Climbers used pebbles or chockstones to jam in cracks and make anchors in the early days. This was followed by the ‘nuts era’ when nuts – as in nuts and bolts – were threaded on a piece of rope and used to place in cracks/fissures in the rock. This led to ‘chocks’ and ‘nuts’ becoming the generic term for just about anything that climbers stuck in a crack. The first artificial chockstones came along in 1961 with a thing called an Acorn and the ever popular MOAC. A plethora of variations followed in the next few decades and the Bi-Caps we have here in the collection were one of the many. Created by a guy called Stefan Engers and made in West Germany they first saw the light of day in 1987 when Bergsport International began marketing them. Unfortunately, they were not a success and were pretty soon relegated to the ‘gear that never quite made it’ columns on the internet. One reason they were a failure is that the two sections on each nut can’t be separated allowing for two different sized placements on each wire – in fact the two little holes on the smaller of each one are there specifically to stop them being separated – how strange! We bought this set on the internet for a few pounds in 2015 making us quite happy with another little piece of mountaineering history.