When I joined the RAF Mountain Rescue Team at RAF Kinloss the knotS I was taught was the Tarbuck knot, the bowline, figure of eight, the Clove Hitch, Alpine butterfly and the prussick knot. It was a bit hard for me to learn them and I kept a piece of old rope in the bathroom and another nearby when watching TV. (A good tip even for today)
The Tarbuck knot was developed by Kenneth Tarbuck for use by climbers, and was primarily used with stranded nylon ropes before the advent of kernmantle ropes made this use both unnecessary and unsafe. It is used when the rope is subject to heavy or sudden loads, as it will slide to a limited extent thus reducing shock. The knot is non-jamming.
History : This knot was devised around 1952 by climber and skier Ken Tarbuck to cope with post-war nylon climbing ropes. It was an end man’s tie-on to a karabiner, intended to absorb sudden loads by slipping until the load was reduced to a safe weight (when the knot would hold). But no sooner had it become widely known through Tarbuck’s expert writing and lecturing, than kernmantel (core-sheath) climbing ropes emerged. These absorb shock loading by their elasticity and the Tarbuck knot can ruin such ropes, gripping and stripping the outer sheath. It is therefore no longer recommended for its original specialized purpose.
How things change!
Well worth having a look at the Scottish Mountain Heritage Collection a great website of interesting gear!