Greater protection

The American National Standards Institute (ANSI) will soon approve for publication a series of new standards that set requirements for fall protection equipment and employer training for workers at height. These standards will directly affect the equipment used by workers in aerial lift devices.

The current national voluntary consensus standard for personal fall arrest equipment used in general industry is ANSI Z359.1–1992(R1999), “Minimum Safety Requirements for Personal Fall Arrest Systems, Subsystems and Components.“ Around June, a new series of fall protection standards will be released that become effective on October 15, 2007 (see sidebar).

Equipment requirements have been expanded now to include work positioning and restraint, as well as fall arrest. The expanded scope contains specifications for strength and performance that are consistent across the family of standards.

Important changes in equipment design and testing include the following:

Gate strength for all snaphook and carabiner connectors will increase to 3,600 lbf, a ten–fold increase over current requirements,

Twin–leg lanyards will be tested to resist a 5,000 lbf static load at the point of connection between the two legs, and Full body harnesses with frontal attachment points will now be rated for limited fall arrest, up to a 2 feet free fall and a 900 lbf maximum arrest force.

The importance of connector gate strength

The first improvement in connector design occurred in the ANSI Z359.1–1992 standard with the requirement for self–closing and self–locking connectors. Current designs of snaphooks on ll protection lanyards greatly duce the potential for accidental sengagement, or “roll–out.” owever, the gate of the snaphook r carabiner has traditionally een the weakest point in the fall rotection system.

In some applications, including tie–off in aerial lift devices, the ompatibility of the snaphook with e anchorage connector must be arefully evaluated to ensure that e gate of the snaphook cannot e loaded in such a way that ressure on the gate could cause e mechanism to be forced open a fall.

The new standards will require snaphooks and carabiners to ithstand a static load of 3,600 f, or twice the maximum loads ermitted in a fall arrest system. his will ensure that the entire ll protection system will have at ast a 2:1 factor of safety at each ement in the system exposed to otential fall arrest forces.

The increased strength of the gate mechanism in snaphooks and carabiners will:

Significantly reduce the potential for accidental disengagement of the fall protection system, and

Provide greater latitude in making compatible connections.

With the higher gate strength, snaphooks and carabiners can now be attached to a variety of anchorage connecting means that were previously not compatible due to their size or shape. Please note in the picture above that the strength of the anchor and anchorage connector must still meet the requirement for 5,000 lbf tensile strength (or two times the maximum load, when certified) as described in ANSI standards and OSHA regulation.

Twin-leg lanyards are important safety components that are widely used in aerial lifts with large platforms. The twin–leg lanyard enables workers to maintain 100% tie–off while moving laterally to points of anchor within the platform. The increased testing required for twin–leg lanyards will ensure that the strength of these lanyards will be sufficient to withstand high impact loads at a junction which has been demonstrated to be a potential weak point on some twin–leg designs.

Improvements in the strength and performance of personal protective equipment do not eliminate the need to exercise care in making connections in aerial lift devices. Some important guidelines include:

Tie–off only to the anchor points identified by the manufacturer of the lift

Read and heed all labels and instructions provided by the manufacturer(s) of the personal fall protection equipment,

Follow all safety rules and procedures in your employer's program for safe use of aerial lift devices. These generally include the prohibition against standing on the mid–rail or top–rail of the lift and maintaining approved connection with the fall protection system at all times when working at height.

The release of new standards for fall protection equipment coincides with similar improvements in the design of fall protection anchorages in modern aerial lift devices. The general consensus of best practice in the industry emphasizes fall restraint within the aerial work platform when working aloft. Restraint systems limit the operator's movements to a point where the person's center of mass remains below the top-rail of the lift platform or basket.

Whenever possible, select a fall protection system that enables the operator to perform their duties while tied–off to a suitable anchor within the work platform, but which prevents the person from falling outside the aerial lift device. As a general rule, if the operator must perform work outside the confines of the aerial lift platform, they should be tied–off to a separate fall arrest anchor located on an approved structural member, not to the aerial lift device.

In conclusion, new ANSI safety standards will provide workers in aerial lift devices with fall protection equipment that meets higher strength and performance requirements than ever before. To obtain copies or information about the new ANSI Z359 standards, contact the American Society of Safety Engineers.