If workers will be exposed to fall hazards that you can't eliminate, you'll need to prevent falls from occurring or ensure that if workers do fall, they aren't injured. A fall protection system is designed to prevent or arrest falls.
Check out this short audio clip by Dan Clark of the theSafetyBrief.com. Personal fall arrest systems (PFAS) are life savers in construction and industry. Hear how to use and maintain them in this podcast.
There are seven general fall-protection systems:
The following methods may also be appropriate for preventing falls:
Wherever possible, you need to try to eliminate fall hazards. In many situations, you won't be able to eliminate fall hazards. Make sure you identify hazards that you can't eliminate and evaluate each one. The evaluation will help you determine appropriate fall-protection systems for your work site. Consider the following:
A personal fall-arrest system consists of an anchorage, full body harness (FBH), and connection systems, that work together to stop a fall and to minimize the arrest force. Other parts of the system may include a lanyard, a deceleration device, and a lifeline.
The personal fall-arrest system is effective only if you know how all of the components work together to stop a fall. Before you use a personal fall-arrest system, you should know the following:
An anchorage is a secure point of attachment for lifelines, lanyards, or deceleration devices. How can you be sure that an anchorage is secure? An anchorage for a personal fall-arrest system must support at least 5,000 pounds. Anchorages that can't support 5,000 pounds must be designed and installed under the supervision of a qualified person and must be able to maintain a safety factor of at least two - twice the impact force of a worker free-falling 6 feet. If you don't know how much weight an anchorage will support, have a qualified person check it before you trust your life to it.
Anchorage strength is critical, but is not the only factor to consider. Also important:
A Full-Body Harness (FBH) is used in general industry, construction and any other industry where work at height is required. Its use protects workers against falls from heights and allows for travel restraint, positioning, suspension and/or rescue.
The full-body harness has straps that distribute the impact of a fall over the thighs, waist, chest, shoulders, and pelvis. Full-body harnesses come in different styles, many of which are light and comfortable.
Body belts have a strap with means both for securing about the waist and for attaching to other components such as a lanyard used with positioning systems, travel restraint systems, or ladder safety systems. Since 1998, OSHA standards which address fall hazards call for the use of body harnesses rather than body belts when used as part of a personal fall arrest system. They should be used for positioning only.
Before you purchase harnesses, make sure they fit those who will use them, they're comfortable, and they're easy to adjust. A full-body harness should include a back D-ring for attaching lifelines or lanyards and a back pad for support.
Keep the following in mind:
A lanyard is a specially designed flexible line that usually has a snap hook at each end. One snap hook connects to the body harness and the other connects to an anchorage or a lifeline. A special type of lanyard, called an "integrated" lanyard only has a snap hook at one end. Lanyards must have a minimum breaking strength of 5,000 pounds. They come in a variety of designs, including self-retracting types that make moving easier and shock-absorbing types that reduce fall-arrest forces. Don't combine lanyards to increase length or knot them to make them shorter.
Deceleration devices protect workers from the impact of a fall and include shock-absorbing lanyards, self-retracting lifelines or lanyards, and rope grabs.
A shock absorber reduces the impact on a worker during fall arrest by extending up to 3.5 feet to absorb the arrest force. OSHA rules limit the arrest force to 1,800 pounds but a shock-absorbing lanyard can reduce the force even more - to about 900 pounds.
Because a shock-absorbing lanyard extends up to 3.5 feet, it's critical that the lanyard stops the worker before the next lower level. Allow about 20 vertical feet between the worker's anchorage point and the level below the working surface. Always estimate the total distance of a possible fall before using a shock-absorbing lanyard.
Example: Lanyard length (6 feet) + deceleration distance (3.5 feet) + worker's height (6 feet) + safety margin (3 feet) = 18.5 vertical feet from anchorage to lower level.
Never use a shock-absorbing lanyard if the shock absorber is even partially extended or if the lanyard has arrested a fall.
Self-retracting lanyards and lifelines offer more freedom to move than shock-absorbing lanyards. Each has a drum-wound line that unwinds and retracts as the worker moves. If the worker falls, the drum immediately locks, which reduces free-fall distance to about 2 feet - if the anchorage point is directly above the worker. Some self-retracting lanyards will reduce free-fall distance to less than one foot. Self-retracting lanyards are available in lengths up to 20 feet. Self-retracting lifelines, which offer more freedom, are available in lengths up to 250 feet.
If you use a self-retracting lanyard or lifeline, work below the anchorage to avoid a swing fall. The farther you move away from the anchorage, the farther you will fall and the greater your risk of swinging back into a hard object. Swing falls are hazardous because you can hit an object or a lower level during the pendulum motion.
Rope grab: A rope grab allows a worker to move up a vertical lifeline but automatically engages and locks on the lifeline if the worker falls. When using a rope grab, keep the following in mind:
Lifelines: A lifeline is a cable or rope that connects to a body harness, lanyard, or deceleration device, and at least one anchorage. There are two types of lifelines. (Vertical and Horizontal)
Vertical lifeline: A vertical lifeline is attached to an overhead anchorage and must be connected directly to a worker's full-body harness, lanyard, retractable device, or rope grab; it must have a minimum breaking strength of 5,000 pounds.
When a worker needs to move horizontally, however; a vertical lifeline can be hazardous due to the potential for a swing fall - the pendulum motion that results when the worker swings back under the anchor point. A swing fall increases a worker's risk of striking an object or a lower level during the pendulum motion.
Horizontal lifeline: Unlike a vertical lifeline, the horizontal lifeline stretches between two anchorages. When you connect a lanyard or rope grab to the horizontal lifeline, you can move about freely, thus reducing the risk of a swing fall. However, horizontal lifelines are subject to much greater loads than vertical lifelines due to what is called "sag angle."
Sag angle is the angle of horizontal lifeline sag when a fall occurs. According to OSHA Standard 1910.66 App C, when the angle of horizontal lifeline sag is less than 30 degrees, the impact force imparted to the lifeline by an attached lanyard is greatly amplified. For example, with a sag angle of 15 degrees, the force amplification is about 2:1 and at 5 degrees sag, it is about 6:1. But, as you'll see below, sag angle is not the only factor that determines force amplification.
Impact force, as used in this context, is the force or "shock" imparted to a lifeline by the attached lanyard. If the lifeline is not so tight, it will sag more and the impact force on the lifeline will actually be less. It's important to know that impact force is determined by a number of factors in addition to the sag angle of a horizontal lifeline. The type of material used for the lifeline, the amount of "spring" in the lifeline, and the elasticity of the horizontal supports at the end of a fall. (T. Dranger, "Design of Horizontal Life Lines in Personal Fall Arrest Systems", Engineering Journal, Vol 52, No.2)
Example: If the sag angle is 15 degrees, the impact force, or force amplification, imparted to the lifeline is only about 2:1. However, when the sag angle is decreased to only 5 degrees, it's tighter, and the impact force imparted to the lifeline increases to about 6:1.
Remember, lifeline anchorages must be strengthened as impact forces increase. To reduce loads on a horizontal lifeline, increase the sag angle or connect to the lifeline with a shock-absorbing lanyard.
Fall from a Telecommunications Tower
A worker was climbing down a 400-foot telecommunications tower when he lost his footing. The ladder safety device or system (consisting of the carabiner, carrier rail, safety sleeve and body harness) he used failed to arrest his fall. The safety sleeve did not activate correctly to stop the worker’s fall, the chest D-ring ripped out of the body harness, and he plunged 90 feet to his death.
Likely Causes of Incident
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