CSA Z259-17-16:2020 pdf download.Selection and use of active fall-protection equipment and systems
5.3 Swing falls
Lateral movement during a fall can be produced by a pendulum effect (swing fall). This can result in a falling worker striking an object during the swing. It can result also in the severing of the lanyard or lifeline by cutting or abrasion against an edge. Two common consequences of the pendulum effect are ilustrated in Figure 6 (collision with a fixed object) and Figure 7A to 7B (extended fall distance).
To avoid or reduce the effects of a swing fall during a fall arrest, the following methods may be used:
a) For the dual anchorages method, a second assembly is attached to a second anchorage at the same time as the primary anchorage. The geometry of the dual system prevents the swing fall.
b) For redirect anchorages, the fall-protection system shall be diverted through, or captured by,secondary anchorages, such that the lanyard or lifeline runs freely through the second anchorage points or connector as shown in Figure 3. The maximum arrest load on the redirect anchor should be determined along with the primary anchorage requirements. As demonstrated in Figure 4, it may be greater than that on the primary anchorage.
c) Edge stops, such as vertical projections, are placed along the edge of the roof, platform, or stage on which the worker is situated, as shown in Figure 5. In the event of a fall, the distance the lanyard or lifeline can slide along the edge is limited by the stops. Edge stops should not be located in such a manner as to provide a trip hazard themselves, particularly if they are located close to the edge of a roof or other potential fall location.
5.5 Fragile work surfaces
Fragile work surfaces include but are not limited to roofs, tank tops, roofs of truck or trailer cargo bays,skylights, and drywall ceilings where a fall through the surface is possible because it might not be strong enough to support the worker.
Where work is to be performed on a fragile work surface, a walkway, or a platform, an active fall-protection system or a combination of these shall be used.
Where work is to be performed near a fragile surface, a guardrail, or a warning line barrier, an active fall-protection system that prevents the fall (travel-restraint system), or a combination of these shall be used. A warning line barrier shall be located at least 2 m (6.6 ft) from the hazard.CSA Z259-17-16 pdf download.