Mast Climbers

Mast Climbers: Regulations & Requirements


Mast climber work platforms are currently covered by OSHA regulation, 29 CFR 1926 Subpart L- Scaffolds, which contains general requirements, including capacity, construction, access, loading, clearance from power lines, fall protection, and training. OSHA also relies on its General Duty Clause 5(a)(1). The appendix to Subpart L lists specific guidance and tables for 27 types of scaffolds, but with the exception of referencing the American National Standards Institute’s voluntary standard – ANSI A92.9-1993s, Mast Climbing Work Platform, it currently does not include specific guidelines for mast climbers. (Subpart L and General Duty Clause)

OSHA Advisory Committee on Construction Safety and Health (ACCSH) Minutes of meeting December 9-10, 2010, presentation on CPWR Reaching Higher report and ACCSH decision to form a Mast Climber Workgroup to develop recommendations for OSHA on regulating this type of scaffold.

OSHA Advisory Committee on Construction Safety and Health (ACCSH) Minutes of meeting December 4-5 2008, presentation by IPAF’s International Mast Climbing Work Platform (MCWP) Committee on mast climbing scaffold safety.

American National Standards Institute (ANSI)

An updated version of the voluntary standard A92.9-1993 was approved by ANSI on February 25, 2011, published March 4, 2011, and is scheduled to become effective on August 4, 2011. Provisions related to design and manufacturing apply to all mast climbing work platforms manufactured on or after the standard’s effective date. All other requirements outlined in the standard apply to new and existing units available for sale, rental, lease or other use when the standard goes into effect.

California, which is covered by a state plan, incorporated A92.9-1993 in its General Industry Safety Orders (GISO) Section 3638 in February, 2006. As a result, companies in California must comply with the requirements in A92.901993.

ANSI A92.9-2011 standard for Mast-Climbing Work Platforms 

Additional Information

OSHA Letter of Interpretation July 2011 – Applicability of OSHA’s Cranes and Derricks standard to hoists attached to mast climbing platforms

OSHA: A Guide to Scaffold Use in the Construction Industry

OSHA-Scaffold Industry Association Alliance Program

Harvard College Construction Health & Environmental Safety Exhibit: Scaffolding, example of general scaffolding requirements, including mast climbing, and inspection guidelines.