Tying a knot in a rope immediately reduces its strength to between 50% and less of the unknotted rope, but obviously knots have to be tied to use the rope.
The tying on knots are often secured with an overhand knot tied with the tail of the rope around the live rope.
A tail of at least 15cm must be left after the knot is tied.
Only the standard bowline requires this precaution to be safe, however with the other knots it provides reassurance that sufficient tail has been left after the knot is tied.
Knot Knot Methodology
Good Knot Qualities Inspectable, secure, strong, easy to tie & untie. A well-dressed knot is clean, has an adequate tail, is backed-up if appropriate, and is easy to inspect by touch & sight. http://disaster-risk-management.blogspot.com
Anchor Point knots
Knots Joining Two Rope
There are three types of Basic Knots applied during the Rescue Operations:
Anchor Point Knots
Figure of Eight
Figure of Eight Follow-up
Bowline Knot The bowline has been called the king of knots. It will never slip or jam if properly made and is excellent for tying around a person in a rescue.
Clove Hitch A clove hitch is formed from two loops of rope and is mainly used for making a rapid and adjustable connection to anchors, by tying it through a karabiner. http://disaster-risk-management.blogspot.com
Clove Hitch This is one of the most widely used knots. Because it passes around an object in only one direction, it puts very little strain on the rope fibers. It is the knot we use the start and end lashings. It is usually tied around a pole.
Figure 8 Knot The Figure of Eight is one of the easiest knots to tie. It is often used in such places as the end of a string when tying a package with a slipknot or in the end of a rope forming a loop. http://disaster-risk-management.blogspot.com
Figure of 8 follow through This knot is formed from a "bight" of rope. It's very handy to just grab a bight of the rope anywhere along it and tie it off in this manner. Useful for belay set ups, or rescue work, or to backup ascending a rope, and all sorts of applications.
Knots Joining Two Ropes
Figure of Eight
It is formed from two overhand knots each tied round the opposite end: it is very suitable for rope in general and is used mainly for small stuff. Single Fisherman Knot Double Fisherman Knot
Water Knot Thumb Knot The water knot is arguably the strongest knot you can tie in webbing. It is essentially an overhand follow-through. This simple knot and its cousin the barrel knot can be used to back up another knot. http://disaster-risk-management.blogspot.com
Sheet Bend The sheet bend is the most important knot for joining two rope ends, especially if the ropes are of different sizes. This knot is tied in a thin rope to allow it to grip a thicker rope. When weight is applied, the barrel of the knot tightens around the rope gripping it more firmly.
Reef Knot Commonly used to tie two lines together at the ends. You can loosen the knot easily by either pushing the ends toward the knot or by "upsetting" the knot by pulling back on one end and pulling the other through the loops.
An excellent knot, probably the nearest to the perfect bend. It is symmetrical, easy to tie, will not slip nor ham, is very strong and is easily untied. Its particular use is as a bend for hawsers and cables. It can be used in two forms, drawn up or open and seized and it should always be tied so that the two ends are diagonally opposite. Carrick Bend Knot http://disaster-risk-management.blogspot.com
Special Rescue Knots
Bow Line with Three Loops
Bow line with Two Loops
Prusik Knots Prusik knots are sliding hitches that lock on the rope when loaded, but can be moved along the rope when unloaded. The original Prusik knot is a double or triple girth hitch. The grip of prusik knots on the rope depends on the thickness of the rope relative to the sling, and on the flexibility of the sling. The three hitch Prusik knot is recommended as the preferred version, as the original two hitch version can unexpectedly slip. http://disaster-risk-management.blogspot.com
Bowline with two loops Bowline-on-a-bight : A double loop knot which is tied in the bight when the two ends are fixed or inaccessible. The strain should come equally on both standing parts. A good rescue climbing knot or chair knot.
Bowline with three Loops http://disaster-risk-management.blogspot.com
A loop tied in the bight. One of the several so called 'Butterfly knots' which are used for the middle man on a rope when rock or mountain climbing. More than one of these knots has been called the 'Alpine' Butterfly but the knot illustrated is believed to be the most effective in use. Alpine Butterfly
BACHMANN KNOT This prusik knot incorporates a karabiner within the coil of sling, with the advantage that it frees much more easily than the previously described prusik knots. It is mainly used in rescue systems
Clime Hitch This is a different type of 'prusik' knot, which is easier to use on kernmantel rope. Normally three turns of the sling are made, but this can be increased if more grip is needed. The knot works best if the loop the sling is fed through is kept small. A Klemheist knot can be tied with webbing slings if prusik slings are not available. A loop of the sling is coiled upward around the rope three times and the other loop passed through it.
For more topics: Please visit: http://disaster-risk-management.blogspot.com Thank you for your time