Its about the stretch...

2 types of stretch. 

1.Constructional

2.Material. 

1. Constructional stretch is about aligning the braids of a rope in a

straight line with load. 

2. Material (elastic) stretch is inherent in the solid material properties.

Braided line has constructional stretch, unless you pre-stretch it

at elevated temperatures which is exactly what Dynex Dux is. For

low loads (as a percentage of breaking strength) Dynex Dux has

almost no constructional stretch.  

Below is a chart showing exactly why you can use Dynex Dux for

standing rigging. 

The elastic stretch of Dynex Dux is similar to wire rope.  

Breaking Strengths and Colligo Marine recommended Safe Working Loads of Dynex Dux:

                 Breaking Strength         SWL

7 mm                  15,000 lbs-f          3000 lbs-f

9 mm                  24,000 lbs-f          4800 lbs-f

11 mm                36,800 lbs-f           7360 lbs-f

13 mm                49,000 lbs-f           9800 lbs-f
 

We recommend sizing line at 20% of breaking strength.   This will also mean that creep is almost

non-existent.  Below is a chart of creep approximations with load for various line diameters:

The important thing to remember here is that creep has an exponential relationship to stress (Force per unit area).  Keep the loads low relative to breaking strength and the creep goes way down to levels we can manage.

Example: Flying Tiger One Design sailboats have pre-tensioned shrouds to about 1200 lbs-f tension on a 1/4, 1x19 wire.  You could use 7 mm dux and deal with less than 1/2 inch creep per year or go with 9 mm and have about .06 inches per year of creep on a Flying Tiger!  Not to mention reducing standing rigging weight by at least 75% with most of that aloft and affecting righting moment, sailing more upright and lighter means more speed!

Keep in mind the above is calculated using creep data from Hampidjan on Dynex Dux but using a derived creep relationship equation on SK-75.  Dynex Dux will actually have less creep than shown above, we just don't know how much less. We are working on a relationship equation for Dynex Dux but the problem with creep (deformation over time) is that it takes time.

Breaking Strength Comparison to wire rope and rod rigging.

Weight Comparisons

**Wire rope Specifications are from Loos and Co.

For more information, download our brochure or send us an

email or call us at

480.703.3675.