GLOSSARY OF ROPE TERMINOLOGY

Abaca
A natural rope fiber produced from the trunk of the tropical plant Musa testilis (abaca tree), which is a member of the banana plant family. Grown almost exclusively in the Philippines. The fibre is processed to become Manila rope.  Abaca is the strongest of all the natural rope fibers. Also grown in Central America, Sumatara and Borneo.

Abrasion
The damage that occurs when a rope is rubbed against a rough surface or edge.

Abrasion Resistance
The degree to which a fiber or rope is able to withstand surface wear and rubbing due to motion against other fibers (internal abrasion) or an external surface (external abrasion).

Acceleration Stress
Additional stress placed on rope due to increasing the velocity of load.

After Spring Line
Leads aft from the ship and keeps the ship from moving forward.

Alaskan King Crab Line
A specialty rope of various materials used in King Crab fishing. Characterized by its firmness of lay.

Anchor Line
Rope with a thimble spliced into one end for attaching an anchor.

Aramid Fiber
A man made high modulus fiber of polyphenyleneterepthalamide (PPTA).

Average Breaking Strength
The mean of destructive break test data.

Awning Cord
Small diameter cord used for many utility purposes; most commonly a cotton braid with stretch resistant fiber core.

Back Splice
A method to finish off the end of a rope by burying the end back into the center for braids or splicing the strands back into the body of a twisted rope.

Backstay
A stay to keep a mast from leaning forward. Can either be fixed or running. Running backstays are rigged on both sides of the boat and are set up or slacked off depending on the point of sailing.

Bail-Out Rope
A 7.5-9.5mm rope designed for emergency escape from a threatening situation. Also referred to as personal escape ropes or escape lines.

Baler Twine
Single ply twine, usually of sisal or polypropylene, used by farmers for tying bales of hay.

Bend
A knot used to join two ends or two separate ropes together.

Bight
A U shaped bend formed when the rope is doubled back, but does not cross.

Binder Twine
A twine used in binding and for other utility purposes; most commonly of natural fibers - jute, sisal, etc...

Bitt
A post or pair of posts with or without a crossbar (norman) for securing heavy lines; usually in the bow of a boat.

Bitter End
In tying knots or splicing, refers to the end opposite the end in use. Used to give mechanical advantage when lifting or pulling heavy weights.

Blend
A combination of rope mix of different synthetic fibers to form one rope.

Block
A pulley; there are many kinds - single, double, snatch, cheek, etc... The rope runs over the sheave set between the two shells (cheeks) of the block. Also a die of steel in the form of a tube of a desired diameter into which yarns are fed to be formed into a strand of rope.

Block Creel
A rope construction method where the rope is fabricated without splicing or knotting of any of its components

Blown Filament
Monofilament polypropylene into which is blown a special gas during extrusion. This produces a lighter, less expensive and less strong rope, size for size, than standard polypropylene; also called foamed filament.

Bollard
A round heavy post for securing lines; sometimes on a boat but usually on a pier.

Bonding
A liquid coating that increases abrasion resistance and prevents water absorption.

Bow Head Line
Runs through the bullnose and controls aft movement and assists the breast lines.

Braid
A rope constructed from an inner hollow single braided rope (core) which has another hollow single braided rope constructed around its exterior (skin). Both the core and skin share the load on the rope but not necessarily in equal amounts. Also referred to as Double Braid, Marine Braid, and Yacht Braid.