Okey dokey, you asked for it:
from 'gashmore' at the Toss discussion list:
"I have finally started some quantitative testing on a sample of 9mm Dynex Dux. I have not completed the creep test but the dynamic stretch figures are in. I am getting a page together on my web site with all the gory details but I thought I would report the preliminary results here.
The purpose of my examination is to get some numbers to compare to 1x19 wire. I tried to follow the Cordage Institute's procedures but as the sample had only 28" clear of undisturbed rope I used an electronic positioning sensor called an LVDT capable of detecting .00005" movement. By adjusting for the specific weight of the rope I had estimated from Strong Ropes figure of .00055 in/in/1000lb for 11mm that 9mm should have an elongation of .00084, about equivalent to 5/16" 1x19. The tested figure (average of 20 pulls after 50 cycles to 20% of MBL was slightly better at .00078 in/in/10000lb. I have to attribute this to the possibility that the fiber is slightly more in line with the load in the smaller diameters.
One major difference I found was the hysteresis or rate of recovery after the load is removed. 1x19 will recover 90% or more of the elongation immediately and the rest over just a few seconds. Relaxed from 5,000lb to 2,000lb Dux only recovers about 60% immediately and another 30% over the next half hour to 45 minutes. It took almost 12 hours to recover all the elongation. What I think this means is that you shouldn't try to tune a rig immediately after it has been loaded heavily. If you dial in the tension before the shroud has fully recovered it will be to tight a few hours later. Also I think it is possible that the leeward shrouds might seem slightly slack immediately after a tack. I will have to examine this more closely.
The other interesting fact is the almost complete lack of torsional deformation. 1x19 will try to rotate as the lay straightens but braid remains in line. I don't think I would do away with cotter pins in the turn buckle though. :-)
Creep test begins next week and will take a couple of months."
...continued, the creep test from 'gashmore'....
"Well, after almost 2 months at 2,000 lb load at 80F on my 9mm sample I have almost nothing to report. .01" difference in the 24" gauge length. I just boosted it to 4,000 lb and will keep it there for another month but so far this is about as exciting as watching paint dry.
A further note on the slow recovery. I have received a couple of emails asking if the line stretches more if it is loaded again before it recovers. The answer is no. Loading fully recovered line from 2000 lb to 5000 lb the stress/strain curve is basically a straight line. Overlaying the curve from loading an unrecovered line there is a little variation as the load first increases until the slack is taken up. From that point on both are essentially equal."
