

Did you know...
...that the type of rope that Greenlee recommends and sells for cable pulling is not a good configuration for high-force pulling? While the D/N (polyester jacket/nylon core) configuration does have a higher minimum tensile strength than D/D due to the nylon core, nylon stretches considerably more than polyester. This is undesirable as the core fibers are designed to be the strength of the rope and the jacket fibers provide abrasion resistance. The problem is, once the rope gets loaded to the point that the nylon begins to elongate, the polyester jacket begins to take the load. You want to use a rope that has a jacket with the same or greater stretchiness than the core. That way, the load stays on the fibers that are designed to handle it!
... that nylon is stronger than polyester? The problem; it can elongate - stretch - up to 30% at a point of break. Polyester, on the other hand, typically elongates only 15% - 20%. Remember: in high-force pulling operations, elongation/stretch = BAD.
Want to see a document about choosing the right pulling rope? (Oddly enough, it's called "Choosing the Right Pulling Rope")
The information presented here is a partial reproduction of the Polyester Double Braid Datasheet #DD Rev 008
D/D Polyester Double Braid provides an excellent combination of high strength, low stretch excellent weathering and easy handling. Of all the popular fibers polyester has the best weathering characteristics and the best wet abrasion resistance. Polyester Double Braid comes standard with an overlay marine finish and is available on special order with a spliceable polyurethane finish in clear or any of six colors.
Features
Low stretch
High strength
Soft hand
Torque free
Excellent wet strength
Meets MIL-DTL-24677B
|
Nominal Diameter |
Circumference |
Weight (lbs/100') |
Min Tensile Strength |
|
9/16" |
1¾" |
11.1# |
10,750# |
|
5/8" |
2" |
13.1# |
12,300# |
|
3/4" |
2¼" |
18.8# |
17,400# |
|
7/8" |
2¾" |
25.6# |
24,000# |
|
1" |
3" |
33.5# |
31,200# |
|
1¼" |
3¾" |
52.3# |
48,100# |
Tensile Strengths are determined in accordance with Cordage Institute 1500, Test Methods for Fiber Rope.
Weights are calculated at linear density under standard preload (200d2) plus 5%
Other types of rope are also available from Cortland/Puget Sound Rope that will out-perform double-braided polyester in many ways, although they tend to be considerably more expensive:
Vectran® 12 Strand braided rope has good temperature, abrasion, tension, and flex fatigue resistance as well as negligible creep. Vectran® 12 Strand Datasheet V3/V33 Rev 003 PDF Document, 43.2 KB
Spectra® 12 Strand provides very high strength, low stretch and excellent abrasion resistance in a single braid construction. Pound for pound, it is over 3 times as strong as polyester and has less than one half the elongation. Spectra® 12 Strand Datasheet #S3/S33 Rev 008 PDF Document, 71 KB
Plasma® 12 Strand is the highest strength synthetic rope available. Plasma® 12 Strand Datasheet #T3/T33 Rev 011 PDF Document, 71.5 KB
Vectran® 12 x 12, Plasma® 12 x 12, Spectra® 12 x 12: The 12 x 12 Construction is designed specifically for high modulus, high strength fibers such as Spectra®, Plasma® enhanced Spectra®, BOB® , and Vectran® . This patented construction addresses the most critical properties of the fibers to provide a very high strength translation efficiency for larger ropes. This design allows for long lay lengths, making the rope more flexible for bending applications and rope that is easy to inspect and can be quickly spliced using standard 12 strand splicing techniques.
Rope