The Tao of Cordage – Part 1 , by J.M.

If you ask anyone involved in preparedness ‘what are five things I should always include in my kit?’, the one item that is guaranteed to appear near the top in every list is ‘cordage’, or more specifically, parachute cord {“paracord”). The idea of including cordage as part of your survival preps and everyday carry kits makes a lot of sense, as it has dozens of uses in survival situations, including:

These are just a few of the things you can do with the right cordage. However, all cordage isn’t the same, and the typical 550 paracord may not always the best answer. My goal in this article is to provide you with some details on a number of common options for cordage in order to help you select the right one(s) for your specific needs.

Factors

When you’re looking at cordage as part of your various preps, you need to understand what your requirements are in order to make the best decision. Think about the various situations you may run into and how you might use cordage in each of them. In many instances the best answer may be to stock different types of cordage for different situations; that’s obviously a lot easier to do at home or in your vehicle as opposed to when you’re on foot, but given the light weight and relative strength of modern cordage options, carrying two or three different types of cordage makes a lot more sense today than it did a few decades ago.

Once you have a handle on your requirements you next need to understand what the strengths and weaknesses are for different types of cordage options. Like everything in life, different types of cordage have different characteristics, so you’ll need to balance your requirements and the tradeoffs of each type in order to make the best decision.

Style

Pretty much all modern cordage is made of multiple smaller strands combined in one of three styles – twisted, braided or kernmantle. Twisted cordage is arguably the most traditional style and one of the easiest to make. Individual strands are wrapped tightly together to make thicker cords, and these in turn are then wrapped together to make the final cord or rope. One disadvantage of twisted lines is that they tend to want to untwist, especially at the ends when cut, so you need to make sure any end cuts are tied off or sealed. One common approach to improving the stability and durability of twisted line is to coat the line with a material that holds the strands together. The most common type of twisted line used in survival and wilderness situations is called ‘tarred bank line’. Twisted line tends to be slightly less flexible than other options, have more stretch (which can be good or bad), be more prone to abrasion and cost less.

Braided line is a type of line where the individual strands are woven or braided together in an overlapping pattern. Braided line comes in three sub-styles – hollow, which is created by braiding groups of strands together to create a tight tube of rope with an empty center, solid, which is a braid that has a filler core which gives it more strength than hollow, and double braided, which has a braided core that is covered with a braided jacket. Braided tends to be more flexible (particularly hollow braided), stronger than twisted, and holds knots better than twisted.

Kernmantle is cordage made up of an inner core (or ‘kern’) of multiple twisted lines, covered with a braided sheath or ‘mantle’. It shares many of the features of twisted and braided, but can also amplify some of the disadvantages of both. The most common type of kernmantle cordage is the 550 paracord so loved by preppers everywhere. One of the biggest advantages of kernmantle cordage is that you can remove the inner strands and use them for lighter tasks like fishing and sewing, and still use the outer mantle for heavier tasks.

Materials

The type of material cordage is made from can have a significant impact on its characteristics. While in the distant past your only options were natural fibers like hemp, modern materials science now allows cordage to be created with numerous different manmade materials that significantly outperform anything nature can provide.

One of the most common materials for making cordage is nylon. Nylon was invented in 1935 by DuPont as a replacement for silk, and it shares many of the characteristics of silk. It is extremely strong for its weight, tends to return to its original shape and strength when stretched or bent (e.g. knotted), and is resistant to rot, mildew, abrasion, and fading from UV exposure. One of nylon cordage’s biggest weaknesses is its reduced performance when wet – it tends to absorb water, which weakens it. True mil-spec 550 paracord is made from 100% nylon.

Another very common material for cordage is polyester. Like nylon, polyester was developed in the 1930s, but it wasn’t use widely until the 1950s. As with nylon, polyester cordage is UV resistant, abrasion resistant, wear-resistant, and rot-resistant. However, it doesn’t stretch as much as nylon (may be good or bad, depending on usage), and doesn’t lose any strength when wet. Polyester also tends to be less expensive than nylon. Because of the reduced cost, many cheap 550 paracord knock-offs are made from polyester instead of nylon.

Several newer cordage materials have been introduced in the last few decades as competitors for nylon and polyester. Kevlar was patented in 1966 and was originally used exclusively for body armor. It has a higher strength-to-weight ratio than steel, and has been used as a replacement for steel liners in racing tires. Kevlar cordage is waterproof, floats, is very low stretch, handles very high temperatures (800°F) and is significantly stronger per size and weight than both nylon and polyester. Its biggest disadvantages are that it’s not very resistant to UV damage and tends to be very expensive.

Another modern wonder material used for cordage is Dyneema (also called ‘Spectra’). It was invented (by accident) in the late 1960s, became commercially available in the 1990s, and is technically an ‘Ultra high molecular weight polyethylene (UHMwPE)’. Like Kevlar, Dyneema is waterproof, floats, is very low stretch, and is significantly stronger per size and weight than both nylon and polyester. However, it is also a lot more resistant to UV light and corrosive chemicals than Kevlar, so it’s used extensively for things like spear fishing line. Dyneema’s biggest disadvantage compared to Kevlar is heat resistance – Kevlar can withstand temperatures up to around 800°F, whereas Dyneema tends to melt at around 130°F.

Strength

One of the most critical considerations when selecting cordage is whether it’s strong enough to handle all of the tasks you need it to without weighing you down when you have to carry it with you. 1” thick twisted rope can probably handle any task you throw at it, but you probably don’t want to carry 100’ of it as part of your everyday carry (EDC). It’s important to understand how the strength of cordage is measured in order to make an informed decision. Any time you see a weight number on cordage packaging, you’re seeing what known as the ‘tensile’ or ‘static’ strength – that’s how much weight the cordage can support without breaking, with no knots tied in it and the weight hanging perfectly still. For paracord it’s usually the number in front – e.g. ‘550’ paracord can support 550 pounds of static weight. However, the real world is very seldom static – things swing, fall, pull, etc., all of which increases the load on the cordage. A weight falling 3 feet can double the amount of strain placed on a line, and knots can reduce its strength by up to 40%, so that’s why using 550 paracord for climbing when you weigh ‘only’ 180 lbs is a really bad idea.

As I mentioned, knots in cordage can significantly reduce its tensile strength. That’s due to the fact that the individual fibers in the cordage are being bent at tight angles, which weakens them. Depending on the material, environmental conditions, type of knot and a bunch of other factors, this strength reduction can partially remain even after you’ve undone the knots. The rule of thumb is that knots reduce a line’s tensile strength by 20%-40%, but people that rely on ropes to protect their lives use a 50% reduction as a safety factor. Note that it’s not just knots that reduce cordage’s strength – just looping it over a small diameter pole or branch will result in a reduction of strength (with small being defined as anything less than 4” in diameter.)

Picking cordage with the right strength can be critical to your preps. A line rated at 550 lbs. may sound better than something rated at 100lbs., but if you’re just building shelters, tying off gear or other lightweight tasks, 100 lbs. is more than strong enough and you can carry 4-5 times as much for the same volume and weight, giving you a lot more flexibility.

One other note on strength – some manufacturers, particularly those that make lines and gear for climbing, rate the strength of their cordage and ropes in KiloNewtons (kN), which is actually a measure of force, not weight. The formulas used by climbers are way beyond the scope of this article, but if you insist on wanting to translate that to weight, 1 kN equals about 224 lbs. of force.

Stretch

Stretch is how much cordage increases in length as tension is applied. Some cordage like paracord is actually designed to have a lot of stretch (30% according to military specifications) so it can absorb more shock, and stretch can be desirable in some circumstances. Imaging you’re tying a ridge line tightly between two trees to hang up a tarp, and the wind picks up at night and the trees start swaying back and forth. If the cordage you used couldn’t stretch it would probably break. Conversely, if you used cordage to make a travois to haul a wounded person to safety, you probably don’t want the tie-offs stretching and then coming lose.

Environmental conditions can also cause cordage to stretch – some cordage made from nylon and/or polyester can stretch more in extremely hot environments.

Size/Weight

As every prepper and backpacker knows, size and weight matter a lot when you have to carry everything on your back. Most people’s inclination is that bigger and heavier means stronger, but modern materials science has turned that notion on its head when it comes to cordage. For example, 100’ of 550 paracord rated at 550lbs. tensile strength has a diameter of .16” and weighs ½ lb. (8 oz.), but 100’ of braided 2.5mm Kevlar cord rated at 900lbs. has a diameter of .10” and weighs less than half as much (3.65oz.). I can get 45% more strength for half the weight and size (but at a higher cost, of course). For a given type of cordage the “bigger/heavier = stronger” formula tends to be true – .45mm/.20oz. Kevlar line is rated at 50 lbs., while 3.5mm/7oz. line is rated at 1,800 lbs.

One other factor that is impacted by cordage size is knotage (I made that word up 8-)) – the thinner the line the more difficult it can be to tie and (especially) undo knots. Have you ever tried to undo a knot in braided fishing line? If your hand sausages are anything like mine, tying and untying knots in thin line can be extremely exasperating, which is why I switched to small carabiners and line tensioners for most of my rope work these days. Companies like Dutchwear Gear and Lite Outdoors offer ultralight line hardware designed to work with thin lines so you don’t have to deal with too many knots.

Other Factors

There are a number of other factors you need to consider when evaluating cordage:

  • Flotation – If you operate near or on water, you should consider whether your cordage floats.
  • Absorbency – If your cordage might get wet due to things like rain or snow, you should know whether it absorbs or sheds water. Packing away soaking wet cordage is no fun, and in cold temperatures it can turn into solid sticks of ice.
  • Cost – Cordage made from exotic materials like Kevlar and Dyneema tend to be a lot stronger for a given weight and size, but they’re a lot more expensive per foot.
  • Abrasion Resistance – If your cordage will be moving and rubbing against hard or sharp surfaces a lot, its ability to resist shredding and tearing will be critical.
  • Color – Using neon orange line to tie up a nicely camouflaged tarp kind of defeats the purpose, but having color options can be useful. For example, I used small loops of different colored cordage tied to the zipper pulls on my various small organizing pouches to indicate what it contains.
Options

Now that we’ve covered everything you never wanted to know about cordage, let’s take a look at some of the more common options available.

(To be concluded tomorrow, in Part 2.)