June 7 - Richmond, Virginia based W.O. Grubb Crane Rental has used a 300-tonne capacity Manitowoc MLC300 crawler crane to replace an industrial lime kiln at a plant in Wilmington, North Carolina, USA.
The plant was located near a river in a coastal region, meaning that the terrain was soft and wet. The MLC300 with its variable position counterweight (VPC) was chosen to handle the lift due to its capacity, small footprint and low ground bearing pressure, claimed Manitowoc.
Jeff Collins, vice president of engineering and administration for W.O. Grubb, explained: "We had to erect the crane in an alleyway and only had an allowable ground bearing capacity of 2,000 lbs per sq ft (9.7 tonnes per sq m) to work with. Without the VPC, we couldn't have made the crane light enough to safely complete the job."
The crane was first used to lift the 195-tonne old lime kiln, measuring 25 ft (7.6 m) in diameter, through a 35 ft x 75 ft (10.6 m x 22.8 m) opening in the roof of a 45 ft (13.7 m) high structure. The kiln was then placed on stands and hauled to a remote laydown area. Following the removal of the old kiln, the MLC300 lowered a replacement kiln through the same opening, ready for welding into place.
"We were working in a very tight spot," said Collins. "The crane had to be positioned within inches of a building wall at one end, with only a three-inch (76.2 mm) vertical clearance between the top of the counterweight stack and the bottom of a pipe rack under which the counterweights were forced to swing."