Boulders lifted during construction of new elephant enclosure for ARTIS

On behalf of IJbouw bv, Koninklijke Saan provided assistance at ARTIS with the placing of various heavy elements in the new elephant enclosure. The large body of water and the elephants’ basin was to be clad with various heavy boulders that had all been shaped differently.

Saan’s cranes assisted with placing 32 elements of the rock structure. Not only was the shape of every boulder different but the weight of the pieces varied between 3 and 22 tonnes. First the heaviest elements were lifted and positioned with two cranes working together. Because the boulders were delivered on their sides, these rocks first had to be tilted between the two cranes lifting in tandem so that they could be placed upright around the basin. All the elements were given a letter and number and were lifted in the right order when called off by IJbouw so as to be placed in the spot with the same letter and number combination. Then the rocks were immediately released and secured in place.

The boulders weighing up to 18 tonnes were positioned with a telecrane. Each element was separately assessed to see how best to tilt and lift it. To this end, each element was first placed on the sand and then moved with lifting equipment on the lifting rings. Then each imaginatively shaped element was tilted so that the bottom could be lifted horizontally on to the rim of the basin. Each element was then positioned with the greatest precision. The lifting work was completed successfully and entirely within the timetable.