The installation vessel worked in batches of six.
It loaded six complete turbine sets at Hull, each one a nacelle, three blades and a tower section, then carried them 121 miles out across the North Sea, set them on their foundations and turned back for the next six.
The first turbine went up in March of last year.
There were 99 more to go.
And the seabed those foundations stand on is one of the strangest platforms in the North Sea.
Why a wind farm this far out could still be bolted to the seabed
The Dogger Bank sits between 50 and 120 feet below the surface, roughly 65 feet shallower than the sea floor around it, shallow enough that a steel tube can be driven into it and held firm. That shallowness is an accident of ancient geography. The bank is the largest continuous expanse of shallow sandbank in UK waters, shaped by glacial processes and then drowned by rising seas, and it formed the high ground of a lost landscape called Doggerland, walked by Stone Age hunters until the water closed over it around 8,000 years ago.
Because the bank barely qualifies as deep ocean at all, crews can plant fixed bottom foundations there despite being more than a hundred miles from any coast. Without that quirk of geology, the site would need floating platforms, a technology still at a far earlier commercial stage.
The Dogger Bank wind farm holds 100 turbines rated at 14 MW each, giving it a combined capacity of 1.4 gigawatts, enough to supply the equivalent of 1.2 million British homes. The power travels 137 miles back to a landfall at Redcar on the northeast English coast through a high voltage direct current circuit laid across the ocean floor.
How tall a turbine looks at 827 feet
Each machine stands 827 feet from the sea surface to the tip of its highest blade, about half again as tall as the Washington Monument. The three blades are 354 feet long apiece and sweep a rotor circle of nearly 10 acres with every revolution. Getting components that size 121 miles offshore, with no staging base anywhere near the array, is why the vessel carried six sets per trip and kept a service vessel stationed at the site.
The foundations beneath them are single steel tubes up to 29 feet in diameter and up to 302 feet long, weighing as much as 1,690 tons apiece. They were driven into a seabed of loose glacial sand and gravel, then fitted with ladders, boat landings and work platforms before a turbine could go on top.
What the seabed gave up before the crews arrived
During the last ice age, when sea levels were much lower, Britain was connected to mainland Europe by a broad landmass stretching from the east coast to the Netherlands and the western coasts of Germany and Denmark. The bank itself, about 160 miles long and up to 60 miles wide, rises roughly 65 feet above the surrounding sea floor. It is not ocean in any deep sense; it is a hill that happens to be wet.
For centuries the bank has been one of the richest fishing grounds in the North Sea, worked for cod, haddock and plaice. Trawlers dragging it have also brought up lumps of peat, the remains of mammoth and rhinoceros, and occasionally Stone Age tools.
So the seabed beneath a 1.4 GW wind farm is simultaneously a drowned Stone Age landscape and a glacial bank shallow enough to anchor a structure 827 feet tall. That is the geological luck the project runs on.
From one turbine to a hundred, and what set the pace
After the first machine went in during March of last year, the campaign ran through all four seasons, reaching the halfway mark in September. All 100 foundations and the array cables were in place by then, and the vessel kept cycling back to Hull through the winter and spring. It reached 80 turbines in mid-April and 91 by late May.
That rhythm mirrors the multi machine runs described in the construction of Denmark’s largest offshore wind farm, where batching components per trip proved the most efficient way to close out a large turbine count. Half of the turbines here carry recyclable blades, 150 of them, manufactured in Hull and all installed last year, the first use of the technology on a UK offshore project and the largest deployment of it so far.
What a complete set of turbines still waits on
The hundredth turbine was installed on 10 June this year, ending the offshore installation campaign. Standing is not the same as generating. Testing and commissioning of the high voltage direct current system is still running before the turbines can be connected to it.
The offshore converter platform, which lifts the 66 kilovolt alternating current from the array to 320 kilovolt direct current, was set on a jacket foundation in 2024. From there the cable running 137 miles to Redcar will carry the output ashore as direct current, the form chosen to hold down losses over that distance. The remaining work depends on North Sea weather windows that cannot be scheduled far in advance.
What Dogger Bank already shows is that 8,000 years of submersion left a platform sturdy enough to hold some of the largest structures the offshore wind industry has yet built, more than a hundred miles from the coast it will feed.
