The sheer number and diversity of knots that was once in use would be bewildering to the modern city-dweller. About 4,000 different knots are described, ranging from the very simple to the extremely complex.
Not so long ago, each profession or trade had adopted the knots best suited to its requirements, and knotting was part of their daily lives. There are some good knotting reference books available online, and all of them are older than most of us.
Knots can be subdivided according to their general purpose: to attach a rope to another rope (fastening knots), to attach a rope to an object (hitches), to shorten a rope without cutting it (shortening knots), to form an enlarged end on a rope (ending knots), or to attach two rope ends together in such a way that they represent a smooth and even surface (splices).
In addition to these practical knots, there are many kinds of fancy knots used in ornamenting the ends of ropes, decorating shrouds of vessels, railing and similar objects (which will not be covered here).Below I will outline some basic knots and highlight remarkable examples of this technology.
Basic knot technology
Desirable features of most knots are that they may be quickly tied, easily untied and will not slip under strain. A number of terms are generally used when tying knots. The "standing" part of a knot is the principal portion, or longest part of the rope.
The "bight" is the curved part, looped or bent while working or handling the rope in making the knot, and the "end" is that part used in forming the knot or hitch (illustration above, left). All knots are begun by loops or rings known to mariners as "cuckolds' necks" (illustration above, right). These may be overhand or underhand. If the loose end of the rope is passed over the standing part and through the cuckold's neck, the simplest of all knots, known as the "overhand knot" is made (illustration on the 
right).
This is the knot that everybody can make. I hope that my readers are more knot-savvy than me, but I have to confess that it is the only one that I am able to make, when I tie my shoelaces.
Fastening knots
With a bit more sophistication, much better knots can be made. The "figure eight knot" (commonly used to prevent a rope from running through an eye or ring or tackle block) is almost as simple as the overhand knot, and only a step beyond this is the "square knot", which is one of the best all-round knots known (above, left). It is very strong, never slips or becomes jammed when being strained, and is readily untied. Beware of the "granny knot", though, which looks very similar but is utterly useless. In spite of its versatility, however, the "square knot" is not always ideal.
For example, it is not reliable when joining two ropes of unequal size together, because they will slip. In this case, the "open-hand knot" can be used (illustration on the right). In joining small lines, the "weaver's knot" is the best option, while the "fisherman's knot" is valuable when it is important that the two lines may be drawn apart with just one pull.
The "hawser knot" is the best to use when joining two stiff and heavy ropes and the "bowline knot" comes in handy to tie a horse or cow so that they will not choke themselves. For every possible application, our forefathers seem to have developed a suitable knot. Tools to be used in tandem with knots also exist: in a number of cases a toggle is used either to aid in making the knot or make it easier to untie it after a strain has been applied (illustration on the left, applied to a decorative knot called the "monkey chain").
Two distinct types of fastening knots are "ending knots" and "shortening knots". Ending knots prevent the rope from unravelling - some form of an "artificial eye" is one way to do that (illustration on the right). Shortening knots are useful when the rope is too long and where it is awkward to have the free ends hanging loose, or where the ends are in use and the slack must be taken up in the middle of the rope. Both types come in a wide variety and are also used extensively for their ornamental value.
Splices
Thanks to knots, ropes can be made as long as you please - regardless of the length of the ropewalk. However, many times it is necessary to join two ends together in such a way that the union is as strong as the rest of the rope and still not too large and irregular to pass through a hole or pulley block.
The method of joining two ropes to meet the above requirements is called splicing. There are two general types of rope splices, known as the short splice and the long splice. The long splice is preferable since it is stronger and does not increase the volume of the rope at all. A well-made long splice cannot be distinguished from the rope itself after a few days use. Splices can also be applied to steel "wire ropes" (below).
Hitches
When fastening a rope to a stationary or solid object, instead of fastening rope ends together, another class of knots used are called "hitches".
Again, the diversity of hitches is overwhelming, with each knot designed to meet some special requirements. Some are designed for fastenings where the pull is continuous, others were invented to hold without slipping on wet timber, and others serve extremely well when a knot should be easily untied. The pro's and con's of specific hitches can be crucial knowledge in pertinent situations. The "blackwall hitch", for example, has the interesting property that it holds more securely the greater the strain is, but it is unreliable if the rope is slack.
Other hitches are especially designed for certain objects. The "catspaw" (illustration on the left) is useful for hoisting with a hook. Others are suitable to hoist an open barrel ("sling for a cask"), and others are used in hoisting pipe, where no special clamp is available for attaching the hoisting tackle to the pipe ("pipe hitch").
Handcuffs
There are hitches designed for attaching a rope to a ring, hitches used in tying up light packages, or hitches invented to form a seat for men to be lowered over cliffs or buildings. Many hitches will pull tighter the harder the strain, and are still easy to untie. The "tomfool knot" (illustration on the left) is used as a pair of very secure handcuffs. One of the most high-tech knots around is the "diamond hitch", used to tie loads to pack animals. Full instructions of it can be found in this 1916 manual & this 1922 manual.
Knots (and ropes) are fast on their way to become an obsolete technology.
© Kris De Decker (edited by Shameez Joubert)
Lost knowledge: ropes and knots They are among the most ancient and useful technologies ever developed by man, predating the wheel, the axe and probably also the use of fire. Today, ropes and knots are fast on their way to become an obsolete technology.
Aerial Ropeways: automatic cargo transport for a bargain These days, we use them almost exclusively to transport skiers and snowboarders up snow slopes, but before the 1940s, aerial ropeways were a common means of cargo transport, not only in mountainous regions but also on flat terrain, with large-scale systems already built during the Middle Ages. Cargo tramways can be fully or partly powered by gravity, and some deliver excess power that can be utilized to generate electricity or to drive cranes or machinery in nearby factories. Some innovative systems have been constructed in recent years.
Human powered cranes and lifting devices From the earliest civilisations right up to the start of the Industrial Revolution, humans used sheer muscle power, organisation skills and ingenious mechanics to lift weights that would be impossible to handle by most power cranes in operation today.
The art of producing sustainable consumer goods: basketry The craft of basketry might be one of our species’ most important and diverse technologies, creating homes, boats, animal traps, armour, tools, cages, hats, chariots, weirs, beehives, shelters and furniture, as well as all manner of containers. Basket weaving makes use of fast-growing biodegradable materials -- branches, twigs or shoots -- that requires the forest to be cultivated rather than cleared. Basketry allows almost anyone, with little or no money and few tools, to create a large variety of useful goods in a way that is one hundred percent sustainable.
Main page
, JC Turner & P van de Griend (1996). Free access in some libraries.
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You may want to expand this article by adding a section on decorative / personal knotting. I'm referring to macrame ( http://en.wikipedia.org/wiki/Macram%C3%A9 ) and gimp braiding ( http://en.wikipedia.org/wiki/Scoubidou ). I've made key chains from gimp and seen others make a sort of bolo tie from it. My current key chain is macrame, 150# nylon, using four knots : gimp square, cored half-hitches, pineapples (variant of the gimp square), and an overhand.
While knots have faded due to professional changes I think they will continue to be taught and preserved. There are groups like the various scouts, Amish, SCA (it's not just swords and chain mail), etc. My own profession, comp. eng., could use natural fiber cordage for strain reliefs and cable organizing in machine rooms that require low static-electricity materials. While writing this comment I saw in my mind's eye a cored half-hitch braid that mixed copper (core strands, good for grounding), hemp twine (smooth as possible), and a pair of steel eyes for the ends. The copper core would allow the safe draining of ESD's while the braid would provide an anchor point for a variety of cables. Such a braid could be screwed onto a rack mount or the wall.
Posted by: Ted K. | July 03, 2010 at 10:09 PM
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The easiest to use knot guide I've found is here
http://www.animatedknots.com/
Posted by: STW | September 11, 2010 at 04:41 AM
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A couple of observations: one field where knot-tying is still absolutely essential is climbing: https://en.wikipedia.org/wiki/Glossary_of_knots_common_in_climbing
Only ropes which are laid (made of strands that can be separated) are joined by splicing; for most purposes lines will be connected by a class of knots called bends, with the sheet bend being one of the simplest to tie:
https://en.wikipedia.org/wiki/Sheet_bend
Also a general note is that as versatile and useful as knots are, they weaken the line they are tied in, to varying degrees. Some also are more prone than others to jam, that is, to resist untying after they have been used.
Posted by: Toby | July 24, 2012 at 07:13 PM
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The best way I have found to tie two ropes together is to take the first rope and bring the end around so the rope crosses itself with the end over the length with several inches sticking off to the side. Then take the second rope and lay it on top of the first in exactly the same manner. Now stick both ends through both loops from the bottom and pull them till the slack is gone. Finally pull the other ends of the ropes apart till the knot is tight.
This knot holds the ropes together quite well even when the ropes are of different thicknesses and when the time comes the knot unties easily.
Posted by: Slowburn | August 15, 2015 at 09:32 PM