muddyface wrote:The first pit over 200 feet I did I began with 5 bars engaged, the rope wouldn't move at all so I went down to 4 bars. This worked nicely for the first part of the drop but part of the way down the rope was wet so suddenly I was going too fast for my comfort. Instead of stopping to engage a 5th bar or push the 4 closer together I just relied heavily on my braking hand which didn't work too well since the rope was wet. So the rest of the descent turned into dropping at unsafe speeds and then clamping down with my hand which caused me to bounce up and down while rappelling. I reached the bottom at a safe speed but lesson learned is to take it slow and be aware of the rope conditions, especially on a drop you haven't done before.
this is a classic early experience sir.......any vertical caver has had this happen..........if you are right handed and when you are experienced you should be able to successfully rappel without a right hand glove, though i don't endorse or recommend it i merely point out that the focus of control is in the bars engaged on the rack, and their ruler, the LEFT hand...(i have also suggested long ago in a land far away that people should rap left handed cause the right hand would then be pushing on the bars.......total point being the total critical part of rappelling is the spacing between the number of bars you have engaged......and spacers and spacing......
spacers set the speed of the rack......i recommend spacers the same size as the rope you are using.....used between the first two bars...use another set or even more if the rack is a mega-rack.............this makes the rack factor more predictable and not effected by your adrenaline or its opposite the limp thoughtless pressure you use to snug up bar number two and three....or, another factor seen sometimes, the pressure created by the lip as it's rock on rack friction creates a slower rappel for you by squeezing the bars together..pinching the rope tighter than its diameter if no spacers are used...all or any of these factors will set the speed of rappel you experience....think of it, bars one and especially two have at least half of the friction.....why let this pressure be variable?...why not make the spacing between the bars and the rope predictable?..
..of course, if desired, the spacers could be made slightly less than rope diameter for a predictably slower rack.....
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for those with no or little experience with using bar spacers........be very aware that using spacers creates certain dangers..
..if the width of the spacer exceeds the diameter of the rope being used it will result in a very substantial and dangerous increase in rappel speeds due to the loss of friction and should at no time be used...7/8 rope, use 7/8 or 3/4 spacer.......ANY larger will cause the rack to be FASTER..
..as spacer size goes up friction lost goes up faster........really people..larger spacers belong only on mega-racks........oh lord here i go inciting a debate........larger spacers belong only on mega-racks and limited rescue rack situations.......
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muddyface.....keep getting muddy.......next time use five bars to start with and bars three four and five space them apart after you get on rappel.....then gently pull down number two and note it's affect on the friction situation.....forget that gripping the rope......thats a last resort, loss of control, unusually slick or small rope final action in a loss of bar control, left hand control, of the rap......but i loudly and strongly add, nothing wrong with using hand friction if its in a controlled situation where hand grip is more controllable.....a not uncommon situation.....but for the bulk of the freefall and other descent where some speed is not unsafe..bars are the answer...
..but at the end and sometimes in between hand grip friction can provide better sensitivity control some of the time over controlled bar spacing.......read my posts at least twice if you don't understand something or something seems confusing.........