OCIMF_Mooring_Equipment_Guidelines_(Second_Edition)

Nylon

Rope Circ Diameter (Polyamide)

Size No. mm. (See Note 2) Polypropylene (See Note 3) Polyester

(See Note 2) (See Note 2) mm. In. tonnes tonnes tonnes

I (^24 8) 0.33 0.9 1.2 0.9
1.25 30 10 0.4 1.3 1.9 1.4
1.5 36 12 0.5 1.8 2.7 2.0
1.75^42 14 0.6 2.5 3.7 2.9
2 48 16 0.67 3.1 4.8 3.7
2.25 54 18 0.7 4.0 6. 1 4.6
2.5 80 20 0 .9 4.9 7.4 5.7
2.75 66 22 0.9 5.8 9.0 6.9
3 72 24 1.0 6.7^11 8.2
3.5 84 28 1.1 9.1^14 11
4 96 32 1.3 11 18 14
4.5^108 36 1.5^15 22 17
5 120 40 1.7 t7 27 22
5.5 t32 44 1.9 2t 32 26
6 144 48 1.9 25 38 30
6.5 156 52 2.0 28 44 35
7 168 56 2.2 32 50 40
7.5 180 80 2.5 37 57 45
8 192 64 2.7^42 65 52
9 216 72 3.0 53 81 65
10 240 80 3.3 65 99 80
11 284 98 3.7 78 119 95
12 298 96 4.0 92 139 113
Notes:
t) Spliced strength is approximately 90% of unspliced strength. Based on British Standard breaking strengths.
2) Rope size number is the nominal circumference of the rope in inches. All circumferences and diameters are
approximate, as determined by common rope industry practices.
3) We! nylon Slrength Is about 80 % of dry strength. Accordingly, the strengths of nylon prOVIded in this table
should be reduced for direct comparison with polypropylene and polyesler.

TABLE 6.2: TVPICAL STRENGTHS OF SVNTHETlC 3 STRAND AND e STRAND ROPES

(New, Dry Rope With Splices)

6.3.1.3 Polypropylene

Polypropylene rope has approxi mately [be same elast icity as polyes ter rope, but is significantly

weaker than either polyester o r nylon. Polypropylene has a low melting point and tends to fuse

under high friction. H also has poor cyclic loading characteristics. Lastly, prolonged exposure la the

sun's ultraviolet rays can cause polypropylene fibres ro disintegrate due to actinic degradation.

Polypropylene is lighter than water and can be used for floal i'ng messenger 1ine5. Otherwise. the use

of po[ypropylene for mooring i not recommended.

6.3.1.4 Polyelhylene

Polyerhylen e is sim ilar [0 polyp ropylcne in appearance, but is generally weaker and is less resistant

(0 abrasion. It has about the same elasticity as pol. propylene. Polyelhylene rope is accep[able for

floating messenger lines provided they are constructed from top quality fibres.