The Cliffhanger Question
I am not a mountain climber but I sure want to give it a try. Hanging from a cliff with just a rope to support you is no kidstuff. I’ve got acrophobia within me or fear of heights but of course I do enjoy watching people scaling mountains of great heights.For me they are my superheroes.
Imagine you were hanging off a cliff.
Is it safer to be attached to two ropes or a single rope that is twice as strong?
To arrive at an answer to the above question, a study was made by a private firm based in Australia presenting a detailed examination of the two key design aspects — factor of safety and redundancy. They were explored for various cliff-hanging arrangements and their associated probabilities of failure were analysed quantitatively. The exercise shows that not only factor of safety and redundancy are separate aspects that can be independently incorporated into a system; they also have different impact on the probability of failure of the system. It demonstrates that factor of safety and redundancy are not the same, and it will be erroneous for redundancy to be quantified using factor of safety. Different redundancy arrangements, including load-sharing and standby, were also explored. It is shown that, with the appropriate arrangements, it is safer to be attached to two ropes than a single rope that is twice as strong.