Knot Security

[TheTreeSpyder]

Continued from thoughts about knot strength as presented Page 5 of Mid-Line Knots/Knots on the Bight Thread .

It is one thing for a knot to be strong, another to be easy to tie, then to untie etc.; and also high on the list of requirements, especially with working knots; is knot security.

Generally this is thought to be done if needed by dogging/jamming machine of knot against slippage with a stopper knot (Overhand, Fig. 8, Stevedore etc.),or 2 half hitches to self etc. strategies.

Another popular, dependable pattern can be discerned; of a knot/lacing "sitting on it's own bootstrap", locking itself positively. Generally i think of this as both ends have pull, and reducing one end of pull with wraps and turns to what a baby could hold even if it was a bus smoking the tires, then taking that away from kid and trapping that line under the mainline tension. Even better to catch twice! This can be with the tail, or with a bight of tail in the slipped form rendered for the given knot/hitch. Now of course you have to give more security so in times of intermittent pull from different directions, the tail of reduced pull doesn't fall out from it's position under the mainline tension (or as close as ya can get to).

i think realizing knot functions in these forms affords easier breakdown and familiarity, logical sense, inspection of systems, making up lacings for special stuff, especially away from trees etc.; but still magic with a piece of rope in the applications!

Or something like that...

 

[TheTreeSpyder]

Knot Security altered by small changes in way knot is formed. Why a clove after a turn or round turn, can either be 2 1/2 hitches or a buntline, and why a buntline is more secure.

SheetBend for most security should take the most intense, direct pull of locking half hitch/choke ring; and place it immedeately to work securing the loose tail of the bight side, or else sheetbend is less secure.

 

[TheTreeSpyder]

Continuation of above drawing.

i have found that decoding these common mechanics from the recurrent examples, i can better make sure lines are set correctly, knots made and chosen right, to take predicted pulls correctly, to lace tiedowns and rigs etc. to be maximum to these principals; even though far from there examples.

A sheet bend to me is a great example of topics, a quick down and dirty knot, quick release. i prefer a modular eye-metal link-eye arraingement (like 2 bowlines DBY's joined by shackle/carabiner). Or if synthetic must grind on synthetic girth hitched slings/eyes or muenter to muenter of Carrick.

SheetBend is more of a lesson base, or quick and dirty bend; slipped is really great!

 

[TheTreeSpyder]

Part 3 of drawing parted out to meet attatchment limits of file size.

Becket eye in place of bight in SheetBend, to make a Becket Bend, a more secure form, especially when joined with RoundTurn strategy on lock side. Still quick releases away nicely under tension when made with slipped form.

 

[RescueMan]

Your "baby hitch" is commonly used in rescue as the "tensionless hitch" (see attachment) - tensionless because it is finished off with a knot (instead of a less secure tuck) and there is no tension on the knot, so the full strength of the rope is available. It's also called a high-strength tie-off, and is the standard anchor for high-lines (or tyroleans), similar to the arborist's speedline.

 

[Tim_Gardner]

It is also known as the Well-Pipe Hitch. It works great for pulling fence post using rope so that you don’t mar the finish like a chain can.

 

[TheTreeSpyder]

i think the tensionless hitch is a lesson in itself, and should really be loose as you picture on carabiner end, so as not to bend load line at all; or else it should go to seperate anchor(?). It seems to me at some time it would have to walk and carabiner would bend line, losing strength?

But, ya guys are ahead of me there!! i'm still looking at 'lesser knots' with the frailty of the crossing of lines etc. i don't mean to call it a baby hitch at all; i just mean that the 'bus pull' tensioned end has enough force to trap what a baby could hold (because the bus pull was reduced in the choking friction of the turns to a baby pull level)underneath it, in a basic knotting form. Looking at patterns that define properties, to make better judgements in knot choice and system assembly, from the lessons in the common knot forms.

i did get the "Ashley Book of Knots" for $46 from WalMart.Com after Tom and Tim mentioning it should be on the shelf. It is prolly worth the $75, the reason noone has done a new/better manual since hte writing ~70 years ago, is because it is such a large comprehensive work and undertaking, that many prolly shy from it rightfully!! There are a lot of decorative/non working knots, but plenty of meat too, and a 1/3 off the price, makes it easier to bite on!

Thanx guys..
-KC