For 10 years I ran the security for my cousin who owned the company at Glastonbury which was a very interesting time especially when starting out with the flimsy fences they had. It was the punters job that didn't have tickets to get in and part of our job was to keep them out. One of the many things that was confiscated was a rope ladder which has very strong and dense rungs. Because of the weight of them I think it might be Lignum Vitae and I've made this streamline from it. Someone might be able to say otherwise but it is very heavy.