Re: [try2live] Shallow ... Deep.... "Deeper" brake settings and usage :)
I heard this argument so often now, and for me it neither makes sense in theory, nor any of the (few) videos of riser disconnects show that the slider helps, in fact, im really sure that a riser disonnect without a slider will give you less sink rate than with a slider in for the majority of cases.
have a look at my attached drawing, there are 3 scenarios in case of one side riser disconnect. first on the left, what happened to sketchy andy. as you can see in the video aswell, the disconnected side of the canopy just flopps up, and is fully collapsed and not carrying any weight anymore. (theres another video of a aussie guy at griset, video says august 2007), which is outside video that shows exactly the same that the disconnected side is fully flopped up and collapsed although there was a slider in the system.
the only thing that the disconnected side does, is that it pulls up the slider further towards the canopy, deforming the "good" side of the canopy. to which degree that happens will of course greatly depend on how much pressure and air the "good" side still gets, so i suppose this will vary greatly with wingload, canopy type, and if its vented or not.
im pretty sure that drawing on the far right with one side completely disconnected from you, but the other side fully open not deformed will "fly" or at least slow your decent down more than a deformed "good" side as with the left one. (since you have a bigger projected area of fabric open above your head)
i suppose we would have to do multiple droptests with both configurations with multiple different canopies and wingloads to really see if theres a difference in decent rate, but im really sure, that if it makes a difference, that the slider in version would be worse.
the only scenario where the slider could do a helpful job is when the riser that is still connected is the one that has the slider secured to it, and that it is secured good enough so that it will carry sufficient load to keep the disconnected side from flopping up and away, see drawing in the middle. i think that the tape-with-a-button-on securing thing that some manufacturers build on their risers to secure the slider will not do the job in most circumstances and will open, leading to scenario on the right side.
also something that pops up in my mind here is that in this scenario the disconnected side will have the front riser pulled down significantly further than its back riser. im unsure if this configuration is actually more desirable than a completely disconnected side, i wouldnt bet any money on it at the moment.
so we end up with: the slider could possibly help in case of a riser disconnect, IF the riser that disconnects is not the one where the slider is secured to, and IF the slider is tied down in a manner that it can bear some load, while it would worsen the situation IF any of the above is not the case, and of course this is a scenario that one would think of IF one has a 3 ring system on the rig.
for me thats a WAY too specific scenario to make a valid argument for leaving the slider in...
so, i would love to once and for all put this to the test. lets get a datalogger and do some skydives.
edit to add links:
https://www.youtube.com/watch?v=SnR5fsm3K2w https://www.youtube.com/watch?v=h52bFl9qqmE