3 Pulley Systems – Complex Pulley System

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Largely considered as an advanced climbing technique, rigging a climbing pulley system whether it’s one of the 3 pulley systems mentioned below or some other pulley system, is an essential skill for any climber who decides to move from indoor rock climbing to the outdoors. Whether it’s hauling climbing and mountaineering gear over a high wall or self-belaying on a route, you’ll find simple, compound, or complex pulley system outlined below most useful.

Simple Pulley System

In a simple pulley system, the rope runs between pulleys on the anchor and the load. If there are ‘traveling’ pulleys (pulleys that move instead of being fixed to an anchor), these will be moving in the same direction and with the same speed as the load. That is, they will be moving towards the anchor at a constant speed.

Compound Pulley System

A compound pulley system is two simple pulley systems put together, like combining a 3:1 pulley system with a 2:1 pulley system. In any case, when you pull the rope, all the pulleys will be moving in the same direction just as the case with a single pulley system. The difference is that they will be moving at different speeds towards the anchor.

Complex Pulley System

Simply put, a complex system is one that doesn’t meet the definitions of a simple pulley system or a compound pulley system. Like the two aforementioned pulley systems, the complex system also has ‘traveling’ pulleys. However, unlike simple and compound pulley systems where the ‘traveling’ pulleys move in the same direction as the load, the ‘traveling’ pulleys in a complex system move in the opposite direction of the load.

You’ll also notice that when you pull the rope, the pulleys will be moving towards each other. At some point, the pulleys will eventually hit each other or ‘collapse’. When this happens, you need to reset the pulley system.

This usually isn’t a problem when you have a spacious area to work with; however, if you are in a cramped area like a tiny rock ledge, constantly having to reset the pulley system can be quite bothersome, to say the least. This is why many climbers and rescuers choose to use a simple pulley system or a compound pulley system because they are easier to rig and operate.

Pulleys and Pulley Systems: Which One to Use?

All the 3 pulley systems mentioned above (as well as others that aren’t included in this article) have their place in the climbing world. From mountain and ice climbers to rescuers and others, learning how to set up and operate various pulley systems is an essential skill that everyone in the said industries should develop and master.

Regarding which pulley system to use, there’s no quick and easy answer. It will all depend on the circumstances that require the use of a pulley system. Note also that there are instances where the use of a pulley system isn’t really necessary.

Take rock climbing for instance. If you are climbing walls and boulders at your indoor climbing facility then you most likely wouldn’t need pulleys. The same is true when doing short routes in the outdoors. In such cases, you’re going to be spending more time with your belay device than a pulley.

On the other hand, if you’re a big wall adventurer or a simul-climber, then learning how to set up the 3 pulley systems mentioned above and other pulley systems is a must.

Pulley systems are useful in a variety of climbing scenarios related to the ones mentioned earlier. Need to haul heavy bags and backpacks up a high alpine wall on your mountain climbing expedition? Then setting up a pulley system is your best option. Want to make your simul-climbing adventure much safer? Then a reliable climbing rope and a pulley system with an auto-locking pulley and an attached piece of protection should help catch the bottom climber’s fall without pulling the leader of the wall.

From hauling your team’s mountain climbing gear, executing an assisted raise with your climbing partner, to performing a self-belay these pulley systems are bound to be of great help.

FAQ

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Q: What are the 3 types of pulleys?

A: 

The various types of pulleys generally fall under one of three main categories: pulleys that change the direction of the force (e.g. fixed pulley), pulleys that change the magnitude (e.g. movable pulley), and pulleys that are a combination of the two, meaning it changes the magnitude and the direction of the force (e.g. compound and complex pulley system).

Q: How do you build a 3 pulley system?

A: 

To build 3 pulley systems, follow the steps below:

  1. Rig a simple 1:1 pulley system, where the rope goes through one pulley with one end attached to the load and the other to a controlling force, which could be you, your rock climbing buddy, or a motorized / electric capstan to pull or release the rope as needed.
  2. Tie ‘capture’ Prusik knot near the anchor or pulley. These will hold the load if you let go of the rope.
  3. Add a ‘travelling’ pulley on the working end of the rope, then attach a carabiner to it.
  4. Tie a ‘travelling’ Prusik on the lead end of the rope and clip it to the carabiner.
  5. Pull on the rope that exits the “travelling” pulley.

Q: What is pulley system?

A: 

A pulley is a mounted rotating wheel with a curved, convex rim where the rope, chain, or cable moves along. Pulley systems can be as simple as a fixed pulley system (which uses a single pulley) or as complicated as a complex pulley system (which uses two or more pulleys).

Q: What is the formula for a pulley?

A: 

There are different formulas that can be used to calculate various aspects of pulley systems such as Newton’s Second Law where F (force) = M (mass) x A (acceleration) and the Third Law where F = T (tension or force in the rope) + G (force of gravity).

Q: What is the principle of pulley?

A: 

The pulley is one of the six simple machines; hence, making it a device designed to change the direction or magnitude of a force. It has a wide range of applications and is predominantly used to make moving and lifting objects easier.

Q: What is an example of a pulley?

A: 

Examples of pulleys are pretty easy to spot on a daily basis. Passing through a construction site and you’ll probably see a construction crane or cargo lift systems, both of which uses pulleys. The elevator and window blinds on you workplace or apartment also relies on pulleys. Even the humble flagpoles and wells operate with the help of pulleys.

Globo Surf Overview

Knowing how to set up and rig the 3 pulley systems mentioned above is an essential skill that climbers must develop. By studying how to rig a simple pulley system, a compound pulley system, or a complex pulley system you should be able to perform a variety of actions and maneuvers that you won’t otherwise be able to do without a pulley system. From hauling your multi-day mountain climbing gear or just performing a self-belay, or even in emergencies like performing a crevasse rescue, these pulley systems can go a long way in helping to make these things easier and even safer.

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My name is David Hamburg. I am an avid water sports fan who enjoys paddle boarding, surfing, scuba diving, and kite surfing. Anything with a board or chance I can get in the water I love! I am such a big fan I decided to start this website to review all my favorite products and some others. Hope you enjoy!