A historical exposé on the medium and why I'm through dealing with it.
Grab a shirt! https://bit.ly/3gkACTA
Support the show (https://www.buymeacoffee.com/V4r9HUtIW)Support the show (https://www.buymeacoffee.com/V4r9HUtIW)
So every year articles are published by parachute manufacturers and the different line types offered for select canopies. And today on the show, I wanted to highlight one spectra or what some manufacturers in the industry called micro line and why you should never use it on main canopies. And if you have a flat trim, can it be like a pilot or a similar.
Or God forbid, you're lining a steeper canopy with spectra, such as the older saber twos. You should consider what the manufacturer offers as an alternative, as a rigger, other than reserve repacks for sport jumpers and packing bailout pilot rigs that require quick deployments at low altitudes. I'm officially done servicing me.
These were spectral line sets. Some alternative spectra include HMA Dacron or something else. And manufacturer recommends certain lawn types based on the opening characteristics of the canopy. But first of all, let me state that any time, whether it's in a magazine around the drop zone or in some publication that there's a mention of micro line.
What they mean in the industrial textile world is spectra or polyethylene. And they will hear the two thrown around together, but the terms are synonymous with one. Dyneema is another term you might hear of. And that is also spectrum and the field, many master rigors build their line sets and they purchase raw materials from companies like CSR in Pennsylvania lines are rated like other webbings and fabrics.
Based on their tensile strength. So HMA 700 is supposed to have a tensile strength of 700 pounds, which means that it fails or breaks under a load of 700 pounds. Most material issued by the suppliers actually rated 80% of tests. So dynamically that 700 HMA should be able to withstand 840 pounds of pull force.
Anyways, spectra comes in various sizes. And you will often see a manufacturer like performance designs treat or code a spectral line and call it micro line because of this coding, they add a hundred pounds to the line number. Whether in fact it does add a hundred pounds of strength. I would like to see some experimental data suggesting it does in fact do so, but in the 1980s, manufacturers began to experiment beyond the commonly seen caught and Kevlar line types, and they were looking for a line type that could pack even smaller would be more durable.
And after many trials. Failure spectra, which was originally used in the sealing industry, became commercially available. The problem with spectra is that more often than any other line type on the market, its properties change in short, the polyethylene coating on spectral line and the smaller diameter of the line compared to any of the other types of line on the market means that the slider can and will come down faster, accelerating hard openings and altering the line outside of its original measurements.
And. And short with spectra there's serious potential to slam the jumper and it is absolute pain in the ass to pack and maintain and take care of over time heat from the slider, sliding down the lines after your belly to earth at say 150 miles per hour. And the environmental factors such as desert or dry heat only exists.
The situation, the lion's going out of trim. Again, you might often hear of lines on a canopy going out of trim or even see videos online of self-proclaimed know it all experts attempting to put a line back into trim over a period of time before they can afford to take the time to proper rely on it, such as bending or pulling on a piece of fabric to test its integrity.
The fibers that make up a spectral line once taken out a trim cannot be restored without the entire line being replaced. It just can't happen again, more so than any other parachute line on the market spectra subject to. Factors, namely heat that can and will affect its integrity. Over time. I line out of trim can cause significant problems ranging from built-in turns to asymmetrical flares.
That can be the difference between a standup landing and breaking a leg for a student or a less experienced jumper. Now, a word on spectrum. Hope. There's a great post right now in drop zone.com we're executives at UPT. Well, their relative workshop at the time mentioned that based on their own internal results, that there is a significant correlation between micro line and hard openings based on stretch factors like para cord and other polyesters Dacron provides shock absorption capabilities at a higher drag coefficient resulting.
Thicker line with a greater surface area that has more potential to abate reoccurring or the occasional slammer, hard opening with all other factors being equal relative workshop points to a great analogy between stretch factors and elasticy being the primary driver for why you don't see folks bungee jumping with steel cable, which likes spectra like the HMA and like the Vectron offer virtually no plasticity or opening shock absorber.
As aforementioned spectrum. Maine's an ideal choice on emergency bailout, Ricks, and reserves where the user demands fabric over their heads in the shortest amount of time possible. But our main canopies to be jumped hundreds of times by the average user, the risks of a slammer coming from an occasional, but inevitable heart opening and skydiving is not worth the risk for me, nor the performance of being able to fit an already small canopy into an even smaller, main packing tray and go a few miles.
Faster. So all this said I am officially through in dealing with spectra on main canopies and I will no longer send them out for real.