Radium Vs. Mariners

[Rush ff-132]

Hi everyone,

I was wondering if anyone knows if there would be a problem in using a radium hitch instead of a mariners knot for a load and release knot/hitch for rope and water rescue situations.

Thanks

[jdcalamia]

I prefer the 3:1 RRH to any other LRH for it's simplicity in tying and deploying. There are several documented cases of the webbing in the mariner's hitch "melting" or "fusing" when deployed under load. Another option that has recently surfaced is utilizing a device such as the Petzl ID or CMCs MPD at the anchor to replace the LRH. This allows for controlled lowering and converting to a 3:1 MA to raise w/o an LRH. Makes for a simpler operation as well as a less crowded rigging plate at the anchor. "Rigging for Rescue" did a study I believe in 1990 titled "Release-Devices: A Comparative Analysis", $20 from their web-site. They tested 32 variations of 11 release-devices. This study actually led to the development of the RRH. It's a good read and very informative. The simple fact is that the Mariner's Hitch is popular because it's really the only LRH available as a commercially prepackaged item. When actually the RRH or BC (which are the two LRHs required to be tied in the NFPA 1006 Rope Tech. curriculum currently being taught). can be constructed with 33' of 8mm prussik cord and two carabiners, which most likely are readily available in most Depts. equipment cache.

[cctrtlt2]

All of our training from the State (New York) has been on two systems. The mariners, primarly taught for low angle, and the BC hitch, for high angle. My feeling is that the BC can do everything that the mariners can, and would rather go with that.

There is also some though to using the Aztek system for a LRH. I have not done this yet, but plan to train with it and see.

We have the Petzl ID, but are just learning with it. i wish ther was a good youtube videeo of it in use.

I have an MPD on order, just not in hand yet.

For the Mariners, we always make ours, as we do not have the commercial version, and dont plan on buying any right now.

[servantleader]

Echo the first reply: The 3:1 Radium release hitch (RRH) out-performed all the other release devices tested by RFR. This testing provided evidence that the mariner's hitch might have a substantial flaw: melting/fusing of the mariner's webbing was observed in BCCTR belay competency drop tests.

In static situations, e.g. passing a knot on a lower, the mariner's hitch is probably ok, but, I wouldn't use it as the release device on the belay line. Anyways, the RRH is easy enough to tie and operate. So, why not use it anywhere a release device is needed?

[Lewiston2FF]

All of our training from the State (New York) has been on two systems. The mariners, primarly taught for low angle, and the BC hitch, for high angle. My feeling is that the BC can do everything that the mariners can, and would rather go with that.

There is also some though to using the Aztek system for a LRH. I have not done this yet, but plan to train with it and see.

We have the Petzl ID, but are just learning with it. i wish ther was a good youtube videeo of it in use.

I have an MPD on order, just not in hand yet.

For the Mariners, we always make ours, as we do not have the commercial version, and dont plan on buying any right now.

I have heard that the State is beginning to teach the RRH as part of the Intermediate and Advanced rope classes. I have also heard that the state has revised the curriculum and will be changing the class starting next year. Minor changes from what I heard but there will be some changes.

[cctrtlt2]

The state needs to update the courses. The radium was talked about, as " one of the other hitches out there", but no instruction. One of our last instructors is real fond of the petzl ID, and said that will be getting brought into the program.

i also hear rumor of maybe a 16 hour tower rescue class, but nothing firm on that one.

[Lewiston2FF]

The state needs to update the courses. The radium was talked about, as " one of the other hitches out there", but no instruction. One of our last instructors is real fond of the petzl ID, and said that will be getting brought into the program.

i also hear rumor of maybe a 16 hour tower rescue class, but nothing firm on that one.

I absolutely think the state needs to update the program. I believe from the state instructors I know that is in the process of happening. I think instead of the RRH being mentioned as "one of the other LRHs out there" it will be discussed in depth. It would be nice if the Petzl ID is included as well. They mentioned mechanical devices for both ascending and descending but thats all it was. In fact they said mechanical rope grabs were prohibited in state classes. Heres hoping the state instructors get together and re-write it so that things are more up to date.

I would be interested in a 16 hour tower class if one is offered. Lots of towers around here. It would certainly be another tool in the box!

[cctrtlt2]

The only thing that rope grabs, Gibbs, were even allowed for is to ascend. Funny thing though, i just helped to teach a Rescue TEch Basic course here, and in the state manual, they show the gibbs as an aceptable alternative for a prussik in a low angle system.

The only thing my team carries them for is ascending though.

[jdcalamia]

When a Gibbs fails it either cuts rope (2000 lbs of force) or comes apart into pieces. When a prusik fails it melts to the line and stops the system. I'll take prusik anytime.

[GTRider245]

When a Gibbs fails it either cuts rope (2000 lbs of force) or comes apart into pieces. When a prusik fails it melts to the line and stops the system. I'll take prusik anytime.

Ditto.

We were taught in Rope Technician to use the 3:1 RRH for load release as well. Since then, I have had a chance to use both the Aztec and the Petzl i'D as a LR device, and both work well. Using a device like the i'D cuts down on needed equipment and lets you do multiple jobs with one device.

I like it.

[Always_learning]

Hello all,
I've been following the thread but I'm lost at how the ID is being used in the same manner as the LRH?
How are you using it, is it just rigged into the line at the anchor as a static rappel line, locked and when needed it is released (Contingency Anchor)?
Just playing catch up..ha-ha

[stickboy42]

Always_learning,
The I'D would be used as the belay device as well as a load release mechanism. In the case of loaded belay line you would simply use the I'D as a descent control device until the load is transferred back to the main line.

There has been discussion on this and whether the I'D is acceptable as a belay device, some believe it is and some don't. Here's a link to that discussion (I'D discussion near the bottom): http://www.facebook.com/topic.php?ui...58&topic=11725

-mike