Glossary of terms

Rope Terminology Glossary

Welcome to our glossary of rope terminology. We hope the definition you are looking for is included here.

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).

Anchoring line

Rope (or assembly of a rope with chains and/or steel cables) for the anchoring of a vessel in a bay or in open waters.

Braided rope / Cover

Rope in which a number of strands are braided to form a core, and around which are plaited further strands to form a sheath.

Breaking strength

Maximum force applied in straight tension to a cordage article which causes it to rupture.

Cyclic loading

Variable loading in which the applied load varies cyclically. In testing the lower and upper loads and the period are usually constant.


Increase in length produced by tensile stress.

Fiber types

PP – Polypropylene
PES – Polyester
UHMPE – Ultra High modulus polyethylene
PE – Polyethylene
PA – Polyamide


Textile fibre of very great length considered as continuous.

Floating rope

Rope where the specific gravity is lower than 1.0 for inland navigation or 1.04 for sea going vessels.


Loop formed into the rope as the result of excess turn being concentrated in a specific section within the length.

Lay length

Length of one complete turn a strand, or a strand in a rope, measured in a straight line parallel to the axis of the strand or rope.

Linear density/linear mass

Mass per unit length of linear material. The mass per unit length of fibre, yarn or rope is usually expressed in units of tex.

Measured diameter

Diameter of the circle circumscribed about the cross section of the rope. Should be measured under a given reference tension.

Messenger (rope)

Light rope used to transfer the end of a larger rope across a gap, for example, from ship to shore.

Minimun Breaking load (MBL)

The load required to break a rope in tension; also caled Min. Breaking Force (MBF).

Nominal diameter

Reference value for a given product.

Plaited rope / Core

Rope formed by braiding or plaiting the strands together as opposed to twisting them.

Realization factor

Actor used in the calculation of the breaking strength of ropes for which a suitable testing machine is not available. It is used in conjunction with the force of the component yarns, and varies with the construction, size, and material from which the rope is made.

Ringtail or grommet

Endless rope sling.

1) as a result of joining the ends of one rope by short/end-to-end-splice or
2) made as a grommet or
3) as a result of joining the ends of one rope by a long splice (see 6.1.13) or
4) as a result of joining the ends by means of a metal tube into which the ends are pressed


Product obtained when three or more strands are twisted or braided or set in a parallel construction to provide a composite cordage article larger than 4 mm in diameter.


Winding, under tension, a smaller item of cordage onto a main member in spiral formation such that each turn touches the two adjacent turns on either side of it.

Single sling

Length of rope formed into a sling by having an eye spliced at each end of it.


Method of joining a rope to itself or to another rope, or of producing an eye in its end or ends by interweaving the strands to give a positive and secure join which retains a high proportion of the original strength of the rope.


Product obtained by twisting together two or more yarns prior to laying into a rope.

Tensile stress

Stress applied to stretch an article, calculated by dividing the applied force by the original cross-sectional area.

Tex system

System of expressing the linear mass of fibres and yarns or other linear textile materials. The basic unit is the tex, which is the mass in grams of one kilometre of the product. Tex is a recognized SI unit. Tex = 1 gram per kilometre.


Rigid, shaped component for insertion into an eye for the purpose of protecting the eye from contact.


Thimbled eye

Eye spliced into a rope which contains a thimble within it.

Tuck (process)

In splicing, the process of passing a strand over and under other strands in the rope.

Twist: „S“ twist

„S“ lay is a left hand lay. The product has S twist if, when it is held in a vertical position, the spirals or helices formed by the fibres or filaments around its axis incline in the same direction as the central portion of the letter S.


Twist: „Z“ twist

„Z“ lay is a right hand lay. The product has Z twist if, when it is held in a vertical position, the spirals or helices formed by the fibres or filaments around its axis incline in the same direction as the central portion of the letter Z.


Twisted or laid rope

The rope in which 3 or more strands are twisted around the central axis.

Working load limit (WLL)

Maximum mass which a sling or sling assembly is permitted to lift in use.


Twisted entity composed of filaments, staple fibres, or fibrillated film held together by twist.