Learning the Ropes
Introduction to Climbing Ropes
By John Walter
Picture this, you're 300 feet off the deck, fifteen feet above your last piece of protection, forearms burning, and youíre tied into that rope your cousin got for a song at his neighborís garage sale. You hope that stain on it isnít from battery acid, or worse.
Climbers are notorious cheapskates, or better yet, dirtbags. There are plenty of stories about how this or that person lived in a cave at Yosemite for 4 years and scrounged leftovers from the tables in the cafeterias. Scrounging for food is okay; scrounging for a rope, however, is not.
Ropes are the most important piece of climbing equipment that you can buy. Buying whatever is the cheapest is definitely not the best way to think about a rope purchase, although a great rope can be relatively economical (say around $125.)
Climbing has broken out into several very specialized disciplines. Rope manufacturers make specific ropes for each of the different disciplines. So how do you know which rope you should buy? By understanding all the rope industry's cryptic phrases, like impact force, static elongation, sheath slippage, and falls held, all of which are useful in rating a climbing rope.
Dynamic Rope Construction
Rope manufacturers make two different types of ropes for climbing, static and dynamic. Static ropes donít stretch to absorb impact much and are a great deal more durable than dynamic ropes. They are typically used for rappelling and hauling but never leading a climb. Dynamic ropes stretch quite a bit to absorb impact generated in a fall and are manufactured specifically for lead climbing. Dynamic ropes are the focus of this article.
Modern dynamic climbing ropes are far different than the old hemp three-strand braided ropes of old. Modern ropes are known as kernmantle ropes. The kern is the inner core of the rope and the mantle is the braided sheath. The mantle protects the kern from damage due to abrasion.
Single, Double, or Twin
Single ropes are the simplest rope to climb with, and the lightest. A single rope is designated by a circle with a 1 in it on the end of your rope. Most climbers use single ropes for climbing. Single ropes the most common type of dynamic rope on the market, and the most widely used.
Double or half ropes are designated by a ì1/2î symbol in the end of the rope and must be used in pairs. The benefit of half ropes becomes evident when your route wanders all over the cliff. A single rope will put a great deal of friction in your system, which feels like youíre climbing with a Mac Truck on your harness. In contrast, half ropes allow you to stagger the ropes in your protection, reducing the amount of friction. They are also a backup in case one rope gets cut in a rock fall or by being stepped on by a crampon. Half ropes are great for ice climbing and alpine rock.
Twin ropes are similar to half ropes with one major difference. Twin ropes must both be clipped into the same piece of protection. These arenít as popular as the other ropes but are still useful in alpine situations when you want to shave those ounces. Twin ropes are marked with an infinity symbol in the circle at the end of the rope.
Rope lengths are measured in meters. Slightly longer 55- and 60-meter ropes are now replacing the old standard sized 50-meter (165-foot) ropes. A longer rope is heavier, but useful for climbing longer routes and running pitches together. Ropes are commonly manufactured in lengths of 50, 55, 60, and 70 meters.
The diameters of ropes are measured in millimeters. The standard diameter of climbing ropes is changing as well. Fifteen years ago, you would be hard pressed to find people climbing on 10 mm single ropes; 11 mm was the standard. Now 10.5mm and 10 mm ropes are very common. There are even single rope diameters down to 9.6 and 9.4 mm. The thicker ropes have a greater margin of safety and durability and are still the choice on big wall climbs. The thinner ropes are useful for hard climbs, and alpine situations. Half ropes are from 8 mm to 9 mm and twin ropes are even smaller at 7.8mm.
Weight is measured in grams per meter. To find the weight of a rope, multiply the given number by the length of the rope, i.e. multiply the grams-per-meter by the number of meters. Weight can be a better selection criteria than diameter when choosing a rope, i.e. instead of choosing a smaller diameter rope to reduce weight, and thereby reducing safety, consider instead looking at same-diameter ropes grams-per-meter numbers.
Rope Testing Standards
The International Union of Alpine Associations (UIAA) is the governing body that develops testing standards to evaluate climbing ropes. It is important to understand these standards and testing procedures, and how they compare to actual use of climbing ropes.
The UIAA test that determines a ropeís strength is called the drop test. The test uses a 176-pound (80-kilogram) weight for single ropes and 121 pounds (50 kilograms) for half ropes. In the test, the weight is tied onto the rope above an anchor. The weight is then dropped 16.4 feet on a 9.2-foot section of rope. This creates a fall factor of 1.8. The fall factor is determined by dividing the amount of rope out of the anchor by the vertical distance fallen. The most serious theoretical fall is one with a fall factor of 2. The higher the fall factor, the more limited the rope is in absorbing the energy of the fall. During the test, the weight is dropped repeatedly until the rope breaks, and that is the number of falls held.
The UIAA fall test puts a great deal more force than on a rope than real climbing situations. If you have a rope that held 7 falls in the fall test doesnít mean you need to retire it after 7 falls while sport climbing. But if your rope has sustained long, hard falls close to the belay, then you should retire it.
Impact force is determined during the same fall test. A climbing rope is manufactured to stretch during a fall to absorb the energy generated by the fall. The UIAA standards for impact force states that no more than 2640 pounds are to be transferred to the climber during the first fall of the test.
This measures the amount of stretch the rope will experience with the same 176-pound. weight hanging on the rope. Dynamic climbing ropes will stretch when hanging, jumaring (ascending the rope), or rappelling. The UIAA standard allows no more than 8% stretch of a single rope and 10% for half ropes. During a fall, however, the forces on the rope will cause it to stretch 20-30 percent in the UIAA drop test.
Rappelling and belaying place a great deal of friction on the rope, and can cause the sheath of the rope to slip along the length of the core. This UIAA test measures the amount of sheath slippage on a 2.2-meter section of rope run through plates five times under a load of 121 pounds. The slippage must not exceed 40 millimeters. Excessive slippage of the sheath can cause the core or sheath to protrude unevenly.
Probably the best thing you can do to take good care of your rope is to buy and use a good rope bag. Rope bags will keep your rope clean and protect it if from any unfriendly chemicals that might be lurking about in your carís trunk or your basement. Be kind to your rope; never subject it to heat or direct sunlight for long periods of time, protect it from any chemicals, and never step on your rope, as it will grind dirt and rock particles deep into the fibers of your rope, causing serious wear. Store your rope in a cool dry place. When your rope becomes dirty, wash it in a large volume front-loading washer with a non-chemical detergent, such as Woolite. Top loaders will seriously kink your rope, making it difficult to manage.
Retire your rope after it has held a hard, long fall, or when it begins to show serious wear, or when you can feel ìflat spotsî in your rope. Over time, the usage that you put your rope through will begin to wear on the rope. If you climb 3-4 times a week, you can expect to retire your rope after about 4 months. If you climb every other weekend, retire your rope after about 4 years, as the nylon threads will weaken with age.
Take care of your rope and it will take care of you.
John Walter is Climbing Editor at GearReview.com