The way rope is constructed is integral to its performance and utility. It impacts the rope’s shape and how it performs with different loads.
Ropes are either twisted or braided. The latter is the most common and the type that has been used historically. Twisted ropes are generally more affordable and easier to splice. They are however not as strong as braided rope and therefore struggle with larger loads.
There are several different types of braided rope. The single braid is often used as a temporary lashing that is to keep an oar stowed on a speed boat for example. These braided ropes are formed by braiding together 8 to 10 thin fibers into a tubular braid which means that it is not often perfectly round due to its tubular nature. The most common material used to create the single braid is polypropylene and nylon.
The double braid is extremely hard wearing and therefore is a popular choice for industrial uses. It is constructed with two single braids one inside the other. Unlike a single braid it does not lay flat and is available in a variety of materials. In some cases, each single braid is constructed of different materials to ensure the right balance of strength, flexibility, and durability for the job in hand. The exterior material must be resistant to the elements of course and the interior core strong.
A third type of braided rope is the kernmantle which is a specialized rope with a braided shell but internal twisted fibers. Uses of the kernmantle braided rope system include rock climbing where a specific amount of strength, abrasion resistance and stretch is needed.
Braids do not unravel as easily as twisted rope and so are much more reliable. They can however also twist if used consistently as part of a winch rope system. Braided rope is the show horse of the rope world and a well-made braided rope is constructed using fibers that are aligned in a single direction and overlap in a certain manner.