Seaspan Shipyards has named Algoma Steel and Stigterstaal Canada as primary steel plate supplier for up to six of the Canadian Coast Guard’s multi-purpose icebreakers (MPI), turning a 2025 feasibility pact into a firm order.

Why it matters: The agreement puts Ontario-made plate into one of the largest builds under the National Shipbuilding Strategy (NSS). It is also the first concrete result of the three companies’ July 2025 effort to re-establish a domestic steel supply chain for Canadian shipbuilding.

Driving the news: The deal is valued at about $182 million and covers up to 24,000 tonnes of structural steel, or 4,000 tonnes per vessel.

The details: The Seaspan-designed MPIs will run about 100 metres long, displace nearly 9,000 tonnes and carry a crew of 50.

Algoma said the MPI work forms part of the largest polar-class steel order in the mill’s history. That order also covers Seaspan’s heavy polar icebreaker, the future CCGS Imnaryuaq.

What they’re saying: “This agreement represents another important step towards ensuring that future Canadian Coast Guard vessels are built with Canadian materials, support skilled Canadian jobs, strengthen Canada’s industrial capabilities, and deliver long-term value for Canadians,” said Kate Morton, vice-president of supply chain management at Seaspan Shipyards.

“When Canadian shipbuilders choose Canadian steel, the impact reaches well beyond the shipyard,” said Rajat Marwah, chief executive officer of Algoma Steel. “This is the largest order of polar-class steel in our mill’s history, and a proud moment for our team in Sault Ste. Marie and for Canadian steelmaking.”

Ronald de Groot, chief executive officer of Stigterstaal Canada, said the milestone came out of joint work to determine how Canadian steel could be integrated into complex shipbuilding programs. “For us, this is about much more than supplying steel,” he said. “It is about helping build a strong and resilient Canadian maritime supply chain.”

Joël Lightbound, Minister of Government Transformation, Public Works and Procurement, said the agreement “means that Canadian Coast Guard icebreakers will be built in a Canadian shipyard with Canadian-made steel.”

By the numbers:

The bigger picture: Ottawa has tied recent procurement policy closely to domestic content. “In recent months, Canadian steel has found more openings through Buy Canada policies, the National Shipbuilding Strategy, and the Defence Industrial Strategy,” said Terry Sheehan, MP for Sault Ste. Marie–Algoma.

Algoma is in the midst of a shift to electric arc furnace steelmaking alongside a modernized plate mill. Stigterstaal has committed to meeting 100 per cent Canadian content on Seaspan’s NSS programs through direct and indirect investments under Canada’s Industrial and Regional Benefits policy.

The MPI design also carries weight beyond Canada. A production-ready Seaspan-Aker version of the design was selected for the U.S. Coast Guard’s Arctic Security Cutter program, with those ships to be built in Finland and Louisiana.

Background: Seaspan, Algoma and Stigterstaal signed a memorandum of understanding in July 2025. It set out a framework to assess whether Algoma could supply class and non-class steel to Seaspan, with Stigterstaal acting as commercial and logistical subcontractor.

That agreement initially focused on the heavy polar icebreaker, on which Seaspan cut steel in April 2025. The new deal extends the arrangement to the MPI program.

What’s next: The companies did not release a delivery schedule for the plate or a construction timeline for the first MPI.