I remember them too. Why , we were encouraged to act like growing men in those days, laughing off a broken leg ("Don't wince. You've got a spare"), and taking crushed fingers as a matter of course (though it was hard to hold a slate and pencil then).Of course, playgrounds were for softies, really. The real fun was falling out of trees and dancing on 15 foot high walls with broken glass on the top (which latter pastime my late mother enjoyed in the 1920s).
In contrast, our village has trouble persuading the local playground safety inspector that a hinge on a gate needn't be 'proofed' against a child trapping a finger. The fact that, to achieve that injury, the child would need fingers the size of sausages, remarkable dexterity, and, in the normal course of events, arms about a metre long, does not satisfy him.