The two crawler cranes arrived first, each rated at 250 metric tons.
They were there to lift parts of a machine far beyond anything either could carry alone.
A third machine, a 140 metric ton mobile harbor crane, joined them on the yard.
Together, all three were just the tools to build the tool.
At Westdorpe in the flat southwest corner of the Netherlands, a ring crane was going up piece by piece, and it needed its own fleet of heavy lifters to do it.
So what does a machine that takes three cranes to build actually do?
How a ring crane carries what nothing else can
A conventional crawler crane stands on two tracks and grows unstable if the load swings too far to one side. A ring crane answers that by riding on a circular rail track, spreading its own weight and the load across the whole circumference rather than concentrating it at two points. The slewing platform can pivot through a full 360 degrees with a full load on the hook.
The bigger the ring, the more the machine can carry. This crane, assembled at the Westdorpe facility, is described by its operator as the world’s strongest land based crane, built for offshore wind components, for modular construction at nuclear facilities and for new build and expansion work in oil and gas. Maximum capacity is reached using 4,200 metric tons of ballast, at a maximum ground bearing pressure of 30 metric tons per square meter.
Stability on this scale has to be bought with weight and a prepared surface. The crane can also launch foundations and build turbine sections without reconfiguration, which matters on yards where the work changes shape week to week.
What 6,000 metric tons actually means at ground level
Six thousand metric tons, roughly 6,600 US tons, is the maximum rated lift. The second number is the one most yards care about: the crane can place a 3,000 metric ton load at a height of about 720 feet, roughly the roof of a 70 story building. No crane on the market had previously offered that combination of height and capacity.
For scale, the machine usually named as the strongest before it is rated at 5,000 metric tons and was built for a nuclear site in Somerset, England, where it set a 245 metric ton dome onto each reactor building in turn. On maximum rated load, the Westdorpe crane sits 1,000 metric tons ahead.
Reach is the other half of the specification. The maximum radius is about 472 feet, and trade press reported the finished crane could be seen from more than 6 miles away across the flat Dutch polder. It breaks down for transport into roughly 300 shipping containers.
The assembly at Westdorpe, piece by piece
Initial assembly covered the slewing track, the base frame, the power packs and the control room. That work began in June 2024, with completion scheduled for the fourth quarter of the same year. Three cranes supported the build throughout: two 250 metric ton crawlers and a 140 metric ton mobile harbor crane working in coordinated shifts.
Project manager Koen Brouwers said the crane “will offer a hook height, outreach, and lifting capacity far in excess of any crane on the market.” It runs on full electric power from battery or grid supply, and can also be powered by a traditional diesel engine, giving yards flexibility on sites where grid connection arrives late.
Where this machine goes to work next
After assembly the crane went into testing at Westdorpe before deployment. Trade coverage at the time reported it would be transported to a client site in Asia for its first project. The jobs waiting for a crane this size are exactly the ones ordinary equipment cannot reach.
In offshore wind that means lifts in the 3,000 to 6,000 metric ton band, including suction bucket jackets, extra large monopiles and floating wind foundations. In nuclear construction it means setting whole prefabricated sections into a reactor building in a single pick rather than assembling them in place. Ring cranes on rail can also move between lift points, as demonstrated at a major nuclear site in England where the crane runs between three lifting positions linked by more than 3.7 miles of track.
For floating production vessels, the operator says topside modules can be installed from a single position without rotating the hull, which is otherwise costly and slow.
The size that still has limits
Even 6,000 metric tons is a ceiling, and components keep growing toward it. A 26 MW offshore wind turbine began operating in Shandong province with a rotor spanning about 1,017 feet on blades of roughly 502 feet, according to its state owned parent group. Each generation of turbine pushes the margin a little tighter.
The ring crane’s own operator frames the problem plainly: capacity limits force engineers to fabricate smaller modules than would be ideal, tying up yard space and lengthening projects. A crawler transporter faces the same logic on land, where the payload ceiling shapes every rocket program that relies on it.
What the Westdorpe assembly changed is narrower than a record and more useful: a single land based machine can now take picks that would otherwise be split into smaller pieces or handed to a crane vessel. That is the difference those three cranes were there to build.
