COMMITTED TO SAFETY AND VALUE ENGINEERING - SINCE 1985
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April 1998

ANCHORS

By | Fall Protection, OSHA Standards & Regulations, Resources | No Comments

Fall protection is a hot issue. Let’s face it – who wants to fall? The federal Occupational Safety and Health Administration (OSHA) clearly expects scaffold users to have some form of fall protection when on a scaffold platform above ten feet. Usually that protection is a guardrail system on supported scaffolds since it is a passive system, a system that requires little or no action on the part of the user to be effective. But what about users who choose to use personal fall protection systems that utilize harnesses, lanyards, rope grabs, vertical lifelines, and suitable anchors. Do users really appreciate the forces that are exerted on the individual components? What about erectors of scaffolding? When a safety officer, or for that matter, an OSHA compliance officer, requires erectors to be “tied off,” do they fully understand the ramifications of that request, especially as it relates to the anchor that is the key element of the protection system?

 

It is truly frightening to see what some individuals consider to be a suitable anchor. If it weren’t life threatening it would be comical. Unfortunately, if the individual who selects an anchor based on poor judgment, lack of expertise, and plain old misconception must use that poorly selected anchor, the experience may be truly unpleasant and even deadly! The fact is that workers, and more specifically erectors, are constantly directed and expected to utilize anchors that are inadequate and/or deadly. The selection of a suitable anchor for positive fall arrest is a serious decision that should never be left to amateurs. The look good theory of anchorage, whereby an erector ties off to a convenient location that “looks good” is an invitation to disaster.

 

OSHA, in Subpart L of the Construction Industry Regulations requires that non-designed anchors must be capable of supporting 5000 pounds. Designed anchors, anchors that are engineered, and are part of a complete fall arrest system, must have at least a two to one safety factor. Let’s face it; 5000 pounds is a lot of weight. Try hanging a large automobile from the next anchor you select and you’ll get a feel for what the regulations require. The next time you see a worker tied off to the guardrail of a scaffold, think about that automobile. Do you think the guardrail will hold it? (On the other hand, just think what an excellent anchor the automobile would make!) It must be remembered that the 5000 pound load is based on a maximum fall distance of 6 feet. What effect do you suppose a fall of 12 feet would have on an anchor, a situation that might occur if the scaffold erector is required to tie off at his/her feet. Hey – this stuff can get tricky.

 

I am continually amazed at how little people understand about this concept of fall protection and am continually impressed at how these forces are grossly underestimated. (I even underestimate it more than I would like to acknowledge.) The peculiar fact here is that when an unqualified individual requests that a worker “tie off 100 per cent of the time” this individual may in actuality be asking the worker to violate the OSHA regulations, and safe practices. It must be remembered that 100 per cent tie off is usually never 100 per cent fall protection. In fact, it takes quite a bit of work to guarantee 100 per cent fall protection. Most of the time scaffold erectors will never achieve it. That’s why training for scaffold erectors is so important.

 

What constitutes a good anchor? If a personal fall arrest system must be used, then choose the anchor carefully. The choosing must be done by a qualified person, a person who understands the forces that will be exerted on the anchor. Frankly, this person must know what he or she is doing. For vertical lifelines, the anchor ideally should be directly overhead of the user. This minimizes horizontal forces that may occur. If the anchor is welded, the welds must be designed so that they can handle the impact and possible tension loads. The welding must be done by a qualified welder. If the anchor is bolted, the bolts must be of adequate size, and must be properly secured. If an eye bolt is used, never rig the lifeline at a vertical angle to the bolt; the force exerted on the eyebolt must be in line (parallel) with the bolt to achieve maximum strength. If the lifeline is wrapped around a beam make sure that the beam connections to other structural components are adequate. Make sure the beam is adequate. It takes a qualified person to make that evaluation. If you’re thinking about tying to a scaffold, think about that automobile hanging there. Can the scaffold handle it?

 

If you think, after reading the previous paragraph, that no answers or good designs have been provided, you’re correct. Since the selection of an anchor can be so complex, it is impossible to present an anchor design to fit any occasion. The choice is yours: Have a qualified person specify the anchor, or somehow guess that the anchor you use will support 5000 pounds. The wrong choice may be hazardous to your health.