I'm much more concerned with the fact that if everyone countered the Coriolis effect at the same time, would the planet stop spinning. Therefore, would all the cavers migrate to the dark side of the planet.
Geary -----Original Message----- From: Brian Riordan [mailto:[email protected]] Sent: Thursday, June 11, 2009 10:46 AM To: Geary Schindel Cc: Linda Palit; Lyndon Tiu; [email protected] Subject: Re: [Texascavers] Figure-8 not proper for caving? So there should be no twist issues at the equator? Or do you rig it to have a forward or front exit at that latitude?... So many nuances to this issue! :) On Thu, Jun 11, 2009 at 10:19 AM, Geary Schindel<[email protected]> wrote: > That's correct, > > To counteract the spin, some folks have found that if you rig the figure > 8 for a left exit from the device in the northern hemisphere, the twist > imparted in the rope is neutralized by the Coriolis effect and you won't > spin when ascending the rope. :) LOL > > > Geary > > -----Original Message----- > From: Linda Palit [mailto:[email protected]] > Sent: Thursday, June 11, 2009 9:36 AM > To: Geary Schindel; 'Lyndon Tiu'; [email protected] > Subject: RE: [Texascavers] Figure-8 not proper for caving? > > Figure 8's twist the rope. That is bearable for a 20 or 30 foot rope, > but I > ask people not to use figure 8's on my rope if the drop is longer. It > just > creates hassles in coiling and using the rope that seem unnecessary to > me. > I do have several, and they have uses, but not on long drops and seldom > on > drops on my rope -- > > Linda > > -----Original Message----- > From: Geary Schindel [mailto:[email protected]] > Sent: Thursday, June 11, 2009 9:23 AM > To: Lyndon Tiu; [email protected] > Subject: RE: [Texascavers] Figure-8 not proper for caving? > > Couple of comments on the Figure 8. > > They are suitable for caving as long as you are aware of and willing to > put up with the limitations, much as any rappel device. > > Pros > They have no moving parts and can't be easily rigged > incorrectly. > They are relatively cheap in comparison to other devices > They are light > They are compact > They can be easy to drop if you don't know some of the rigging > tricks, as you have to disconnect the device from the harness to attach > to the rope. > Some have ears (rescue 8's), which are bulkier, but all Figure > 8's can be locked off. > Commonly used in Youth Programs because they are hard to screw > up, cheap, and simple to use > Relatively durable on CLEAN ropes. > They can be used with single or double ropes > They will accept a wide range of rope sizes > Generally, most folks like to limit their use to drops of less > than 200 feet and I don't like to use them on drops over 100 feet. > Depending upon the drop, you may have to feed rope with longer > drops. > They are a non-variable friction device is that the friction > from the device can't be easily changed with a standard Figure 8. That > is why some of the newer design variants such as the Piranha, > which do allow you to easilt add or subtract friction, are becoming more > popular. > They may be slightly easier to learn on in the sense that you > can't modify friction which is one less factor you have to teach for the > first timer. > > > Cons, > Big folks may find them fast, > They wear very quickly, as in one rappel, on a dirty rope (read > rat tail file). > If you use them on dirty ropes, you will have to replace them > more often than rappel devices that allow you to change out the friction > surfaces, so for cavers, they may not be economical > They twist the rope, which can make ascending nauseating from > the spin in the rope. It is a misconception that repeated use of a > Figure 8 may damage the rope. There are more rappels done with > a Figure 8 than any other device and probably all devices combined. > There has never been a rope failure caused by a Figure 8. However, > barfing on the rope probably isn't good for it. > There is a risk of dropping the device during changeovers. > > Regarding Bill's comment that it may be necessary to obtain more > friction by rapping the rope around the hips, this is not generally > recommended for a couple of reasons. For example, if the user is right > handed, rigged in this fashion, the rope exits the rappel device on the > left side of the person, passes behind the back (hips) of the rappeller, > then reaches the right brake hand, this can present a couple of > problems. If the rappeller let's go of the rope with their right hand, > the rope will fall to the back of the rappeller, they will not be able > to gain control of the rope and will be unable to arrest or control the > rappel. They will probably not be able to recover the rope. Second, > the rope will usually find an indication to ride in around the hips. > This is usually caused by the webbing so you will now have a moving > piece of nylon (the rope) running against a standing piece of nylon (the > harness), which may create severe abrasion and possibly failure. If you > need more friction, use a different device. There are ways to modify > the friction on the device using either a double rap or another > carabineer, but they are beyond this discussion. > > When would I use a Figure 8. For short caving drops, especially a long > distance into the cave, for rock climbing, and for canyoneering. > > Geary Schindel > > > > > > --------------------------------------------------------------------- > Visit our website: http://texascavers.com > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > > > --------------------------------------------------------------------- > Visit our website: http://texascavers.com > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > > --------------------------------------------------------------------- Visit our website: http://texascavers.com To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
