Playground swings have existed in some form or another for a very long time, with the current designs perhaps not quite as high as some of us might be able to recall, reaching upper pivot elevations of 8 feet, 10 feet or even much higher. You can probably remember one from childhood at a local park or school where there was perhaps a 10 foot chain, with either hard packed dirt, a field, concrete or blacktop surface around it.

The competitions on swings normally involved seeing how high one could swing to achieve temporary weightlessness, sometimes resulting in excess chain slack that could cause such severe and sudden shock, causing the child to lose their grip and plummet to the ground. The other involved doing this intentionally, seeing how high one could swing, before letting go and flying off the swing seat near it's highest apex to briefly experience flight and see how far they'd go. Unfortunately, gravity works, and there always was an impact of some level. There were even fights designed to dislodge someone on an adjacent swing from their seat, makig them fall. None of these swing contests were safe, with many ending up in serious fall impact injuries, so changes were made for the elevation, spacing between adjacent swings, and greater safety zones where a child is most likely to impact during a fall (even if flying is involved).

In each direction of the normal path of a swing, the doubling of the distance from the upper pivot point to either the bottom of the swing seat or top of the playground safety surface, with the criteria being age 6 and older for the former, under age 6 for the latter. What this means is, for a swing where there is a 5 foot measurement from the upper pivot location to the bottom of the swing seat, with 1 foot of space from the seat to the safety surfacing, the applicable safety zone would be either be 20 feet (10 feet in either swing direction) for ages 6 and older, or 24 feet (12 feet in each direction) for under age 6. It may seem it should be the other way around, but younger kids can wander into swing safety zones that send them airborne upon impact.