The choice of snaphooks to link rope-grab components is a vital safety matter. Only instructions from the manufacturer of the rope grab should be followed to ensure the hardware is compatible. No other snaphooks should be used to avoide potential roll-out or burst-out. Other parts of this book address the problems of mixing and matching and misuse. All snaphooks should be of self-locking design, maintained in optimum operating condition, and discarded if they are jammed or damaged.

Ladder rungs or steps, and guardrails or railings of any kind, should not be used for fall arrest anchorages unless they are designed and labeled specifically for that purpose. Steel members should be used for anchorage-point structures whenever possible. Masonry fittings can be suitable when used with through-bolts and plate washers. Expanded anchor bolts should be specified by a registered professional engineer.

It should be noted that a manually operated mechanical device could be utilized optimally at a lift rate of 10 to 20 feet per minute under demonstration conditions. Remember that the object of the retrieval process is to extricate the worker within 4 minutes, the rule-of-thumb limit for the onset of brain damage from oxygen deprivation. Therefore, when manually powered hoists are used to provide access from more than a 50-foot depth, a pneumatic operation should be the primary lifting force. Another factor in the 50-foot limit is the static, muscle work duration for upper-body cranking, set at approximately 30

Because of difficulties in training residential roof workers, elimination of hazards seems to be the most feasible goal. A large enough crane capacity and boom length, plus pre-assembly at ground level, can go a long way toward the elmination of fall hazards.

Cable systems used for anchorages around buildings or structures on the roof should be made of stainless steel, with fittings attached according to the wire-rope manufacturer’s instructions or standard rigging handbooks. Cable systems used for anchorages should be designed, installed and tested by a licensed professional engineer experienced in such design, prior to being used for the attachment of suspension or fall arrest lines.

Ladders comprise an almost infinite combination of steps and handholds for ascent and descent from one level to another. In general, there are 12 inches between each level, and the horizontal gripping element and foot placement are called “rungs”. Rungs can be supported by side rails at each end, typically 16-18 inches apart. If ladders can be moved by hand or crane, they are called portable. If they are bolted or welded to the structure, they are called fixed. Sidestep refers to rungs that continue up and the climber steps to a platform at the side. A walk-through is a