Technology
A turbine is installed only when a vessel with a tall enough crane and long enough legs is free on a calm day. Turbines have grown faster than the fleet has, so the ships able to install the largest machines number in the low tens worldwide, and their charter books run years ahead of the projects that need them.
In one sentence
Offshore wind installation vessels are the jack-up and floating heavy-lift ships that transport and erect foundations and turbines at sea, together with the cable-lay and rock-placement vessels that install and protect the array and export cables.
A jack-up lowers its legs to the seabed and lifts its hull clear of the water, giving the crane a stable platform in a way a floating vessel cannot. Two numbers then decide what it can do: leg length caps the water depth, and crane height and capacity cap the turbine. Because both are fixed at the design stage, each generation of larger turbines retires part of the existing fleet from the newest projects.
The fleet is several distinct businesses. Foundation installation needs heavy lift and a pile hammer; turbine installation needs crane height; cable-lay needs a carousel and burial equipment; rock placement protects what has been laid; and service operation vessels look after the farm for decades afterwards. A newbuild jack-up costs several hundred million dollars and takes about three years from order to delivery, from a short list of yards, so supply responds to demand with a long lag.
The crane must lift a nacelle above hub height and place it on a tower, so the required reach grows with every increase in rotor diameter. Some vessels can be re-craned and some cannot, and a re-crane costs a year of availability. This is the mechanism by which turbine growth, which lowers cost per megawatt, tightens the installation market at the same time.
Ordering a vessel means a three-year wait at one of a small number of yards, mostly in Asia, and a capital commitment underwritten by charters signed before the steel is cut. Owners therefore build against contracted work rather than expected demand, which keeps the fleet tight through the part of the cycle when projects most need it.
United States cabotage law requires vessels carrying cargo between American points to be built and flagged there, which the European jack-up fleet is not. Projects have worked around it by keeping the installation vessel on station and shuttling components out on feeder barges — an extra operation, an extra weather exposure and an extra cost — until compliant vessels exist in numbers.
Jacking, lifting and cable-lay all have limits on wave height and wind speed, and a vessel waiting on weather is still on charter. Seasonal availability therefore feeds directly into project cost, and a delay upstream in fabrication can push a campaign into a season where far fewer workable days exist.
3 of these are marked as a chokepoint: a handful of qualified suppliers, a multi-year lead time, or a single geography.
Cable-lay vessels are booked around cable factory output, so a slipped cable delivery idles a vessel that cannot be rebooked at short notice.
High-voltage cableAdding a capable jack-up takes about three years at one of a few yards, so the fleet cannot respond to a demand spike.
Vessels load at ports with load-bearing quays and laydown area; without one within reach, the campaign lengthens or a feeder operation is needed.
Crane operators, jacking engineers and technicians are a limited pool, and workable sea states restrict when any of them can work.
Where domestic-build rules apply, the qualified fleet is a fraction of the global one and installation methods change accordingly.
Other pages in this map that name Installation vessels as something they cannot do without.
What each company supplies at this step, and — where a public figure exists — its share of this specific market — with what that share measures, the period it covers and who published it. Some rows also show the company’s own reported revenue for the segment covering this step, which is a different thing: it says how much this business matters to that company, not how much of the market it holds. Not a ranking and not a recommendation.
Operates the largest fleet of purpose-built turbine and foundation installation jack-ups.
Installs foundations and turbines with jack-up and heavy-lift vessels, and lays cable.
Marine contractor installing foundations and turbines and laying inter-array and export cable.
Installs foundations and cables for offshore wind through its Seaway7 business.
Owns Fred. Olsen Windcarrier, an operator of turbine installation jack-ups.
Operates heavy-lift installation and cable-lay vessels for offshore wind.
Owns the first turbine installation vessel built to United States cabotage requirements.
Whether the jack-ups ordered for the largest turbines deliver on schedule.
Whether United States projects continue to rely on feeder barges rather than compliant vessels.
Whether quayside assembly for floating projects reduces demand for offshore heavy lift.
Each page explains one technology in plain language, states what it depends on, and names companies by what they supply at that step. Company roles are described qualitatively and deliberately carry no market shares, revenue figures or rankings — those change faster than an explainer can, and a stale number is worse than none. Ticker links point at company pages on this site and are provided for reference only.
Nothing here is investment advice, a recommendation, or a forecast. A company named on a page about a technology is not thereby a good investment, and the chokepoints described are structural facts about supply chains rather than predictions about prices. Technology moves; where a page describes something as unresolved or in development, that was true when it was written.