Sources: Vacuworx, Tulsa, Okla.; CP staff
The National Park Service’s Frederick, Md.-based Historic Preservation Training Center (HPTC) deployed a Vacuworx lifting system to set 46 new Missouri limestone slabs, topping out at 2,400 lbs., during the recent White House South Portico stairway reconstruction. The diesel-powered device pulls a vacuum between lifting pads and objects to be placed, securing a positive seal.
“With the [machine’s] remote operation, we can safely pick up and maneuver materials without compressors, hoses or other accessories presenting trip hazards,” says HPTC Exhibits Specialist Jessica Gordon. “Everything is self-contained, in one unit.” Vacuum lifting eliminated the need for hoisting and placing the steps and stones by strap, she adds, and also mitigated the risk of chipping the limestone pieces. The 10-in. long x 7-in. deep x 20-in. wide steps and 11-ft. long, 7-in. thick and 6-ft. wide landing stones were cut from block quarried at Phenix Marble Co., Springfield, Mo.
HPTC rented the Vacuworx MC 5 lifter and three custom pad assemblies from Extreme Seal & Rigging, Warrenton, Va. Rental options suit the agency, Gordon notes, whose Masonry, Woodcrafting and Carpentry division handle 35 to 40 projects a year, typically in the $50,000–$400,000 range. The $1 million South Portico step project entailed dismantling of a Truman-era staircase, and overlapped a $3.4 million remodeling project at 1600 Pennsylvania Avenue.