Mastclimbers in Nashville break away from ground
By Patrick Hill02 July 2008
"Ground breaking" is how Mastclimbers LLC describes the access system it designed as part of extension work at the Vanderbilt Hospital in Nashville, Tennessee. There is literally no room at the base of the structure, so Mastclimbers mounted its masts on bolted fabrications of steel beams on the fifth floor.
"There was no viable solution for the provision of access on this job until we got involved," said Bobby Reese, co-founder of the Atlanta, Georgia-based company. "The extension...is in a tight city centre environment, and since the original hospital was built, there have been many building additions and traffic management changes, making it impossible to erect anything from the ground up."
Working for its client, Alexander Metals in Nashville, an architectural products installer, Mastclimbers designed support structures comprising W8 I-beams that are bolted to the fifth floor of the hospital. These bear 4.8 m long W14 I-beams that protrude through the building sides at 22 m of height to support the masts of the 11 Hek MSM Super and 8 Safi Jolly Junior mastclimbers (all-electric) on the job.
Shoring columns at each floor transfer the loads of the support structures to the ground. Top faces of floor slabs holds the mast ties, whose legs extend through gaps in the pre-cast panels of the building walls.
"Balfour Beatty, the general contractor on the project, needed access to the external façade areas for multi-discipline contractors. The key was to achieve this aim safely, while the hospital continued its day-to-day business undisturbed," said Mr Reese.
Those business activities included "...ambulances racing out of the ground level area and helicopters landing on the helipad on the roof, and in between we had to provide façade access for the specialist trades!" said Steve Kunz, project manager for Mastclimbers. "There was only room on the job to unload one truck at a time, and concrete drilling was prohibited after 8 am."
The mast climbing equipment was craned into position from trucks below to start the project, which will continue for another two to three months.