Toast Posted April 16, 2003 Share Posted April 16, 2003 After wading through a ton of CRAP, my main man came up with TechWeenie. Check it out. Quote Link to comment Share on other sites More sharing options...
rr666 Posted April 16, 2003 Share Posted April 16, 2003 Fish rocks For as low tech their website is, sure got a lot of damn good info, as well as gear!!! Quote Link to comment Share on other sites More sharing options...
catbirdseat Posted April 16, 2003 Share Posted April 16, 2003 I've noticed a handful of rock climbers use Yates Screamers. Screamers are mostly used by ice climbers to reduce the chance that ice screws would pull out in a fall. It seems to me that they might also be a good idea in rock climbing for those critical first one or two pieces of protection where fall factors are high. For those who don't care to read all the way through, the upshot is that testing shows that use of a screamer on a bolt (or piece of pro) would reduce the load on that piece from from 2000 lb (9 kN) to 1200 lb (5 kN) in a FF 0.5 fall. There are some types of pro, for example small nuts, that would fail at 9 kN but hold at 5 kN.  The following is clipped from the above Techweenie link:  Physics of Screamers by YATES Author: John Yates/ Pro Design USA Email: prodesig@snowcrest.net Date: 1998/12/08 Forums: rec.climbing  (Snip) Screamers are a stitch ripping device that allows forces to be decelerated over a longer time interval than they would be if the Screamers were not in the system. Standard Screamers or ICE-Screams are configures from stitch patterns consisting of 6 rows of zigzag stitching sewn into each wing of the unit. This stitching is done by means of a computerized sewing machine. The machine can be configured to allow the Screamer to activate basically anywhere between 1 and 650 lbf. We chose to use an average activation of 550 lbf. because it seamed to be about the right force to use as a upper limit for marginal protection and ice screws. Not every thing is a real science.  Some interesting things happen when you look at how much energy is "absorbed" in the system when a screamer is used. If the "True" absorption is measured in a completely static system, lets say doing a drop test with a steel cable and weight we will see that about 5-600 lbf was absorbed by the stitch ripper (Screamer). When a Screamer though is put in a system which uses dynamic climbing rope instead of static steel cable the amount of energy which is absorbed is increase by 25-40%. We see that the absorption of energy increases to 800-900 lbf. I can attribute this extra energy we see being absorbed to the fact that the "Dynamic" climbing rope in the system is allowed to elongate and remain dynamic for a longer time interval than it would be, if there was no screamer in the system.  An example: A dynamometer or load cell is placed on a bolt hanger. A climber takes a fall which generates a fall with a factor of 0.5. This generates a force of 2000 lbf as seen on the dynamometer. When a Screamer is hooked in the system below the dyno. the same fall only shows a peak force of 1200 lbf. We know from extensive testing that the Screamer can only absorb 500 lbf. So how do we account for the extra 300 lbf seen in this example??? The increased time interval(duration) of the fall allowed the climbing rope to be more absorptive!! Thus Screamers limit loads and dissipate energy over a an increased time interval. This increase in the duration of the fall is most important in a "Dynamic" systems because it allows the rope to do its job even better than it was designed to do.     Quote Link to comment Share on other sites More sharing options...
Bronco Posted April 16, 2003 Share Posted April 16, 2003 Also a good option for sketchy pitons in the mountains and aid routes. Make sure and use one for those duct taped hook placements Quote Link to comment Share on other sites More sharing options...
JoshK Posted April 16, 2003 Share Posted April 16, 2003 screw screamers and dynamic ropes, I'm gonna start climbing on chained up rubber bands! Quote Link to comment Share on other sites More sharing options...
rbw1966 Posted April 16, 2003 Share Posted April 16, 2003 Have someone post a TR after your first lead fall. Quote Link to comment Share on other sites More sharing options...
cluck Posted April 16, 2003 Share Posted April 16, 2003 How about leading long overhangs on a bungee? (the kind used when you jump off bridges, not the kind used to strap shit to the roof of your Pinto) Climb 20 feet past your last placement then bail. You could combine 2 extreme sports into one fun filled afternoon....... Quote Link to comment Share on other sites More sharing options...
iain Posted April 16, 2003 Share Posted April 16, 2003 maybe 3 sports, since you could get some caving in when you blast into the side of the wall on the rebound Quote Link to comment Share on other sites More sharing options...
lummox Posted April 16, 2003 Share Posted April 16, 2003 Toast said: After wading through a ton of CRAP, my main man came up with TechWeenie. Check it out. wow. that shit be like 5 year old. youre right on top of it. Quote Link to comment Share on other sites More sharing options...
catbirdseat Posted April 17, 2003 Share Posted April 17, 2003 rbw1966 said: Have someone post a TR after your first lead fall. Hmm, have "someone" post a TR...oh, I get it. I wouldn't be the one to do it because I would be dead. That's funny. Quote Link to comment Share on other sites More sharing options...
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