stu said:
c**tplaces said:
is this the right one?
http://www.animatedknots.com/fig8loopdouble/
Yes... well it appears to be, it's quite swift even on the slow setting.
I don't think that this is the one. The link is for a double Fig 8 on a bight.
The false Alpine butterfly which Geoff R refers to is generally just called the Butterfly Knot (No "Alpine") in the UK. It has been used by cavers for decades with no problems if used in the correct setting.
It is identical in appearance to the Alpine Butterfly Knot except on the rear of the knot the two parts of the rope are parallel and in the Alpine Butterfly they cross over each other. This crossover makes the knot more secure.
Some people have an issue with the Butterfly Knot because "Experts" say that it can slip or deform, this is true, but when used in the correct way it is not an issue and does not compromise saftey. The Butterfly should be used in the middle of a rope for rigging "Y" hangs or tension traverses. It is simple and easy to tie and very easy to adjust> It is absolutely secure in these situations.
It should NOT be tied in the end of a rope (by end I mean not trapped between two other knots) as it could concievably come undone in some situations.
The Alpine Butterfly is slightly more complex to tie (although not by much) It is also harder to untie when it has been loaded. It is more dificult to adjust due to the crossover, this can be an issue when rigging long "Y" hangs, such as the one in Stream Passage Pot, where it is already difficult enough without having to struggle adjusting the rigging any more than necessary. When used in the same setting as the Butterfly it is no more secure.
Perhaps we should start a debate on the most suitable knots...
...on second thoughts it has probabaly already been done here somewhere