IN Brief:
- The largest delivered monopiles exceed 105 metres in length, 11 metres in diameter, and 2,300 tonnes.
- Hornsea 3 will use 197 turbines across a planned 2.9GW offshore wind development.
- Manufacturing, port handling, and installation must remain aligned as offshore foundation work accelerates.
Haizea Wind Group has shipped another batch of XXL monopiles from the Port of Bilbao for Ørsted’s 2.9GW Hornsea 3 offshore wind project in the UK North Sea.
The largest foundations in the delivery exceed 105 metres in length, measure 11 metres in diameter, and weigh more than 2,300 tonnes each. Haizea describes them as the largest monopiles manufactured in southern Europe and the largest industrial structures yet produced in the Iberian Peninsula.
Moving foundations on that scale is an engineering operation in its own right. Mammoet transported the monopiles within the port using self-propelled modular transporters, Grúas Aguado provided logistics support, and Cadeler handled load-out and offshore installation arrangements.
The piles are being installed by Cadeler’s Wind Ally, which began foundation work at Hornsea 3 in May. Each unit is driven into the seabed to form the primary support for a turbine, with secondary steel, access systems, cable interfaces, and other components added as construction progresses.
The latest shipment is larger than the first Hornsea 3 foundations that arrived in the UK from Bilbao earlier in 2026. Those initial monopiles were around 90 metres long and averaged approximately 1,670 tonnes. The difference reflects the variation required across a large offshore site, where water depth, soil conditions, turbine loading, and installation tolerances influence each design.
Hornsea 3 will use 197 Siemens Gamesa SG 14-236 DD turbines, rated at 14MW excluding power boost. The project lies about 120 kilometres off the Norfolk coast and is expected to enter operation in 2027, with projected generation equivalent to the annual electricity use of more than 3.3 million UK homes.
The first foundation was installed in May by a team involving Ørsted, Cadeler, and Menck. That milestone shifted the programme from component production and marshalling into sustained offshore construction, making the pace and reliability of foundation deliveries increasingly important to vessel utilisation.
Haizea and Ørsted agreed the manufacturing contract in 2022, while the Spanish company was developing a new monopile plant alongside its existing offshore tower facility in Bilbao. The contract covers material procurement, fabrication engineering, production, and delivery at the port.
The order provided an anchor workload for a facility designed around larger offshore wind components. Its deep-water location avoids the need to move completed monopiles by road or through constrained inland routes, while adjacent handling areas allow the structures to pass directly from fabrication and coating into storage and vessel loading.
That arrangement is becoming more important as turbine ratings rise. Larger rotors and higher hub loads require foundations capable of handling greater static and dynamic forces, while projects in deeper water can demand more steel and longer piles. The resulting components place heavier requirements on rolling, welding, non-destructive testing, coating, lifting, storage, and transport infrastructure.
Diameter and mass also reduce the number of suitable ports and installation vessels. Quays must carry concentrated loads from transporters and stored foundations, cranes and handling systems need sufficient capacity, and vessels must combine deck space, lifting capability, and pile-handling equipment. A delay at any one of those interfaces can leave expensive offshore assets waiting.
Quality control becomes more demanding as the structures grow. Longitudinal and circumferential welds must meet tight tolerances across very large steel sections, while dimensional checks ensure that flanges, lifting points, and installation interfaces align offshore. Coating systems must also survive storage, transport, handling, and decades of marine exposure. Any dimensional or surface defect discovered late can disrupt both factory sequencing and offshore vessel plans.
Hornsea 3’s foundation supply involves several manufacturers and logistics chains, reflecting the scale of a 197-turbine programme. Haizea and Dajin Heavy Industry are producing monopiles, while completed units are marshalled and transferred through UK facilities before installation.
The Bilbao deliveries show how southern European heavy manufacturing can serve North Sea projects when fabrication capacity is paired with suitable port infrastructure. The work extends well beyond forming steel cylinders: the plant has to coordinate plate supply, welding sequences, dimensional control, surface treatment, internal transport, quayside storage, and vessel schedules around components weighing well above 2,000 tonnes.
Manufacturing progress must now remain aligned with installation weather windows and vessel sequencing. The record-sized structures have left the factory, but they still face sea transport, offshore handling, pile driving, secondary works, inspection, and commissioning before they become operating foundations beneath Hornsea 3’s turbines.
