Login
Join Rigging Lab

Mechanical Advantage, Part 3

Written By: Lance Piatt

Complex MA systems provide high lifting power for heavy rescue loads. Explore compound and intricate pulley setups for demanding scenarios. 
Thanks Peak Rescue Institute
Full Video at the bottom

All right. The next mechanical advantage system in our progression is a five to one mechanical advantage system. And this is a simple five to one mechanical advantage system. So we’ve already differentiated between simple and compound. The last system that we showed was a four to one, and that was a compound four to one where you had a haul system, a two to one haul system pulling on a two to one haul system.

Now we’re back to a simple mechanical advantage system where we just have a pulley. We have multiple pulleys in the system, but they’re all moving in the same direction and they’re moving at the same speed. And that’s by definition, that’s a simple mechanical advantage system. And again, this is a five to one.

At this point in the discussion, I’m going to go ahead and omit the one from our T just in the interest of saving space. You can just assume that T is the same as one T. So again, I’m going to start at the haul strand where the haul team’s actually going to input the tension into the system. We’re going to assign T to that, and follow T down to our first pulley. The T enters on one side T exits on the other side, and we have two T.Basically transmitted through the first prusik to the load strand of the rope.

Continuing we follow the T that came out of the first pulley up to our first change of direction pulley. T goes in, T comes out. T continues down to the second pulley, T goes in, T comes out and another two T is transmitted to the main line.

We continue to the second change of direction pulley, T goes in; T comes out. This T’s transmitted down the line and it bumps into the first two T, and we move on to the second two T. So we have T, plus two T, plus two T , equals five T. We have a five to one mechanical advantage system.

And let’s go back and balance our equation. We have 1, 2, 3, 4, 5 Ts up at the anchor. And in this case, our anchor is carrying four fifths of the load. The other fifth of the load is being supported by the haul team. So we have five T on the anchor as well, and we balance.

And Now For Something You’ll Really Like

All right, the next haul system in our progression is actually also a five to one haul system. You’ll notice this system looks slightly different, though. This is an opportunity for us to talk about the third and final type of mechanical advantage system. This haul system is what is known as a complex mechanical advantage system.

Probably the most accurate way to define a complex system is it’s neither simple nor compound. Some defining characteristics are you have moving pulleys, pulleys that are actually performing work and moving a load that are moving in opposite directions of each other. And as you see this system function, you’ll see, I have two haul pulleys that are actually moving in opposite directions.

Some advantages of this complex five to one haul system over the simple five to one haul system are that I can actually build this with fewer pieces of equipment I’ve actually removed one pulley from the system.

So, if I have fewer pulleys and I want to build a five to one, I might be able to build a complex five to one versus the simple five to one.

Another advantage is that you’ll notice we’re pulling away from the anchor. So if we want to pull downhill, for instance, I might build this complex five to one, so I can actually walk downhill and use gravity to assist our haul.

Disadvantage is that it needs to be reset a lot more often. You’ll see the pulleys come together and they come together basically twice as quickly as the pulleys collapse in the simple five to one. So at some point I’ll have to stop and reset the system, which brings us to another point.

One thing that’s missing from all of these systems is a progress capture device. We’ve omitted the progress capture device.

Ordinarily. We would affix a prusik probably here below the first change of direction pulley so that any uphill progress that we make would be actually captured on that press. But we’ve omitted that for this discussion.

All right, moving on to analyzing our, our final mechanical advantage system, our complex five to one. As always, we start with our one T where the haul team is hauling. Then in this case, the whole team is hauling to in the direction of the load. One T goes in; one T comes out, and we have two T transmitted through this prusik. This T continues, T goes in, T comes out and another two T on our second prusik. T continues up and it runs into this two T, and we actually have three T and again, whatever goes into a pulley has to come out of a pulley.

The pulley, the pulley has to balance the tension. So now for the first time, we actually have more than one T going into a pulley and we have three T, three T comes out, three T transmits down the line to where our two T is waiting on the second prusik. We can add those together for a five to one haul system.

Balancing our equation, we have three T plus three T equals six T on our anchor. This is similar to our hauling a one to one through a change of direction where we’ve actually doubled the load on our anchor. We’re seeing a load on our anchor that’s greater than the result of our mechanical advantage. We’re actually seeing six T. The reason is we have five T on our load, and we are pulling an additional one T against the anchor in the direction of the load. So this five T is added to this one T and this also equals six T.

All right. So what we’ve covered here is basically an introduction to several different levels of mechanical advantage that we can construct in order to help us move rescue loads. We’ve shown everything from a one to one haul system, which is essentially us pulling on a rope, or pulling on a rope that travels through a change of direction pulley. We’ve showed a two to one, three to one, a four to one, and we’ve shown two different five to one haul systems.

There’s in the process of this demonstration. We’ve also seen that there are different types of mechanical advantage that range from simple mechanical advantage. to compound mechanical advantage. to complex mechanical advantage. Examples would be simple two to one mechanical advantage where we’re just pulling through a pulley that’s attached to the load, or that’s attached in the direction of the load, a simple three to one.

And then here we move to a compound four to one where we have two, two to ones haul, or two to one hauling on a two to one. So we have a mechanical advantage system hauling on a mechanical advantage system. That’s that, which makes it a compound mechanical advantage system.

And then our final system, this complex five to one haul system that has some benefits and some drawbacks. Benefits including requires less gear, and you’re able to pull downhill or pull away from the anchor if you want to. But the disadvantages that the pulleys tend to collapse more quickly on one another.

And then in terms of the team method, if you learn the basic roles of the team method and apply them, you should be able to analyze any mechanical advantage system, any combination of ropes and pulls and rope grabs and determine what the actual mechanical advantage is.

The basic roles of the team method, again, are assign one unit of tension to whatever the input is. Whatever the input, the haul team’s able to enter into the system in terms of amount of tension, and then follow the line continuously through the system, understand that each pulley doubles whatever amount of tension enters one side, that same amount of tension enters the other side and where that pulley is attached experiences doubled the amount of tension that entered the pulley.

 

Peace on your Days!

Lance
Categories

About The Author:

Picture of Lance Piatt

Lance Piatt

Beginning his career in the rescue and rigging world as a “blue collar” SAR member with Deschutes and Jefferson County teams. Lance Piatt owns and operates Red Ibex Solutions, a sales and marketing wheelhouse blending rope rigging education and exquisite imagery with equipment knowledge and understanding; housing Rigging Lab Academy and Rescue Response Gear… Lance is producing high-end video education, working with several experts and instructors to produce unique series of “how to videos” and courses for rope rigging: Such as; the first ever full-length rescue training DVD, 'Tower Rescue', released in fall of 2005. As well as a series of scenario-based rescues ranging from cave rescue to cliff rescue.

99 thoughts on “Mechanical Advantage, Part 3”

  24. Israel night club

    Nice post. I learn something totally new and challenging on sites I stumbleupon everyday. It will always be helpful to read articles from other writers and use something from other sites.

  53. שירותי ליווי בתל אביב

    אנחנו יכולים לומר שכולנו כבר התרגלנו
    להיות במצב של לחץ ואף למדנו
    בקושי לשים לב עד כמה העצבים שלנו מתוחים.
    לאזור התמיכה הקשה בעזרת לחץ מהיר.
    עיסויים אלו מתאימים במיוחד לבני זוג שרוצים להפתיע או לבלות
    יחד ערב רומנטי וקסום, להירגע ולחוות אינטימיות בדרך נעימה ומקרבת.
    הדירות הדיסקרטיות ברחובות ממוקמות ברחבי
    העיר ומשמשות כמוקד למתן שירותי עיסוי ופינוק ולהתייחדות של
    בני זוג. עיסוי הכי טוב באשקלון
    .מזמינה אותכם להתפנק בקליניקה פרטית.
    בוקר טוב. אשמח להזמין עיסוי זוגי לגבעתיים.העניין
    שאני לא ממש מבינה בסוגים השונים, אשמח
    להלמצות לגבי סוגי עיסויים לזוג שלא ממש מבין.
    עיסוי מתיחת שרירים, רצועות, פאסיה, מפרק מתיחה מתבצעת לאחר המישוש.
    היעלמות הכאב, הסרת עווית שרירים, עלייה בנפח
    התנועה, לאחר מניפולציה נכונה, השפעה זו אינה נמשכת זמן רב ונדרשת
    מניפולציות חוזרות ונשנות.
    מבחינה היסטורית, מניפולציה על המפרקים נחשבה לבסיס הטיפול הידני.
    לכן, נסיגת הבקע אינה נכללת לחלוטין בהתבסס על חוקי הביומכניקה על פי תפיסות מודרניות, יש
    להפחית באופן משמעותי את שיעור הטכניקות המניפולטיביות בארסנל של אמצעים שונים לטיפול ידני.

  71. Med

    The only thing I don’t love about the holidays is all the makeup. I’ve been known to wear more than a dozen different shades of eyeshadow and glitter in a single day—and that’s without any special occasion. I just can’t help myself. I’m like my mother—a makeup junkie.. Read more about how to make white face makeup at home and let us know what you think. What types of clown characters can you design with makeup? If you are the type of person that rarely remembers to wash off makeup before bed, this tip may be especially hard for you to hear. Make sure that you wash your face paint and costume makeup all the way off before you hop into bed. The longer it sits on your skin, the more likely it will be to break you out. Editor’s Tip: Lightly sweeping powder across your face without buffing in can cause it to look dry and chalky.  So use a dense powder brush and buff the product into your skin until it blends in seamlessly to warm up the product and give it a skin-like finish.  https://shipitshoutit.com/community/profile/lilaworth28107/ Next: Here’s How Makeup Artists Achieve Flawless Eye Shadow Looks Every Damn Time Pay: $15.00 per hour Darlings, unlock the secret to a runway-ready BRONZE, SCULPT and GLOW with my NEW! Glowgasm face palette in Nudegasm! Inspired by my globally-loved Glowgasm palettes and backstage beauty secrets, this nude makeup palette of universally-flattering, blurring, smoothing and illuminating effect shades brings instant SUPER STAR MAGIC to any makeup look for EVERYONE, EVERYWHERE! Standard delivery in 6-12 business days from despatchFinal mile delivery will be with your local postal service Your bag is empty. %2Fon%2Fdemandware.static%2F-%2FSites-masterCatalog_Pupa%2Fdefault%2Fdwc8803424%2FImmagini%2Flarge%2F040276A001_8011607302659_MakeupStoriesSpicyNudes_big_28052018142321.png Makeup by Mario The Nudes 1 is a limited edition eye palette that retails for $25.00 and contains 0.2 oz.

  77. Daf

    It looks like your request isn’t going through. Try again and if it still Poker at River Rock Hotel Rooms Tuscany tuscany3.jpg Players start Ultimate Texas Hold ‘em by receiving two cards. The dealer also receives two cards. All are dealt face down. Five cards are placed face down in the center of the table. Casinos & Resorts In the third or last betting round, turn and river cards are dealt face up. This way now there are a total 5 community cards that have been dealt till now. Since you are playing online, all these cards would be dealt automatically one by one, though you can place the bets as per your strategy for ultimate Texas Hold’em. Now, in this round according to the strategy for ultimate Texas Hold’em Poker the bet is usually 1X the stake or fold. Since this is the last round in Texas Hold’em poker players have a fair chance of turning the game in their favor if they bet according to the best strategy for ultimate Texas Hold’em: https://www.vela.co.il/index.php/community/profile/beatricebest78/ Canadian players seeking free spins in 2021 might notice that several casinos are not offering free spins anymore. Instead of free spins offers, you will see “extra spins” or “bonus spins” offers bandied around instead. However, this is in most cases a change in terminology that certain operators are implementing to be extra sure that they fall in line with online gambling regulations. This guide will explain the differences between these two bonuses. We’ll look at some of the best online slots free spins games, and tell you how to activate these rewarding features. Furthermore, we’ll examine the array of online casino Free Spins that you can pick up, ranging from no wagering offers to the latest Free Spins no deposit deals. At this point, players may be wondering why casinos actually give away free spins. By giving away free spins, online casinos are, essentially, giving away money to the players. This doesn’t gel well with the overall impression that casinos are out to make money, not give it away. However, by offering free spins with no deposit, casinos aren’t actually losing out at all.

  81. Tisha Womac

    Wow! This can be one particular of the most useful blogs We have ever arrive across on this subject. Actually Wonderful. I’m also a specialist in this topic therefore I can understand your hard work.

Comments are closed.

Helpful Links

Courses