In 1969 Chris Deij built his very own crane: for assignments that he received for his forge, he needed to perform some lifting work on a regular basis. His crane made an impression, and it wasn’t long before he got hired to do lifting work on a regular basis. The foundations for his company were laid and in the eighties the family business changed its name to Barneveldse Kraanverhuur (BKV), specializing in crane rental.
Now, 42 years later, the company rents out its cranes not only in the Netherlands, but across Europe. Although wind turbines only partly make up BKV’s portfolio, the Barneveld company has got quite some experience in building, dismantling and maintaining wind turbines.
Daan Deij is director of BKV; he runs the family business with his three brothers. “There are about two hundred crane companies in the Netherlands, but there are very few with a range from a 40 tons telescopic crane to a 750 tons crawler crane.” The crawler crane Deij refers to, is the Liebherr LR 1700, the latest addition to BKV’s fleet of approximately thirty cranes.
The recently purchased crane is typically one that, BKV expects, will be widely used in the construction of wind turbines. Deij: “It is the sixth of its kind being built; we expect to receive it next February. The new crane has a boom length of 165 meters and a jib of 12 meters and can lift up to 104 tons.” This shows the clever design of the LR 1700: although it is just as compact as its older brother LR 1600, that one can only lift to 70 metric tons.
This compactness is a necessity: wind turbines are becoming larger and larger and therefore require cranes that are higher and higher in order to being able to build them. Those cranes also have to be built up on location, but according to Deij, farmers are prepared to give up less and less land to use for the building up. “The stamp is getting smaller and smaller, but cranes and wind turbines are getting increasingly bigger.”
However, even with these challenges it is still possible to perform the work properly, Deij says: “Often, project developers involve us very early on in the project. They ask us how much space we need to erect
our cranes, and what the load-bearing capacity of the ground should be, things like that. In this way, we get by just fine.”
Higher and higher
Wind turbines sizes are increasing and, according to Deij, the end is nowhere near in sight yet. “Onshore wind farms are becoming larger and larger. A few years ago, the altitude was still around 130, 135 meters; now it is already 155 meters and there are plans to build wind turbines with heights up to 165 meters on land. And developments are already underway to create 185-meter-high turbines. I think we will see onshore wind turbines over 200 meters in height before the year 2030.”
Ever larger wind turbines also mean increasingly larger cranes to be able to build those turbines. Aren’t we going to run into a wall? Deij doesn’t expect this to happen any time soon: “The wind turbine builders are in close collaboration with the crane factories. After all, you don’t want to design a turbine that no one is able to build.”
What about Lagerwey’s climbing crane? That crane climbs into the wind turbine tower and as such doesn’t need to increase in size when constructing larger wind turbines. It also needs less space for building up on location. Does BKV see anything in the use of this type of crane? Deij: “That crane does an excellent job, but it is only suitable for one type of tower.There is also only one brand, Enercon, that uses this crane and that is not surprising, considering Lagerwey is part of Enercon.”
More than installation
Wind turbines might be getting higher, but BKV’s cranes are not exclusively used for the construction of new wind farms. And even in the wind energy sector itself, construction only makes up part of the activities: maintenance and dismantling also make up an important part of BKV’s order book. “Maintenance comes in as soon as a wind farm has been built. As for dismantling of wind farms, that usually starts at an average age of ten years and above,” says Deij. “Usually, we use slightly smaller cranes for the dismantling, because at the time these wind farms were built, the wind turbines were smaller.”
When building new wind turbines, the challenge lies in the height, with dismantling it lies in the documentation, says Deij. “You have to get your hands on the old documentation, to know what all the parts weigh and in order to get the right lifting tools which were also used when those wind farms were built.”
Not a single assignment is the same as any other one, but some really stand out from the rest. One such project is the
dismantling of five wind turbines from the Hartelkanaal wind farm in Rotterdam. Since 2003, these turbines have been located along the A15, on the edge of the Hartel Channel. These wind turbines weren’t dismantled on land, but on the water; it was a nearshore project. An LR 1600 from BKV, together with a 100 tons crawler crane from HEBO Maritiemservice, a company with which BKV worked together on this job, stood on a pontoon which was a 100 meters long and 33 meters wide. Deij: “Such a project with nearshore turbines is a special kind of assignment; it’s a bit in between onshore and offshore dismantling. When doing lifting work on a pontoon, the stability of a crane is completely different, and you have to think carefully about how to distribute the counterweight to keep the pontoons steady during the works.“
BKV also does a lot of assignments abroad. Deij: “Not too many years ago we operated approximately eighty percent abroad and twenty percent in the Netherlands; today it is the other way around. The construction of wind turbines is finally catching up here and we expect this to go on in the next few years.”
Recently, BKV completed a project in Ireland for the Derrynadivva wind farm. The project was special in several respects. For example, the BKV employees had to obtain a special diploma just to be allowed to work in Ireland. This also typi es the work abroad, Deij says. “Regulations differ completely between all countries: the number of working hours, the required permits, when you are allowed to drive on which roads… Nowhere it’s the same.
The Netherlands is quite a liberal country when it comes to exemptions to transporting cranes. In Belgium and France, you are not allowed on the highway; in Germany you are, but only at night.” That is why it is very important to be well-informed about the regulations in the countries in which you operate, which BKV makes sure it is.
And what is it that makes BKV unique? “All are employees are very well attuned to one another,” Deij says. “This is what makes us special: we work closely together. Actions instead of words, that is our corporate culture.”
Liebherr crawler crane LR 1700, technical data:
Max. load capacity: 700 t
At radius: 8.50 m
Main boom, lightweight/heavyweight from: 30 m
Main boom, lightweight/heavyweight up to: 165 m
Max. load torque: 9,650 tm
Lattice jib from: 12.00 m
Lattice jib up to: 96.00 m
Derrick boom from: 36.0 m
Derrick boom: 42.0 m
Central ballast 90 t
Counterweight at superstructure: 230 t
Derrick ballast: 375 t
Engine power: 400 kW
Driving speed: 1.20 km/h
This article appeared in the 2021 September edition of Windpowernl.