Thread: 5/8" Lifeline

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    Default 5/8" Lifeline

    I was looking to see if anyone had some ideas on what to use 5/8" static kernmantile lifeline rope with. My dept has had 2 bags of it never used excellent condition, but we have all 1/2" rope we use for rescues. I was just looking for some ideas that we could use it with in our operations.

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    We also carry two 5/8 ropes one is 300' one is 600' (way to heavy to be very mobile). We mainly use them for highline operations as the mainline. 5/8 seems to be too large for most routine operations but i do think it is very useful in the high stress loads applied during highline operations. IF this isn't what you were looking for please clarify.

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    We dont do highlines as of yet. We have 2 150' lines. Im just looking for some ideas on how to integrate them into our operations. Highline use is a great idea due to the strength of it. I wasnt looking into anything specific, just things we could use them with.

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    Quote Originally Posted by CaptDon View Post
    I was looking to see if anyone had some ideas on what to use 5/8" static kernmantile lifeline rope with.
    Use it for vehicle tow lines.

    It's heavy, unwieldy, and incompatible with most rescue hardware (with the exception of kootenay carriages). Given the 9000+ lbs strength of 1/2" kernmantle, there's no reason to include 5/8 rope in a rescue cache.

    - Robert
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    You hit the nail on the head. 5/8" is too cumbersome and not needed. 1/2" NFPA rope is more than enough. Just be careful that it is certified rope. That guarantees minimum breaking strengths that we need and expect. Uncertified rope may break at lower numbers.

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    Quote Originally Posted by jbrescue View Post
    Just be careful that it is certified rope...Uncertified rope may break at lower numbers.
    This is an unfortunate misunderstanding. If your AJH (agency having jurisdiction) requires NFPA certification, then you must use rope with the NFPA manufacturer's label.

    If, however, you only need to make sure that your rope meets of exceeds the NFPA standards (9,000 lbs mbs for general use rope), then you can go by the manufacturer's in-house testing and certification of rope strength. The manufacturer's rated rope strength is typically less than its actual tested strength, as all manufacturers are conservative in their advertised specs.

    No manufacturer is going to risk the liability of advertising rope at a strength rating that it does not meet or exceed, and as long as the end user is working within the manufacturer's specifications and recommendations, then there will be no liability to the user.

    In some cases, NFPA certified equipment (such as SMC's locking D carabiners) are identical to their non-certified carabiners except in price. You pay more for that NFPA stamp, but you don't get any more.

    - Robert
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    I totally agree, that is not what I meant. If you get NFPA certified 1/2" rope, it will be rated for at least 9000#. Some of the non rated ropes are rated for a lot less weight. It gets more pronounced at the smaller diameter ropes. If you look at 7/16" rope for example. Lots of them out there are intended for single person loads. However the rated ropes have higher breaking strengths. Many of the non rated ropes have significantly lower numbers. I will always recommend doing your own testing if you choose new ropes or brands. We are fortunate enough to have a guy in our area that does this type of testing frequently.

    Jason

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    Quote Originally Posted by jbrescue View Post
    If you look at 7/16" rope for example. Lots of them out there are intended for single person loads.
    I'm not sure what you mean by "non-rated" since all rope manufacturers rate their rope by either MBS (static line) or number of falls (dynamic line).

    7/16" rope has been the standard in mountaineering, caving and mountain, cave and water rescue for decades, from the early goldline laid rope to the modern kernmantle, both nylon and polyester. 7/16" rope (unless NFPA certified) is not rated for single person loads (as that's an NFPA standard), but for a specified MBS or, occassionally a SWL or WLL.

    In mountain and cave rescue, 7/16" (11mm) static rope is often used for two-person loads and even highlines. The only reason NFPA rope is specified as 1/2" and 9,000 lbs MBS is because of their unsually high 15:1 SF. Mountain and cave rescue is based on a much more reasonable 10:1 SF.

    The more significant limits for 7/16" rope are stretch and gripability, not strength.

    - Robert
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    I would not use it in a normal "Rescue Rigging System"... I would stick to the 1/2 inch Rescue Rope.

    But since you have it and you want to use it...I would maybe use it in anchor systems where you dont want to use up your 1/2 inch Rescue Rope. We have a couple "High Rises" in our City that have nothing on the roof to anchor to except the elevator house. What we do is a very large double wrap around the house with rescue rope as the anchor. This would be a good use for your 5/8 inch rope.

    If you cut it up into sections and make loops from it you will have very nice anchor straps.

    We use that size rope for alot of things in the USAR field (structural collapse stuff). Tie backs and anchoring in place or lifting of heavy things.

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    The new NFPA standard has changed for rescue rope. It no longer specifies that 1/2" is two person load. They based that old information on 300# rescuer and victim. They have actually rethought this since most rescue guys are smaller. This allows you to use NFPA rate 7/16" rope for a two person rope. What I was saying was related to that. The NFPA rated 7/16" ropes all have very similar breaking ratings. The non-rated ropes can be all over the place for their breaking strengths. For instance, PMI 7/16" has a 6550 mbs. While Sterling HTP has a 7667 mbs. Most 1/2" ropes are much closer in ratings. These are both NFPA rated ropes. Just be careful what you buy and make sure that everyone using it knows the limitations.
    Jason Brooks
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    IACOJ

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    Quote Originally Posted by jbrescue View Post
    The new NFPA standard has changed for rescue rope. It no longer specifies that 1/2" is two person load.
    Actually the NFPA 1983 standard (2006 revision) has only eliminated the terms "one-person" and "two-person" but has not changed the standards. The two categories are now called "light use" and "general use", indicating that the issue is not how many people are on the rope but how much weight.

    The SWL standards, however, are the the same as they've always been and so is the implied SF of 15:1. Light use is still SWL of 300 lbs and general use SWL of 600 lbs (sections 6.5.2.2 and 6.5.2.3), and light use rope must have an MBS of 20kN (approx. 4500 lbs or 15 x SWL) and general use rope must have an MBS of 40kN (approx. 9000 lbs or 15x SWL).

    This allows you to use NFPA rate 7/16" rope for a two person rope.
    General use rope must still have a diameter between 1/2" and 5/8" (section 7.1.4). This is for abrasion and cutting resistance and for gripability.

    3/8" to 7/16" rope can be used for light use applications if it meets the strength and stretch requirements (sections 7.1.1 and 7.1.3).

    - Robert
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    The NFPA 1983 (2006) does not reference a SWL for ropes any more. It simply indicates MBS, elongation and size criteria. This is why you will now see manufacturers listing different SWL numbers for their ropes. Sterling, for example, uses a 10:1 safety factor when suggesting SWL's. General use ropes can now be as small as 11mm(7/16). The technical committee made this move to make way for new technology in rope construction that may result in a smaller rope that meets the strength and elongation requirements.

    http://www.sterlingrope.com/2005/sup...nicalspecs.pdf

    http://www.cmcrescue.com/assets/repo....00.110806.pdf

    The 15:1 worked with the understanding that when you tie a knot in the rope, you end up with about a 10:1 safety factor. The problem was, when you rig a highline track rope without any knots, you were still handcuffed by the 600lbf limitation. In reality you can go up to 900lbf and have the same margin of safety. The new language allows for this.

    SWL's are still indicated for auxilliary system components and still use the 300lb and 600lb figures. However, it is possible to have a device that falls somewhere in between the two values. The Petzl Id ("L" version) has a SWL of 550lbs. Not quite enought to make the G rating but can still be used for rescue loads.
    Sometimes, in order to make an operation idiot proof, you must remove the idiot!

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    Quote Originally Posted by resqtek View Post
    The NFPA 1983 (2006) does not reference a SWL for ropes any more.
    No, but neither did it ever specifically reference a 15:1 SF. It was implied by the 9000lb MBS and the 600lb SWL.

    The current version still defines general use, in the sections on accessory devices and carabiners, as 600 lbs working load and light use as 300 lbs. By implication, these are still the limits for general and light use, otherwise accessory equipment would be over capacity.

    General use ropes can now be as small as 11mm(7/16).
    Unless the language was changed since the 2006 Draft, section 7.1.4 states: "General-use life safety rope shall be tested for size as specified in Section 9.1 of Cordage Institute Standard CI 1801, Low Stretch and Static Kernmantle Life Safety Rope, and shall have a diameter of 12.5 mm (1/2 in.) or greater and less than or equal to 16 mm (5/8 in.). For the purpose of reporting, the calculated diameter of all new life safety rope shall be rounded to the nearest 0.5 mm (1/64 in.)."

    The 15:1 worked with the understanding that when you tie a knot in the rope, you end up with about a 10:1 safety factor.
    This rationale makes no sense since the universally recognized 10:1 SF already takes account of knot weakening of rope. The NFPA 15:1 standard exceeded any such standard in the world by 50% and was always excessive.

    SWL's are still indicated for auxilliary system components and still use the 300lb and 600lb figures. However, it is possible to have a device that falls somewhere in between the two values. The Petzl Id ("L" version) has a SWL of 550lbs. Not quite enought to make the G rating but can still be used for rescue loads.
    The standard for auxilliary equipment is explicit about requiring a 600lbs SWL, and in fact the new Petzl I'D "L" is rated at 600 lbs (2.67 kN).

    http://en.petzl.com/ProduitsServices..._D20900-04.pdf

    - Robert
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    Quote Originally Posted by Riversong View Post
    No, but neither did it ever specifically reference a 15:1 SF. It was implied by the 9000lb MBS and the 600lb SWL.

    The current version still defines general use, in the sections on accessory devices and carabiners, as 600 lbs working load and light use as 300 lbs. By implication, these are still the limits for general and light use, otherwise accessory equipment would be over capacity.
    I agree that there is a possibilty for overloading aux. components but there are ways to rig systems to account for this, which is why the Tech. Committee did not want to handcuff us. Also,some manufacturers will actually list the SWL higher than 600lb(2.67kn) which is acceptable as well.

    Quote Originally Posted by Riversong View Post
    Unless the language was changed since the 2006 Draft, section 7.1.4 states: "General-use life safety rope shall be tested for size as specified in Section 9.1 of Cordage Institute Standard CI 1801, Low Stretch and Static Kernmantle Life Safety Rope, and shall have a diameter of 12.5 mm (1/2 in.) or greater and less than or equal to 16 mm (5/8 in.). For the purpose of reporting, the calculated diameter of all new life safety rope shall be rounded to the nearest 0.5 mm (1/64 in.)."
    Apparantly it has. The standard states:
    7.1.4* General-use life safety rope shall be tested for size as specified in Section 9.1 of Cordage Institute Standard CI 1801, Low Stretch and Static Kernmantle Life Safety Rope, and shall have a diameter of 11 mm ( in.) or greater but less than or equal to 16 mm ( in.). For the purpose of reporting, the calculated diameter of all new life safety rope shall be rounded to the nearest 0.5 mm ( in.).

    Quote Originally Posted by Riversong View Post
    This rationale makes no sense since the universally recognized 10:1 SF already takes account of knot weakening of rope. The NFPA 15:1 standard exceeded any such standard in the world by 50% and was always excessive.
    NFPA=ridiculously simple. If you take a 40kn rope and tie a knot in it, you now have roughly 28kn strength. If I tell a firefighter that he can only put 2.67kn of tension on that rope, I can assume that the operation will be safe because a 10:1 SSSF is still being met. If however, I tell him that he can put up to 4kn on it, there could be trouble if knot weakening is not accounted for.

    The firefighters that can not perform a system analysis to determine whether or not the system is safe can always go the cookie cutter route and just use NFPA G equipment and maintain the 600lb SWL.

    Wouldn't it just be easier to state a safety factor? I don't know why they couldn't have gone with the universally accepted 10:1 as you stated. I think there is actually an ASTM standard on safety factor within the F32 search and rescue standards.

    Quote Originally Posted by Riversong View Post
    The standard for auxilliary equipment is explicit about requiring a 600lbs SWL, and in fact the new Petzl I'D "L" is rated at 600 lbs (2.67 kN).

    http://en.petzl.com/ProduitsServices..._D20900-04.pdf

    - Robert
    When I referred to the "L" version, I meant the one that is certified to 1983 class "L". It has a 550lb SWL even though the NFPA states 300lbs. This is an example of the manufacturer giving actual user information. It falls 50lbs shy of meeting the "G" requirements. This does not mean that I can only use it with up to 300lbs. I still would like to see the words "at least" placed in front of the 300lb and 600lb SWL language to clarify this.

    Lets keep in mind that the 1983 standard was not intended to be a user standard and the recent changes to the language were intended to reflect that. The tech. copmmittee has recognized the widespread misuse of the standard and are trying to fix the problem by removing language that implies any user requirements. It is up to the manufacturer to tell us how tio use their equipment, not the NFPA.
    Sometimes, in order to make an operation idiot proof, you must remove the idiot!

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    Quote Originally Posted by resqtek View Post
    .......Lets keep in mind that the 1983 standard was not intended to be a user standard and the recent changes to the language were intended to reflect that. The tech. copmmittee has recognized the widespread misuse of the standard and are trying to fix the problem by removing language that implies any user requirements. It is up to the manufacturer to tell us how tio use their equipment, not the NFPA.
    A definite move in the right direction. It will only take a generation or so for the confusion and misunderstanding to work through the system!

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