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]
