Reaching the heights of creativity
WINNER OF INDUSTRIAL AWARD
Owner: Shell Canada Energy
CISC General Contractor/Fabricator/Detailer/Erector: Eskimo Steel Ltd.
CISC Engineer: BPTEC-DNW Engineering Ltd.
While designing and building overhead crane runway support systems is nothing out of the ordinary, the project to retrofit the Shell Canada Energy Reactor Building into a fabrication facility presented the design-build team with different challenges requiring creative design and installation solutions.
Shell wanted to convert a large, empty, pre-engineered steel building into a fabrication facility to support a scheduled shutdown and for future use. The building was to accommodate three interior overhead crane runways supporting one five-tonne, one 10-tonne and two 20-tonne cranes. Shell specified that the support system was to be independent of the existing building structure. In addition, the company wanted the system to achieve maximum hook height.
"We had to do considerable design up front in order to bid," says Brian Watson, president of Eskimo Steel Ltd. and project manager. His company brought BPTEC-DNW Engineering Ltd. in on the preliminary design phase.
"One of the early challenges was the special requirement to absolutely maximize the area of travel of the overhead cranes," Watson says. "It was akin to trying to stretch a cube in three dimensions without touching the perimeter."
The team's solution was a series of three-dimensional tower columns recessed between the existing pre-engineered building columns. The towers support not only the gravity loads, but also the lateral loads imposed by the cranes, eliminating the need for horizontal trusses, and maximizing overhead crane span and lateral hook travel.
"This system is unique in that it's totally free-standing," Watson says. "It's also quite tall in relation to the span."
What's also unique is that the towers are cantilevered from the pre-existing one-metre thick structural slab-on-grade, says Brian Kennedy, director of BPTEC-DNW Engineering Ltd. "We utilized the strength of that slab to anchor the towers, so we didn't have to build a new foundation."
Scheduling was a major challenge on the project. "The timeline was tight between the awarding of the bid to commissioning of the cranes," Watson says. "This meant we had to work as a team, share information and get Shell's approvals quickly at each step."