ffj's journal II Rope Rescue Technician

What skills to learn, what tools to get
ffj
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ffj's journal II Rope Rescue Technician

Post by ffj » Tue Sep 05, 2017 11:59 am

This is going to be an experiment which I hope benefits not only myself but also others who happen to read it. I'll be curious to see how many people who would actually be interested in this subject on this type of forum but let me explain myself:

I am a Rope Rescue Technician who teaches this subject for the fire service. I want to write a book to make this subject clear for my students as well as anyone who works with rope. There are a number of books already written on the subject but I personally find them lacking in many cases, especially for firefighters who have to learn this discipline in addition to the multitude of other skills they have to acquire.

I believe photos and illustrations convey a message much more rapidly than text or words so this journal will be heavy with that type of medium. All photos will be my property unless noted otherwise.

Please feel free to comment on anything I post as my goal is to impart understanding of how these systems work. I would really appreciate feedback, and honestly, the less you know the better questions that will probably be asked. Note that my postings may not be in order of operations, chronological or otherwise. I'll post when opportunity and interest strike so things may become scatter-shot so bear with me.

Thanks again to Jacob for allowing this experiment and I hope everybody gets something out of it.

____________________________________________________________________________________________________________________________________

So let's get started.



One of the most important and fundamental aspects of becoming a rope rescuer is knowing how to effectively and quickly tie approved rescue knots. Having the ability to tie approved knots is a fundamental building block to create systems to effect a rescue. It is very important that this skill is practiced in a multitude of conditions and landscapes. Many times this skill set is neglected and the truth is that unless one can tie the knot around or on a multitude of potential anchors, often times in awkward positions, or in poor viability or less than ideal weather conditions, then one really hasn’t mastered the art of tying knots. Remember that our rescue scenes often presents situations that don’t remotely resemble our training grounds at home.

It is also good to remember that tying knots in a rope will reduce its working capacity, so we want to ensure that the knot we use has been approved for rescue work and has been tied correctly. Knots are often rated for their efficiency, usually expressed as a percentage of the remaining strength of the rope. For example, if I were to tie a figure eight on a bight that has a 80% efficiency on a rope that has a MBS (minimum breaking strength) of 9,000 lbs, then my working capacity for that rope would have reduced to 7,200 lbs. Also keep in mind that most rope degrades over time, whether it is used often or not, and that sometimes it is better to reduce the working capacity even further due to degradation. Most nylon and polyester products have a working life of 10 years or less for life safety, and testing has proven that these products will degrade over time whether put into service or not, so even “brand new” rope will be weaker with age. Obviously, there are many factors to consider so a good rule of thumb to conservatively follow is to reduce the MBS by 50% anytime a knot is tied in a rope.

The Bowline

A bowline is also very useful in the rescue world with many applications for a fixed loop. With an efficiency of 70-75 percent it provides a strong knot that is easy to tie and untie, although one must use a safety knot at times due to its propensity to work itself loose under the right conditions.

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Followed with a safety:

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Bowline on a Bight

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Last edited by ffj on Sat Sep 09, 2017 9:27 am, edited 1 time in total.

jacob
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Re: ffj's journal II Rope Rescue Technician

Post by jacob » Tue Sep 05, 2017 1:10 pm

What, no mention of how the rabbit comes up the hole and goes around the tree and down again? :geek: As far as I understand, fancy climbers can tie a bowline behind their back with one hand. If you're two-handed, get in the habit of forming the loop the same way all the time so the tree is always pointing up. That makes it a lot easier for the rabbit.

For sailing, the bowline is great because it's possible to untie by hand even after it's been under a ton of load. Headsails are tied with bowlines. (Wondering whether that's where the name came from?) Never had one of those come loose on it's own---guessing because they're under constant load. I have tried tying tarps with bowlines ... they did come loose---guessing because they got wind-flogged ... load on..off..on... off. No good.

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Ego
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Re: ffj's journal II Rope Rescue Technician

Post by Ego » Tue Sep 05, 2017 2:02 pm

ffj wrote:
Tue Sep 05, 2017 11:59 am
It is also good to remember that tying knots in a rope will reduce its working capacity, so we want to ensure that the knot we use has been approved for rescue work and has been tied correctly. Knots are often rated for their efficiency, usually expressed as a percentage of the remaining strength of the rope. For example, if I were to tie a figure eight on a bight that has a 80% efficiency on a rope that has a MBS (minimum breaking strength) of 9,000 lbs, then my working capacity for that rope would have reduced to 7,200 lbs. Also keep in mind that most rope degrades over time, whether it is used often or not, and that sometimes it is better to reduce the working capacity even further due to degradation. Most nylon and polyester products have a working life of 10 years or less for life safety, and testing has proven that these products will degrade over time whether put into service or not, so even “brand new” rope will be weaker with age. Obviously, there are many factors to consider so a good rule of thumb to conservatively follow is to reduce the MBS by 50% anytime a knot is tied in a rope.

Nice project. I expect I am going to learn a lot.

Coupla questions....

I had to look it up to learn that climbing rope is rated in kilonewtons. So if I have a 9.2 kilonewton rope that's ten years old..... Using the google calculator 9.2 kilonewtons is 2068 pound force. Is pound force equal to working capacity?

And if so... if my friend was to tie an 80% efficiency bight using that ten year old rope and attach it to his climbing harness then.... 2068 X 50% =1034 X 80% = 827 pound force. If he's a big guy (250 pounds) and falls ten feet before I belay him, might he exceed the 827?

Thanks!

ffj
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Re: ffj's journal II Rope Rescue Technician

Post by ffj » Tue Sep 05, 2017 2:17 pm

@Jacob

The ole rabbit, haha. Absolutely though, consistency is key when you first learn and it should become muscle memory after a while. I've got some alternate ways to the tie the bowline coming up, so hang on and see what you think. Isn't a bowline the first knot every sailor learns?

@Ego

Excellent question and to be fair I'm going to dedicate an entire post to just your question because it encapsulates so many factors. I don't have time at the moment but hopefully tonight I will. That's kind of a neat problem to solve actually.

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Re: ffj's journal II Rope Rescue Technician

Post by McTrex » Tue Sep 05, 2017 3:17 pm

What's a bight?

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Ego
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Re: ffj's journal II Rope Rescue Technician

Post by Ego » Tue Sep 05, 2017 3:50 pm

ffj wrote:
Tue Sep 05, 2017 2:17 pm

@Ego

Excellent question and to be fair I'm going to dedicate an entire post to just your question because it encapsulates so many factors. I don't have time at the moment but hopefully tonight I will. That's kind of a neat problem to solve actually.
I realize it may be jumping ahead. If so, I can wait until you build up to it.

ffj
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Re: ffj's journal II Rope Rescue Technician

Post by ffj » Tue Sep 05, 2017 8:51 pm

@McTrex

Here is a page from Vertical Academy by Tom Briggs:

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People often get confused by terms invented from long ago and different trades have different lingo, but above is what is common for modern rope rescue.

ffj
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Re: ffj's journal II Rope Rescue Technician

Post by ffj » Wed Sep 06, 2017 9:40 am

@Ego

"Nice project. I expect I am going to learn a lot.

Coupla questions....

I had to look it up to learn that climbing rope is rated in kilonewtons. So if I have a 9.2 kilonewton rope that's ten years old..... Using the google calculator 9.2 kilonewtons is 2068 pound force. Is pound force equal to working capacity?

And if so... if my friend was to tie an 80% efficiency bight using that ten year old rope and attach it to his climbing harness then.... 2068 X 50% =1034 X 80% = 827 pound force. If he's a big guy (250 pounds) and falls ten feet before I belay him, might he exceed the 827? "


One could write an entire book just discussing the various factors that are involved in your question. But I am going to try to make it simple for simplicity sake. Down the road I am going to discuss various factors in more detail.

You mentioned kiloNewtons, which is the unit the rope and rescue industry uses to designate MBS. A kiloNewton is defined as a unit of of force, with one newton being the force necessary to accelerate one kilogram of mass one meter per second squared in the direction of applied force. Most people will just convert the number indicated in kiloNewtons to either imperial units or metric. Multiply by 224 for pounds or 101.97 to get kilograms.

You also mentioned a climbing rope which is dynamic versus a rescue rope which will be static in nature. A static line will be low stretch whereas a climbing line will have much more stretch to absorb the energy from a fall.

"Is pound force equal to working capacity?" Not at all. As a general rule, we don't want to exceed 25% of the MBS on any system or component of that system. Other industries will designate the WLL, which is the working load limit and much simpler to understand, as that number indicates a weight or force not be exceeded.

What we are looking for is the FOS (Factor of Safety) or the SSR (System Safety Ratio), which is defined as the minimum MBS of the weakest component of a system divided by the Maximum Anticipated Load. Different industries require different safety ratios.

So in your above scenario we would halve your 9.2 KN rope to 4.6KN because of the knot. We'll make your buddy 1KN for simplicity sake and we don't need to further degrade the rating because we've already halved it. So basically (without the fall factor) this would have a safety factor of 4.6:1. There are other factors involved here but as rescue technicians we have to be able to ballpark scenarios very quickly with conservative estimates.

The last issue is the fall factor. Fall factor is defined as the distance a person falls divided by the length of rope in play. A fall factor will be designated anywhere from 0 to a 2, with anything up to or greater than a 1 potentially dangerous. The reason climbers can take huge whippers is because of the length and type(dynamic) of rope in play. Conversely, someone tethered to a lanyard with no energy absorber can take a fall as little as your hypothetical 10 feet and be severely hurt. Most fall arrest devices require some sort of energy absorber that will decelerate the person falling and the weight of the person does indeed a play a role.

Hope this helps and in the future I would like to get a bit more technical with some of this stuff to increase understanding. Thanks for the question.

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Re: ffj's journal II Rope Rescue Technician

Post by 7Wannabe5 » Wed Sep 06, 2017 10:03 am

Neat project. A book written on a topic like this would likely hold its value within niche market for many years. I would pick it up at a dealer's sale without bothering to check current used retail. Hobbyists, and specialists, want to own every published book in their niche, and will hold on to them forever. Pay attention to your marketing, especially your cover art, don't print too many copies, (if any), be vigilant about plagiarists, and you will probably be able to count on a fairly steady, small passive income from sales as part of your retirement portfolio.

ffj
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Re: ffj's journal II Rope Rescue Technician

Post by ffj » Wed Sep 06, 2017 7:50 pm

@7
Thanks for the advice. I've got a long way to go before I can even remotely think of publishing anything but I will keep your words in mind. If I get a pamphlet out of this for my local students I'll be happy. ;)

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Re: ffj's journal II Rope Rescue Technician

Post by Ego » Wed Sep 06, 2017 8:19 pm

Wow. This is certainly one of those areas where I learn a little and it reveals the staggering amount that I don't know. Thanks!

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Re: ffj's journal II Rope Rescue Technician

Post by ffj » Thu Sep 07, 2017 11:53 am

Here is a quick way of tying a bowline around an object. Once one practices this a few times it becomes a very fast method to secure a line.

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Grab the running end and the tail with one side of the loop and pull. This will dress the knot.

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Practice that a few times and see how how fast you can become. Much better than the rabbit around the tree method.
Last edited by ffj on Sun Oct 29, 2017 3:06 pm, edited 2 times in total.

ffj
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Re: ffj's journal II Rope Rescue Technician

Post by ffj » Fri Sep 08, 2017 10:11 am

One of the most important and versatile knots a rope rescuer needs to know is the figure eight knot and its variants. With an efficiency rating of approximately 75-80 percent it is an excellent knot with many different applications.

The double figure eight (bunny ears)

Often used in anchor systems, bunny ears are easily adjustable for different offsets.

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Re: ffj's journal II Rope Rescue Technician

Post by FBeyer » Fri Sep 08, 2017 11:26 am

It's been a hobby of mine for a couple of months to practice some knots in the evening. I don't have anything sensible to add to the topic right now, I just wanted to chime in and tell you that I appreciate your efforts tremendously. I really do, and I'll definitely follow along.

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Re: ffj's journal II Rope Rescue Technician

Post by ffj » Fri Sep 08, 2017 11:48 am

@FB

Thank you! Seriously, I am terrible about working in the dark with no feedback whatsoever. This way I can get very quick advice about whether this content is any good or understandable, and it keeps me motivated! And I really want to hear if the content is off or bad because I am approaching this from the perspective of teaching complete neophytes how to rescue with rope, correctly and safely.

I've got more knots coming up.

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Re: ffj's journal II Rope Rescue Technician

Post by enigmaT120 » Fri Sep 08, 2017 8:28 pm

Interesting thread. Will any of these knots prove useful for tying down objects to secure them, like the bow and stern lines of my kayak going to parts of my pickup? Those ropes do get some wind whip. I could see where the bow line would be good for attaching the rope to the kayak, (or is there a better one for that?) but I was more thinking about how to tie the other end while keeping the line under tension.

Sorry, I know your purpose is for rescue, but if some of the knots have other uses could you mention it?

Thanks

ffj
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Re: ffj's journal II Rope Rescue Technician

Post by ffj » Sat Sep 09, 2017 9:21 am

@enigma

The truckers hitch is great for securing loads. It's not a life safety knot however but for tying stuff down you can't beat it for its simplicity, and I use it all of the time. Note that if the slip loop intimidates or isn't easily memorable, just tie a simple overhand loop in the rope. However, it will be hard to untie once you're done but if it's cheap cordage you may not care.

I got a chuckle out of how intense this guy is showing us how to tie a knot but he does a good job.

https://www.youtube.com/watch?v=TSVbEfcZ8ps

ffj
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Re: ffj's journal II Rope Rescue Technician

Post by ffj » Sat Sep 09, 2017 11:10 am

Let's look a basic figure of eight knot. This knot is absolutely essential to learn in a rescue environment and fortunately it is easy to learn.

Figure of Eight on a Bight

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Now is the stage to dress the knot. Usually it is as simple as taking this top strand and pushing it down.

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And your finished and dressed knot should look like this:

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ffj
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Re: ffj's journal II Rope Rescue Technician

Post by ffj » Sat Sep 09, 2017 11:24 am

Btw, if some of you are interested in buying quality rope for practice that will also handle a life load check out this website for arborists:

http://www.wesspur.com/index.html

Go to the tab "Specials" and then click clearance rope. All rope is new but of varied lengths as they are end of the spool off-lengths. Your can research the details of each rope type in the website. I would recommend getting a climbing line and not a rigging line. It's a cheap way to get started with quality rope.

ffj
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Re: ffj's journal II Rope Rescue Technician

Post by ffj » Mon Sep 11, 2017 7:23 am

And some more knots. I promise that we will move on from knot tying at some point but they really are the basic building blocks from which all other skills are developed. The other good news is that there is a limited set of them for rescue work that will achieve 99% of everything you will ever need to do and also a lot of them are variations of their original selves, so once one learns the knot of origin, all variations are fairly simple.


Variations of the Figure of Eight Follow-Through


The first variation is used to complete a closed loop which creates a knot that is not prone to slipping like a bowline. This knot is often used by climbers to tie in or by rescuers to secure a rope around an object.

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The other variation allows one to join two ropes together or two ends of the same rope to create a loop.

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