TOWERS LIFTED WITH EXPANDED CAPACITY UNIT
From Crane & Hoist Canada, Fall 2010
Connacher Oil and Gas has two new evaporator towers secured in place at its Algar Oil Sands Project, thanks to an engineered lift that took a year of planning and some careful work on the ground. LaPrairie Crane performed the lift last October in what was the company’s largest lift to date. The larger of the two evaporator towers measured 143 feet tall and weighed in at 476,000 pounds.
The job involved a lift team of 15 and three of the company’s crawler cranes, each equipped with computerized Load Moment Indicator (LMI) technology to maintain stability during the lift. Three LaPrairie Crane crawler cranes — two Manitowoc models and the other a Kobelco machine — prepare to lift an evaporator tower into place at the Algar Oil Sands Project near Fort McMurray, Alta.
LaPrairie’s vice-president of operations, Reagan LaPrairie, said a Manitowoc 16000 was the lead crane on the lift, but the addition of MAX-ER attachments allowed the crane to greatly increase its load capabilities. “The 16000 — its base crane is 440 ton, and we had the MAX-ER attachment, which actually brings it up to chart capacities that are comparable with 650-ton machines in certain ranges,” LaPrairie said. “We anticipated to be in that class of work you needed that type of chart so we thought the 16000 was the way to go because, as a base machine, you can move it around still fairly easily compared to a 600-ton machine.”
The Manitowoc was balanced with 335,000 pounds of counterweights to provide 630,000 pounds of lift capacity. Assisting the 16000 as tailing cranes were a 235-ton Manitowoc 888 and a 200-ton Kobelco rigged for 290,000 pounds and 230,000 pounds respectively. LaPrarie said it took about three weeks to erect the 16000 and MAX-ER attachment and about a month for the customer to do site preparation, which involved compacting the entire lift pad area.
Once the site was prepared, LaPrairie and his team used more than 250 five-foot by 30-foot crane mats on the compacted surface. “That just flooded the whole site so that the whole lifting site was sitting on crane mats,” he said, noting that another couple of days were spent getting the cranes moved into position. Once everything was lined up, the 16000 began its role of hoisting the 476,000-pound vessel towards its final destination.
“When we started hoisting, the main crane — the 16000 — essentially just started hoisting straight up. It never did really swing that much,” LaPrairie said, noting that the two tailing cranes kept the base of the vessel about 10 feet off the ground. “As we were going higher, the tailing cranes were crawling towards the 16000 together in sequence. The tailing cranes were doing quite a bit of the work, while the main crane was just going straight up, taking the load on until it got totally vertical.”
LaPrairie said once the load arrived at the tipping point, the tailing cranes let off, allowing the load to become plumb. “We were at a 36-foot radius with the 476,000 pounds,” he said. “From there we had to swing it over to its front access and then propel the 16000 about 15 feet towards the final resting place for the vessel.”
In addition to being the company’s largest lift to date, it was also LaPrairie’s first experience with the MAX-ER attachments.
Download as PDF
