Top: To set the masts up in this narrow area, Riley turned the bases sideways and tied the mast back to the already completed concrete walls. Middle: The mast-climbing work platforms provided a working deck completely around the perimeter of the elevator cores. Bottom: The wide platform provides a safe space for working and stockpiling materials.
Top: To set the masts up in this narrow area, Riley turned the bases sideways and tied the mast back to the already completed concrete walls. Middle: The mast-climbing work platforms provided a working deck completely around the perimeter of the elevator cores. Bottom: The wide platform provides a safe space for working and stockpiling materials.

Kenosha, Wisconsin-based Riley Construction had several years ago purchased mast-climbing work platforms from Bracing Systems, Inc., for its masonry division. When it was awarded the job for St. Luke's hospital addition in 2002, it had a challenging question for Bracing Systems' Steve Wydenka: Could workers use the platforms for their concrete division to place reinforcing steel, set forms, and place concrete for the 100-foot-high elevator shafts it had to construct?

Wydenka and mast-climber manufacturer Hydro Mobile's engineering team developed a special setup that provided a safe working area and increased productivity on construction of the four elevator cores. One challenge was a 30-foot-high retaining wall located directly adjacent to one of the elevator shafts. With only about a 5-foot-wide area to set one of the platforms, Wydenka instructed workers to turn the base of the mast-climber to fit into this tight area. Workers removed the center support of the base, turned the base 90 degrees, installed additional jacks, set up 30-foot masts, and anchored them to the concrete wall. The platforms were then set by crane onto the towers, which extended above the retaining wall.

Riley got increased productivity because of the large platform area and found that it was able to reduce the amount of concrete formwork it would normally have rented for this job. It was also able to strip and clean the forms right on the deck. This resulted in a considerable reduction in crane time versus its old method of working off an outrigger with two planks. Using the old method, it would have had to strip and lift the forms to the ground, clean them, and then raise them back up for repositioning. Another benefit was being able to stock the steel rebar on the large, high-capacity deck area. Riley commented that it was able to cut time off the schedule and reduce labor-hours on each 16-foot lift.

For more information, contact Hydro Mobile at www.hydro-mobile.com or call 888-484-9376.