A provision for fall clearance in itself does not guarantee that a fall will not result in impact with a structure, unless provision is made to ensure that a swing fall does not result in impact with an object to the side of the fall line. An impact from a swing fall (or pendulum fall) can be just as serious as an impact with the ground.
Swing falls are a particular hazard with retracting cable life-lines, because the length of line that is available allows a major swing fall even if the vertical component of the fall is arrested immediately.
To limit swing falls it is important to use anchors as far as possible directly above the work area. If substantial horizontal movement is required, a horizontal life-line is the best solution (see previous section). However, bear in mind that the this gives freedom of movement in only one orientation. Excessive movement at right angles to the life-line may result in a dangerous swing fall.
Another solution is to use two lanyards connected to anchors at different positions. In the case of the self-retracting life-line, it may be possible to use a lanyard connected to a nearby anchorage to counter the swing, or even a rope and rope grab tied to an anchorage opposite the anchorage for the life-line. As the least preferred solution, the anchorage for the life-line might be raised a few metres in order to reduce the angle of the swing.
Generally the use of two anchorages is necessary to eliminate swing falls. Depending on the work-site, it may be possible to use a separate restraint line, or otherwise an anchor rope fitted with a rope grab to allow movement, in conjunction with the main fall-arrest system.
Avoiding swing falls from roofs is covered in the section on roof work.