Different types of Rope used in boating

Different types of  Rope

The seaman’s life is not always as exciting as novels and adventure films would have us believe. And yet, the seaman’s tasks are vitally important to navigation. For water rescue purposes, “seamanship” means the knowledge involved in handling and storing ropes, tying knots and performing practical tasks such as mooring and anchoring.

On a boat, we rarely use the word “rope” but rather “lines” to describe all of the ropes and cords used in navigation.  Moreover, each line has a specific name, such as the painter, halyard or fender line. Lines can be stranded or braided.  A stranded cord consists of fibers twisted in one direction to form a rope yarn which, when twisted again in the opposite direction, creates the strand.  Three strands are then twisted again in the same direction as the fibers to create the final rope.  This alternating torsion causes the line to tighten on itself and thus prevents it from unraveling.  A braided line comprises a core of braided or stranded threads covered with a sheath.  The center or core of the line gives it strength, and the sheath performs more of a protective and aesthetic function.

Figure 2.15 — Stranded Rope

Figure 2.16 — Braided Rope

Stranded Rope	Braided Rope
Stiff	Flexible and smooth (slips through pulley easily)
Less resistant if worn	Less resistant if core is damaged
Becomes rigid and shrinks if submerged for long	Remains flexible
Defects are readily apparent	Difficult to detect defects
Knots hold firmly	Some knots easily come untied

Four materials are commonly used to manufacture rope: nylon, manilla, polypropylene and polyester. Each of these materials has its advantages and disadvantages, and therefore suits a specific use.

	Polypropylene	Nylon	Polyester	Manilla
Cost	Low	Med. to High	high	Low
Strength	Satisfactory	Excellent	Good	Poor
Elasticity	Good	Excellent	None	None
Buoyancy	Good	None	None	None
Weight	Heavy	Average	Light	Average
Abrasion resistance	Poor	Good	Excellent	Satisfactory
Rot resistance	Excellent	Excellent	Excellent	Poor
Sun resistance	Satisfactory	Good	Good	Satisfactory
Shock resistance	Satisfactory	Excellent	Good	Poor
Standard uses	Painter linesFloating linesFender lines	TowingMooringAnchor lines	Painter linesHalyard	Painter linesFender line
Main features	Buoyancy Strength	Elasticity	Strength	(strength reduced on contact with water)