Fullriggerøya is an artificial island in the Trondheim Fjord where homes, boat yards and commercial buildings are being built. The first homes were completed already in 2013, and now the construction of a completely new recreational- and public swimming area has also begun. Nordic Crane was in place to lift and install a new pedestrian and cycle bridge, making access to the swimming area easier.
Grilstad Marina AS is building over 800 homes and a marina for 1000 boats in connection with an artificial island out in the Trondheim Fjord. Although much is finished, there is still some work to be done with regards to completing green spaces and recreational areas. On site, construction of a new bathing/swim area is underway and to improve access, a new pedestrian and cycle bridge has been installed over the “canal”.
“When we started planning last summer, we thought we had to use a 650-tonne crane. With the total weight and distance of the lift, this was initially quite obvious, says Reidar Røhjell Skarsem from Nordic Crane dept. Trondheim
“Along the way, however, it became clear that the job had to be done with a smaller crane. There wasn’t enough parking space for a large crane and the distance was simply too far,” he continues.
The solution was to use a Liebherr LTM 1230-5.1 which has a 75-meter telescopic boom. The final plan was to transport the mobile crane in by barge and use this as parking. In collaboration with Boa Offshore AS, calculations were made regarding the crane’s weight, counterweights and how the barge would behave when the crane moves with/without load.
Reliant on good weather and good planning
-We were of course particularly reliant on good weather and the job was postponed twice, but on the third day the weather gods showed us mercy and we got a whole day without wind and waves, explains Skarsem.
The crane was driven on and off the barge at Trondheim Harbour and transported to Grillstad Marina by tugboat, before two smaller tugboats took over, as it became too shallow for the large one.
With the crane and barge safely placed, three bridge elements were lifted into place. Two of 28 tons and one of 12 tons.
“In order for us to stay under a certain amount of pressure on the barge, it was calculated that the crane should not hoist the bridge elements further than 18 meters.
“There’s a lot of planning in a job like this. Many calculations. Skilled employees, modern equipment and experience are essential. Here we used the Liebherr crane’s integrated system and external PC programs to find the pointed centre of gravity. Once we have this, we know which boom angle/radius to stay on, so the barge doesn’t tilt too much. This time we set a limit of 2° inclination laterally,” explains Skarsem.
Terje Ingvaldsen was behind the controls of the mobile crane, and the job was carried out exactly according to plan.