Date: Thu, 25 May 1995 07:13:16 -1000 From: dhiggins@bfsec.bt.co.uk (Declan Higgins) Message-Id: <3q2drc$7pl@pheidippides.axion.bt.co.uk> Organization: BT Labs, Martlesham Heath, Ipswich, UK Subject: The Bowline Knot Has anyone tried using the bowline knot on sleeved dyneema instead of the overhand loop for line termination. I like the knot - it is more compact and easy to *untie*. Comments anyone ? ps For an illustration of the knot (and others) look at http://www.ida.his.se/ida/~jan/knopar.eng.html Nice page , (knot) ! -- Declan Higgins - dhiggins@bfsec.bt.co.uk BT Belfast Enginerring Centre ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ "Mihi crede, hoc mihi magis quam tibi nocet" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Fri, 26 May 1995 07:27:38 -1000 From: daveculp@bdt.com (Dave Culp) Message-Id: Organization: Beckemeyer Development, Oakland CA Subject: Re: The Bowline Knot In article <3q2drc$7pl@pheidippides.axion.bt.co.uk>, dhiggins@bfsec.bt.co.uk (Declan Higgins) wrote: > Has anyone tried using the bowline knot on sleeved dyneema > instead of the overhand loop for line termination. I like the > knot - it is more compact and easy to *untie*. > > Comments anyone ? > According to studies done by a rope-making company (I forget which one), the bowline is the knot least likely to break any line or rope. It's a function of the diameter opf the knot's loops, and thus the strain put on the line's fibers. KITEJAG's absolutely right about the figure 8 in the bitter end (experience here, too) According to the same manufacturer's study, any knot, even the bowline, degrades line strength by at least one third (!). I know sleeving minimizes this (I wish I knew a study which quantifies this). For years I have used a "no-knot" splice I learned from a kite-spool insert (I can't find it just now, but if interested, I'll look for it, scan it, and ask Andrew Beattie to post it on his Web page) Claim is, it doesn't degrade breaking strength at all. I've flown many hours at *very* heavy tensions (kitesailing) and broken many lines; never at a spliced loops, though. DAve Culp = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Fri, 26 May 1995 09:30:42 -1000 From: sasaki@netopd.harvard.edu (Marty Sasaki) Message-Id: <3q5a92$k7v@netope.harvard.edu> Organization: Harvard University - OIT/NSD Subject: Re: The Bowline Knot Time for my periodic recommendations of two books on knots. For different types of knots I prefer the original "Practical Fishing Knots". For a number of good quality knots get "Practical Fishing Knots II". Both are by Mark Sosin and Lefty Kreh. Most kite line is interchangeable with fishing line and both of the above books have good descriptions of high strength knots... -- Marty Sasaki Harvard University Sasaki Kite Fabrications sasaki@noc.harvard.edu Network Services Division 90 Melrose Street 617-496-4320 10 Ware Street Arlington, MA 02174 Cambridge, MA 02138-4002 phone/fax: 617-646-1925 = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Fri, 26 May 1995 04:11:57 -1000 From: kitejag@aol.com (KITEJAG) Message-Id: <3q4njd$kp9@newsbf02.news.aol.com> Organization: America Online, Inc. (1-800-827-6364) Subject: Re: The Bowline Knot For the past two years I have used the bowline quite effectively in the situation you describe though I am not familiar with theline you mention...I use the knot with sleeved spectra. A word of caution...be sure to put a figure eight knot in the bitter end of the sleeving or the spectra will slip through the sleaving...the bowline is a relatively loose knot and does allow this slippage if you forget the figure eight...voice of experience here!! I also use two knots per loop...one bowline about one inch from the bitter end with a second asclose to the bitter end as possible. I've never had a knot failure or a line break at the knot despite the fact I fly my competition kites on very lite line. I don't know if this is owing to the bowline or as a friend says, dumb luck...life is like a box of chocolates...or sleeved spectra!! have a great weekend John A. Gabby Jr. Think kindly thoughts. = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Fri, 26 May 1995 13:30:22 -1000 From: nop@euronet.nl (Nop_Velthuizen) Message-Id: Organization: Euronet Internet Subject: Re: The Bowline Knot >Has anyone tried using the bowline knot on sleeved dyneema >instead of the overhand loop for line termination. I like the >knot - it is more compact and easy to *untie*. >Comments anyone ? First off all, for those that might not know, DYNEEMA is the European brand name for the same material as SPECTRA. Secondly, I don't believe any standard liturature on knot-strength apply's to sleeved knots in Dyneema or Spectra. The Stuf is so increadably slippery!!. I have a small Homebuild rope tester (up to 200 kgs) and have tested hundreds of lines with a variety of knots with or without sleeves. The thing is not very scientific but resembles our kiteflying situation perfectly. The problem with Bowline knots in sleeved lines is slip. Invariably the Dyneema/Spectra core will slip through the knot which will leave you with a decreased loop for line handling. Simple overhand knots in your end-loops are as strong as any other sofisticated knot and are less likely to slip. Even untieing always remains possible ( I managed after hours of ice-buggying without any feeling left in the finger-tips) as opposed to an overhand knot in unsleed line. I agree with Dave Culp that knot-less splices are even stronger. But its difficult to do in some off the nicest tight-braid Spectra line and you would also miss the protective sleeve on the loop where the lines are likely to wear on contact witth rings, clips, shackles etc.. The absolute strongest an long lasting best results I have found with sleeved end loops on my lines that are not knotted but connected by ZIG-ZAG stich on the sewing machine. (not a very practicle way of doing things) MAZZEL NOP = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Sat, 27 May 1995 12:43:00 -1000 From: perry.farmer@thefarmbbs.com Message-Id: Organization: THE FARM BBS Subject: Re: The Bowline Knot >According to studies done by a rope-making company (I forget which one), >the bowline is the knot least likely to break any line or rope. It's a >function of the diameter opf the knot's loops, and thus the strain put on >the line's fibers. KITEJAG's absolutely right about the figure 8 in the >bitter end (experience here, too) > If interested in good knots to use to minimize problems with breakage, while maintaining slippage control, ask a med student to pick you up a book on the different types of knots used by surgeons. I have seen a study on that done by the University of Washington Medical Center and there is some good information available. Perry T H E F A R M ___________________________________________________________ ^. .^ ^. .^ ^. .^ ^. .^ ^. .^ ^. .^ ^. .^ ^. .^ ^. .^ ^. .^ ( @ ) ( @ ) ( @ ) ( @ ) ( @ ) ( @ ) ( @ ) ( @ ) ( @ ) ( @ ) ___________________________________________________________ WHERE HOGS GATHER TO PLAY = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Sat, 27 May 1995 21:00:56 -1000 From: andrew@tug.com (Andrew Beattie) Message-Id: Organization: /usr/lib/news/organisation Subject: Re: The Bowline Knot dhiggins@bfsec.bt.co.uk (Declan Higgins) writes: >Has anyone tried using the bowline knot on sleeved dyneema >instead of the overhand loop for line termination. I like the >knot - it is more compact and easy to *untie*. > >Comments anyone ? I don't feel strongly enough about this to argue about it (it's my line so I'll do it whichever way I like...), but I've rejected bowline of the somewhat crude double-overhand loop because: 1) It is trivial to the the knot just right, first time (my sleeves are the same length, so if I fold the sleeve in half, I end up with matching line lenghts). 2) When I over-stress the line, I have a preference for breaking the line close to the knot, where repair is trivial (cut off the end and re-terminate) Andrew -- New to rec.kites? START HERE! | To: www@kfs.org send an email message like this->| Subject: service /-\ () >< () |\/| () >< () /-\ | http://www.kfs.org/kites/welcome/index.html Spam-posters brain required for research. $5/lb guaranteed by return post. = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Mon, 29 May 1995 06:09:38 -1000 From: David Macfarlane Message-Id: <3qcrk2$o6q@worm.inch.com> Organization: The Internet Channel Subject: Re: The Bowline Knot Hi. Knot Knewbie here and I don't know the lingo. Which end is the "bitter end"? The end where the strain is or the open end of the short piece of line? -----------(^)-----(~)----- () (=) ) ---(_)------()----- ^ ^ ^ first knot second loop where the strain is Are you putting a figure eight at the first knot and the bowline at the second? That would make sense to me since the bowling would take the major strain and the figure eight would keep the bowline from unravelling. Or am I missing something. Thanks. David. = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Wed, 31 May 1995 03:16:53 -1000 From: kitejag@aol.com (KITEJAG) Message-Id: <3qhq85$h88@newsbf02.news.aol.com> Organization: America Online, Inc. (1-800-827-6364) Subject: Re: The Bowline Knot The bitter end is the very, very end of the line before any other knots are made. The purpose of the figure eight is basically twofold. First, it does serve as a guard agaist other knots unraveling but I sure wouldn't count on this function to any great degree. The second, and more important function for our purposes, is a backup to keep the spectra from slipping through the sleeving. The figure eight should be used, no matter what primary knots you use to form the loops on your flying line. Something else we may all want to think about...in a recent posting, Andrew did have a good point...maybe for many appications the knots we use SHOULD BE the weak link in the line connection to the kite. Just this past week-end I had a hundred foot spectra line break darn near dead center...trash a hundred foot of spectra...or maybe I have a new set of forty five foot lines. This particular spectra isn't real expensive (eighty pound)...but two hundred pound buggy lines are another story. John A. Gabby Jr. Think kindly thoughts. = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Wed, 31 May 1995 15:28:47 -1000 From: "John D. Kell" <74631.3357@CompuServe.COM> Message-Id: <3qj54f$635$1@mhade.production.compuserve.com> Organization: Coyote Computer Company Ltd. Subject: Re: The Bowline Knot It depends on the line. Bowlines suck in monofilament, of course, but a properly tied bowline is the strongest and most reliable knot. Easy to undo, too. Try a bowline-on-the-bight. I use this knot almost everywhere, and its yet to let me down. Breakage in a bowline usually happens on the standing part of the line. For the record, I teach knots and splices for CYA certification, and have a master of crafts in knots. -- Dan Horn Victoria, BC Why be constant when you can be arbitrary? = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Wed, 31 May 1995 12:32:02 -1000 From: aburlison@cix.compulink.co.uk ("Alan Burlison") Message-Id: Organization: Alan Burlison Subject: Re: The Bowline Knot The figure-of-eight is also good. It is easier to undo than an overhand knot. The definitive knot book is 'The Ashley Book of Knots', which has over 3,800 knots. Alan Burlison aburlison@cix.compulink.co.uk = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Thu, 1 Jun 1995 09:04:44 -1000 From: sasaki@netopd.harvard.edu (Marty Sasaki) Message-Id: <3ql30d$laq@netope.harvard.edu> Organization: Harvard University - OIT/NSD Subject: Re: The Bowline Knot In article <3qj54f$635$1@mhade.production.compuserve.com>, John D. Kell <74631.3357@CompuServe.COM> writes: |>It depends on the line. Bowlines suck in monofilament, of course, |>but a properly tied bowline is the strongest and most reliable |>knot. Bowlines "suck" with braided nylon and braided dacron as well. There are knots that are far stronger than the bowline. You don't need a fancy machine to compare knot strengths. Just put one knot on one end of a length of line, then put another on the other end. Pull on the line until something breaks. The knot that didn't break is the stronger line. I've done this with braided dacron and braided nylon. Most fishing knots do a better job in these materials than the bowline. The bowline is easy to tie though... Very few knots are stronger than the line, most breaks occur within a few inches of the knot, so any knot will act as a fuse. It makes sense to use the strongest knot possible. -- Marty Sasaki Harvard University Sasaki Kite Fabrications sasaki@noc.harvard.edu Network Services Division 90 Melrose Street 617-496-4320 10 Ware Street Arlington, MA 02174 Cambridge, MA 02138-4002 phone/fax: 617-646-1925 = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Wed, 31 May 1995 22:30:00 -1000 From: jim.oliver@welcom.gen.nz (Jim Oliver) Message-Id: <9506021002574585@welcom.gen.nz> Organization: WELCOM BBS Subject: Re: The Bowline Knot daveculp@bdt.com (Dave Culp) wrote : DC>In article <3q2drc$7pl@pheidippides.axion.bt.co.uk>, DC>dhiggins@bfsec.bt.co.uk (Declan Higgins) wrote: DC>> Has anyone tried using the bowline knot on sleeved dyneema DC>> instead of the overhand loop for line termination. I like the DC>> knot - it is more compact and easy to *untie*. DC>> DC>> Comments anyone ? DC>> DC>According to studies done by a rope-making company (I forget which one), DC>the bowline is the knot least likely to break any line or rope. It's a DC>function of the diameter opf the knot's loops, and thus the strain put on DC>the line's fibers. KITEJAG's absolutely right about the figure 8 in the DC>bitter end (experience here, too) DC>According to the same manufacturer's study, any knot, even the bowline, DC>degrades line strength by at least one third (!). I know sleeving DC>minimizes this (I wish I knew a study which quantifies this). For years I DC>have used a "no-knot" splice I learned from a kite-spool insert (I can't DC>find it just now, but if interested, I'll look for it, scan it, and ask DC>Andrew Beattie to post it on his Web page) I have made a study of the strength of lines with and without knots, and the effects of different knots etc. I used exclusively a special braided linen (flax fibre) thread that is used widely to stitch shoe components together. This has almost no stretch, is very "limp" and is quite soft and non burning on the skin. The breaking strain (unknotted) is about 40 kgs. (Multiply Kgs by 2.2 to convert to lbs) The knotted strengths don't vary much with different knots and roughly halve the unknotted strength, i.e about 20 kgs. The bowline is the only one the goes over 50 and this consistently acheives about 60 0r 25 Kgs breaking strain. Other breaking strain tests I did using polymeric materials such as nylon or terylene (Polyester) threads show variable results depending on the rate of pull applied. If the strain was applied at a rate of (say) 500 mm /minute the breaking strain is higher than if applied at 20 mm/minute, this is especially true of very stretchy materials. A sharp jerk will often produce higher or lower values depending on the material and it's construction (i.e braided versus twisted or monofilament) I found for monofilament sleeving didn't give any higher results to knotting, and knotting is much easier. My favourite knots are the inline double overhand for joining lines, and bowline for attaching lines to solid objects. Jim Oliver (3:771/370) * SLMR 2.1a * = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =