Ship made for rough seas

Minna Kalajoki


Swedish Steel Yachts SSY and its partner enterprises were tasked to build a strong and maintenance-free ship for demanding offshore patrolling.


Outokumpu Forta stainless steel was used to build the entire patrol ship. In addition to strength and durability, stainless allows for less material and lighter construction resulting in reduced fuel consumption.


Steel grade: Outokumpu Forta SDX 2507
Product form: Plate and sheet
Surface finish: Specular/2P polished

The town of Gävle, two hours north of Stockholm by the Baltic Sea, is known for its shipbuilding industry. In the mid 1800s, four of the six largest shipyards in Sweden were located there. Now, history is being made again in the spacious premises of Swedish Steel Yachts AB (SSY) in the town’s old shipyard area. The family company is working on an innovative prototype ship under the title “Project P16”.

The vessel is made entirely of stainless steel and it will be used for offshore patrolling by the coast guard, military, and sea-rescue services, or as a civilian transport boat. Other, highly-specialized Swedish companies are involved in the joint project, too.

“The idea is to find solutions for some of the key challenges in the boatbuilding industry and to provide more efficient, safer and greener ships for the future. This project can potentially open a whole new market for high-performance and sustainable vessels of this type,” SSY’s Head of Marketing Petra Rosén explains.


Design inspired by Vikings

P16 Prototype is built by using an innovative design concept, developed by SSY’s founder Håkan Rosén and inspired by the features of a traditional Viking boat.

“The patented construction provides progressive flexibility, which means that the hull moves in a controlled manner when subjected to powerful wave pressure, just like in the Viking age. Steel’s own qualities are used to add strength and performance. The ships’ technical lifecycle is basically unlimited,” Petra says.

The innovative design also made it possible to build an extremely lightweight ship. “The lightness of the P16 clearly reduces fuel consumption. The ship is maintenance-free, which saves precious time and money. It’s extremely resistant to saltwater, and can even be used when the sea is partly frozen – a useful feature in Scandinavian waters,” Petra points out.


No need for anti-fouling paints

For the ambitious project, SSY selected Outokumpu’s Forta SDX 2507 super duplex stainless steel. Outokumpu Nyby and Avesta delivered six to seven tonnes of stainless steel in 33 different sized plates.

“Forta SDX 2507 is the only option with the product qualities the end-users require. It is high-strength, durable, one-hundred percent corrosion-resistant, and maintenance-free with very good tensile strength. The whole boat is made of this grade,” Petra says.

Last but not least, all metal under the waterline is specular/2P polished, which ensures that marine organisms attached to the hull can be removed either with a low-pressure hose or even at very low speeds. As a result, there’s no need for environmentally hazardous and expensive anti-fouling paints.

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Nyby, Sweden

Steelmaking is deeply ingrained in Nyby. Nearly 200 years after the mill’s founding, Nyby continues to be recognized worldwide for uniquely customized, exceptionally high performance stainless steel.

Avesta, Sweden

Fueled by a high-octane blend of advanced technology and a long, proud tradition, the Avesta mill showcases precision performance. One of Outokumpu’s fully integrated production sites, Avesta redefines excellence.

Automotive and transportation

In transportation, today’s solutions must be dynamic enough to carry us to the future. Safe, strong, economical, durable and sustainable: Stainless steel delivers a new dimension of unmatched performance.


Stainless steel is the clear choice for use in marine environments – particularly for vessels that are ever lighter, stronger and easier to clean and maintain


The Forta range contains duplex and other high strength stainless steels that enable thinner structures and weight reduction (measured in Rp0.2 > 400 MPa. PRE 16 to 43).

Hot rolled stainless steel coil, strip and plate

Offering exceptional versatility, Outokumpu hot rolled coil, strip and plate are used in virtually all industries and markets. In addition to plates, Outokumpu produces quarto plate that is available in thicknesses up to 130 mm. 

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