GLOSSARY OF ROPE TERMINOLOGY

Cork Line
A floating line, braided or twisted, made of regular or foamed polypropylene. May have nylon or polyester protective covering for greater abrasion resistance; also called float line.

Crab Lay
An exceptionally tight twist given to rope used in the crab fishing industry. The hard lay is necessary to prevent hockling.

Crab Trap Line
A small diameter cord used for lifting crab traps. May be twisted or braided. Cotton is the most common though various fibers may be used.

Cracker
Manila rope spliced to the end of a wire rope drilling line.

Creep
Deformation (most often in the form of gradual elongation) which is exhibited by cordage that has been subject to a load over a continuous length of time. The rope may or may not return to its original state after the removal of the load. Delayed deformation may be recoverable or non-recoverable following removal of the applied load. Also referred to delayed deformation. The "taffy effect" - a slow flow of synthetic material such as polypropylene under high temperature or great pressure

Crotch
The point at which two legs come together as an eye splice

Crimp
To bend, kink, curl or wave a fiber to give it more loft.

Crown Splice
Braiding or splicing the end of a rope into itself to prevent fraying and unraveling. An alternative to whipping.

Curtain Cord
Small diameter cord used for drapery, traverse cords, etc. Most commonly made of braided cotton with various fiber core.

Dacron®
DuPont trademark for polyester.

Degradation
The loss of desirable physical properties by a textile material due to some process of physical/chemical phenomenon.

Delayed Deformation
Deformation (often in the form of gradual elongation) which is exhibited by cordage that has been subject to a load over a continuous length of time. The rope may or may not return to its original state after the removal of the load. Delayed deformation may be recoverable or non-recoverable following removal of the applied load. Also referred to as creep.

Design Factor
Defined by the Cordage Institute as a factor that is used to calculate the recommended working load by dividing the minimum breaking strength of the rope by the design factor. The design factor should be selected only after a professional assessment of risk.

Diamond Braid
Cordage construction with 8, 12 or 16 strands of fibers braided under and over each other in a circular direction. The center of the rope may be hollow, such as in a hollow braid, allowing for easy splicing; or it may have a center rope of parallel fibers. It is generally stronger than solid braid, but not as strong as twisted or braid on braid cordage. A cylindrical braid which is formed by rotating half the yarn strands in one direction on the braider, while the other half rotate in the opposite direction. These cords may be hollow, or they may have a center core of parallel fibers. Also referred to as Plain Braid.

Dielectric
A non-conductor or poor conductor of electricity. Polypropylene has excellent dielectric properties.

Double Braid
Cordage construction with a jacket braided over a braided rope core; two ropes in one. Both the core and the skin share the load on the rope but not necessarily in equal amounts. A very strong and flexible rope that doesn't hockle, kink or rotate under a load. It is spliceable; also called braid on braid, double spliceable braid and yacht braid and marine braid.

Downhaul
In sailing, tackle lifted to the boom gooseneck to keep a proper strain on the forward edge of the sail.

Drapery Cord
Braided cord of small diameter made usually of cotton with various types of fiber core, such as fiberglass, polyester, etc. Used as draw cords, traverse cords and curtain cords.

Dress
Partially closing the knot by drawing up the knot to make sure the knot is tied correctly.

Dynamic Load
The increase in force due to dynamic loading as a result of lifting, moving or halting movement of a load. The more rapidly the action occurs, the greater the increase in force on the load will be.

Dynamic Loading
A sudden or rapid force applied to a rope caused by stopping, jerking, swinging, etc. In some cases, the force may be two, three, or even more times the normal load involved. For example, picking up a tow on a slack line or stopping a falling object, can cause a dynamic loading of a rope. Working loads do not apply under such conditions.

Dynamic Rope
High stretch ropes most often used by climbers, which are designed to elongate and therefore absorb the energy during a fall.