maretus 0 #1 January 15, 2004 Howdy all ! This is a question that has been bugging me for some time and none of my friends has been able to give a satisfying answer. Why do we use standard sail slaiders with hole in the middle in skydiving reserves and mesh slaiders in BASE canopies ? Cause the way I figure it, both those canopies are quite similar in structure (7-cell, low AR, F-111) and have quite similar characteristics and criterias as well (opening speed, not prone to offheadings or linetwists, etc...). Can someone give a proper explanation to this ?http://www.ufufreefly.com Quote Share this post Link to post Share on other sites
jdthomas 0 #2 January 15, 2004 not all Opening speeds are the same. little things like pilot chute in tow are not going to slow down your freefall speed much. Even thow that little slider has a hole in it, that still helps slow the opening a bit more then just mesh would.www.greenboxphotography.com Quote Share this post Link to post Share on other sites
Hooknswoop 19 #3 January 15, 2004 QuoteWhy do we use standard sail slaiders with hole in the middle in skydiving reserves and mesh slaiders in BASE canopies ? Only a few reserves that I can think of use a hole in the slider. Why not mesh? I don't know, but I would guess that mesh sliders weren't around when the reserves were designed or that the manufacturer(s) felt that a mesh slider wouldn't be durable enough for a reserve. I'm sure someone on DZ.com knows the real answer.............. Derek Quote Share this post Link to post Share on other sites
JohnnyUtah 0 #4 January 15, 2004 Sometimes it is necessary to open your reserve at terminal velocity. A mesh slider is not designed for terminal and will result in a very hard opening (I know because sometimes I end up there). The slider with a hole in it results in a quicker opening than a full-sail slider but will slow down the opening more than a mesh slider. In general: A BASE canopy is designed to open as fast as possible whereas a skydiving main canopy is designed to open slow. In practice I find that a full-sail slider works best at terminal for both canopy types in their respective disciplines. Typically a mesh slider is used for delays from 4-8 seconds. Unless you are just humming it on a medium size object. A reserve is different in the sense that you cannot predict (or plan) what situation you will be in when you need it. Therefore it is set up to work as best it can in two very different situations. 1) At low airspeeds and possibly very close to impact (such as a low cutaway). 2) At terminal velocity (perhaps even head down). I hope this helps. Have fun, don't die! Johnny Utah johnnyutah101@hotmail.com johnnyutah.com Quote Share this post Link to post Share on other sites
TomAiello 26 #5 January 15, 2004 I think that the canopies (BASE v. skydiving reserve) are intended for different uses. A mesh slider yields faster (and harder) openings, than a sail slider. A skydiving reserve is typically deployed at altitudes sufficient to allow the use of a sail slider. If I was packing my own skydiving reserve, I'd probably use a mesh slider. Then again, I've taken a mesh slider to terminal hundreds of times (that's pretty much the standard configuration for terminal BASE jumps), so I'm used to the openings. If you aren't, I'd probably recommend sticking with the sail slider.-- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com Quote Share this post Link to post Share on other sites
maretus 0 #6 January 15, 2004 QuoteA BASE canopy is designed to open as fast as possible whereas a skydiving main canopy is designed to open slow. In practice we find that a full-sail slider works best at terminal for both canopy types in their respective disciplines. Still many BASE jumpers jump terminal walls with mesh sliders so that must be a question of personal preference ? For example check out the thread " How are people packing for Norway?" from BASE zone where our moderator Tom Aiello says "I'd go with a mesh slider. I generally use a large hole mesh slider at terminal." I kinda still don't buy the idea that sail works better on terminal than mesh since if hole-in-the-middle sail slows openings more than mesh and openingspeed is crucial factor in both reserves and BASE canopies, shouldn't we then use mesh sliders in reserves too because (if) they produce faster (yet survivable) and more consistent openings ?http://www.ufufreefly.com Quote Share this post Link to post Share on other sites
riggerrob 643 #7 January 15, 2004 I have only repacked one reserve with a mesh slider and that was made by an obscure Canadian company. The dominant reason for installing fabric sliders on skydiving reserves is to satisfy the high speed end of the envelope. Without some fabric they open hard enough to break bones! Cutting a hole in a fabric slider is a compromise to satisfy the low speed end of the envelope. Quote Share this post Link to post Share on other sites
JohnnyUtah 0 #8 January 15, 2004 Quote A sail slider yields faster (and harder) openings, than a mesh slider. Are you sure you did not say it backwards from what you really mean. Like you continued to say, “I'm used to the openings”. By this I gathered that you are use to the harder mesh openings. If this is not what you meant, please clarify. My opinion is this: A full-sail slider will slow down the opening more than a mesh slider. Quote Then again, I've taken a mesh slider to terminal hundreds of times (that's pretty much the standard configuration for terminal BASE jumps) Tom, you and I both made the same mistake in stating that either mesh or sail is the standard configuration for terminal BASE. Here you go. You and I disagree on something that is absolutely personal preference. I agree that both mesh and sail sliders are used. Both are safe to use. Mesh sliders just hurt me more on terminal openings. Quote A skydiving reserve is typically deployed at altitudes sufficient to allow the use of a sail slider. There are an awful lot of low cutaways in the world. Manufacturers of reserves design reserves with this scenario in mind. They use small sail sliders and sometimes design the slider with a hole in it. Like I said before. Quote A reserve is different in the sense that you cannot predict (or plan) what situation you will be in when you need it. Therefore it is set up to work as best it can in two very different situations. 1) At low airspeeds and possibly very close to impact (such as a low cutaway). 2) At terminal velocity (perhaps even head down). Johnny Utah Senior Rigger johnnyutah101@hotmail.com johnnyutah.comHave Fun, Don't Die! Johnny Utah My Website email:johnny@johnnyutah.com Quote Share this post Link to post Share on other sites
JohnnyUtah 0 #9 January 15, 2004 In the past few years numerous freeflyers have been saved by a cypres firing. I know at least one freeflyer has died from the hard opening shock caused by his cypres firing while he was freeflying. Would you really want to get yanked out doing head down terminal with a mesh slider on the canopy? I personally think that would suck. Johnny Utah Free Flyer Quote Share this post Link to post Share on other sites
TomAiello 26 #10 January 15, 2004 QuoteQuote A sail slider yields faster (and harder) openings, than a mesh slider. Are you sure you did not say it backwards from what you really mean. Ah. Yes. That was an error on my part that occured somewhere between brain and keyboard. Thanks for the catch. I've edited the original post.-- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com Quote Share this post Link to post Share on other sites
maretus 0 #11 January 15, 2004 QuoteWould you really want to get yanked out doing head down terminal with a mesh slider on the canopy? I personally wouldn't want get yanked out doing head down terminal with any slider. :) Your statement conserning high speed deployments is absolutely valid but I don't think that it is a major design aspect for skydiving reserves since most reserve designs date way back when freeflying wasn't even invented. Also most skydiving reserves are not designed for extra opening shock if deployed from HD terminal (even though many of them do endure it and don't blow up). You stated that you know one fatal incident conserning headdown terminal reserve deployment, I bet that it was with sail slider ? I don't say that the result would have been anyway different with mesh slider but that proves that headdown terminal reserve deployments are very dangerous and can be fatal regardless of the slider. But thanks everyone for answers and keep your opinions coming !http://www.ufufreefly.com Quote Share this post Link to post Share on other sites
TomAiello 26 #12 January 15, 2004 QuoteIn practice I find that a full-sail slider works best at terminal for both canopy types in their respective disciplines. More discussion on this topic has been sparked on the BASE forum. Also a poll has been posted. My only other thought is: I bet the manufacturers do a bunch of testing on their reserves. I'd be hesitant to step outside the tested configuration on my last shot.-- Tom Aiello Tom@SnakeRiverBASE.com SnakeRiverBASE.com Quote Share this post Link to post Share on other sites
