I have more experience rock climbing, including big-wall aiding, than I do sailing, and I find it interesting to compare the knots and rigging systems used by sailors vs. those used by climbers.

One thing I notice is that sailors love to use a figure 8 as a stopper knot, whereas climbers would tend to use a double overhand stopper knot, illustrated here: http://www.animatedknots.…/stopperrescue/index.php I wonder if there's a reason for this?

Both climbers and sailors use the bowline, but it's gone out of favor among climbers as a primary tie-in knot, because it has a reputation for to coming untied in climbing rope when it's not continually under tension. I consider it safe when done with a "Yosemite finish", and I use it to tie in to my harness, but most climbers avoid it like the angel of death. Sailors don't seem to worry about bowlines coming untied, even when left not under tension.

Just musing aloud...

Good question and the answer is simple. The figure 8 is easier to untie after heavy loads than the double overhand, and it has a very nice shoulder to stop against. The flat stopping surface of a double overhand is more tapered and likely to pull through or wedge into the stopping surface. I do on occasion see some of the mono guys using the double overhand. That's probably because they sip wine as to guzzling beer.

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Philip
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The other answer is a question of consequnces. If a figure 8 undoes itself on your boat your traveller flies to the stop and you scramble to retie it. If a figure 8 undoes itself on a crag you become a traveller that gets scrambled! :)

Sailors tend to favor knots that are easy to untie after being under extreme load and climbers are more concerned about holding power and reliability. That and their rope tends to have a lot of give in it where ours is prestretched/low stretch.

D.

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Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
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bowlines can undo when not under load, but most of our knots would stay under load and can be additionally secured with any tape. the chances of them coming undone, while taped is very slim... if not none(keeping in mind few knots are a matter of life and death on our cats, since steel cables handle most of the dire loads)

Another thought may be the line the knots are tied with. I do not have much trouble with my bowlines coming undone, but leave a tail sticking out incase it does slip some. Are the rock climbing ropes different and maybe stiffer from what I recall? That would tend to allow the knots to open easier and come undone when not under load.

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Scott,
‘92 H18 w/SX wings
‘95 Hobie Funseeker 12 (Holder 12)
‘96/‘01/‘14 Hobie Waves
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Typically, bowlines do not come untied when tied and loaded properly, especially in our sport where we use mostly smaller control lines. Ever try tying HMPE? It is much more common today and it is slick, very slick. Say you want to tie you spin pole bridle (which frequently needs adjusting for proper spin halyard tension) using HMPE. You could use a stack of 10 half hitches and tape the snot out of it, and it will still slip, or you could tie a . . . .
single bowline!


. . . examples of HMPE are Dyneema, Spectra, Amsteel

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Philip
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Great question. When I was taking sailing lessons, there were 4 knots that were the must haves: bowline, round turn and two half hitches, reef knot, figure eight.

I've never thought about why climbing knots are different, but the comments here make a lot of sense. Sailing knots need to be able to be untied after being under load and wet. A knot failing (especially on smaller boats) is not likely to be fatal. Larger boats have more specialized knots than most of us are taught in basic sailing classes. On larger boats, I have seen the bowline replaced with the water bowline and the double bowline (two loops instead of one and variations on how to thread it) both of which reduce the chance of slipping.

If a climbing knots fails is it likely fatal. Thus instead of a bowline, a double figure 8 with a keeper knot for the working end is worth the extra time to tie and untie.

as a sailor, climber and lover of knots I like the topic. All good thoughts on the difference in uses and consequences. The bowline is now in fashion for sailors. A knot called the buntline hitch was once used more commonly to attached sheets to jibs etc. It is bomb proof, once tightened will not shake out no matter how vigorously the sail flogs and can be tied right up to the cringle/clew of the sail. The draw back, and likely reason it has been replaced by the bowline, is that once tensioned it is very difficult to untie. It was usually just cut.

As mentioned, the bowline is a great knot but in stiff climbing rope can come undone when not under tension. I would never use on to tie my self in. A figure eight trace is much better.