Berwick Bank B Moves to Preferred Supplier Stage: Seaway7 Named for Foundations and Inter-Array Cables, but No Contract Yet

SSE Renewables has named Seaway7 — Subsea7's renewables arm — as preferred supplier for the engineering, procurement, construction and installation (EPCI) of wind turbine foundations and subsea inter-array cables on Berwick Bank B, the 1.4 GW second phase of its 4.1 GW Berwick Bank development in the outer Firth of Forth.

The phrase that matters commercially is "subject to final contract award." This is a preferred-supplier appointment in the exclusivity phase, not a signed EPCI contract. SSE has not disclosed contract value, foundation type, foundation count, cable length or the fabrication yards that will roll the steel. For a project of this scale, those are still the questions that decide who gets the work.

What is actually settled

That is a thin but telling set of certainties. Two of the hardest gates — planning consent and a CfD — are already cleared, which is more than most Scottish offshore projects at this stage can claim. What remains is the commercial engineering: turning a consented, subsidised capacity into a buildable, priced asset.

Why the sequencing is unusual enough to note

Most UK offshore wind projects of this era have gone to auction somewhat naked — consent in hand, supply chain unmobilised, and a nervous wait for a strike price before anyone commits capital. Berwick Bank B has effectively inverted that: the CfD came first (AR7, January 2026), and the supply chain is now being assembled around a revenue certainty that already exists.

That should, in principle, give SSE more leverage in negotiating EPCI terms than a developer bidding into an auction with unhedged costs. It also means the preferred-supplier stage is being run with a known price floor rather than a hoped-for one — relevant to how much risk transfer Seaway7 will accept on installation weather, vessel availability and fabrication slots.

The gap between the CfD (January 2026) and this announcement (October 2026) — roughly nine months — is a reasonable proxy for how long it took SSE to reach a preferred-supplier position on its largest offshore package. FID is then targeted for 2027, meaning the final EPCI contract, foundation fabrication awards and the marshalling port decision should all land within that window.

The technical uncertainty that matters most

Nothing in the available disclosure specifies the foundation type. That is not a small omission. At ~38 km offshore in the outer Firth of Forth, the choice between monopiles, jackets and any suction-bucket variant turns on water depth, seabed stratigraphy and turbine rating — none of which SSE has published in connection with this award.

The EPCI scope itself hints at a conventional approach: foundations and inter-array cables bundled into a single package is the classic monopile-plus-array-cable structure that Seaway7 has executed repeatedly at Beatrice, Seagreen and Dogger Bank. If jackets were the intended solution, one would typically expect a more differentiated fabrication strategy and a different vessel mix.

On capacity, 1.4 GW implies — as our own planning estimate, not a disclosed figure — something in the order of 70 to 100 turbines at 14–20 MW class, with one foundation per turbine plus any offshore substation structures. No turbine supply contract has been announced, so even the unit rating is unresolved.

The steel question: still open, but narrowing

For fabricators and plate mills, the commercially honest answer is that this award creates no confirmed order yet. Seaway7's appointment as preferred supplier for foundations is an EPCI scope, and Seaway7 is not a fabricator; it will subcontract structural steelwork.

Three procurement layers therefore remain genuinely open, in sequence:

1. Final EPCI contract to Seaway7 — the gate that unlocks everything below it.
2. Foundation fabrication subcontracts — not yet awarded, yards not named. UK content expectations in the SSE messaging suggest a strong pull toward UK and Scottish yards, but no facility has been identified.
3. Steel supply to those fabricators — plate and section grades, tonnages and delivery schedules will be set by the fabricator's buy, not by SSE directly.

On tonnage, any figure would be speculation. Published designs for 8–15 MW-class monopile-plus-transition-piece assemblies in the North Sea commonly run in the region of 1,500–2,500 tonnes per unit, but that range is illustrative context, not a Berwick Bank-specific estimate, and jacket solutions in deeper water would be heavier still. Applying it to a 70–100 unit envelope would produce a number of tonnage significance — several hundred thousand tonnes of structural steel — but the reader should treat that arithmetic as indicative only.

What is more useful is the timing signal: with FID targeted for 2027, foundation fabrication contracts would need to be placed during 2027 to hold installation slots in the 2028–2030 window. Steel buying for those contracts would follow fabrication awards by months, not years.

Employment claims: developer projections, not independent estimates

SSE's headline figures are worth presenting accurately because they are frequently misquoted. The company projects 465 UK jobs supported by the planned work, of which 400 in Scotland; about 160 direct Seaway7 roles led from its Aberdeen base; roughly 105 UK supply-chain jobs; and a further ~200 direct and indirect roles through foundation marshalling at a Scottish port still to be named.

Added to the Montrose Port O&M base — 100 long-term jobs plus ~30 construction roles — SSE reaches a total of around 600 UK-wide and over 500 in Scotland. These are developer projections, not independently audited figures, and the marshalling-port component is contingent on a decision that has not been made.

Reading the Seaway7 selection

Seaway7's Scottish track record — Beatrice, Seagreen, and ongoing Dogger Bank work — is the obvious rationale, and it is genuine. But the more interesting structural point is what the preferred-supplier route signals about competition in the EPCI market.

Bundling foundations and inter-array cables into one EPCI package narrows the field to contractors with combined heavy-lift installation and cable-lay capability, or with credible consortium arrangements. That is a short list. SSE choosing to signal its intent more than a year ahead of FID suggests an appetite for locking vessel capacity early — a rational response to a European installation market where heavy-lift and cable-lay spreads are increasingly contested.

Whether that translates into a competitive price for SSE is unknowable from outside. Preferred-supplier arrangements can deliver cost certainty; they can also entrench the incumbent.

What to watch

• The final EPCI contract. Until it is signed, the Seaway7 appointment is an intention, not an order.
• The foundation type decision. It determines steel intensity, fabrication geography and vessel requirements simultaneously.
• The marshalling port. An unnamed Scottish port is doing a lot of work in SSE's job figures; naming it will indicate where fabrication logistics concentrate.
• The turbine supply award. No OEM has been announced, and the unit rating directly sets foundation count and tonnage.
• Phase A. Roughly 2.7 GW of consented capacity remains without revenue support. Whether SSE bids it into a future allocation round — and when — determines whether Berwick Bank becomes one build programme or two.

Assessment

Berwick Bank B is now the most advanced unbuilt Scottish offshore wind project by revenue certainty, if not by construction readiness. The preferred-supplier appointment is a real milestone, but it sits before the two decisions that actually move steel: the final EPCI award and the foundation fabrication contracts. Fabricators and steel suppliers should read this as a scheduling signal for 2027 procurement activity — not as an open tender today.