ffj's journal II Rope Rescue Technician

What skills to learn, what tools to get
ffj
Posts: 1812
Joined: Thu Aug 26, 2010 3:16 am

Re: ffj's journal II Rope Rescue Technician

Post by ffj » Sat Dec 30, 2017 9:08 pm

Our next mechanical advantage system will be the 2:1. On any even numbered system the end of the rope will terminate at the anchor and a movable pulley(s) will travel with the load. The load in this case is 15 pounds and with a 2:1 in place, the operator will only have to pull 7.5 pounds of force to move the load. He will also have to pull two feet of rope to move the load one foot. Similarly, the speed is also affected. The speed of the load moving is half of what the operator's pulling speed. Note that I am not including friction or any other inefficiencies when making these comparisons. I'll discuss those factors later.

Image

The progress capture device is placed with the movable pulley which could be a disadvantage at times.

Image

We can also add a change of direction pulley at the anchor which can help redirect the direction of our pulling force. This can be very handy when obstacles prevent pulling in certain directions.

Image

On a 2:1 the most direct way to add the prusik progress capture device is on the line closest to the load, and has the benefit of becoming a shock absorber that will actually start slipping around 4.5 KN, which can be a good proactive measure against allowing the system to become overloaded. I would seriously question the need for that much force on a system and that feature can act as a warning system. A disadvantage or possible advantage of the PCD traveling with the load is that the rescuer and/or victim may need to tend it depending on the operation. However, we can also add the PCD indirectly at the COD pulley which keep it accessible to rescuers at the anchor. Here is an example:

Image

This allows more than one strand of rope to absorb any shock loads also. You'll notice that independent 4:1 utilizes this concept.

Now notice how easy it is to convert this into a 4:1 simply by adding another pulley.

Image

The same ratios apply with a 4:1. This time the operator only needs to pull a quarter of the weight of the load while pulling 4 times the length of rope to raise or move the load one quarter of that length. A 4:1 system is commonly used in rope rescue most notably in a "set of fours" or a haul safe. With two double pulleys it is very easy to create a compact 4:1.

Start by tying off to one of the beckets of the double pulleys. I've used a splice here but a figure eight on a bight knot will also work. Then start loading the bottom sheaves of the pulleys and finishing off by loading the two top sheaves. Try to keep everything tidy without crossed lines if possible.

Image

Image

Here is what it should look like under tension:

Image

We can add a PCD which is placed on the strand opposite the tail.

Image

Image

A haul safe is just a larger version of a 4:1 mechanical advantage pulley system often used in confined space access. Instead of a prusik as a PCD it utilizes a mechanical rope cam. To disengage a locked rope, one must pull tension on the system while pulling the wire loop of the cam, which will release the rope. One can also lock the cam out of the way to create a free spool system too.

Image

Image
Last edited by ffj on Mon Jan 01, 2018 6:53 pm, edited 1 time in total.

User avatar
daylen
Posts: 491
Joined: Wed Dec 16, 2015 4:17 am

Re: ffj's journal II Rope Rescue Technician

Post by daylen » Sat Dec 30, 2017 11:48 pm

It is always interesting to see theory translated into practice!

ffj
Posts: 1812
Joined: Thu Aug 26, 2010 3:16 am

Re: ffj's journal II Rope Rescue Technician

Post by ffj » Sun Dec 31, 2017 10:06 am

@Daylen

Glad you enjoy it.

It's gets real interesting once we move beyond the basic building blocks and get into entire systems. We'll get there at some point, I promise.

ffj
Posts: 1812
Joined: Thu Aug 26, 2010 3:16 am

Re: ffj's journal II Rope Rescue Technician

Post by ffj » Sun Dec 31, 2017 10:25 am

Our next pulley system is a 3:1, which is a very common haul system utilized in rope rescue. A lot of people will call it a Z drag or something similar and many beginning rescuers learn this one first.

We start with the end of the rope terminated at the load and a stationary pulley at the anchor.

Image

Add a second moving pulley:

Image

And add our prusik rope grab and our prusik PCD:

Image

Image

And under tension:

Image

By this point the ratios should be self-evident in regards to amount of rope pulled/distance load moved, speed, and amount of weight (force applied) to move the load.


Just as it is quite easy to convert a 2:1 to a 4:1, it is equally easy to convert a 3:1 to a 5:1. We would do this if we have a limited number of haulers or we need to slow the speed down considerably. Start by replacing the single pulleys with double pulleys and load the pulleys very similarly to how the 4:1 set of fours was loaded.

Image

Image

Image

Image

User avatar
daylen
Posts: 491
Joined: Wed Dec 16, 2015 4:17 am

Re: ffj's journal II Rope Rescue Technician

Post by daylen » Sun Dec 31, 2017 11:05 am

One thing I recommend is to develop a classification system for navigating this information based on utility, complexity, and application. All this is second nature for you by this point, but such a system would useful for some beginners such as myself. Though, it also depends on your target audience.

User avatar
Seppia
Posts: 529
Joined: Tue Aug 30, 2016 9:34 am
Location: Italy

Re: ffj's journal II Rope Rescue Technician

Post by Seppia » Sun Dec 31, 2017 1:02 pm

This is so amazing thanks a TON for sharing.
Quick tangent
I am blown away by the amount of useful (or potentially useful) information that revolves around this ERE microcosm.
It's like people "speak" only if they have something useful to add, and the average high quality raises the bar, so others also are pushed to only post if they have something useful to say.
Thanks to the community as a whole, and ffj in particular for this thread.

ffj
Posts: 1812
Joined: Thu Aug 26, 2010 3:16 am

Re: ffj's journal II Rope Rescue Technician

Post by ffj » Sun Dec 31, 2017 2:09 pm

@Daylen
I understand. We are still in the building blocks phase however. Before one picks the best haul system, he first has to know what is available to choose from. Imagine what I am showing at the moment is sort of like the knots. We have to learn those before we start tying anchors, for example.

I've completed the simple systems and I'll be moving on to compound systems next. Stay with me, I promise it will all come together at some point.

@Seppia

My pleasure. I've been pleasantly surprised on the positive feedback on this thread. I really thought no one would care to be honest. Seriously, it means a lot when I receive compliments from people like you.

ffj
Posts: 1812
Joined: Thu Aug 26, 2010 3:16 am

Re: ffj's journal II Rope Rescue Technician

Post by ffj » Mon Jan 01, 2018 7:24 pm

Compound Mechanical Advantage Systems

A compound system is a simple system acting upon another simple system. While a simple system standing alone can accomplish most applications of rope rescue, there may be times when a compound system is called upon depending on availability of gear or the need for a greater mechanical advantage. It's important to remember that the collapse rates of each system are going to be different, even when the same ratios are used. A common tactic is to anchor the secondary system further back so that the throw is much longer. Here are some examples and if you will concentrate on the initial simple system connected to the load it becomes quite easy to determine each system.

A 6:1 compound system. Here the initial system in orange (3:1) is being pulled by a 2:1 in green. We multiply the individual systems to figure the compounds mechanical advantage.

Image

A 9:1 compound system. This is simply a 3:1 acting upon a 3:1.

Image

And a 12:1 compound system. Here we have a 4:1 acting upon a 3:1, resulting in a 12:1 mechanical advantage. This is also an example of a piggyback system wherein a separate contained system (4:1 set of fours) is attached to the tail of the 3:1.

Image

Keep in mind that all of these systems shown have been greatly compressed so that I could photograph them in one frame. In operation, one needs a fair amount of room to operate a compound system due to the amount or rope involved and many times separate anchors. These are also powerful systems that I have used to flip horse trailers and tractors in training scenarios, so they are quite strong.
Last edited by ffj on Mon Jan 01, 2018 7:53 pm, edited 1 time in total.

ffj
Posts: 1812
Joined: Thu Aug 26, 2010 3:16 am

Re: ffj's journal II Rope Rescue Technician

Post by ffj » Mon Jan 01, 2018 7:51 pm

Complex Pulley System

A complex system is defined usually by what it isn't, as it is neither a simple or compound pulley system. These systems typically will have a pulley that moves toward the load also. Here is an example of a complex 5:1. The anchor is to the left and the load is to the right.

Image

This set-up could be handy for a single rescuer that's confined to a small cliff edge for example. The disadvantage is the amount of resets and throws this system would entail. Normally, and if possible, rescuers want to utilize the MAS (mechanical advantage system) that results in the least amount of resets for the rescue assuming they have the manpower to facilitate that plan. Complex systems are an outlier in rope rescue work for the most part.

ffj
Posts: 1812
Joined: Thu Aug 26, 2010 3:16 am

Re: ffj's journal II Rope Rescue Technician

Post by ffj » Wed Jan 03, 2018 9:19 pm

Now that a few options have been shown in regards to pulley systems, we need to quickly pick a system that will meet our needs at the time of a rescue. In order to do that we must ask ourselves several questions:

1. What is the load, and how much does it weigh? Are we raising a single person, a horse, or a victim and and a rescuer, for example? Typically we tend to stick to simple systems and a 3:1 or a 5:1 can accomplish quite a wide range of applications, especially for one or two-person loads. We want to employ the least amount of rope necessary and the least amount of resets, which happens when the traveling pulley reaches the stationary pulley. When this occurs, we set the progress capture device so that it holds the weight of the load and advance our traveling pulley back towards the load. This is something that I will probably illustrate in the future.

2. How many rescue personnel are on scene to effect the rescue and can we plausibly use other emergency personnel for pulling? There is a technique for pulling on the tail end of a pulley system that lay people may not understand. If I have say 4 people pulling then that means that all four are holding on to the rope and walking in unison directly away from and in line with the pulley system. There is no hand over hand motion while stationary, rather one simply grabs hold of the rope and walks when told to do so and at a speed that an Incident Commander or an Operations Commander indicates. Most importantly, the pullers stop immediately when told to do so. When the lead puller comes to an obstacle or simply runs out of room, he immediately lets go of the rope and gets back in line right behind the last puller. Raising a victim should be a very smooth operation and all pullers should be paying close attention to the orders given.

If we are severely limited by the number of rescuers present, we can upgrade our pulling capacity for example from a 3:1 to a 5:1 simply because there aren't as many people raising the load. This makes it easier for the rescuers but it will take more time.

3. What equipment is available? Not all emergency departments are alike in rope rescue equipment or training. Sometimes the most ideal set-up isn't attainable simply because the equipment just isn't there or the rescuers present don't know how to do a certain technique. That is why it is so important to be proficient in several methods for almost every application in rope rescue.



Also, what I've shown so far are basic systems that don't involve any of the many aids available in rope rescue. For example, here is a 3:1 that I personally carry for pick-offs or small applications.

Image

Notice that the stationary pulley actually has the progress capture built into the device.

Image

Image

This is a device called a mini-Traxion:

Image

Image

I wanted to illustrate that there are several devices that incorporate this feature in their haul systems and as rescuers we must be proficient in their use as well as mechanical rope grabs and more sophisticated devices such as the CMC MPD. However, before we advance to the popular devices available we must conquer the most basic systems with a couple of pulleys and some prusik cord, because again not all departments will have the same equipment.

Image

Image

Image

ffj
Posts: 1812
Joined: Thu Aug 26, 2010 3:16 am

Re: ffj's journal II Rope Rescue Technician

Post by ffj » Wed Jan 10, 2018 7:41 pm

Just for fun, here is a system that enables two people to pull at the same time. This could be used when the victim is able to help pull himself out of a hole for example. Not widely used but I thought it may be of interest to others here. The long tail could be dropped to the victim while the rescuer up top could pull on the shorter tail coming from the Mini-Traxion.

Image

Image
Last edited by ffj on Thu Jan 11, 2018 8:01 pm, edited 1 time in total.

ffj
Posts: 1812
Joined: Thu Aug 26, 2010 3:16 am

Re: ffj's journal II Rope Rescue Technician

Post by ffj » Wed Jan 10, 2018 8:04 pm

Rigging a Rescue Litter for Low Angle

There are several ways to rig a rescue litter for low to steep angle rescues. It is important to know several ways due to rescue variabilities such as equipment selection and availability. We'll be focusing on an anchor or attachment to the front of the litter due to the preferred orientation when raising or lowering. We'll also cover high angle rigging later.

A low to steep angle is just that, and it covers terrain with a small slope that is somewhat difficult to travel up to steep angles that completely necessitate rope systems to keep ones balance and more importantly not further injure the patient. A typical litter will look like this:

Image

In most cases, we want to form an attachment point on the end where the patients head would rest. This allows the patient to keep his upper body naturally higher when raising or lowering.

This particular litter has attachment points so naturally we would use those if possible.

Image

And it is a simple matter of forming a loop with a water knot and finishing the attachment point:

Image

Image

ffj
Posts: 1812
Joined: Thu Aug 26, 2010 3:16 am

Re: ffj's journal II Rope Rescue Technician

Post by ffj » Wed Jan 10, 2018 8:13 pm

Other methods are utilized if the attachment points aren't a part of the design. Sticking with a loop of webbing, here is a simple alternative:

Image

Pull a bight through the middle. Pay attention to where the water knot ends up.

Image

And form two wraps on each end:

Image

Image

Gather all three loops and dress the anchor:

Image

Image

ffj
Posts: 1812
Joined: Thu Aug 26, 2010 3:16 am

Re: ffj's journal II Rope Rescue Technician

Post by ffj » Wed Jan 10, 2018 8:26 pm

Method three utilizes a rope with a figure of eight tied in the middle:

Image

Tie two clove hitches onto the top rail outside of the upright posts.

Image

Then we want to take the tails and wrap them around the top rail towards the foot of the litter.

Image

At the foot, and importantly once the patient is secured in the basket, we can tie the two ends together with a square knot. If it is preferable, one can also tie two clove hitches onto the top rail on either side before tying the square knot. Since the square knot is subject to loosing, we will always back it up.

Image

Image

Image

And finished:

Image
Last edited by ffj on Thu Jan 11, 2018 8:03 pm, edited 1 time in total.

ffj
Posts: 1812
Joined: Thu Aug 26, 2010 3:16 am

Re: ffj's journal II Rope Rescue Technician

Post by ffj » Wed Jan 10, 2018 8:34 pm

Before we move on to directly tying into the litter with rope, there is one more method that is quick and easy. This is a great way to attach tag lines very quickly. Start by weaving the webbing around the upright posts:

Image

Center the middle loop with the two ends and then simply tie an overhand knot.

Image

Image

Image

Image

ffj
Posts: 1812
Joined: Thu Aug 26, 2010 3:16 am

Re: ffj's journal II Rope Rescue Technician

Post by ffj » Wed Jan 10, 2018 8:59 pm

Instead on forming a separate attachment point with webbing or accessory rope, we can always tie in directly with a main line. By far the simplest way is to tie a figure of eight follow through, or retrace eight:

Image

Image

If we want to utilize a more self-equalizing system, we can tie a bowline on a coil. This knot can be intimidating at first, but once you realize it is simply a bowline with the middle coil captured inside the knot it becomes much more easy to visualize and in turn tie. Start by weaving the rope from right to left as such:

Image

Image


Form a loop(be very specific here) and place it inside the center coil:

Image

Image

Pick up the loop:

Image

And form a bight with the standing part and place it into the loop. Notice this how the center coil becomes captured.

Image

Image

Now simply place the tail of the working end into the last loop created. The last step is to dress the knot by pulling on the tail and standing part.

Image

Image

Image
Last edited by ffj on Thu Jan 11, 2018 8:04 pm, edited 1 time in total.

DSKla
Posts: 251
Joined: Wed Dec 24, 2014 11:07 am

Re: ffj's journal II Rope Rescue Technician

Post by DSKla » Wed Jan 10, 2018 10:52 pm

Super cool stuff! I wish there was somewhere to sign up to learn how to do this, short of being a fireman, even as a volunteer. I'd be all over that.

User avatar
Gilberto de Piento
Posts: 1082
Joined: Tue Nov 12, 2013 10:23 pm

Re: ffj's journal II Rope Rescue Technician

Post by Gilberto de Piento » Thu Jan 11, 2018 9:49 am

Some places have volunteer search and rescue teams where you would be able to learn and use these techniques.

ffj
Posts: 1812
Joined: Thu Aug 26, 2010 3:16 am

Re: ffj's journal II Rope Rescue Technician

Post by ffj » Thu Jan 11, 2018 8:56 pm

@DSKla

Communities are always looking for motivated people such as yourself, and as Gilberto has alluded to, many of them are volunteer. If you are serious I would find a department that had a search and rescue team and volunteer your services. Don't worry if you don't know anything just yet, that will come with training. And it's a lot of fun too.



I thought I would show a simple low-angle scenario that kind of ties everything together thus far. A lot of rope rescues involve some fairly minor slopes. Imagine a hiker that has fallen off of the trail down an embankment and injured themselves or a vehicle crash that involves driving off of the roadway down into a grove of trees for example. Low to steep angle rescues are the bread and butter of rope work.

So we have the rescue litter where our imaginary patient would be and we need to get them up the hill.

Image

We want to insure that the rope used to pull the litter up is secured correctly.

Image

Our next step is to elevate the rope off of the ground if possible as we want to keep our rope and system clean and minimize any friction that the ground would create. Trees are very handy for this if available but other structures or objects could suffice.

Image

Let's focus on this COD (change of direction) anchor. This is a variation of the wrap three, pull two anchor illustrated elsewhere. If the force will be applied downward as in this case, then more wraps and thus friction will be required to keep it in place. Here I've used a wrap four, pull one but any variation within reason will work. I easily could have used a wrap five, pull two here if my piece of webbing had been longer. Be mindful that a wrap three, pull two will not create enough friction in a case like this.

Image

Now I need to focus on finding an anchor on top of the hill and creating a haul system. Here I am using a telephone pole with a 3:1 haul system. Notice how long my throw (how far up the secondary moving pulley) is in relation to the base anchor. We always want to make this as long as possible to minimize resets of the system.

Image

As we pull the system will collapse until the pulleys are close to one another.

Image

At this point if the patient isn't to the top of the hill, then we would set the progress capture device(the prusik at the anchor) to eliminate the chance of the litter sliding backward and reset our throw. Grab the prusik of the traveling pulley and advance it as far as it will go.

Image

Image

Then we are ready to haul again.

Image



Now we can also lower from the same set-up. Simply place a lowering device at the anchor and proceed down. Of course in a real situation there would be people manned at each station.

Image

DSKla
Posts: 251
Joined: Wed Dec 24, 2014 11:07 am

Re: ffj's journal II Rope Rescue Technician

Post by DSKla » Thu Jan 11, 2018 9:16 pm

Moving soon to an area that would be S&R prime real estate, so I'll look into it--even though they probably do it so much that they take care of it in-house with pros.

Post Reply