CHOOSING THE CORRECT MARINE ROPE

What marine rope is right for you

CHOOSING THE CORRECT MARINE ROPE

Material:

1. Dyneema (HMPE) has the highest strength of any rope and is traditionally used as a braided core, covered with diamond double braid polyester for easy handling. Dyneema has a significant price premium and is recommended for halyards, replacing traditional stainless steel wire.
2.Nylon (polyamide) has the highest elasticity and strength compared to polyester and polypropylene, high UV rating, excellent abrasion, rot, mildew, marine growth and chemical resistance and is recommended by Whitsunday Discount Marine for dock-lines and mooring/anchor lines. It has high shock absorbance properties.
Nylon rope does not float.
3. Polyester has 25% less elasticity than nylon rope, high UV rating, excellent abrasion, rot, mildew and chemical resistance and is recommended by Whitsunday Discount Marine for rigging. Polyester rope does not float.
4. Sllver rope (polypropylene) floats on water. The downside to polypropylene is it degrades over time from UV rays and it is not as elastic as Nylon. Silver rope is only recommended to be used for transient moorings and not where permanent dock-lines are required.


Weave:

1. Twisted Rope or Laid Rope is a type of rope consists of several strands of fibre twisted together. Each strand is also twisted from smaller strands. The strength of the rope will be determined by the number of strands and also the type of fibre. Twisted rope can further be classified as follows:
  • Three-strand:  this line consists of three strands. The most popular stranded rope and is easy to splice.
  • Four Strand: this line is made from four instead of the usual three strands.
  • Multiple strands or cable laid line: the line comprises of more than four strands making it extremely strong.
2. Braided Lines are highly elastic, have more strength than three strand ropes and are attractive and long wearing. They are either single or double braided for greater strength:
  • Solid braid: This line is very strong and won’t fray after cutting. Very hard to splice.
  • Diamond Braid – no core: this is the simplest type of braided line. Since it doesn’t have a core, splicing the ropes is relatively easy.
  • Diamond Braid - with core: this line comes with a solid core thus making it quite strong. Splicing is harder than with diamond braid-no core. This is the strongest and most reliable of all braided ropes. This type of double braided rope is used exclusively by Whitsunday Discount Marine.

Whitsunday Discount Marine recommends nylon (polyamide) rope in preference to polypropylene and polyester for mooring, docking and anchoring.

The majority of rope sold in the North American leisure marine market is nylon. The majority of rope sold in the European and Australian leisure marine market is polyester.

The below table illustrates the most popular rope's relative strength.

COMPARISON OF BREAKING AND WORKING LOADS OF ROPES

  Braided &      3 Strand Dyneema Core Nylon Polyester Polypropylene (Silver)
Rope Size
Breaking Load
Kg
Working Load
Kg
Breaking Load
Kg
Working Load
Kg
Breaking Load
Kg
Working Load
Kg
Breaking Load
Kg
Working Load
Kg
8mm 2,200 610 1,215 338 918 255 630 175
10mm 3,400 950 1,872 520 1,431 398 981 273
12mm 7,200 2,000 2,700 750 2,043 568 1,386 385
14mm     3,690 1,025 2,862 795 1,881 523
16mm     4,770 1,325 3,690 1,025 2,520 700
18mm     6,030 1,675 4,635 1,288 3,150 875
20mm     7,470 2,075 5,760 1,600 3,870 1,075