System Safety Factors

[irons308]

What are the feelings of the rope rescue guys about differing SSF for high angle, low angle, and Con-Space. We have been kicking around the notion of using a 15:1 SSF for high angle, 10:1 for low angle/and Con-space. Just looking for opinions, to fuel thinking

[bolt109]

Irons, it would be very difficult in my opinion to have a SSSF of 15:1 due to the fact that NFPA rated ropes are usually only 15:1 ratio, I know if you used a 5/8" line it might possible but as soon as you knot that rope it is going to drop your safety factor below 15:1 right off the bat, also most carabiners aren't rated that strong either, if you think about a 180 degree change of direction with a two man load (600lbs.) that is going to be 1200 lbs. at that change of direction which means you would need a carabiner and pulley with a minimum breaking strength of 18,000 lbs. to get your SSSF to 15:1,so in my opinion 15:1 SSSF is almost impossible to achieve and again in my opinion it is overkill, I think 10:1 is much more possible and is plenty of safety factor as long as your tending your lines right to keep from any large amount dynamic loading in the event of a failure, on this subject I'm curious to see what others input is as I have been toying with this myself and as I've said I try to build my systems to 10:1, now I must also ask are you talking about the safety factor you are planning on building into your systems or the safety factor that you would like to have built into the equipment your purchasing?

[irons308]

Both I guess, our planning is in such an incipient phase, that I was just curious. After I had received more formal ropes training, is when I realized how out in left field the NFPA is in terms of rope rescue. I do not have the codes in front of me; Does NFPA state that Fire Service needs to maintain a 15:1 SSF, and/or if all G(2 person) rated equipment have a 15:1 SSF?

[bolt109]

Irons,
There used to be a 15:1 standard in NFPA 1983 that applied to life safety rope, however that is no longer in NFPA 1983, and no must of the hardware MBS that NFPA 1983 states as General use is less than 15:1, especially on descenders and rope grabs, and something else interesting is there is nothing about webbing in this standard, as for any other NFPA codes I've looked through 1670 and 1006 and never seen anything about a SSSF, however I've heard that NFPA recomends a 10:1 SSSF however I've never seen this in writing, anyway take a look at 1983 you'll be suprised about some of the MBS required for "G" rated equipment

[irons308]

Thanks for the info, I find it also unnerving that NFPA does not have any standard practice for bottom belay, for climbing, in either 1006 or 1670. Does anybody know what gives, this could potentially be the most dangerous part or a rope rescue.

[DCFDRescue2]

Are you wondering why it says nothing about bottom belay, or are you glad that it is not in the standard?

[ADSNWFLD]

Equipment and procedures need to be jurisdiction relevent. steel carabiners and big ropes are fine and safe but if you have to hike a mile to get to a victim or climb 1,000 vertical feet then the weight is prohibitive. As for the bottom belay, without looking through 1670 or 1006 it doesn't spell out specific techniques for any skills. If your trained in bottom belay for climbing then use it. By us we don't have any mountains, our lead climbing is limited to water towers and radio masts. Once the first guy is up he sends down a belay line and handles it from the top. So without the mountain experience we have never needed a bottom belay. We used to use a bottom belay technique when our primary decender was the figure 8, but that's about it.
In our environment we make sure our systems pass the whistle test. In otherwords if someone blew a whistle and everyone let go the rescuer or victim wouldn't drop to his death.
As for the 15:1 their is just to much stuff that is far under that. Learn the system its limitations and capacities and make the best choice based on that info.
Just a general question, does anyone's sop's allow a rescuer to go without a belay/safety line? Do you guys use separate safetys for every rescuer and victim, or do you combine them?

[mcaldwell]

I used to think that we needed to try and maintain the 15:1 margin for the entire system, but was corrected a while ago to the fact that it was for the rope only.

You are right in that we cannot maintain that margin across the board with standard systems.


We still use the steel gear and 16mm rope for most of our high angle and over the bank work. I like the confidence in the system, and the knowledge that we can overload it a little if we needed to raise or lower a basket full of extrication tools, etc.

We do however, also keep a backpack kit of lightweight gear and 13mm rope for the remote backcountry stuff. It is simply impractical to try and carry the big stuff in on foot, and I'm confident that we have left the original intent of the NFPA margin (i.e. compensation for a heavy, bunkered FF) behind, and are working within the BC SAR reccomendations.

[jbrescue]

A lot of good discussion here and more to come I am sure. We use a belay for everything unless it is a hazard. Confined space is the only place that I can truly think of this happening. We do not use independent belays for victim and rescuer. We can share as llong as each person has two attachment points to the system. We rig to the basket and the victim and the basket and the rescuer. Pick offs get a belay that ends up either only to the rescuer or to both, but either way, they get two points of attachment (pickoff strap and daisy chain). We use 1/2" (13mm) for everything, there is talk of going to 7/16" (11mm) for some stuff. We have two teams in our immediate area. The other team uses 7/16" for tower. We feel that one rope and no mistakes can be made by putting it in the wrong place.

A two person load is no longer defined as 600#, it is a two person load. Most rope guys aren't that big. And we are not wearing full turnouts and SCBA. That being said, you can even use 7/16" for a two person load if you get NFPA rated ropeand still maintain a 10:1 factor. Make sure all or your hardware is G rated, unless it is for one person use. We tend to make sure that everything is G rated for the KISS factor. There are even steel biners available now that are almost as light as aluminum and G rated.

[irons308]

I agree that 7/16" rope is strong enough for 2 people, however with the addition of knots the strength would be reduced. This would mean that a 7/16" rope with a breaking strength of 6000lbs, would be reduced to 4800lb breaking strength with one figure 8(20% loss?) tied into it.

It is my worry that with the sue happy culture we live in, that if we dont follow nationally recognized standard(i.e. NFPA 1983) we will be setting ourselves up for problems. What are the thoughts of legal implications of deviation from the standard.

I agree that mountaineering techniques and practices have a place in the fire service. These techniques are developed and honed by those who are far more educated and experienced than the above average rescue firefighter, however are there standards that mountaineers follow that would hold up equally to NFPA 1983?

[jbrescue]

What are you referring to? I believe the verbage of NFPA 1983 changed so that it does not refer to a two person load as 600#, but an actual 2 person load. So how are we deviating from it with 7/16" rope situation dependent?

[jmatthe2]

I was scanning the forum and have a couple of quick notes to add.

The old 15:1 rope safety factor in NFPA 1983 was an implied standard to the manufacturers. A 9,000 lb rope with a 600 pound load is a 15:1 SF. THis has all been deleted in newer versions of the standard and all that remains is that a general use rope should not break at less than 40kN.

NFPA 1983 is a manufacturers standard and not a users standard. It is a great guide to see how strong a product is suppossed to be as well as understanding G, L, and E uses.

No NFPA standard sets a system safety factor (SSF). I can tell you most teams use 10:1 and have been known to go done to 8:1. While NFPA no longer states a load size, it is common practice to expect a General (G) load is 600 lb, and a Light (L) is 300.

From talking to some folks NFPA changed language to allow a rescuer more flexibility. Frankly, I think are doing a pretty good job. Someone commented about no NFPA info on a bottom belay. WHy should there be? NFPA 1006 states you should be able to belay a falling load. They don't tell you how, that's up to you Mr. Rope Technician!

Climbing is not addressed perse. NFPA 1983 states that the standard is good up to a fall factor of .3. (Going of memory so may be off) Again, NFPA isn't there to train you on how to climb, but NFPA 1006 says you must ascend rope. There are other standards for climbing gear such as the UIAA. Structural climbing can be "figured out" using OSHA. Rock climbing is thought of as entertainment and I doubt it will become part of NFPA for some time.

[bolt109]

NFPA no longer states a 300 lb. rescuer load, however 1983 (06ed.) requires when doing testing manufacturers use a 300 lb. test dumby, and the 15:1 statement I believe was removed in 1995, however the strength of life safety rope is still the same 15:1 but this is for Life Safety Rope ONLY not the system it's being used in, and as for using 11mm rope, I think that's risky business while I agree that most rescuers are not 300 lbs. if you figure the weight of all of our gear that is also being supported by the System (rope 10lbs./100', harness, carabiners, pulleys, basket, etc.) I think that in a rescue situation when all of this is present, that the rescuer along with gear certainly comes close to 300 lbs., I work in an urban area and do not have far to carry gear so I would much prefer the extra safety factor as opposed to hurting someone, however I sympathize with mountain rescue groups as mountaineering is a passion and a couple pounds can mean alot when hiking 6 miles, 1983 (06ed.) does list a statement that frees mountain rescue oragnizations from using 1983 equipment as well as some other organizations, and 1983 is definatly a manufacturer's document, however if you belong to an NFPA organization I think that NFPA 1983 is a relevant document when deciding what equipment to buy and use, again this is a great disscusion topic and I am certainly benefiting from alot of these posts, so stay safe till next time

[jmatthe2]

Bolt - You sum it up nice.

Since the standard exists and organizations are familiar with the 1983 standard, they would be crazy to not purchase 1983 equipment or deviate from use guidelines.

[irons308]

What are you referring to? I believe the verbage of NFPA 1983 changed so that it does not refer to a two person load as 600#, but an actual 2 person load. So how are we deviating from it with 7/16" rope situation dependent?

I hope you didnt think I was being critical. I was just theorizing that if a 7/16" rope had a 20% loss of strength, it would be rated for 4800lbs. A 10:1 ratio creates 480lb working strength, I felt it may be a little weak.

The reason for my concern with NFPA not addressing bottom belay is selfish, my state fire academy will not teach bottom belay/or lead climbing due to the fact that it is not outlined in 1006. Just have to get private instruction I guess.

[jmatthe2]

Irons308 - Personally, I feel there is limited need for the use of an 8 plate descender in rope rescue, thus eliminating the need to train on bottom belay. (Although I will say it is a good team cofidence exercise.)There are simply too many better ways to get the job done safer. However, if your academy uses 1006 as the reason NOT to teach it they are misinformed. As you know, NFPA is performance based. It says you have to belay a load. Not how you will belay the load.

When you mention lead climbing are you talking towers or rock? I would expect tower climbing to be included in furture editions of 1006, although it will not be in version coming out in 08.

I agree with your assessment on the 7/16" rope and don't think it would be the best choice for fire service based rope rescue. Most department's don't spend enough on rope to work with such small safety ratios.

[jbrescue]

My personal concern with 7/16" rope is for a two person load. The decreased friction on your brake rack is pretty significant. Try it in training, you go faster and have less control than with 1/2" rope. Just because the standard has changed and you can now use 7/16" doesn't mean that it is a good idea fr rescue situations. I know that nobody has been critical in this post. I think that this has been a good exchange and that there is a ton of great knowledge and experience here. I am a big advocate of only using G rated gear. This way there is no chance of putting the wrong hardware in the wrong spot. I know that even our team talks about weight and aluminum biners. I just don't want any chance of one of my guys needing something and using what is on there waist at the wrong time. There are steel biners out there now that are G rated and alost as light as aluminum. Safetey is important. Forget the victim, protect yourself and your crew.

[irons308]

[QUOTE=jmatthe2;872923]

When you mention lead climbing are you talking towers or rock? I would expect tower climbing to be included in furture editions of 1006, although it will not be in version coming out in 08.



I am talking mostly about tower rescues, I think it would be rare to have to lead climb on a rock in a rescue situation, in most fire service districts. Could you imagine the cost of a "G" rated removable anchors.

As for 7/16" rope if it is smoothed from use, at 225 with a Rescue 8 I have some trouble with even stopping to lock off. I agree with jbrescue that reduce friction is almost as important as the breaking strength. We have also started buying only "G" rated gear to reduce confusion with the less trained guys.

Great discussion, it has made me dust of some of the old text books.

[MtnRsq]

[QUOTE=jmatthe2;872923]

When you mention lead climbing are you talking towers or rock? I would expect tower climbing to be included in furture editions of 1006, although it will not be in version coming out in 08.

I am talking mostly about tower rescues, I think it would be rare to have to lead climb on a rock in a rescue situation, in most fire service districts. Could you imagine the cost of a "G" rated removable anchors.

As for 7/16" rope if it is smoothed from use, at 225 with a Rescue 8 I have some trouble with even stopping to lock off. I agree with jbrescue that reduce friction is almost as important as the breaking strength. We have also started buying only "G" rated gear to reduce confusion with the less trained guys.

Great discussion, it has made me dust of some of the old text books.

Rescues invovling lead climbing situations introduce a whole additional set of concerns that need to be understood and planned for. IF you have areas where a climbing-based rescue might be required you'd do well to do some extensive pre-planning.

The introduction of dynamic ropes, removable anchors (rock/snow/ice), etc. all need to be planned and trained for. I would tend to agree with the comments that most fire-based rescue organizations are not likely to need this capability. Those areas that do tend to have specialty teams that are trained to handle these rescues.

Most mountain rescue teams tend to use 10:1 as their normal static safety factor. Some situations may result in systems with far less than that, but these systems are typically being built and run by rescuers with substantial experience.

Striving to build systems with the highest margins of safety should always be the goal. Factors, like the anchors themseleves, may limit your SSSF. Being able to recognize a marginal situation should be the first thing in addressing how you can improve the safety of the operation.

I have seen more than one "experienced" rescuer assume all is OK 'cause they clipped a G-rated 'biner into a system where the underlying anchor is likely to blow at 20% of the 'biner's MBS.

I've also seen rescuers spend 45 minutes trying to build a bombproof 15:1 anchor while the hypothermic victim waits.....