Basket setup?

[JAFA62]

I have just come across an article on a SARBAC site and they talk about where to connect carabiners to a Stokes or Litter basket. They are suggesting not to directly connect the carabiner to the basket it self. And heres why?
One,- is poor load distribution in the carabiner causing point loading - a dynamic force will cause the weaker of the two materials to crack or break.

Two,- a static load can even cause cracking of the litter frame or carabiner.

They suggest you attach webbing in your connection points then attach carabiner there. Has any one heard of this before. And what do you use?

[ADSNWFLD]

This is one of the few times we use metal on metal. We attach the carabiner to the rail (gate down and in). If your using a real rescue litter (not the orange FERNO) then I can't imagine how much it would have to be used before you had a problem.
The straps or rope you use will twist a bit so I don't see where the forces to damage the litter are comming from.

Do you have a link to the site?

[mcaldwell]

We have both in service.

Our old light-duty aluminum baskets and fernos have webbing on them, but our new Gazelle does not. The Gazelle has relatively sharp eyelets for the beaners to clip to, and I think the webbing would be more of a failure risk than the beaners.

[JAFA62]

This is the site I found it on. http://www.sarbc.org/sarbc/rope1.html

Our Department uses the Bradco Basket made by International Rescue Systems and we connect the carabiner directly to the basket as well gate in. Maybe Im reading this article wrong however I would still stick with carabiner directly to our basket.

[DCFDRescue2]

I've heard of this before. The logic is that the radii of the biners and basket rail aren't the same and you therefore are placing all of the weight on to very small portions of the rail where the biner and the rail touch. I don't know if this has ever actually been a problem since we are only dealing with a two person load (generally), but I understand the logic in the argument.

On the other side ofthe coin, you are adding an extra step in the whole process and eating up valuable head space when coming out of a hole or over an edge.

[herbroberson]

The article you refer to has been on the BCSAR site for several years. I understand the information they put forward, but am just wondering if anyone any where has ever had a problem with this type of fracture to their baskets or their 'biners? I am no engineer but I it would seem to me that this would be more of a problem with aluminum 'biners and hardware than with steel. Just wondering...looking forward to the comments!:rolleyes:

[jmatthe2]

herbroberson - You beat me to this point. I was wondering the same thing. I also agree with the comment that was made with regard to using webbing on the basket. The longer the bridle and its connection to the system and the basket, the more difficult edge transitions can be.

I am wondering what fall factor was used in gaining the information in the acrticle. Basket work is faily precise and baring a total failure of a line, and poor belay operator, I can't imagine a drop that would create such damage to a basket with 4 points of attachement to distribute the shock.

I will say this...If you are concerned about a basket or carabiner failure tie the secondary to the victim and not to the basket. This way if there is a catastrophic failure the victim is still connected to the system. The rescuer should be tied into the belay and most likely into the bull ring that connects the basket rigging to the primary and secondary systems.

[Geinandputitout]

We lace the basket with a rescue rope, and then put an eight on a bite to tie off to the system. In training we attach a back-up line directly to the victim. It's not required during emergency response per our SOP, but the back-up line is usually applied during rescues as well.

[jmatthe2]

North Carolina teaches similar "alternative" means of basket lacing with a section of rope. It is taught more from a "minimalist" perspective than out of fear of basket failure.

[ADSNWFLD]

I just don't know where these incidents have occurred. A steel NFPA G rated carabiner is tested by using metal bars and having the force applied. I would like to know how this setup is going to generate forces over 10,000 lbs to damage the carabiner? Wouldn't you get some failure of something else first?
I don't like the idea of webbing because of the risk of abrasion between the liter rail and a wall, cliff face, etc.
Not to sould like a doubting Thomas but I want to see the indentation or cracks alaong with the scenario that created the problem.

[MtnRsq]

It's been a while since I weighed in on these forums, but this is one of those areas where we need to step back and apply a bit of critical thinking.

Is there a risk associated with point loading between 'biners and basket rails? No doubt. Is the risk significant? I would like to see more objective evidence before I was convinced.

I agree with others that soft connections, e.g., webbing are potentially subject to significant abrasion problems - particularly connection points close to a face/wall where it may be difficult for an attendant to keep the basket's inside rail from contacting the surface. It takes very little for webbing rubbing against a rough surface under tension to abrade to the point of failure or serious compromise.

Depending on the conditions in which you operate, I would bet that abrasion risk would top 'biner/rail failure. Given other factors that must be considered when rigging this isn't going to be a biggie. Age and condition of equipment and other factors should be considered of course.

Good questions and it's nice to see some questioning. Blind acceptance of dogma is a problem in the rope rescue area.

[FIRELT03]

As mentioned above the use of a soft link usually will cause a failure prior to a carabiner breaking due to the abrasion. With that being said having taught tech rescue for a few years at a sate academy we teach a solid contact with the basket, the litter bridle will take twisting before it reaches the rail itself, as mentioned above the gate should be down and in to alleviate unlocking on it's own. We also discuss a belay through the bridle onto the harness of the victim, one could also use a secondary attachment point off the rescuers belay for this. Either way would work, as with most techical rescue thou, it comes down to local options and personal opinion as long as you do not exceed the manufacturers recommended uses of their product and stay within the guidelines of the piece of equipment being used. With all that being said no one can say right or wrong to a positive connection point which may change from time to time depending on th eenviron,ment in which it is being used

[Riversong]

I would like to know how this setup is going to generate forces over 10,000 lbs to damage the carabiner? Wouldn't you get some failure of something else first?
Yes, the failure - if it were to occur - would be of the litter rails which are either smaller rod or hollow tubing.

I don't like the idea of webbing because of the risk of abrasion between the liter rail and a wall, cliff face, etc.
I agree that webbing would be problematic, but I would not hesitate to use cordage for soft tie-ins (and I keep four adjustable purcell prusiks hitched onto my litter rails, mostly for steep angle raises, as attendant tie-ins).

I also agree that the "problem" is overstated in the SARBC article, as it's written from a climber's perspective based on the linking of aluminum biners and the potential for substantial falls and fall forces.

It is, however, worth keeping in mind. I use round-stock steel carabiners with an internal radius closely matching the radius on the 1" diameter SS top tubing of my Titan Traverse litter. Doesn't hurt to keep the mismatch to a minimum and reduce the potential for damage to the litter rails, which would happen only in the event of a significant fall and shock loading.

- Robert

[Riversong]

Reed Thorne, of Ropes That Rescue in Sedona AZ, has gone away from using hard links on his Titan litters. As you'll note in this picture, small diameter cordage is hitched around the vertical struts to prevent abrasion.

The new Titan litters incorporate interior welded eyes to keep all bridle rigging inboard of the top rails, whether carabiner or soft link.

You'll also notice that he uses tied-off jiggers to the litter bridle to allow changing the litter angle or performing a patient scoop.

http://www.ropesthatrescue.com/images/ASRW06monty.jpg

[herbroberson]

I also notice that the cord attachments are on a smaller D space bar which is somewhat protected from abrasion by the larger tubular railing. Man, there are SO many ways to SAFELY do rigging. Brings me back to a statement in another thread a long while back...Two basic rules I always ask...1) Is it safe and 2) Does it work in an efficient manner! Just me thinking out loud again:) ...