Long ago when I was less aware of my own mortality I used to go rock-climbing. During that period climbing technology took a giant step forward.Previously climbers had been linked by hemp rope, a material better suited to public hangings than sport. To achieve the strength required to hold a falling leader, hemp needed to be quite thick. Thus heavy. Since it was absorbent rain made it heavier. Hemp also deteriorated although it was hard to spot the evidence of this. It tangled easily.
Once nylon climbing rope became available in the early fifties I imagine most hemp rope was converted into oakum. Nylon was stronger per millimetre diameter, didn't absorb water, did not deteriorate and was less prone to tangling. And it had one further special quality. A long fall arrested by hemp rope often bruised the climber's waist. But nylon stretched!
Which was kinder when you fell but alarming when you stepped down on to the rock face to begin an abseil (eg, see the indented clipart).
