Mast Climbers

They run materials up a mast or two and we salute
By A.S. Berman
February 1, 2007


Chances are when a glazier tackles a job on a high-rise, medical center, or any size building in between, he relies on a mast climber. These units, which haul personnel and materials to upper floors via a motorized platform that rises up one or two vertical “masts,” are especially helpful when it comes to working on buildings with inclined walls and other unusual features. The following is a representative assortment of mast climbers for rent and purchase in the United States. Equipment manufacturers, if your brand of mast climber does not appear below, please write to  Jane Holtje at, and have your information added to a version of this chart.

Click here for chart. (16KB, Adobe Acrobat

Mast-climber regulations
Though the mast-climber enables glaziers to whisk themselves and their materials to great heights quickly and easily, the technology is not without risks.

In April 2006, in one of the highest-profile cases to date, two individuals on a mast-climber’s platform and another on the ground were killed during construction of a new building adjoining a dormitory being built at Emerson College in Boston. The accident occurred when workers disconnected the metal ties that stabilized the equipment against the building while others were still on the platform, according to the general contractor’s report. Left to balance at the top of the mast, the equipment’s platform fell away from the building, plunging 13 stories into a busy street. At press time, the incident is still under investigation.

The Department of Labor’s Occupational Safety & Health Administration provides regulations for the use of mast-climbers under the 1926 Safety and Health Regulations for Construction – Subpart L: Scaffolding, says Sherman Williamson, OSHA Safety Engineer in Washington, D.C.

OSHA’s semiannual regulatory agenda lists no plans to revisit the standards in the first half of 2007. The agency reviews its regulations for many reasons. “Sometimes it’s calls from Congress, sometimes it’s a high profile accident,” Williamson said. “Sometimes it's the number of accidents, and sometimes it’s just the recognition that a technology has outpaced the standard.”

The following problems are cited as common mast-climber hazards by the Laborers’ International Union of North America in Washington, D.C., which trains workers on proper use of the equipment through the Laborers-AGC Education and Training Fund, a partnership between LIUNA and the Associated General Contractors of America in Arlington, Va.: overloading the platform; placing the platform too close to power lines; lack of proper fall protection; large gaps between the platform and the building; dropping of tools and materials due to lack of proper barriers; anchoring the mast at locations incapable of supporting the load.

The author is a freelancer in Scottsdale, Ariz., 703/967-8071,