Stavanger.

-We have built a lot over many years and see that the facilities are safe and have a long life. Our products have a design life of up to 50 years, but experience suggests they can operate for up to 100 years. Floating docks are flat on the bottom, making them more stable than a hulled boat. It is of course necessary to build it so that it has the correct weight distribution. Tronstad says stability is “not an issue,” they are designed correctly and float very stable.

He says docks and feeder rafts are being towed long distances. When we visited, they were in the process of completing Finnmark’s feed fleet. The journey takes six to seven days at a speed of three to four knots. Ladekaia was towed at Aker Brygge around the southern coast and into the Oslo Fjord. The structures are anchored by chains to the seabed with sand anchors, concrete weights or bolts. They can also be installed using piles and pile clamps.

– There are not many people who produce floating docks with below-deck chambers, neither in this country nor internationally. Tronstad believes that the potential for developing this concept is great.

A waterproof joint is essential

He says that it is necessary to create a watertight joint between the base plate and the walls and shows us a soft plastic product that is molded between the base plate and the outside of the exterior wall. This ensures a waterproof connection. Rebar holds the structure together and makes it strong enough to withstand the force of weather and the sometimes violent winds along the coast.

– The ship’s hull also has a lot of weight, but it does not sink more than the amount of fluid displaced. The loading dock at Aker Brygge weighs 546 tons with payload. Its dimensions are 15.6 x 12 metres, and calculations indicate that it will sink 2.92 meters into the water, that is, from the waterline to the bottom of the floating dock, says Tronstad.

– The ideal spot for a shark would be about one meter from the waterline to the edge of the pier. We adapt the freeboard according to the purpose for which the dock will be used. The main advantage of floating docks is that the distance from the sea line to the edge of the dock is always constant. This simplifies transportation between the boat and the dock. This is not the case with fixed structures that are affected by tides.

The article was first published in TU Magazine Issue 3/2023