Discusses when a crane-suspended personnel platform may be used and how they must be constructed
Personnel Platforms The use of a crane suspended personnel platform is
prohibited unless there is no safer, practical, conventional means of
access to an elevated work area. Ladders, scaffolds, stairways, aerial
lifts and personnel hoists must be considered before using a personnel
platform. If these options are more hazardous or not possible because
of structural design or worksite conditions, the hoisting of personnel
from a crane is permitted.
A written policy and procedure is recommended to guide your employees through the requirements of OSHA's regulation on crane and derrick safety, 29 CFR Part 1926.550 Applicable crane setup and lifting operation requirements must be complied with when suspending personnel from a crane. The total weight of the load to be lifted must not exceed 50 percent of the crane's load chart capacity. This must be considered when sizing the crane that is needed to safely access an elevated worksite.
Other requirements include a positive locking safety latch on the crane hook, a boom angle indicator readily visible to the operator, a system that regulates the lowering rate of speed of the hoist mechanism and a positive reacting automatic, anti two blocking system. It is also important to perform a trial lift with the unoccupied platform immediately prior to personnel entering the basket or platform. Proof testing the personnel platform and rigging must be performed at 125 percent of the personnel platform's rating capacity by holding the suspended load in position for five minutes. The proof test may be done concurrently with the trial lift. Be sure to include the intended load, people, tools and equipment, weight of the basket or platform, rigging sling and block. Also consider the weights necessary to perform the test. Are they available? A competent person must inspect the crane, the suspension of the platform or basket, and rigging before each use and after each proof test.
Personnel suspended from platforms or baskets must understand and use hand signals or use continuous radio communication. They must also conduct a pre-lift meeting with the crane operator and persons responsible for the task to be performed. The meeting shall be held prior to the trial lift and at each new work location. The pre-lift meeting should include the use of taglines to control the platform. Taglines should not be used if they create an unsafe condition. Be sure to explain how to secure the platform/basket to the structure when personnel are entering and exiting the platform. Also explain the intended use of the basket, tools and discuss what materials are necessary to perform the task. Remember the hoisting of tools, equipment and materials alone are prohibited. Also, personal protective equipment, including fall prevention and protection, must be addressed. Training shall be conducted in the proper tie-off procedure for a structural member inside the basket or the lower load block/overhaul ball. Requirements for work over water are different. Personnel do not tie off, and approved US Coast Guard life preservers, life buoys, and a lifeboat capable of reaching submerged personnel platform/basket in an emergency are required. Life buoys are required to have 90 feet of line and must be provided on the ground every 200 feet.
The platform or basket must be structurally sound, have inboard guard rails, a locking gate that does not swing outward, headroom, overhead protection when hazards exist and smooth surfaces preventing employee injury from lacerations or punctures. Weight of the platform/basket and rated safe working load weights must be conspicuously and permanently marked. Be sure not to exceed the designated capacity. In addition, remember only qualified welders and materials specified in the engineer's design shall be designated for building and repair of personnel platforms. The rigging shall connect each bridle leg to a master link of shackle in such a manner that the load stays evenly divided. All wire rope, shackles, rings, or other hardware must be capable of support without failure at five times the maximum intended load applied or transmitted to each component. Rotation resistant rope requires ten times the maximum intended load. The designated rigging may not be used for any other purpose than hoisting personnel. Training your employees and monitoring the implementation of your program will provide the safe working environment your employees deserve.
Terry Young is on the Safety, Education, and Training Committee for the Specialized Carriers and Rigging Association (SC&RA); 2750 Prosperity Ave., Suite 620, Fairfax, VA 22031-4312; (703) 698-0291; Fax: (703) 698-0291; Internet: scranet.org.
Young is also VP of Risk Management, Southern Industrial Constructors, Raleigh, N.C. (919) 719-4059.