Myths & Hitches 4

Overall I thought the book was very interesting and full of great facts. Personally, I love books like this in terms of its format and topics. The book is broken up into a ton of short paragraphs giving the myth and then the facts showing why they are just in fact myths. Some were more interesting than others, but overall it kept my interest throughout. I really love debunking historical myths, because there are just way too many out there for comfort.

Too many stay in the history books only as a way to bolster an authors biased point of view. Though I thought the research was very well done, I had a few nitpicks: Crusades - The myth in the book addresses the fact that Crusader victories showed their superiority over the Muslim world. Can't say I ever heard of that one before presented as a serious fact. Its more like its amazing they did so well. A mix of European countries, sending forces to a far away land, in unfamiliar fighting conditions, and winning sometimes is an accomplishment.

Plus it is amazing that the European Levant countries left behind lasted so long considering they did not receive a ton of support from Europe after the armies went home, nor were they well positioned to flourish. A better myth to address would be that in fact that both sides of the conflict did some very bad things, or get more into how the Crusades actually got started. Though I give the author credit in saying its motives were not just religious, but political and economic as well.

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Inquisition and Witch Hunts - Overall a pretty good job. Again great job in pointing out the majority of the Inquisitions and Witch Hunts were not done on behalf of the Church, but undertaken by local officials looking to get rid of people they didn't like. Could have also mentioned that most of these horrible deeds were done in areas lacking a strong central government or Church presence or influence. The point I take issue was with the numbers. Same can be said of smaller death toll numbers on the Witch Hunts.

I am not trying to marginalize anyone's death and we should know all about the bad things that happened. However, these numbers were known to be greatly over inflated in the past by various heavily biased accounts. The Inquisition's are nothing compared to the various dictators of the past years, National Socialism, or Communism.

Smallpox - The Amherst claims are true, and remains a possibility that it could have happened, but though likely, there is no hard evidence. Plus unlike what the author states, there are examples of germ warfare long before any European set foot in the New World. Get to Know Us.

Delivery and Returns see our delivery rates and policies thinking of returning an item? See our Returns Policy. In this case, the load on the flat overhand is only pounds. These tests were conducted with a heavily-used Based on these measurements, the following conclusions can be drawn: The flat overhand is about 18 times stronger than it needs to be for rappelling when using two single, dry ropes, and rappelling normally. Very agressive rappelling may cut this margin down to a 5-fold difference.

Under the worst of conditions tested two soaking wet ropes of different diameter , the flat overhand is still 12 times stronger than the anticipated load on the anchor. Very agressive rappelling may cut this margin down to a 3-fold difference. Even if the "roll load" of the knot is exceeded, it would take repeated, increasing loads to cause additional knot inversions. Daisy chains, slings, or a PAS are the best way to attach to the anchor on multipitch climbs.

Daisy chains have limited usefulness if you are not planning to aid climb. They are bulky and are a poor substitute for attaching to the anchor with your rope. Slings are obviously not as bulky as you may be carrying them for your climb, but are also not the best choice for tying in. Jeff Fassett and I conducted a simple test using a dynamometer attached to a bolted anchor. In the first part of the test, I attached to the anchor using a daisy chain so that i hung freely two feet below it.

With a backup rope in place, I pulled myself up a few inches and let go so that I fell statically on to the anchor. The force on the anchor was shocking - the dynamometer measured a peak force of pounds on the first drop. I subsequently took slightly further falls, and found that the force on the anchor was over 2, pounds when falling just one foot.

I stopped at this point simply for comfort. The paper containing this test can be found at http: Similar tests conducted at BlueWater found that a two foot fall with a test weight caused a two-foot sling to completely fail. This is consistant with the simple data we obtained; in sum, it is likely that falling two feet on to a daisy chain will cause at the minimum a failure of that loop.

On a personal note, I can confirm that if you did not cause the daisy chain to fail, you would almost certainly sustain injury. The story changes significantly if you are attached to the anchor with a climbing rope and a clove hitch. Jeff and I repeated the test: I immediately noticed that short, static falls on the anchor were far less jolting, and the dynamometer confirmed my suspicions.

When falling one foot on the climbing rope, the force was about pounds. On subsequent, longer falls, we found that even falling two feet the full length of the rope I had tied the force on the anchor was only 1, pounds. The reason for this is the very limited amount of slipping that occurs when a GriGri arrests a fall.

An ATC, however, allows the rope to slip through the device during a fall, braking more slowly. This is similar to stopping a car: When pushing the brakes more, the car jolts to a stop. Beal did a nice comparison between belay plates ATC and autolock devices GriGri and has it posted at http: Breifly, depending on the rope's impact force and friction in the system, they found that the force exerted on the top piece was consistantly higher when using a GriGri versus an ATC.

Four Myths Of Whiplash

We decided to do a test of our own to get some real-world measurements. After climbing up 40 feet on a sport climb with a heavy, clunky industial dynamometer strapped to my back, I took repeated foot falls and measured the maximum force on the bolt with each fall. After five falls were caught on the GriGri and five falls were caught using an ATC, we repeated the test, this time falling from a bolt closer to the ground 20 feet. When the 10 foot falls were arrested in the first test falling from 40 feet , the average maximum force on the bolt was pounds with the GriGri as opposed to pounds with the ATC.

With less rope out falling from 20 feet , the force exerted on the top piece was higher, although interestingly, the difference between the two devices was smaller: Note that these differences are less pronounced than what the Beal website found. The significance of this for traditional climbing is that the gear used is weaker than a correctly placed bolt.

Moreover, the strength of a traditional placement also depends on the nature of the rock it is in, the shape of the feature the climber is trying to protect, the type of gear that is placed in the feature, and a host of subtleties that are dependant on the skill and experience of the leader.

So while a traditional placement may be as strong as the gear is rated generally 5 to 16 kN, or more simply put pounds , in practice most placements can be weaker. So the question that we need to ask ourselves is how good the gear is on the climb we are planning to do. If you are climbing on bomber gear in bomber rock, the difference between a GriGri and a plate is probably not that big of a deal. If you are climbing on sketchy gear in poor rock, then you'll probably benefit from the softer catch a belay plate provides. I've recieved a number of comments on this piece. A lot of people think that they can provide a soft enough catch with a GriGri with a well-timed jump.

Keep in mind this will be difficult in a hanging belay situation or when tied in close to the anchor.

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I haven't seen research with actual measurements on soft catches with a GriGri vs an ATC but if you are aware of some please send me a link. For background, consider the number of people you know who have used Sharpies or other markers for their ropes. I personally know a number of professional guides who have done this for their institutional ropes. To my knowledge there are no reported rope failures attributed to permanent marker use.

Myths And Hitches 4 Misconceptions Fallacies And False Beliefs About Science And Philosophy Art An

I'll confess at this point that I have used Sharpies on all of my ropes and have yet to notice a difference in wear. Using one of these ropes which was heavily used and re-marked at least five times during its working life I started with a simple pull test. This demonstrated that the marked region was stronger than the figure 8 at the end of the rope. Black Diamond carried out similar tests and posted them here: I began to wonder if the ink even makes it to the core of the rope.

I cut open the rope and found that the ink did not make it to the core of the rope. Well what could happen if the ink did make it to the core of the rope? To find out, I marked and pull tested 10 strands. To minimize loss of strength due to knots, I wrapped the cord around a carabiner multiple times. In all cases I was unable to break the cord at the marked location. There are a couple of caveats worthy of mention: Also, concerns have been raised about ropes cutting more easily over edges if marked - I did not test this for this this short piece.

But if you are in the middle of a 10 pitch descent and your partner mentions that he marked the rope you are using with a marker, you can finish rapping down without worrying about it. Marking pens are fine to use on ropes as long as they are water based laundry markers. Years ago solvent based markers were the norm. Some of the solvents used in these old pens could reduce the strength of the sheath strands marked. These days most pens are water based so this is not as much of an issue as in years passed. We recommend a Sharpie "rub a dub" laundry marking pen.

Why does BlueWater not use factory middle marks on dynamic ropes? Factory middle marks are ok until one end of the rope gets chopped off.

Then the factory mark is no longer in the middle. Hmmm- look at the back of any telephone book here in the great Nation of America. If an end user gets hurts because their mark is no longer in the middle what would one expect to happen?