The first instinct of S&F Concrete Contractors was to bring in a crawler crane for a city centre building project in Boston, USA. But road access was limited and there were high buildings on either side of the site. Given these constraints, a luffing jib tower crane was the only option, according to S&F project manager Patrick Barb.
S&F rented a Potain MRC 45 luffer, the first crane of this model in North America, for its recently completed Tremont Towers project. This luxury apartment block is a 20-storey, concrete-framed structure with four underground levels.
S&F used the crane to lift formwork panels and steel girders, weighing 2t on average. The MRC 45 lifts a maximum 2.9t at 17.3m.
The crane uses jacking frames to climb internally. At the outset it was erected with a 30m-high, nine section mast. During the project it made four climbs, each of 10m, which is equivalent to four storeys.
In the early stages of the project, when a tight radius was needed, the MRC 45’s two-fall goose neck jib was a useful feature. As the building rose, the jib was usually locked into its normal luffing position.
Another benefit of the chosen crane, according to Barb, was that it is electric. “Running the crane from our own power source is cheaper. Most of the tower cranes you see around Boston are diesel models which is more expensive,” says Barb.
