Seaway7 sells six-vessel heavy transport fleet to HEA Energy

Six semi-submersible heavy-transport vessels are changing hands. Seaway7, the offshore wind installation arm of the Subsea7 Group, announced on 5 November that it will sell its Heavy Transport business to HEA Energy, with completion expected in the first half of 2027, subject to regulatory approval. Financial terms stay undisclosed.

The fleet in question is small but strategically placed: six open-deck semi-submersible heavy-transport vessels — five owned outright, one chartered from a third party — used to move the outsized structures that offshore wind construction depends on. That means wind farm foundations, substations and other oversized project cargoes that no ordinary cargo ship can carry.

For an installer still chasing some of the biggest offshore wind contracts in the North Sea, selling the ships that move those components is a curious move. Heavy transport sits near the base of the offshore wind supply chain, ferrying foundations and other substantial components from fabrication yards to offshore installation sites.

Why is Seaway7 letting the ships go?

The answer traces back to July 2025, when Subsea7 signed a merger agreement with Italian engineering company Saipem. The combined entity, proposed under the name Saipem7, would carry forecast annual revenues of approximately €21 billion and an order backlog of around €43 billion. The heavy-transport disposal is linked to that deal — a streamlining that sheds an in-house capability before the merger takes shape.

On the buyer's side, the logic is straightforward growth.

"Heavy transport is a segment we know well as a customer, one where demand is set to grow as offshore structures get larger and move further from shore," said HEA Energy managing director Omar Elali.

"With this fleet, HEA Energy gains a global platform, a second line of business with its own contracted backlog and the ability to combine transport, installation and maintenance into a single offer for our clients," Elali said. "It is the next step in building HEA Energy into a diversified offshore services group."

In short, HEA Energy walks away with vessels, a contracted backlog and an opening into a market where cargoes keep getting heavier and shorelines keep receding. Seaway7 walks away lighter.

Does Seaway7 stay in offshore wind?

Yes — and aggressively so, on paper at least.

In January, Seaway7 secured work at Germany's Gennaker project, covering the transport and installation of 63 monopiles and transition pieces. On 20 October, SSE appointed the company preferred supplier for the engineering, procurement, construction and installation package at its 1.4GW Berwick Bank B project in Scotland. The proposed scope includes about 90 turbine foundations and subsea inter-array cables.

"We are proud to have been selected by SSE Renewables as the preferred supplier for Berwick Bank B and to continue a relationship that has successfully delivered major offshore wind projects including Beatrice, Seagreen and Dogger Bank," said Seaway7 CEO Lloyd Duthie.

"This agreement reflects the benefits of our early engagement, strong collaboration between our organisations and the expertise of our teams in delivering the optimum solution for this complex offshore wind development," Duthie said.

The company's argument, implicitly, is that it doesn't need to own the ships. Seaway7 can execute EPCI contracts using chartered or third-party vessels rather than a captive transport fleet, and there are owners — HEA Energy now among them — willing to fill that role.

What changes in the operating model?

Still, the arithmetic is hard to ignore. A company that continues to pursue projects dependent on moving enormous offshore components — 63 monopiles at Gennaker, roughly 90 foundations at Berwick Bank B — has just disposed of a substantial in-house heavy-transport capability. That is a genuine shift in Seaway7's offshore wind operating model, from owning the logistics chain to renting it.

The customers may not feel the difference immediately. Charter markets for heavy transport exist, and Saipem7's scale — €21 billion in forecast revenues, $43-billion-class backlog territory — gives the merged group plenty of purchasing power for marine spreads. But it leaves Seaway7's wind EPCI bids exposed to third-party tonnage, scheduling and pricing in a niche market where demand, as Elali notes, is set to grow.

The watch items now: regulatory approval of both the sale and the Saipem7 merger, first-half 2027 completion, and whether Seaway7 converts its preferred-supplier position at Berwick Bank B into a signed contract on time and on tonnage it no longer owns.