From the air the hub looks almost normal. Two long blades locked in place, and a third that stops after a few feet.
What is left of it is a torn mouth of splintered glass fiber with an internal web standing exposed in the open air.
Below, pale fragments trail across the water in a line you can follow.
Nobody was hurt. Nothing was struck.
The machine was brand new.
And the failure was not in the design.
What holds a 351 foot blade together
A blade that size is not molded in one piece. It is built as two long shells, like a clamshell, with internal webs running down the inside.
Those parts are joined with a thick structural adhesive, bond paste, laid in beads along the seams before the shells are closed.
When it cures properly that joint is as strong as the laminate around it, and the blade behaves as one object under load.
Lay the bead too thin, miss a stretch, or let it cure short of full strength, and the seam becomes the weak line in an otherwise sound structure.
Nothing about that shows on the outside. A finished wind turbine blade with a bad bond looks exactly like one with a good bond, and weighs the same.
It only declares itself when the loads find it, which on a rotor means after installation.
What happened off Massachusetts
The turbine is AW38, on the first commercial scale offshore wind farm in United States waters, roughly 15 miles south of Martha’s Vineyard.
The blade was 351 feet long, part of a 13 megawatt machine, and it came apart on the thirteenth of July in 2024.
Fiberglass, foam and balsa reached Nantucket beaches within days, and recovery teams worked the south facing shore while vessels tracked floating pieces offshore.
Federal regulators moved fast. They suspended power production across every turbine on the lease, not only the damaged one, and halted installation of new turbines.
They also issued a preservation order to protect evidence for the investigation.
The project is 800 megawatts across 62 turbines, so one seam stopped the entire site.
The finding and the factory
The root cause analysis pointed at manufacture rather than engineering. There was insufficient bonding at certain locations inside the blade.
The manufacturer called it a manufacturing deviation and said its quality assurance program should have identified it, adding that there was no indication of a design flaw.
That distinction decided everything that followed, because a design flaw would implicate every blade of the type while a plant problem implicates every blade from that plant.
The blade came from a factory in Gaspé, Quebec. Regulators then directed removal of every installed blade built there.
That covered 22 turbine locations, and at three blades per turbine the count reaches 66 blades, with two further locations flagged for review.
Each one had to come off a hub hundreds of feet above the water and go back by vessel.
What is still not established
Two more blades were removed, from turbines AT41 and AS42, and those came from the French plant at Cherbourg rather than from Quebec.
Those two were taken down on the operator’s own decision rather than by regulatory order, and the reason has not been made public.
The federal investigation itself has not produced a final report. Seventeen months after the break it was still open, which a lawyer for Nantucket described as far too long.
Reports of layoffs and of falsified quality control data at the Quebec plant come from local media rather than from any regulator, and should be read that way.
It is also not the only blade of this model to fail. One came apart at a British site, where the cause was attributed to installation error instead.
Which leaves two failures, two different explanations, and no published account tying the tip speeds and loads of this machine to either of them.
What the restart actually required
The suspension was lifted in January of 2025, with construction allowed to continue using blades from the French plant.
The conditions attached are the interesting part. Every blade must be visually inspected before it is allowed to operate.
A monitoring system capable of detecting a blade anomaly and notifying the operator immediately has to be running.
Reports go to regulators after each intervention, covering repairs, ultrasound results, visual examination and engineering analysis, and a certified verification agent witnesses the manufacturing steps, adhesive application included.
Separately, businesses on Nantucket settled with the manufacturer for 10.5 million dollars over the debris that reached their shore.
All of that is downstream of a bead of glue, which is the part worth carrying to the next project off Virginia and to every one after it.
