This is my list of knots and splices I use.
There are over a thousand knots uniquely identified - so my list is a selection list of just the knots I find useful in steel construction.
Whereas there are very few splices and I use just about all of them.
A point I have never met but it could be important to some users - both ropes and braids can be knotted using identical knots, whereas the classic splices are only applicable to 3-strand rope.
The knots have a thousand and one uses in any number of impromptu occasions. Whereas the splices are the stolid workhorses of the familiar scenarios.
Subsections within the category of hitches:
Only to be used around fairly simple shapes - tubes and square-sections and essentially cylindrical objects - but endlessly useful.
For when the pull is along the length of what the rope is knotted around.
For joining ropes end-to-end. Joining ropes end-to-end is easily done with a "short-splice" which is stronger, more secure and small (doesn't get caught on objects it's passing) - so less used. Except in an emergency, in the dark - keep them practiced!
For stoppering the end of a rope, so it doesn't fray - and can be pushed through small openings without snagging. With polymer ropes, the ease with which you can melt the end of the rope with a small butane lighter and pinch it to a neat end seal is fine - until you are on a scaffold several storeys up on a building in a high wind with a dirty and wet rope... Then you do want a back-splice!
The general-purpose way of joining ropes together end-to-end to give effectively one long rope. Two main uses I meet:
When manually rope-hoisting up several floors height, can join ropes to make the length required. And easily inspected at a distance for this critical task - as though the splice(s) are small, you can see where they are and their simple cylindrical shape is easy to verify at a distance.
For joining the two ends of a rope together to make a ring of rope - a "strop". Easy to make and endlessly useful. For carrying things, the bigger-diameter region of the short-splice rests comfortably over the shoulder - and putting equal weights on each shoulder makes for carrying a lot of equipment and material with very limited demand on the body. Make strops to exactly the lengths required. Can strop-hitch around handles of equipment to rest on shoulder (load near body-centre) rather than carry by the handle (painful). Then bundle your overalls, high-vis. jacket, etc, together hanging from your shoulder to go home (constrictor knot, which you can form in an endless rope, grips the bundle into a tight package).
Forms an "eye" (small loop) for attaching a rope to things. Very high strength - makes an end termination which is no less strong than the rope itself - a remarkable property.
* less used * Joins a rope in at right-angles to one passing by. One use for this is forming a branching 6mm rope "tree" for tying-off tools (clove-hitch or constrictor-knot) when working on a tower. The "root" of the "tree" is tied to a pole of the tower. So the tools can still be used easily, but you cannot drop them to the ground, nor can they fall off the platform when you are moving the tower.
* less used * Joins two ropes end-to-end and the join region is barely larger diameter at any point than the ropes being joined. Classic use was joining ropes which had to go over pulleys, but no use of block-and-tackle on construction sites for decades now. Keep it practiced just for the sake of honouring old traditions. Can't easily see where the splice is, is less obvious construction to inspect and is less strong than a short-splice, so wouldn't use it for splicing ropes together where a short-splice is fine. But you never know - you might need a belt of some kind (join a rope's own ends together), or something like that, then you'd be the hero of the moment...
In a few narrow circumstances, can be very useful indeed if you need short specific-length strops. A grommet is a ring of rope formed by laying back on itself 3 times in a circle just one strand taken from length of (3-strand) rope. In factory work, if the hoist is on a gantry (frame) giving very limited head-room, can be used to form an electrically insulating break when welding a component "on the crane" ((part) suspended from the crane), without "wasting" hoist height with an over-long commercial sling.
This example is so specific that it makes the general point - keep all these skills practiced - the number of ways they prove useful never ceases to amaze. The number of "difficult" jobs where you can conjure-up a secure, safe, completely-controlled solution will always advantage a practiced rope-user.
(Richard Smith, November 2009)