Ottawa landmark gets Morrow tower treatment

Morrow Equipment Company has supplied a Liebherr 630 EC-H 40 Litronic tower crane for work to the Ottawa Convention Centre, Ontario, Canada.

With a 40 tonne lifting capacity, the saddle jib is thought to be the biggest tower crane in the city. It hook height of 80 m also makes it the tallest freestanding crane in the region, according to Liebherr.

The core design of the new facility, which replaces a 1983 building used for the same purposes, features a 100 m long crystalline construction shaped like a tulip flower laid on its side. The tulip is one of the most prominent symbols of the City of Ottawa.

The design will allow visitors to look out onto nearby Parliament buildings, the Rideau Canal and the National Art Gallery, among other historic sites.

The 630 EC-H 40 was installed in a four day operation in September 2009, demanding good weather and wind speeds of below 20 mph. The crane is mounted on a 630 EC-H stationary undercarriage which has been bolted to the existing second floor slab of the building. The floor slab has been reinforced and shored down to bed rock.

In addition, the 10 x 10 m undercarriage is dead-weighted with 70 tonnes of concrete blocks to prevent uplift. The jib was installed in two sections and has a total length of 70 m.

The crane is equipped with a 147 hp hoist winch allowing hoist speeds up to 140 m/min. Operational wind speed of the Liebherr tower crane is 75 km/h, which, says the manufacturer, is about twice as high as the acceptable wind speed for mobile cranes.

The crane is initially being used to lift and place 30 m long steel roof trusses, weighing up to 15 tonnes each, as well as formwork and construction materials.