SELECTING LIFESAVING ROPE
TRAINING NOTEBOOK
In recent years, rope used by the fire service has come under increased scrutiny. The result has been more stringent rope specifications, especially for life safety ropes. It is no longer acceptable for fire departments to buy manila rope at the local hardware store, put it in a compartment on a piece of apparatus, and forget about it until it is needed months or years later.
In June 1980, two City of New York (NY) firefighters fell to their deaths when a rescue line broke. In response, the International Association of Fire Fighters (IAFF) initiated a study on rope and associated equipment. One result of this study was the publication of “Line to Safety: A Fire Fighter’s Guide to Rescue Rope and Associated Equipment,” an easy-to-understand guide to the various types, characteristics, strength requirements, construction, and applications of rescue rope for fire service use. A short time later, at the request of the fire service, die National Fire Protection Association (NFPA) began work on a rope standard.
NFPA 1983, Standard on Fire Service l ife Safety Rope, Harnesses, and Hardware, was issued in 1985. Two other NFPA standards mention rope. Section 5-5 of NFPA 1500, Standard on Fire Department Occupational Safety and Health Program, references NFPA 1983, stating, “All life safety ropes, harnesses, and hardware used by fire departments shall meet the requirements of NFPA 1983, Standard on Fire Service Life Safety Rope, Harnesses, and Hardware.” It also stipulates that life safety rope not be used for any other purpose (such as for a tow line) and that it be destroyed after being used to make a rescue. ‘ITiis requirement may seem extreme; however, rescues usually are performed under extreme conditions, and there is no safe way to determine whether the rope has been damaged. Therefore, it is safest to destroy it so it cannot be used again as a life safety rope. Rope that is used as a life safety line for training only may be reused, provided it is inspected before and after each use in accordance with the manufacturer’s instructions and a record is kept of its use.
Sections 3-9 and 4-9 of the 1987 edition of NFPA 1001, Standard on Fire Fighter Professional Qualifications, deal with rope and contain performance objectives for identifying construction features and appropriate uses of different kinds of rope. Also listed are several knots and terms firefighters need to know before working w ith rope.
MANILA ROPE
For years, manila had been the standard fiber used in rope construction, and manila rope the standard against which other rope was measured. For years, any rope designed for critical or life safety use was required to be at least equal to a number one grade manila.
Manila rope is made from the fibers from the stem of the agave plant, which originally came from the Philippines (hence the name manila). The individual fibers (each only about seven feet in length) are twisted together to form yarns, yarns are twisted together to form strands, and strands are twisted together to form the rope. The inner fibers of the plant are the strongest and are used in making number one grade and better rope, while the weaker, outer fibers are used for lower-grade rope.
Studies done on manila rope have found that manila can lose 10 percent of its strength per year, even when properly stored. When kept in a compartment on an apparatus, it can lose up to 50 percent of its strength per year. Lab tests also have shown that manila starts to degrade at temperatures above 200°F. Nylon and polyester, on the other hand, show little effect until temperatures reach the 300-to-400°F range. The synthetic ropes also can absorb six to 10 times greater dynamic loads than manila. For these reasons and others, manila rope no longer is considered acceptable as a life safety line; ropes made of synthetic fibers must be used instead.
SYNTHETIC ROPE
Many different types of synthetic fiber rope are on the market, but not all of them are suitable for use as life safety rope. Nylon and polyester (Dacron™) are two fibers used for life safety rope. Rope of either nylon or polyester can be nearly twice as strong as manila rope of the same size. Polyethylene and polypropylene rope have the ability to float, which makes them excellent for water rescue, but they have other properties (such as low temperature resistance) that make them unsuitable for general rescue work.
Nylon and polyester both have a strength/weight ratio far superior to that of manila. The NFPA requires a one-person rope to have a minimum breaking strength of 4,500 pounds and a two-person rope to have a minimum breaking strength of 9,000 pounds. It would take a new Winch manila rope but only a /Winch nylon rope to meet this requirement.
No rope should be stressed to a point anywhere near its breaking strength. For many years, safety factors of from seven to 10 were considered sufficient. Studies have indicated. however, that these are not sufficient, and NFPA 1983 now mandates a safety factor of 15. When this factor is applied to a one-person rope, the working strength becomes 300 pounds. This may seem like a big reduction, but remember: Knots will be tied in the rope, and the rope may pass over sharp corners, may be wet, and may pass through friction devices such as figure-eight carabiners—all of which will weaken it. A safety factor of 15 is necessary to ensure that the rope can absorb these assaults and still maintain enough strength so as not to come close to its breaking strength. Along with breaking and working strengths, the standard sets limits on weight and size, keeping the maximum size down to eliminate the possibility that a rope that is too heavy and unwieldy will be used. Manila cannot meet these requirements.
ROPE CONSTRUCTION
Several types of rope construction are used. The standard three-strand twisted or laid rope construction method is used for manila rope, although synthetic ropes also are available in this type of construction. If the strands are twisted together tightly, the rope is said to be ‘hard laid” and is more resistant to abrasion; however, it is not as strong as rope that is soft laid or whose strands have been tw isted together loosely. A laid rope designed for use in the fire service must strike a balance between the strength of a soft-laid rope and the abrasion resistance of a hard-laid rope. Laid ropes also have a tendency to kink or hockle, and they spin the loads suspended from them, making them less desirable for rescue work than some other kinds of rope.
Plaited or braided rope is made by weaving the strands together (usually in pairs) in a way similar to that used to braid hair into “pigtails.” “Double braid” or “braid-on-braid” is made by braiding an inner core and covering it with a braided outer sheath. Plaited and double-braided ropes generally have lower abrasion resistance than laid ropes or kernmantle ropes and are not as desirable for use as fire service life safety ropes.
The rope that is becoming the most common in fire service work is kernmantle. Kernmantle rope is constructed of an inner core or kern made up of fibers or filaments running through the whole length of the rope. These filaments are bundled together and wound or spiraled into cords, which are covered by a woven outer sheath or mantle, providing protection against abrasion and other damage. It is very hard to damage the inner core of a kernmantle rope without some kind of damage showing to the outer sheath.
Two kinds of kernmantle rope are available. Dynamic kernmantle has a high degree of elongation under load and is used primarily for climbing, where its load-absorbing qualities are needed to break falls. Static or rescue kernmantle is used where the rope normally supports the load, such as in rappelling. It has a much lower degree of elongation than dynamic kernmantle has. In other words, it does not stretch or bounce as much as dynamic kernmantle; thus, it is preferable for use as fire department life safety rope.
Before purchasing rope or institut1 ing any standard operating procedure on life safety rope, obtain copies of NFPA 1983 and NFPA 1500 and study them. Any rope purchased for rescue work must meet the requirements in these two standards.
