So, we're now very happy to be using "hi-tech" Dynema (or UHMwPE) soft shackles, as in the image at right, in several applications on board Crystal Blues. However yesterday we were taught a very clear lesson in just how far these new line technologies have moved ahead.
We visited the Southern Ropes manufacturing facility here in Cape Town, on a mission to analyze the remaining strength in some of our older lines (more on that later). While there we noticed two HUGE soft shackles made of UHMwPE being checked.
Southern Ropes showed us the heat treatment facility where these lines are effectively baked under controlled tension to minimise the "creep" or elongation characteristic that is the one down side of UHMpWE or Dynema in longer term use.
The production line includes baths to die the fiber to desired colors and other stages that apply coatings to enhance the line strength by retaining the fiber alignment as it comes off the hot tension rig.