SHOP NOW FOR GEAR
Login
Join Rigging Lab

System Efficiency of Mechanical Advantage Systems

Written By: Lance Piatt

System Efficiency

Effect of pulley friction. Most rescue pulleys have an efficiency rating of .75 to .90 (only 75% to 90% of tension is transferred from one side of the pulley to another due to friction). A carabiner used as a pulley has an efficiency of only about 50% or less (more for a steel carabiner, less for aluminum).

Effect of rope on rope friction.

Rope rubbing on rope will significantly reduce the efficiency of the system. Avoid crossing strands of rope within your MA system.

Effect of other sources of friction.

A rope touching any surface creates system inefficiency.

Techniques to reduce this friction:

• Cloth edge padding

• Polyethylene edge pads (e.g., ice cube trays)

• Rollers

• Directional pulleys

Effect of Excessive Angles

The angle of rope entering and exiting a pulley affects the force transferred through the pulley (the more acute the angle the more force transferred, the more obtuse the angle the less force transferred). Keep the ropes parallel but not touching for maximum efficiency.

Maximizing Throw of the System

• Ideal systems require fewer re-sets.

• With simple systems move the mainline anchor farther from the edge in order to increase the throw.

• In compound systems, the second system (that which is farthest from the load) will collapse before the first if co-located on the same anchor.

• Staggering anchors in a compound system will reduce re-sets. To maximize potential the first system should chock-o-block simultaneously with the second or earlier.

Use the following formula to determine anchor separation:

• MA of first system x throw distance of the first system = length of throw for the second system; example:

  • 1st throw is a 10 foot long 3:1 10 ft x 3 = 30 ft
  • 2nd throw should be built 30 ft long (regardless of the MA of the 2nd throw)

Progressions

If higher levels of mechanical advantage are needed during a hauling operation, it is significantly more efficient to build upon the existing system than to disassemble it and build a new, more advanced one.

The 2:1 and 3:1 are haul systems upon which progressions of higher degree systems can be easily built without tearing down the original and starting anew.

The 2:1 progression:

• 2:1

• 6:1

• 10:1

The 3:1 progression:

• 3:1

• 5:1

• 9:1

Summary

Manual haul systems are high-load/high-risk techniques and the possibility of catastrophic failure is greater than in lowering systems. Never apply more mechanical advantage than is needed to raise the load. The ability to raise the load will be significantly enhanced by utilizing techniques that increase system efficiency. The rescuer should know how to minimize the effects of friction from various sources, how to maximize system throw, and how to increase mechanical advantage if needed. The rescuer should also know how to calculate the mechanical advantage of a system in order to evaluate forces applied to the anchor and to the system as a whole.

Some Extra Credit!

 

Peace on your Days

Lance
Categories

About The Author:

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.

259 thoughts on “System Efficiency of Mechanical Advantage Systems”

  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.

  67. metrolagu com

    I wanted to check up and let you know how, a great deal I cherished discovering your blog today. I might consider it an honor to work at my office and be able to utilize the tips provided on your blog and also be a part of visitors’ reviews like this. Should a position associated with guest writer become on offer at your end, make sure you let me know.

  70. nuestra empresa

    Sweet blog! I found it while browsing on Yahoo News. Do you have any tips on how to get listed in Yahoo News? I’ve been trying for a while but I never seem to get there! Thank you

  72. negocio

    Hi my family member! I want to say that this article is amazing, great written and include approximately all important infos. I’d like to see more posts like this .

  102. internet providers ottawa

    That is really fascinating, You’re an excessively skilled blogger. I’ve joined your rss feed and look forward to in the hunt for extra of your magnificent post. Additionally, I’ve shared your website in my social networks!

  109. Doova

    Не удивительно, почему в эротологии Китая названия женских и мужских репродуктивных органов связаны именно с этим камнем. У мужчин — нефритовый жезл или стебель, который в женщину входит, у женщин — нефритовые врата или пещера, которая принимает нефритовый жезл, нефритовая палата — матка и нефритовые гроздья — это яйцеклетки в яичниках, способные дать новую жизнь потомству. Нанесите ежедневное увлажняющее средство (сыворотка, крем, маска) на очищенную кожу лица, после чего обработайте лицо массажными роликами. Не превышайте работу массажером более 5-10 минут за один раз. Розовый кварц более известен тем, что способен уменьшить видимость морщи. Несмотря на то что нефритовые роллеры по цене дороже, это весьма мягкий камень, который имеет свойство «изнашиваться», поэтому роллер из розового кварца прослужит тебе дольше. Проверяйте адрес сайта, прежде чем перейти на него https://emilianouodr653208.blogsumer.com/14557328/активатор-для-роста-ресниц Для того, чтобы результат был действительно впечатляющим, необходимо не только умение, но и правильно выбранное средство для подводки. Все чаще популярность приобретают именно жидкие варианты подобной косметики. Все, без исключения, женщины мечтают о красивой, выразительной форме глаз. В наше время есть замечательная возможность осуществить эту мечту даже в том случае, если природа не одарила ваши глаза идеальным разрезом. Сегодня цветные стрелки и контуры продолжают оставаться на пике популярности. Наравне с классическими черными, коричневыми и серыми оттенками в макияже используют синие, белые, зеленые и многие другие цвета. Золотистые и серебристые глиттерные подводки — яркая альтернатива матовому аналогу. Выберите страну Эта подводка для глаз от Max Factor позволит с легкостью начертить тонкие элегантные линии. Ее нежная и шелковистая текстура отлично переносится на веко, повторяя изгибы и равномерно распределяя пигмент. Тонкая и мягкая кисточка поможет вам создать идеальный макияж глаз. Перед применением рекомендуется встряхнуть подводку, чтобы она не подсыхала и давала максимально яркий и насыщенный результат.

  110. cheap rdp

    Nevertheless, it’s all carried out with tongues rooted solidly in cheeks, and everybody has got nothing but absolutely love for their friendly neighborhood scapegoat. In reality, he is not merely a pushover. He is simply that extraordinary breed of person solid enough to take all that good natured ribbing for what it really is.

  115. 홍대키스방

    I dont think Ive caught all the angles of this subject the way youve pointed them out. Youre a true star, a rock star man. Youve got so much to say and know so much about the subject that I think you should just teach a class about it

  122. WilliamRep

    [url=https://clonidine.click/]6 clonidine[/url] [url=https://lasix.ink/]medication lasix 20 mg[/url] [url=https://viagraxtab.quest/]purchase viagra no prescription[/url] [url=https://buyviagrapillnorx.monster/]best viagra for sale[/url] [url=https://ordercialis10withoutrx.monster/]can you buy cialis over the counter in south africa[/url] [url=https://buycheapviagra.quest/]pharmacy viagra price[/url] [url=https://ordermodafinil.online/]modafinil 2020[/url] [url=https://azithromycin.download/]zithromax tablets online[/url]

  130. sbobet

    That’s some inspirational stuff. Never knew that opinions might be this varied. Thanks for all the enthusiasm to supply such helpful information here.

  136. sell credit card processing

    Hi there! I just wanted to ask if you ever have any trouble with hackers? My last blog (wordpress) was hacked and I ended up losing several weeks of hard work due to no back up. Do you have any solutions to protect against hackers?

  153. cutt.ly

    I’m not sure why but this web site is loading incredibly slow for me.
    Is anyone else having this issue or is it a problem on my end?
    I’ll check back later on and see if the problem still exists.

  162. credit repair

    Amazing! Your site has quite a few comment posts. How did you get all of these bloggers to look at your site I’m envious! I’m still studying all about posting articles on the net. I’m going to view pages on your website to get a better understanding how to attract more people. Thank you!

  179. graliontorile

    Thanks for another informative website. Where else could I get that type of info written in such an ideal way? I have a project that I’m just now working on, and I’ve been on the look out for such info.

  186. Switches

    Thank you a lot for sharing this with all folks you actually recognize what you’re speaking about! Bookmarked. Please additionally visit my site =). We can have a hyperlink trade contract among us!

  197. vacate cleaning service

    Good post. I study something more difficult on different blogs everyday. It’s going to always be stimulating to learn content material from other writers and observe a little bit one thing from their store. I’d prefer to use some with the content material on my blog whether you don’t mind. Natually I’ll give you a link in your web blog. Thanks for sharing.

  206. oficina empresa cerrajeros

    We absolutely love your blog and find the majority of your post’s to be exactly what I’m looking for. Do you offer guest writers to write content to suit your needs? I wouldn’t mind composing a post or elaborating on a number of the subjects you write about here. Again, awesome weblog!

  207. WilliamRep

    [url=http://genericviagratabletbuy.monster/]generic viagra 100mg india[/url] [url=http://viagratabsshop.monster/]viagra cost in mexico[/url] [url=http://onlineviagrapillwithnorx.monster/]sildenafil 1mg[/url] [url=http://ordercialis40mgcost.monster/]how to buy cialis without prescription[/url] [url=http://viagramtab.monster/]viagra online cheap price[/url] [url=http://viagragenericpillsforsaleonline.quest/]sildenafil gel 100 mg[/url]

  229. Find Out

    A good web site with interesting content, that’s what I need. Thank you for making this web site, and I will be visiting again. Do you do newsletters? I Can’t find it.

  242. instalacion tuberias

    I dont think I’ve read anything like this before. So good to find somebody with some original thoughts on this subject. cheers for starting this up. This blog is something that is needed on the web, someone with a little originality.

  250. source

    I have read several just right stuff here. Certainly price bookmarking for
    revisiting. I surprise how a lot effort you place to create this type of fantastic informative site.

  251. about his

    Good blog you’ve got here.. It’s hard to find quality writing like yours these days. I truly appreciate individuals like you! Take care!!

  256. lihat sekarang

    I must thank you for the efforts you have put in writing this site. I really hope to see the same high-grade content from you in the future as well. In fact, your creative writing abilities has inspired me to get my own blog now 😉

Comments are closed.

Helpful Links

Courses

Copyright (c) Red Ibex Solutions | Powered by Red Ibex Marketing Solutions

Privacy Policy