Elisha 1 #1 July 27, 2006 What is the Approx lb test for canopy lines? As I mentioned in another thread, I've giving a lunch presentation at work on my "hobby" and want to know what I'm talking about at least a little bit. Is this lb test for EACH line (e.g. 500/700/whatever lbs)? What is it for S-Links? I've heard they're actually stronger than the metal links. Quote Share this post Link to post Share on other sites
riggerrob 643 #2 July 29, 2006 Popular strengths for modern sport parachute suspension lines are 300, 550, 750 and 825 pounds. Tandems tend to use stronger suspension line materials, in the 1,000 pound range. If you test samples of suspension line - in a tensiometer - they will fail within 5 percent of their rated strength. Most sport canopies have between 40 and 48 suspension lines, but since they are not all loaded evenly, strength is not cummulative. Old-fashioned military canopies usually used 550 pound, nylon suspension lines. Early square parachutes used Dacron suspension lines because Dacron stretches much less than nylon. For the last decade, Spectra has been the most popular suspension line for sport canopies. Spectra (aka "Microline') is a polyethelene cord, chemically similar to the plastic used to make shopping bags. Kevlar (a yellow aramid) is used to reinforce and line some square reserves, but is rarely seen outside of reserve containers. Vectran is also a yellow aramid, but it rapidly turns grey, from the heat and friction of slider grommets. High Modulus Aramid (HMA) is the latest fashion for suspension lines because it is thinner than older lines and very stable (dimensionally). Quote Share this post Link to post Share on other sites
JohanW 0 #3 July 31, 2006 QuoteMost sport canopies have between 40 and 48 suspension linesA typical 9-cell would have 40 suspension line attachment points (though a PD Stiletto leaves out the D-lines on the outer 2 cells, leaving, uhm, 36), but those lines of course cascade out from 20 at the risers. A 7-cell would have 32 susp. line att. pts. at the canopy. You're not counting steering lines as suspension lines, are you?Johan. I am. I think. Quote Share this post Link to post Share on other sites
JohanW 0 #4 July 31, 2006 QuoteWhat is it for S-Links? I've heard they're actually stronger than the metal links.See PD's website. No mention is made of the actual type of line they're made from, unfortunately. Also, 'home made' softlinks have been around for quite a while, and they have been made from varying types of line. Parachutes de France also make softlinks (with a metal ring instead of a cloth tab), but their website doesn't seem to mention them at all. Aerodyne - same story.Johan. I am. I think. Quote Share this post Link to post Share on other sites
ZigZagMarquis 9 #5 July 31, 2006 Go search the web and also DZ.com on things like: Spectra Dacron Kevlar Vectran ... you should find some cool "factoids" you can throw into your presentation, if you wish. Quote Share this post Link to post Share on other sites
Elisha 1 #6 August 1, 2006 QuoteGo search the web and also DZ.com on things like: Spectra Dacron Kevlar Vectran ... you should find some cool "factoids" you can throw into your presentation, if you wish. Google actually worked post mortem. Thanks for the response, even though the presentation was last Thursday. Quote Share this post Link to post Share on other sites
