12 Liebherr mobile cranes from Dutch lifting, transportation and piling specialist Boer have been used to lay a one-kilometrelong heating network pipeline in Delft, The Netherlands.

The cranes, with lifting capacities ranging from 90 to 400 tonnes, had to move the pipeline into position to be inserted into the ground. A key challenge, however, was that the pipeline had to retain a predefined curvature – so the cranes effectively needed to bend the pipeline as they lowered it into position. To do this the pipeline was lifted up and placed in a long retractable curve, measuring 275 metres long, so that it could be drilled into the ground at the required angle.

“To get the exact curvature we formed the arch with ten cranes,” explains Harm van Dijk, project manager at Boer. “Each of these cranes lifts 18 tonnes. For this reason we needed machines with a capacity of between 90 and 140 tonnes here.”

The pipeline could not be completely pre-assembled on the ground as a motorway and bridge crossed the route. It was therefore stored on containers at a sufficient height, as required. “On the other side of the motorway we used a 300-tonne and a 400-tonne crane because of the large overhang," van Dijk adds.

Preparations for the pipeline project, called WarmtelinQ, have been underway for around three years. Once complete it will use residual heat from industry in the port of Rotterdam and waste incineration plants to sustainably heat homes and businesses in South Holland. The pipeline runs from the port of Rotterdam to The Hague via Vlaardingen. The project is for Dutch natural gas infrastructure and transportation company NV Nederlandse Gasunie, which has commissioned Belgian construction group Denys to oversee the build.