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zoglet · May 30th, 2007, 05:43 PM

Hi Dave

I recall a long tintynet post where a bunch of peeps were arguing which knot should be used for the loop on your DSMB line.

The argument was loosely that the figure of 9 puts less strain on the line itself and is therefore a stronger knot and easier to untie. Most knots reduce the rated strength of the line by a certain amount, some less than others. The figure of eight reduces line strength more than the figure of nine (55/40 vs 75/55 % on normal/abnormal load) so some argued that the figure of nine was the only knot that should be used.

My argument to the contrary would be (as a non-DIR non knot specialist so pleeeez don't flame me everyone, lol) the principle of a knot is that it does the job required of it (stopper, joiner, loop etc), can be tied and untied quickly and easily and doesn't adversely impact the strength of the rope.

I would have thought that for the purposes of a DSMB loop even reducing the strength of your cave line to 55% is irrelevent on a line rated to 100kg with nothing but free floating sock of air on the end of it and therefore the simpler knot to tie is fit for purpose.

Either way it seemed an amusing topic at the time for a bunch of people to get hung up over so I'm embarassed to have exhumed a nasty smelling well flogged horse carcass for a second round. Then again that's what forums are all about.

"Seconds Out"!

May 30th, 2007, 05:43 PM	#5 (permalink)
zoglet(Offline) New Member Join Date: May 2007 Location: Hemel Hempstead, UK Posts: 24	Hi Dave I recall a long tintynet post where a bunch of peeps were arguing which knot should be used for the loop on your DSMB line. The argument was loosely that the figure of 9 puts less strain on the line itself and is therefore a stronger knot and easier to untie. Most knots reduce the rated strength of the line by a certain amount, some less than others. The figure of eight reduces line strength more than the figure of nine (55/40 vs 75/55 % on normal/abnormal load) so some argued that the figure of nine was the only knot that should be used. My argument to the contrary would be (as a non-DIR non knot specialist so pleeeez don't flame me everyone, lol) the principle of a knot is that it does the job required of it (stopper, joiner, loop etc), can be tied and untied quickly and easily and doesn't adversely impact the strength of the rope. I would have thought that for the purposes of a DSMB loop even reducing the strength of your cave line to 55% is irrelevent on a line rated to 100kg with nothing but free floating sock of air on the end of it and therefore the simpler knot to tie is fit for purpose. Either way it seemed an amusing topic at the time for a bunch of people to get hung up over so I'm embarassed to have exhumed a nasty smelling well flogged horse carcass for a second round. Then again that's what forums are all about. "Seconds Out"!