Rescue ropes are the most important part of any rescue system. They are also the most delicate part of any system. The correct selection, care, and use of ropes is vital. In this text we present important information valuable to anyone involved in rope rescue.
The following text is provided by Sea Air Thai Co., Ltd (http://www.seaairthai.com/) as an introduction to ropes. It is not a complete reference and is written as a guideline only. No text should be used as a replacement for teaching by a qualified instructor and this text is written as a teaching supplement only. We encourage corrections or additions to this text.
Sea Air Thai Co., Ltd. supplies equipment and training to organizations, law enforcement and military units around Thailand. Please contact us to discuss your needs. Construction
Nylon, the world's first totally synthetic textile fiber, was invented by DuPont in 1938. Because of a shortage of natural ropes during WWII, DuPont created the first nylon rope. The structure of nylon makes it easy to create very long continuous fibers of consistent quality, something that can not be done with natural fiber ropes. Since that time, more research has gone into ropes concentrating on new construction techniques and materials.
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Modern rescue rope is made of a kernmantel design. Kernmantel rope is formed of fibers that are twisted together to create a very strong core ('kern'). It is covered by a woven sheath ('mantle') that protects and strengthens the rope.
Rope is constructed as static or dynamic depending on the core design. A dynamic rope has the ability to stretch and absorb energy which is vital in protecting a climber during a fall. Static rescue rope has different properties than climbing rope. It must have very little stretch in order to give the best control. This is also import when lifting since the rope does not have to be tensioned before lifting the load. Do not use dynamic climbing rope in rope rescue operations. Modern rope is made of many different polymers including nylon, polyester, polypropylene, polyethylene, Kevlar, and spectra. Natural fiber rope should never be used for rope rescue operations. All modern rescue equipment, including carabineers and figure 8s, are designed for use with kernmantel rope. When used with natural fiber rope, the results are unpredictable and can lead to injury and death. Modern polymer rope is very sensitive to heat. When heated, polymers will first become soft, then melt, and finally burn. Each type of polymer has a different softening, melting, and burning temperature. It is very important that these numbers are known for each type of rope used. Polymers are also very sensitive to acids, alkalis, and organic solvents. To prevent weakening and shortened life spans, they must be protected from chemicals. Nylon is the main fiber used in modern rope construction. It is very strong, resistant to abrasion, and has the ability to absorb shock forces that many other fibers cannot. Nylon rope is very sensitive to acids but resistant to alkalis. Unfortunately, when nylon rope is wet, it will lose approximately 10% to 15% of its strength. It will also absorb up to 7% water. It is stable up to 100 degrees celsius and starts to melt at 215 degrees celsius. Polyester is also very strong and has excellent abrasion resistance. It has a number of advantages over nylon including less than 1% water absorption and only a 2% loss of strength when wet. It also has better resistance to UV light. It is very resistant to acids but sensitive to alkalis. Polyester has very low energy absorption qualities and should not be used in a dynamic environment. It is stable up to 110 degrees celsius and starts to melt at 254 degrees celsius. Modern rescue ropes typically are made with a polyester sheath over a nylon core. Polypropylene and polyethylene are commonly used in water rescue ropes since they float. They are very sensitive to UV light and have very low abrasion resistance. They should never be used in climbing systems. Kevlar is very resistant to high temperatures and is extremely strong. It can withstand temperatures up to 427 degrees celsius and has seven times the strength of steel. Unfortunately, it has low abrasion resistance. It can not absorb tension and breaks easily if bent tightly. It is not recommended for use in rescue ropes. Spectra (HMPE Polyethylene) is another modern high performance fiber similar to Kevlar. It has ten times the strength of steel. Unfortunately, its extremely low melting point, 66 degrees celsius, makes its use in rappel ropes very dangerous. It is not recommended for rappelling ropes. Strength
Modern ropes are very strong for their size and weight, but it is import to pick one strong enough for its intended use. A safe working load for ropes is defined as 1/10th of its breaking strength. For rescue work, this drops to 1/15th of its breaking strength. For example, a rope with a breaking strength of 34 kN (7600 lbs) can safely be used with a load of 3.4 kN (760lbs) and for rescue work 2.2 kN (484 lbs). A rope with a breaking strength of 44 kN (9900 lbs) can safely be used with a load of 4.4 kN (990 lbs) and for rescue work 2.9 kN (638 lbs).
Most rope failures are caused by abrasion. A rope with a higher resistance to abrasion keeps its strength longer. Edge protectors will also increase the safety and the life of the rope. The stiffer a rope is, the better its abrasion resistance. In testing, static ropes have better abrasion characteristics than dynamic ropes.
The age of a rope can also affect its strength. A heavily used rope can lose from 3% to 5% of its strength each year.
New Rope Care
Before cutting a rope, the cut location should be prepared. The area should have heat shrink tubing applied, but if this is not available, tape can be used. The rope should then be cut with a thermal cutter. Thermal cutters use heat to cut and seal the rope at the same time. Using heat to cut a rope melts the ends together and prevents the rope from unraveling. Do not use a normal knife to cut climbing rope. {MOSImage} Before its first use, a new rope should be inspected to insure there is no damage and the ends are properly sealed. After the inspection, it should be marked with its length, service date, and any other important information. When writing directly on a rope, only alcohol based pens should be used to prevent damage to the rope. A log book entry should also be made at this time to record the future use of the rope. New rope is naturally slightly slippery because of the manufacturing process. This coating protects the rope and keeps it soft. Once this coating is removed, the rope will start to dry out and slowly age shortening its life. To delay this process, it is not recommended to wash, rinse, or soak a new rope before being used for the first time.
During its initial use, the fibers of the core and the sheath will become fixed. At this point, it is beneficial to wash the rope for the first time. This causes the rope to shrink, usually 10% for nylon, to its final working length. This shrinking also has the benefit of making it more difficult for dirt to penetrate into the core of the rope.
A new rope should first be broken in through a few rappels, washed, dried, and inspected before being used for rescue work.
Inspection
There is no test than can 100% determine the condition of a rope. The decision to replace a rope must be based on experience. Inspections must be done visually and also by feeling for damage.
After each use, a rope should be inspected to make sure there are no cuts, broken fibers, soft or hard spots, glazed surfaces, discolorations, or variations in diameter. If any of these things are found, the rope should be replaced. If the rope has absorbed any shock loads from falls, the rope must also be replaced for safety reasons.
Ropes should be replaced after no more than five years of occasional use and one to two years of active use. The maximum life of a synthetic rope is ten years.
A log book should be kept for each rope. The book should have an entry for each use of the rope recording the type of use and the condition of the rope.
If there is any doubt about the condition of the rope, it should be replaced. The old rope should be destroyed to prevent it from being used by accident.
Washing {MOSImage} Ropes should be regularly washed, especially when used in dirty areas. Dirt is an abrasive and will cause damage to the rope if not removed. To wash a rope, a special washer made for cleaning rope should be used. These washers attach to a hose and use a fine spray to remove the dirt. Washers, such as the Bokat Rope Washer, clamp over a rope allowing water to clean all sides. In addition to the water spray, the inside is lined with soft bristles that gently scrub the rope as it is pulled through the washer. It is important that the washer is designed properly and does not force the dirt into the rope.
After most of the dirt is washed off, it should be soaked in a gentle detergent made for cleaning synthetics. Cleansers and bleach can cause damage and should never be used for cleaning ropes. After the rope has been soaked, another pass should be made through the scrubber to remove the detergent from the rope. The rope should finally be soaked in water mixed with a small amount of fabric softener. This works as a lubricant extending the life of the rope. The rope should then be air dried in a cool, shaded area. Ropes should never be dried in the direct sunlight as UV damage can occur.
Never wash rope in water hotter than 80 degrees celsius.
Storage
Ropes should be stored in a cool, dry, area. This area should be free of oil, acids, batteries, or other chemicals that can cause damage to the ropes. Even if the rope does not come into direct contact with these chemicals, their fumes can still cause damage to the rope.
It is recommended to store rope in designated rope bags. Ropes should be placed into rope bags in a random pattern. Rope bags need to be big enough to avoid the need to tightly pack the rope into the bag. It should be relatively lose inside. Packing the rope tightly into a bag turns it into a giant knot causing stress on the rope shortening its life. Ropes stored in bags should be removed regularly, at least once every two months, and repacked to reposition the loops and twists.
An alternative way to store a rope is coiling the rope ‘mountaineering-style’ and hanging it from a post. This allows air to circulate around the rope and prevents mold and mildew. Posts the rope is hung on should be made of plastic. Wood and metal posts can trap moisture allowing mold contamination of the rope.
Creating rope chains using overhand knots is not recommended for long term storage. Rope chains put stress on the rope and can shorten its working life.
Ropes should not be stored in direct contact with concrete. Concrete is acidic and ropes stored in contact with it can become contaminated and weakened.
Additional Recommendations It is recommended that a rescue team standardize on one type, size, and preferably brand, of rope. In an emergency or high stress situation, the type of rope and its properties must be known immediately. Mixing sizes and types makes this difficult task almost impossible. If rope types must be mixed, different colors should be standardized on to make the type of rope and length immediately obvious. For rescue work 11mm or 12.5mm rope is recommended.
Ropes manufactured in America tend to have heavier sheaths than European ropes. This gives them slightly better abrasion resistance. Undyed white ropes tend to stiffen with use. Ropes with undyed white stripes show uneven changes in handling over time. Dyed fiber sheaths are preshrunk and maintain their handling characteristics better. It is recommended to periodically reverse the ends of a rope to extend the rope’s life. This distributes the wear more evenly.
Avoid stepping on a rope. Stepping on a rope will force dirt into the core of the rope leading to the possibility of internal abrasion. This is very dangerous and can not easily be detected. During use, avoid letting the rope touch the ground. If possible, put a tarp under the rope to prevent the lose end from directly contacting the ground. This will keep dirt off of it and extend the life of the rope. Copyright 2005, Sea Air Thai Co., Ltd.
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Rope Rescue 
