By Crane & Hoist Canada Staff
By Crane & Hoist Canada Staff
A wind farm in Holland used a Liebherr LG-1750 crane fitted with a SX3 lattice boom system to erect new turbines with extremely heavy tower components.
“The first four tower sections each weighed 120 tonnes which, when combined with the hook block, meant a load case of around 123 tonnes,” said Johan Bezemer, crane operator and part of the team that worked on the site near the German-Polish border. “This crane with its SX3 boom enables us to increase our capacities so that we can also erect these very large turbines.”
The 165-metre main boom and 12-metre jib gives it a lifting capacity of 127 tonnes, something Bezemer called “really enormous.”
On this job, according to stats provided by Liebherr, the LG-1750 had to manage a gross load of 112 tonnes to hoist the gondola. The SX3 boom system increases the lifting capacity by around 20 per cent, it said.
Wind less of a factor
The 28 or 42 metre boom reinforcement (which is also fully compatible with the Liebherr LR 1750/2 crawler crane) delivers significantly greater rigidity in the boom design and therefore results in less crane downtime due to wind, Liebherr said.
“The earlier systems used on the LG 1750 were calculated on the basis of a maximum wind speed of nine metres per second”, says Jens Könneker, product manager for Crawler Cranes at Liebherr in Ehingen. “The SX system now allows work to continue in wind speeds of up to ten, or in some cases even 11.2 metres per second.”
This is not just a major benefit for cranes working in wind farms, but is certainly a big plus for them.
The VarioTray detachable ballast system minimises the times required for adding and removing suspended ballast. The full counterweight is only required to lower and raise the 180 metre lattice boom.
3 working days saved
On the snowy site where the new Verschoor crane undertook its first job, around 100 kilometres north-east of Berlin, the wind gauge at the top of the boom often provided the answer to the question of whether work was possible on any given day.
Bezemer counts up the number of times when the greater wind tolerance of the SX3 boom system meant that the Dutch team could continue to work with their crane: “I think we managed to save around three working days.”
After all the tower segments had been assembled, the lattice jib had to be extended to 15 metres using an intermediate section so that the crane could provide the hoist height required for the other components, including the 100 tonne gondola. The team from Verschoor required just two hours to modify the jib.
The time required to lower the massive lattice boom was definitely reduced to a minimum as the LG 1750 was also fitted with the “VarioTray” detachable ballast pallet. The 415 tonnes of suspended ballast were actually only required to raise or lower the gigantic boom. The centre section of the counterweight, which can be detached from the remainder using bolts and remains on the derrick boom, was all that was required for the actual hoisting work.
“That saved us an enormous amount of time and effort”, says Bezemer.
“We can get straight on with the job without having to first stack or remove all the ballast.”
The LG-1750 had to manage a gross load of 112 tonnes to hoist the gondola. The SX3 boom system increases lifting capacity by around 20 per cent.
Most powerful crane in the fleet
After spending several weeks in Germany, the team from Verschoor returned to the Netherlands with their LG 1750. Since then, the crane has been working full-time on erecting wind turbines in the north of the kingdom using its SX2 boom.
The new crane is now the most powerful machine in Verschoor’s fleet.
“We will probably only use the LG 1750 for wind power jobs”, says Erik Hans van de Kop, the company’s Managing Director.
The company has a total of 70 cranes and 115 employees divided between its headquarters in Sassenheim (between Amsterdam and Den Haag) and a branch office in Almere. In addition to crane work, Verschoor also provides heavy haulage services and is active in the used crane and crane component business.