News

Preventing Tipovers in Boom Lifts
Date:  2/17/2017
ArticleType:  Safety Flash

 

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A boom lift fell through a 10'x10' whole covered with plywood. 

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Operator escaped serious injury because he was wearing fall protection that prevented him from being ejected from platform.

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Traveling with the platform extended over uncompacted, soft ground could cause the lift to tip over.

Preventing Tipovers in Boom Lifts

Summary

On a recent steel erection project, a worker employed by another specialty subcontractor tipped over in a boom lift. The worker in the platform was elevated at least 60 feet when he drove the boom lift over a 10’x10’ hole. The hole had been covered by two sheets of plywood. Plywood is not of sufficient strength to support a boom lift. The area around the hole should have been barricaded.
 
The worker lost consciousness but escaped serious injury because he was wearing fall protection, which prevented him from being ejected from the platform. The tipover caused damage to the structure and the equipment, and caused the project to be delayed. According to CPWR, The Center for Construction Research and Training, an average of 26 construction workers die each year while using aerial lifts. This is 2-3 percent of all construction deaths. Tipovers in boom lifts account for one-third of the fatalities.

Ironworkers also often use boom lifts and scissor lifts to perform welding and bolting activities at height. The following best practices should be employed to reduce risk of tipover in an aerial work platform.

Best Practices

Conduct work zone hazard inspection, including looking for drop-offs, holes or unstable surfaces, and those that may be concealed. This includes surveying the entire expected path of travel prior to moving the aerial lift. A spotter is recommended for high hazard and congested areas. Prevent access to any hazards in the path of travel with barriers. Set up work zone warnings, such as cones and signs, to warn others of work being performed.

Covers must be installed for any hole or gap two inches or more in diameter. The cover should leave no openings more than one inch wide to prevent tools or material falling through. Covers for floors, roofs, and other walking/working surfaces should be capable of supporting at least twice the maximum load expected to cross over the cover. Covers located in roadways should be capable of supporting at least twice the maximum axle load of the largest vehicle expected to cross the cover. All covers should be secured with a hinge to prevent accidental displacement by the wind, equipment, or employees. The covers should be color coded or marked with the word “hole” or “cover” to provide warning of the hazard.

Always wear proper fall protection. Fall restraint or fall arrest is required by OSHA for construction and general industry when operating boom lifts. Understand correct location of anchorage points for the fall protection system on the aerial work platform. Workers must always stand firmly on the floor of the aerial work platform, and must not sit or climb on the edge of AWP guardrails, or use planks, ladders or other devices for a work position.

Know the weight of lift and whether the surface can support it. This includes understanding the impact of point loading as the boom rotates, which increases the ground bearing pressure being exerted. (For equipment with outriggers, it is recommended to use outrigger pads to spread the load over a greater area.) Operate the lift on level ground. Traveling with the platform extended over uncompacted, soft ground could cause the lift to tip over. If possible use mats to provide a firm foundation for the lift to set up on.

Additional Resources

OSHA Fact Sheet for Aerial Lifts 


Statement of Best Practices for Workplace Risk Assessment and Aerial Work Platform Equipment Selection 

Statement of Best Practices of Personal Fall Protection Systems for Aerial Work Platform Equipment 

Statement of Best Practices of General Training and Familiarization for Aerial Work Platform Equipment

Top 10 Safety Tips for Powered Access Operation

 
 

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