Articles

By Kenneth N. Laidlaw
Published: July 23, 2008
Updated: July 23, 2008
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Abstract

Rope rescue presents special challenges, especially in remote areas. With new equipment constantly appearing on the market and techniques continuously being refined, the craft is a very dynamic experience. This presentation will expose new students to safe, basic fundamentals. Advanced students will increase their knowledge of proper techniques. All experiences are based on current testing and review the techniques of application used by different groups, from cave explorers to mountain rescue personnel. OSHA considerations will be addressed. Both hard and soft techniques for attaching to the rope are discussed. At the end of the presentation, a reader should be able to make safe decisions based on their own needs and budget restraints. They will also know the best references for additional information.

Warning

Rope rescue is a very dynamic experience and what may be considered safe today, may be determined inappropriate tomorrow. Check the date in the lower corner of your edition, if you have an earlier version of this paper, destroy it. The most recent version of this paper is available on the Internet, at:
http://www.basarc.org/papers/roperescue

Notes

An effort has been made to use the historically correct terms and systems international measurements for components to accommodate both North American and European interests. The equipment specifications in this paper describe cordage sizes and hardware that is commonly used in mountain and cave rescue situations. Where larger cordage or stronger hardware is required to meet the Fire Service’s NFPA equipment standards, the specifications for the NFPA compliant equipment is shown in italics.

 

Ropes

Only low stretch kernmantle rope should be used. Kernmantle design consists of a central core or kern of parallel fibers that support the load. This core is covered with a woven sheath or mantle. Low stretch is a type of rope that typically stretches only 2% to 3% when a one KILONEWTON force is experienced. A NEWTON is a unit of force---mass or amount of matter times acceleration or change in speed over time - equal to about .225 of a pound of force. A KILONEWTON would be equal to about the weight of a 100 kilogram (222 pound) person. Remote area rescue usually uses an 11 mm. (7/16”) size because of its weight. Fire Service, using NFPA equipment standards, may use 12.5 mm. (1/2”) size. Several versions of low stretch kernmantle rope are often available and a stiffer type, with a more abrasion resistant sheath, may be applicable. A more flexible sheath version might be easier to use for working components. All versions are usually manufactured with a breaking strength greater than 26.7 kN (6,000 lb.) or 40 kN (9,000 lb.). If ropes pass over rough edges, provide padding to prevent abrasion. One of the best appears to be the CMC® Ultra-Pro™ Edge Protector. Avoid getting grease and pitch on the ropes. Discourage people from walking on the ropes. Regularly wash dirt and grit off the rope. Store in rope bags, in a dry area, out of sunlight. The larger rope manufacturers make excellent products. Unless you must have designer colors, buy rope that has more white strands and it will usually be cheaper. Ropes are the life line to success for the patient and the rescuer. All of the 8 mm. cord used should have a minimum breaking strength of 13.3 kN (3,000 lb.) or 9 mm. 20 kN (4,500 lb.) and should have an appropriate sheath for the Prusik hitch to stay snug.

Serious testing of equipment and techniques began in 1982 with an independent group of rescue teams in British Columbia, Canada, known as BCCTR. Further testing included Arnor Larson, John Dill, Reed Thorne, Hal Murray, and the Clems. Many of the test scenarios they conducted using Prusik hitches were been done on 11 mm. PMI E-Z BEND™ with 8 mm. MAMMUT® and EDELRID® accessory cord.

The ratio of the size of the Prusik cord to the main rope is crucial. Generally, two cross sections of the Prusik cord should equal the cross section of the main line. With many products 8 mm. is the accepted size to use on 11 mm. rope. 9 mm. might be a better choice for 12.5 mm. rope. Practice with the accessory cord and rope you plan to use to make sure they are compatible together. Engage Prusik hitches under a load to see how they grip or break. 8 mm. MAMMUT® accessory cord was the cord of choice for a long time. However, the brand has been sold and the new manufacturer has changed the braiding process twice in recent years and MAMMUT® is no longer popular. PETZL® has come out with VECTOR™ cord made by Samson Rope. It has a polyester sheath over a nylon core that work together to provide supple handling, greatly reduced sheath slippage, ability to retain shape, superior abrasion resistance, a diameter of 8.5 mm., and is rated at 17.8 kN. This cord is available throughout North America. It seems to be a best choice.

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