A helicopter was prefered to a crane for a project to replace air-conditioning units at four of Kohl’s department stores in the Chicago area because it worked out at half the price and was less disruptive to store operations.
At each store a 10.4t unit had to be lifted out through the centre of the roof and new units weighing 7.3t had to be lifted back in.
Building services contractor Air Comfort Corporation decided against using a crane because assembly and disassembly time would have meant it being in the parking lot of each store for a day or more.
By using a helicopter, the contractor could use a staging area away from each store entrance and, on the day of the unit replacement, complete the work on one store before it opened for business. Lifting at the four stores took just four working days.
A 270t crawler crane would have been needed for the lifts, costing $25,000 per store.
In contrast, the helicopter cost $12,500 per store, said project engineer Patrick Golden.
“I suspect that with the logistics involved in moving that size crane to four different stores in four different locations, combined with set-up and tear-down time, we would have been lucky to do one store a week,” said Golden.
The helicopter was supplied by Erickson Air Crane Company of Central Point, Oregon.
