Potain cranes tower over The Fjord City development in Oslo
Manitowoc’s Potain tower cranes are working on the construction of a new corporate and residential district in Oslo, Norway, part of a greater regeneration of the city’s historic waterfront area that will eventually cover 450,000 square meters. Known locally as The Fjord City, the multi-billion dollar project is located in the Bjørvika area of Oslo. It will be a mix of office space for more than 10,000 workers and apartments for 3,000 families. The ground floor levels are reserved for retail and other cultural attractions.
Manitowoc’s main dealer for Norway, Kranor A/S, has six Potain cranes working on the project. Kranor – part of Lambertsson, the largest crane group in Sweden – has been involved with Potain cranes since 1977. It now has a rental fleet of 150 tower cranes, all of which are Potains.
Kranor is renting two Potain MD 485 B and four Potain MD 365 B cranes to the development’s main contractor, Vedal Prosjekt, working for property developer Oslo S Utvikling. Tor Gunnar Stabaek, managing director of Kranor A/S, said the project set a new record for his company. “In terms of monthly turnover, it’s the largest rental project in our company’s history,” he said.
Part of Potain’s Maxi MD line of tower cranes, the MD 485 B cranes are equipped with 55 m jibs for The Fjord City project; they have a maximum capacity of 20 t. Height under the hook for the cranes will increase from the current 87.2 m to 100 m during construction of the tallest building in the development. The cranes will lift a variety of loads including some of the heavier elements, such as sections of the lift shaft, which can weigh up to 15 t and which must be lifted at a 30 m radius.
A second contractor on the project, Contiga, is making use of the four Potain MD 365 B cranes which are sitting on a V 60 base. These cranes are working with a 45 m jib and have a maximum capacity of 16 t. They are lifting the lighter, pre-cast elements on the project, such as the stairs and floors which weigh between 10 t and 12 t. Height under hook for these cranes will increase from the current 69 m to 85 m as the development grows.
“The cranes are working closely together, so the height and lifting capacity is more important than jib length,” Stabaek said. “Because we have so many cranes on this site we are using Potain’s Top Tracing technology to limit where the cranes can go. For example, there is a rail yard behind the construction site which we can overfly but not when we are carrying a load. Top Tracing is perfect for controlling site conditions such as this.”
Not surprisingly for such a development, the build is creating challenges almost every day. The contractor has to use mainly freestanding cranes up to more than 100 m hook height. This is another area where specifying Potain cranes is an advantage, Stabaek said.
“Freestanding hook heights on Potain cranes score over the competition,” he said. “Another advantage is their reliability. The cranes are working between 10 and 12 hours a day and need to be fully functional during that time.”