Thread: Aztek as LRH

  1. #1
    Forum Member
    stickboy42's Avatar
    Join Date
    Dec 2009
    Location
    Idaho
    Posts
    89

    Default Aztek as LRH

    Hi all,
    new to this forum but have been lurking for awhile now and thought i'd start posting some questions regarding things i've been wanting to ask others outside my rescue world for awhile now....

    here goes:

    We use the radium LRH slightly modified to eliminate the potential for complete runout that others have pointed out in the past. Pretty much take the tail of the LRH and put a 8 in and secure to biner. Reduces the total distance the LRH can go but eliminates the potential for completely unwrapping itself. We won't even go there on the subject of the forces we'd see if this actually happened and what the cordage would see...

    anyway we are toying with the idea of abandoning the LRH all together since we are making the transition to using the Aztek for many other applications, the LRH being just one of them.

    Does anyone have any comments on using an Aztek in this way. In training I found the following:

    pros:
    1) much easier to use and it's use is similar in many different applications
    2) it travel is limited passing the whistle test through rope length and prusik capture
    3) handling a 2 person load with a single individual is relatively easy

    cons:
    1) you have to have an aztek
    2) what if you don't have one will you really remember how to tie a radium after years of not doing it?
    3) you have to tie on a prusik loop (although i think i could tie a prusik and connect an aztek faster than undoing a radium that is loaded)

    i would love to hear what others think on this. it sure seems like we could eliminate a clunky component and keep rigging cleaner.

    thanks,
    mike

  2. #2
    Forum Member

    Join Date
    Feb 2006
    Location
    Kansas
    Posts
    59

    Default Hey Stickboy

    Good questions. Aztek kits are a great substitute for LRHs. Now that there's a G rated one, this is an easy choice. With the old style you needed to double them up, which was a pain. The new G rated Aztek kit is a great piece of kit (as is the old version). It sounds like you've had some experience with the kits in the past. Once you demo the kit your coworkers will demand them, so be careful. These kits are a good substitution/replacement for LRH. Some folks have done away with the LRH all together. They just have an Aztek in the ready for a raise/lower. If your going from raise to lower you can remove everything but the haul prusik, that way you will already have the prusik connection for your Aztek LRH (of course you would hook that up first). You can do all of the traditional skills with the Aztek ie: LRH, knot passes, vectors, dynamic fixed brakes, etc.
    The primary mission of the Aztek is personal fall protection. I feel that everyone on your team should have one for this reason alone. There's no reason you can't use the NFPA L version for this purpose - they are on sale at rescue response for about $190.00. The new version is much improved upon. But the philosophy is the same. I say try it out. I've not heard of too many people who return them for a refund.
    Your pros are all correct. There is a very short learning curve with the Aztek, and the techniques and construction are familiar to most firefighters. The haters will say, "what happens if you don't have one when you need one?" That's why you need to have one for each person (for personal fall protection). You should always practice for the "what ifs" anyway. The haters will also talk about the importance of progressive thinking in the fire service, but then scoff at the thought of trying out a new piece of kit like the Aztek. Sure, it's expensive. The LRH does one thing cheaply. There's no doubt about it. The Aztek does many things for more $$$. It's really not apples to apples here. No one is saying to run out and buy 25 kits. You might just need to stagger them out a bit. There's no excuse to not provide the best personal fall protection for your workers. The new Aztek is a good choice for that task and so much more. Good luck and stay safe.

  3. #3
    Forum Member
    stickboy42's Avatar
    Join Date
    Dec 2009
    Location
    Idaho
    Posts
    89

    Default

    thanks a bunch for the comments.
    we purchased an aztek last year when i attended reed's vortex class and from that point forward i've been sold. we recently had some end of year rope money and decided to up our aztek inventory to 7 so we each can have one for reasons you mentioned.
    thanks again,
    mike

  4. #4
    Forum Member

    Join Date
    Nov 2006
    Location
    N. Ridgeville, Ohio
    Posts
    811

    Default

    We just had a three day class/refresher for our team and used them in the class. We have had this same discussion. Other than the cost, not really an issue for what we are looking at, we can't find any negative reasons to have them. We are looking to get a few to put in our kit bags for now. We use body cords (30' 3/8") with prussiks for fall protection. Each guy is or will have one of his own. But, the aztek or similar set up has a ton of uses. This can be used to get you out of a jam pretty quickly too.
    Jason Brooks
    IAFF Local 2388
    IACOJ

  5. #5
    Forum Member

    Join Date
    Dec 2009
    Posts
    4

    Default

    Sounds like AZTEK is an acronym for something. Does anyone know what it stands for? Also, who is "reed"?

  6. #6
    Forum Member

    Join Date
    Nov 2006
    Location
    N. Ridgeville, Ohio
    Posts
    811

    Default

    This site should answer most of your questions. http://www.ropesthatrescue.com/
    Jason Brooks
    IAFF Local 2388
    IACOJ

  7. #7
    Forum Member

    Join Date
    Nov 2007
    Location
    South Carolina
    Posts
    25

    Default

    Acronym stands for "Arizona Technicians Edge Kit." I also must agree, that after a great deal of training with this kit, its a must for any rope technician, and any rope team. I've trained under Reed Thorne, who developed the kit, and have seen many uses for it. Definitely a good substitue for the LRH also.

  8. #8
    Forum Member
    stickboy42's Avatar
    Join Date
    Dec 2009
    Location
    Idaho
    Posts
    89

    Default

    Here's a further question to see what you all think.
    In using the aztek as a LRH do you:

    1) put in the system behind the TPB as we do with a radium LRH or other style.

    or

    2) add it in after the TPB is locked up, add a prusik to the rope, take up the tension with the aztek then release the load back to the mainline.

    I think it would be nice not to use up an aztek with the belay each time since utilization of the LRH is generally not desirable and hopefully not common.

    thanks,
    mike

  9. #9
    Forum Member

    Join Date
    Nov 2006
    Location
    N. Ridgeville, Ohio
    Posts
    811

    Default

    I would think you would put in the same place are your normal use now. The reason for this is speed of use. If you were to put it in after the fact, it will still work. However, it will slow the operations down. It will also potentially cause a "we can get it later" attitude that could be a very big problem should a line hang up. The reason you put it inline is so that it is ready, inspected and able to be deployed immediately.
    Jason Brooks
    IAFF Local 2388
    IACOJ

  10. #10
    Forum Member

    Join Date
    Feb 2006
    Location
    Kansas
    Posts
    59

    Default

    Quote Originally Posted by stickboy42 View Post
    Here's a further question to see what you all think.
    In using the aztek as a LRH do you:

    1) put in the system behind the TPB as we do with a radium LRH or other style.

    or

    2) add it in after the TPB is locked up, add a prusik to the rope, take up the tension with the aztek then release the load back to the mainline.

    I think it would be nice not to use up an aztek with the belay each time since utilization of the LRH is generally not desirable and hopefully not common.

    thanks,
    mike
    Mike,
    Some people rig it in behind the TPB (with the G rated Aztek). Since most folks don't have a bunch of these in play, some don't like to have them locked up. I think you will find it's just as fast to have one extended enough to get in front of the locked up TPB and grab it there. You would need to wrap a prussik as your connection, but the Aztek would be extended and ready for action. This frees up the Aztek in case you need to do a change over on the mainline. In a pinch you could vector the mainline (not always possible). I don't know if one way is better than the other, you would need to try it and see what your guys like best.

  11. #11
    Forum Member

    Join Date
    Jan 2004
    Posts
    235

    Default

    I like the AZTEK very much and am absolutely a proponent of using it for a two person load. But, just as a point of clarity, the AZTEK pulleys are not G rated per the NFPA standard.

    They do, however, meet the kN requirement set forth by NFPA for a G rating. Not that it matters that much; NFPA is a manufacturer standard and not a user standard.

  12. #12
    Forum Member

    Join Date
    Nov 2006
    Location
    N. Ridgeville, Ohio
    Posts
    811

    Default

    I think the reference to G rating meant the overall system meets a G rating. You can take a non G rated pulley in a mechanical advantage system and create a G rated system. The pulley will share the loads and not see the entire force that would put it under a G rating by itself.
    Jason Brooks
    IAFF Local 2388
    IACOJ

  13. #13
    Forum Member
    stickboy42's Avatar
    Join Date
    Dec 2009
    Location
    Idaho
    Posts
    89

    Default

    Jason,
    If I read 1983 correctly the system is not what is being given the G rating but the individual components by an independent testing facility. Even though the Aztek omni pulleys meet the kN requirement for G rating they haven't been tested by an independent lab and certified as such. It is interesting to note that the single and double omni block swivel pulleys are not G rated if you purchase from Rock Exotica but if you purchase the CMC pulleys (which appear to be exactly the same, the single is SS and the double is AL) they are G rated. I wonder if CMC sent them for testing so they could put the 1983 G rating on them? Any insight from tech rescue wise ones out there?

    On the topic of the Aztek inline or after the fact here are some more thoughts:
    1) if there is a lot of line out on the belay, taking up the slack with the aztek may require more than one throw sucking up time? Any thoughts or experiences with that?
    2) inline the aztek would be under tension and only in the situation to extend and add slack.
    3) i'm going to time the various scenarios when i get a chance at work and see if there is a big difference in performance.

    my .02 again.
    -mike

  14. #14
    Forum Member

    Join Date
    Feb 2004
    Posts
    23

    Default Shock absorber function

    One feature of the BC LR hitch and the Radium Hitch is the ability to absorb some of th shock loading in the belay catching a rescue load. Does the Aztec adequetly do this? Has it been subjected to The BCBCT as part of a tandum prusk belay system and what were the results? I agree the concept looks great but I would like to see the test results before changing my rescue belays

  15. #15
    MembersZone Subscriber

    Join Date
    Jan 2003
    Location
    Pa USA
    Posts
    25

    Default

    Quote Originally Posted by basslerga View Post
    One feature of the BC LR hitch and the Radium Hitch is the ability to absorb some of th shock loading in the belay catching a rescue load. Does the Aztec adequetly do this? Has it been subjected to The BCBCT as part of a tandum prusk belay system and what were the results? I agree the concept looks great but I would like to see the test results before changing my rescue belays
    I like this thought. One one the pictures on the AZTEK page, shows them using the edge restraint end to build a radium hitch. I still wonder about the use of the SOF's as the LRH.

  16. #16
    Forum Member
    stickboy42's Avatar
    Join Date
    Dec 2009
    Location
    Idaho
    Posts
    89

    Default

    Hey basslerga and others,

    thanks for the comments. Spent a good chunk of my day looking into the shock absorbing qualities of LRH's and the studies out there on them... Doesn't look like there is a good study (at least that I can find, let me know if there is one) that addresses that specifically and makes me wonder if I should go that route...

    Anyway, here's briefly what I have learned.

    In the RfR Release Devices study they look at everything critically and conclude that the Radium LRH is really the only thing that passes muster. They don't look at the Aztek or other SOFs, probably because the whole jigger concept was fairly new at the time of the study...

    The drop test the hitches were subject to was also done on a single strand of rope without any TPB or LRH and found to be 1.9 kN above the acceptable force of 15kN. Can one conclude that a TPB w/o LRH would absorb some force bringing the total force below the desired 15kN? Probably.

    The other point brought up in the study is that maybe we don't always want absorption because it adds to the distance travelled. Something to consider especially if we can show the force w/o a LRH is within acceptable limits.

    The Radium in the test elongated 6 cm so that shows we do see some sort of absorption but was that due to cord stretching, the munter slipping, or something else? Would a Set of Fours act similarly since they are held by a 6mm prusik and not a munter? Which way is the SOF oriented would make a difference too, 3 or 4 strands in tension? Do the pulleys affect the absorption (if any)?

    Kenneth Laidlaw mentions in his "Considerations for Rope Rescue in 2008" that "The hitch [referring to Arnor's BC LRH] also acted, it was thought, as a shock absorber, increasing the safety factor of the unit. This may be just a myth with 200 kg. loads on modern ropes. Also, if this hitch did function as a shock absorber, you would increase the distance the load would travel causing increased forces." I've emailed Kenneth to see if he can expand on this statement further and will let you all know what I find out...

    I think I need to build a drop tower...

    Mike

  17. #17
    Forum Member

    Join Date
    Jul 2006
    Location
    Southern Illinois
    Posts
    133

    Default

    The purpose behind placing a releasable system in series behind the belay isn't to provide dynamics. It's to have a releasable system (if you feel you really need it). The TPB provides its own dynamics. The AZTEK Elite works well for a releasable system. Plenty strong and don't count on it slipping, as you'd want to have it dogged off anyway in this instance.

  18. #18
    Forum Member

    Join Date
    Dec 2009
    Posts
    4

    Default Gettin' rid of them thar pesky shock force in the be----lay

    I couldn't give one hoot n' a holler about shock absorption in the LRH within the belay system (for the most part). As Eric correctly points out, the LRH is a load releaser---and that is pretty much it. I know that Arnor Larson did testing in the 1980's which pretty much showed that the LRH (then called the British Columbia Hitch or BCH) absorbed heaps of energy at the LRH. I saw a 1989 video once of Reed T up on a tower with Arnor "releasing" a BCH after a factor 1.66 fall (200kg). Reed was untying the BCH post drop and lowering the mass down and reporting on anomalies found to John Dill (YOSAR) who was data-collection on the ground. It appeared that the BCH took the brunt of the impact, leaving the TPB mostly intact. Curiously, in other drops, the reverse was true and the TPB took the hit. There is a graph in the Dill 1990 "Are you Really On Belay" article from Response Mag that shows just how much the BCH "helped" the total LRH and TPB combo in absorbing shock force. If I recall, it was NOT VERY MUCH in the shorter 1 meter or under falls (a .33 FF, or 1M fall onto 3M of rope is the coveted BCCTR test standard). In most of those falls, the BCH did NOT deploy significantly enough, in my humble opinion, to warrant the headache of teaching, carrying and applying the stupid BC Hitch in our team's system. It should be noted though that in the longer drops of, say, beyond 1.5M, the BCH began to be a factor in eradicating some of the falls energy. Anyway, I may be wrong (and many times I am) but THAT is what I gleaned from the testing those three guys did.
    There are plenty of things in there that will absorb that energy in the belay. Many are in this thread. The bloody yoke knot (we use a doubled long tail bowline) is a HUGE item. Unless you're Chuck Norris, the apparent "sloshiness" of the human body patient/attendant package is big (sloshiness is one helluva word, isn't it?). The litter spider arrangement is a nice shock absorber too (we use a litter rig borrowed from RTR which has 3 on 2 prusik hitches on all four legs for that reason). For longer belays (like >150') applying tension on the belay rope is stellar for reducing potential fall distance. In fact, many times we find that using the least stretchy rope in the belay system is desirable because there is always the trade off of stopping distance vs maximum arrest force if the belay does in fact come into play. Our team of intrepid roc-jocks has lots of dynamic rope (with lots of brilliant colors to no doubt arouse the senses of the burned out trad climber!) which we ALWAYS avoid in use in the belay system. We use the rope in the belay with the least amount of stretch. Thats right--the least. We use the climbing rope for the main line (if we have no other low-stretch rope available). To us in the mountains, STOPPING DISTANCE is the watchword on the belay. Don't wanna hit somethin' on the way down! Knee caps are precious things too. Being run over by a fully loaded litter basket on the side of a mountain (or structure) seems like it would not be fun. I would rather take my chances with a higher MAF.
    I think Eric is on to something with his carefully-crafted comments (notice how he says what he means without getting all "wordy" like I am here). But Eric uses the term "dogged off" in his choice of words. My frame of reference and study of older colloquialisms from American blue collar culture indicates that Eric may be a lineman or has had close contact with linemen. There is another term which linemen use that is peculiar. A "snub", or the fact that you have "snubbed something off" indicates that you have temporarily thrown a tie off in a line coming down off of a high point (like a power line) in order to give you a slack section of rope above that tie off to work your rigging. After the rigging is complete, the snub is removed. A "snub off" therefore is different than a "dog off". I heard Reed humorously say that these types of things are "ghetto terms" which are used to indicate something to those found within that particular ghetto.
    Oh, gee...... look at the time!
    Just my two cents on the subject....

  19. #19
    Forum Member
    stickboy42's Avatar
    Join Date
    Dec 2009
    Location
    Idaho
    Posts
    89

    Default

    Eric, thanks for the comments. I'd like to have more discussion about the purpose of the LRH. Haven't most of the studies out there made mention of the shock absorption factor but yet don't come to any conclusions on it? Is it true that the only point of the LRH is to provide a release mechanism? Just my devil's advocate question for the day... One question I have is in trying to find a BCCTR drop test on a TPB w/o a LRH in the system. I'd like to see that data to satisify the physics side of my brain I'd like to see this....I would love to see the omission of a series LRH in our belay, and piggyback an aztek on if we need to but in order to make that recommendation I need to hash out all the questions our team would have and feel like I've addressed them in a relatively scientific/practical way...

    yesterday I was also talking with a guy about this and he mentioned that a possible benefit to the Radium is that it'd be a release only device where as a SOF would require a lift to release the prusik. I'm seeing that if the aztek is muled off as it should be then the prusik would most likely not set and the mule hitch would take the load and then the aztek could released w/o a raise. Is this what you've seen Eric?

    Earlypowernut, i like your comments and discussion. Especially the discussion on the short vs long falls with the BCH. I think it's interesting to note the other points of absorption you mention. We are looking revising our bridle setup which sounds similar to yours minus the DLTB (see the Litter Bridle thread).

    Yesterday I went and read the Rescue Randy vs. Steel Plates drop test paper from last year's ITRS and am intrigued by how differently the test results are with human/randy simulations vs the steel plate simulations. Makes me think that if something passes the BCCTR then if anything the MAF on the person will be significantly lower or at the minimum the same.

    Just a little rambling, thanks guys...
    Mike

  20. #20
    Forum Member

    Join Date
    Jan 2000
    Location
    Somewhere in the Backcountry...
    Posts
    176

    Thumbs up

    I just gotta say it....

    It is great to read the posts from this topic's posters. Great thinking, critical analysis, experience and all that good stuff.

    Not the typical, " never use an XYZ knot" thread.

    Stimulating reading!

  21. #21
    Forum Member
    stickboy42's Avatar
    Join Date
    Dec 2009
    Location
    Idaho
    Posts
    89

    Default

    With any belay you must always use Radium hitch tied with 33ft of 8mm static prusik cord tied around G rated steel carabiners with the munter nearest the gate and the tail daisy chained into equal 1-1/2" loops with a figure 8 on a bight in the end :-)

  22. #22
    Forum Member

    Join Date
    Nov 2006
    Location
    N. Ridgeville, Ohio
    Posts
    811

    Default

    We use the BC hitch. Ours are tied with 20-30' (long story about the variations) 10mm cord. Using one XL and one large carbiner. Very easy to tie and very easy to use. We use the same cords are our body cords for edge protection and assorted other uses.
    Jason Brooks
    IAFF Local 2388
    IACOJ

  23. #23
    Forum Member

    Join Date
    Feb 2004
    Posts
    23

    Default

    Mike
    "Build it and we will come"
    While I loved reading the discussions over whether a LRH is needed in a TPB belay system, what I really want to see is the Aztec system tested as part of a TPB system replacing the BC or Radium hitch. Testing without the TPB will mean nothing to me as I can tell by looking at the ratings of its individual components that it is strong enough, what I need to know is will it perform to the specs of the BCDTM as part of the TPB system.
    I believe Arnor, John, and thorn did test the TP belay without a LRH way back when the BC hitch was developed and had some failures. I cannot remember the details, nor do I have the original test report. I can say this, no disrespect, but if you do not know though testing if it will work, don't ask me to trust it my rescue belay systems. So if you build that tower let me know. Thanks
    George

  24. #24
    Forum Member

    Join Date
    Dec 2009
    Posts
    4

    Default

    Yes, indeed!

  25. #25
    Forum Member

    Join Date
    Jul 2006
    Location
    Southern Illinois
    Posts
    133

    Default

    Just noticed this...

    Quote Originally Posted by stickboy42 View Post
    Eric, thanks for the comments. ... Is it true that the only point of the LRH is to provide a release mechanism?
    It is to me. But otherwise, I suppose it would depend on which releasable system, the application it's being used for, who rigged it, and what's in their head at the time.

    [/QUOTE]yesterday I was also talking with a guy about this and he mentioned that a possible benefit to the Radium is that it'd be a release only device where as a SOF would require a lift to release the prusik. I'm seeing that if the aztek is muled off as it should be then the prusik would most likely not set and the mule hitch would take the load and then the aztek could released w/o a raise. Is this what you've seen Eric?
    Just a little rambling, thanks guys...
    Mike[/QUOTE]

    The lift in order to release the capture Prusik is so minimal, that it's a peripheral issue for me. Anyway, if your premise is that the belayer allowed the TPB to lock up, my first choice of fix will be to vector the main.

    If your capture Prusik is snuggly rigged as it should be, it should capture the rope, especially if you've jetted it out into hold position prior to dogging off the line. If you left a bunch of slack in the capture Prusik, the tightening/cinching of the dog-off is going to allow some rope movement to where the snug capture Prusik with slack behind it will likely capture the rope movement. But this is going to depend on the length of the capture Prusik. Sterling's factory sewn ones are nice and short, as you'll see with the AZTEK Elite. If you've an AZTEK Pro and you've tied your own, therein will lie a variable.
    In short though, just because you've dogged off the SoF's doesn't mean the capture Prusik won't hold.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. LRH Load Releasing Hitches(Rope or Web)
    By shrek85tsvfd in forum Specialized Rescue
    Replies: 19
    Last Post: 08-19-2006, 07:54 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts

Log in

Click here to log in or register