The Icicle Hitch and the Mythbusters

[harper]

It's one of the family of friction hitches, of which the Prusik is perhaps the best known. A common use of these hitches in bondage is when you want to attach a rope to a bamboo pole, dance pole, or similar in such a way that it won't slip along the pole under load.

The claim is often made for the icicle hitch (and one or two others) that it will hold not only on a uniform-diameter cylindrical pole, but also on a tapering one such as a marlinspike or (of course) an icicle. That's with the load towards the narrow end, the other way is no problem!

I've read the claims but I've never seen a convincing demonstration, either live or on video. And I don't believe that the icicle hitch or anything else could live up to the claim (unless on a rough-surfaced spar tapering very gently, when maybe you could fake up a result).

Can anyone prove me wrong? Or is this one for the Knotty Mythbusters?

[Shadow]

(26-02-2010 02:26 PM)harper Wrote: Guests cannot see links in the messages. Please register to forum by clicking here to see links.I've read the claims but I've never seen a convincing demonstration, either live or on video. And I don't believe that the icicle hitch or anything else could live up to the claim (unless on a rough-surfaced spar tapering very gently, when maybe you could fake up a result).

Can anyone prove me wrong? Or is this one for the Knotty Mythbusters?

Guests cannot see links in the messages. Please register to forum by clicking here to see links. shows it on a marlin spike. It is possible the guy fell immediately after the photo was taken, but why would they show it then?

[harper]

Not enough to convince me!

[Shadow]

(26-02-2010 06:28 PM)harper Wrote: Guests cannot see links in the messages. Please register to forum by clicking here to see links.Not enough to convince me!

Is it a question of personal belief or are you interested in actually testing this approach?

[esinem]

You might find rope sticks to an icicle. Think how crap woolen gloves are for making snowballs. Damn! Could have tried it but I just defrosted my fridge and removed a small glacier...

[harper]

(27-02-2010 03:34 AM)Shadow Wrote: Guests cannot see links in the messages. Please register to forum by clicking here to see links.Is it a question of personal belief or are you interested in actually testing this approach?

I don't do belief. I prefer evidence. I'm a rationalist by temperament and a scientist by education and training.

I want to know if there is any good evidence for this claim about the icicle hitch, because I think it is a myth and myths should be exposed for what they are. But I will always change my views in the light of the facts, once it's established what they are. On the other hand, I'm not sufficiently interested to take the time or trouble to investigate for myself without good reason to suppose that I may be wrong.

As for that photo, I can think of half a dozen easy ways it could have been faked without getting my brain out of first gear. One simple way would be to screw a couple of hooks into the back of that marlin spike and tie the icicle hitch around them so that it's actually hanging off the hooks rather than gripping the spike.

Why might someone have done that, or something like it? For a laugh. For a bet. Lots of possible reasons, because human nature is complicated.

[Shadow]

(27-02-2010 10:13 PM)harper Wrote: Guests cannot see links in the messages. Please register to forum by clicking here to see links.I don't do belief. I prefer evidence. I'm a rationalist by temperament and a scientist by education and training.

We'll have to blame linguistics, then, my response was triggered by the following line in your post:

Quote:And I don't believe that the icicle hitch or anything else could live up to the claim (unless on a rough-surfaced spar tapering very gently, when maybe you could fake up a result).

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(27-02-2010 10:13 PM)harper Wrote: Guests cannot see links in the messages. Please register to forum by clicking here to see links.I want to know if there is any good evidence for this claim about the icicle hitch, because I think it is a myth and myths should be exposed for what they are. But I will always change my views in the light of the facts, once it's established what they are. On the other hand, I'm not sufficiently interested to take the time or trouble to investigate for myself without good reason to suppose that I may be wrong.

That's a tad confusing, then; on one hand you're not sufficiently interested to do any investigation about it, but on the other hand you challenge the information available... this I don't find very rational.

(27-02-2010 10:13 PM)harper Wrote: Guests cannot see links in the messages. Please register to forum by clicking here to see links.As for that photo, I can think of half a dozen easy ways it could have been faked without getting my brain out of first gear. One simple way would be to screw a couple of hooks into the back of that marlin spike and tie the icicle hitch around them so that it's actually hanging off the hooks rather than gripping the spike.

Why might someone have done that, or something like it? For a laugh. For a bet. Lots of possible reasons, because human nature is complicated.

This implies you don't credit South Wales Marine to be a serious and professional business, which is fine with me - I don't know them - but again, this isn't very rational.

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(26-02-2010 02:26 PM)harper Wrote: Guests cannot see links in the messages. Please register to forum by clicking here to see links.I've read the claims but I've never seen a convincing demonstration, either live or on video. And I don't believe that the icicle hitch or anything else could live up to the claim (unless on a rough-surfaced spar tapering very gently, when maybe you could fake up a result).

Can anyone prove me wrong? Or is this one for the Knotty Mythbusters?

Quote:the icicle hitch was devised by John Smith of Surrey, England. He demonstrated his knot's quite exceptional grip in May 1990 at the eighth Annual General Meeting of the International Guild of Knot Tyers, held at the training ship Steadfast, a Sea Cadet shore establishment at Farnham in Hampshire. Smith hung by this hitch from a splicing fid, which was suspended, point down, from the ceiling.

why not ask this John Smith for evidence?

[harper]

Time to start again, or these nested quotes are going to get complicated...

@Shadow:

"Belief" is a word with many shades of meaning, and which is often used as a shorthand. When I wrote "I don't believe that the icicle hitch or anything else could live up to the claim" I meant that as shorthand for "Based on my knowledge and understanding of ropes, knots, physics, engineering, etc. I have come to the considered and balanced judgement that, with a degree of probability approximating for practical purposes to certainty, the claim in question - if taken at face value and interpreted as it might be by a reasonable person - cannot be true. IMHO, of course". And what I don't do is "believe" in the sense of "accept on the basis of assertion or authority without evidence or argument". But I think you know that really.

"That's a tad confusing, then; on one hand you're not sufficiently interested to do any investigation about it, but on the other hand you challenge the information available... this I don't find very rational."

There are many things that ideally I might like to do but in reality I don't have enough of something or other to do. For instance, when I decided to re-launch the Convolvulus forum and a chance conversation with Esinem led to it turning into this place, I committed a large chunk of time and effort to it (rather larger than I expected, in fact). Inevitably that means that a number of other things haven't got done. I have several websites that have been shamefully neglected... It comes down to priorities. I'm interested enough in the icicle hitch issue to spend a little time finding out if solid evidence exists, not interested enough (at the moment) to invest my own time in what might well turn out to be repeating what somebody else may have already done. I don't see why you have a problem with that...

BTW I have not challenged the information available, because as far as I know there isn't any worth talking about. Just some unsupported claims and a rather unimpressive photo. I'm trying to find if there is any decent information, and if I find any I'll make my decision about whether to accept it or challenge it.

"This implies you don't credit South Wales Marine to be a serious and professional business, which is fine with me - I don't know them - but again, this isn't very rational."

It isn't rational to question the validity of that photo as evidence? Would you like me to believe everything I read in the papers next? In the tooth fairy? Have you any idea how many faked photos there are on the net?

There is a business in the UK that supplies equipment to physiotherapists. A qualified physio advised someone I know well to buy a shoulder brace from them to help correct a postural problem "believed" to be responsible for shoulder and neck pain. The brace arrived a few days ago, and was obviously a piece of ill-designed junk that could not possibly function as described, didn't fit, couldn't be fastened into position because the straps would have been too long for someone ten stone heavier and two feet taller, and I could go on... On seeing it, the physio agreed that it was completely unsuitable and ineffective. The purchaser was reluctant to return the brace, feeling that it wasn't worth the bother and etc.. I pushed the point, thinking that we had a classic example of a bunch of con-men exploiting a vulnerable audience and relying on embarrassment, good manners etc. leading gullible buyers to just put the thing in a bottom drawer to rot and write off the money paid for it. When I checked the firm's returns policy (actually a "no-returns if you've even opened the box" policy) I found it obviously designed to intimidate dissatisfied customers, and clearly in breach of British and European consumer law. The package will be in the post tomorrow, and we'll see what happens next...

So there are lots of businesses that are less than perfect, and some whose business model is based on pulling the wool over the eyes of the gullible. The entire homoeopathy trade, for a start. And I wouldn't buy anything from South Wales Marine, because IMO that photo - by itself - undermines their credibility. My reasons for that are entirely rational. If they showed a one-shot start-to-finish video of the whole thing I would probably start to change my mind. But extraordinary claims demand an exceptional quality of evidence, and I haven't seen it. I also note that the member who posted the icicle hitch claim here on the forum hasn't responded to my question about whether he had first-hand evidence. Remember the other member who re-cycled the Tipping Tetruss myth and then disappeared rather than answer the question about evidence?

"why not ask this John Smith for evidence?"

Because, from various things I have read about it, this demonstration was not accompanied by elementary controls such as repeatability when tied by someone else and/or with different equipment, or parallel testing with the same rope and the same spike using the Prusik, Klemheist, etc.. The claim is not just that the Icicle Hitch will hold on a tapering spar (interesting that no-one ever quantifies "tapering"!), but that it will hold when other friction hitches don't. And unless the demonstration covered all those areas, it was worth as much as the South Wales Marine photo and it doesn't qualify as real evidence. Faked demonstrations are as common as faked photos. Both Microsoft and Apple are notorious for faking press demos of new technology...

BTW, the structure of the Icicle Hitch isn't substantially different from that of other friction hitches. So where's the reason to suppose that its performance should be substantially different? It won't be unless there is a critically important difference - so if there is one, what is it and how does it work?

[Shadow]

(28-02-2010 03:32 PM)harper Wrote: Guests cannot see links in the messages. Please register to forum by clicking here to see links.The claim is not just that the Icicle Hitch will hold on a tapering spar (interesting that no-one ever quantifies "tapering"!)

In your original post, however, it's the only claim you refer to, and that's what I got interested in and checked the web for. If there's more to it, then it's an entirely different discussion, which I personally don't feel qualified to participate it, and have no real interest in.

(28-02-2010 03:32 PM)harper Wrote: Guests cannot see links in the messages. Please register to forum by clicking here to see links."Belief" is a word with many shades of meaning, and which is often used as a shorthand. When I wrote "I don't believe that the icicle hitch or anything else could live up to the claim" I meant that as shorthand for "Based on my knowledge and understanding of ropes, knots, physics, engineering, etc. I have come to the considered and balanced judgement that, with a degree of probability approximating for practical purposes to certainty, the claim in question - if taken at face value and interpreted as it might be by a reasonable person - cannot be true. IMHO, of course". And what I don't do is "believe" in the sense of "accept on the basis of assertion or authority without evidence or argument". But I think you know that really.

Don't forget that english is not my native language; I tend to stick to the meaning of words as stated in reliable dictionaries, for the sake of clear communication.

Out of curiosity... if I had the adequate tapered object to test with, would you trust my report on this knot?
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[harper]

(28-02-2010 07:56 PM)Shadow Wrote: Guests cannot see links in the messages. Please register to forum by clicking here to see links.Out of curiosity... if I had the adequate tapered object to test with, would you trust my report on this knot?
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How can I possibly answer that without knowing anything about your methodology etc.?

I'm sure you wouldn't want me to show any favouritism. I'm a rational man so I would treat all reports of experimental tests in exactly the same way, irrespective of their origin, and I've already suggested several of the things I'd be looking for.

If you're asking me whether I think you would deliberately fake the results, the answer is no, I don't think you would. But anyone who knows anything about the history of science knows there are plenty of cases where experimenters have unwittingly misled themselves and their colleagues, usually through having too much emotional investment in their ideas. That's one of many reasons why universal equal-opportunity scepticism is the foundation of science.