The 3-ring system is a parachute component extensively used by military paratroopers and sport skydivers. It connects the main parachute’s risers to the harness. Most of us have seen and chatted about the 3-ring system during the AFF course. Also, we mention it every time we do a gear check at the drop zone. Yet many people do not know how it works, who created it (Bill Booth), and how to perform its correct maintenance.
This article is a bit different from what you can usually find here. I’m doing my research and adding articles from various sites in only one spot. Let me know if you have any extra point or correction on the comments.
“The 3-ring system is simple, inexpensive, reliable and requires fewer operations than earlier parachute release systems while reducing the physical force needed.”Unknown
Developed by Bill Booth, the 3-ring system permits us to cut away the main parachute immediately from our skydive harness. We need this system to quickly release our main canopy during a malfunction or emergency. We can deploy our reserve canopy as soon as we have no main parachute connected to our harness.
How does it work?
The larger bottom ring is securely attached to the skydiver’s harness. The middle ring is securely attached to the end of the parachute riser. The smaller ring is securely attached to the parachute riser above the middle ring.
The middle ring is passed through the larger ring and looped upwards; the smaller ring is then passed through the middle ring and looped upwards. Continuing in the same manner, a cord loop is passed through the smaller ring, loop upwards, and finally passes through a grommet to the opposing side of the parachute riser.
A semi-rigid cable attached to a release handle then passes through this loop, securing the loop. Releasing the cord loop by removing the cable with a tug causes the three-ring system to cascade free and quickly disconnect the riser from the harness.
Who’s Bill Booth?
Bill Booth (born 1946 in Coral Gables, Florida) is an American engineer, inventor and entrepreneur in the skydiving equipment manufacturing industry. His invention of the 3-ring release safety device has enhanced skydiving safety. He founded the companies United Parachute Technologies (UPT) and Complete Parachute Solutions, which had 150 employees as of 2015.
Mr. Bill Booth also invented the pull-out and throw-out pilot chute, the Skyhook RSL safety device and the “Sigma System” for tandem drogue release. United Parachute Technologies (UPT) sells the Vector 3 and Vector 3 Micron Harness/Container system. The latest versions incorporate innovations like magnetic riser covers, a spectra ripcord and the Skyhook RSL system.
What is the mechanical advantage of the 3-ring system?
Each ring acts as a “Class 2 Lever”. For example, imagine you are lifting the orange beam shown below from a position close to the pivot (distance y). The force somebody else would need to apply at the far end (distance x) would be smaller by a factor of X/Y.
Imagine now that instead of applying your force directly upwards, you chose to apply it at a shallow angle. You can see that the perpendicular distance to the pivot is reduced, despite the force being used at the same point on the beam. If your applied force (bodyweight in the case of the parachute) remains constant, then the reaction required to stop the beam moving is now even lower.
The way the 3-Ring-Release works is by linking two of these systems together. It’s difficult to show on a ‘classical diagram’ because the fabric wraps around to form the fulcrum in each lever.
The image below illustrates how the reaction force required on the small fabric loop (bottom left arrow) is many times smaller than the force applied by the weight of the human (far right arrow).
It is critical to minimize this reaction force since if it were too large, then the friction force against the ‘pull cord’ (yellow in your original .gif) would be too big and it would become difficult to remove the cord and release the parachute.
There is no “pulley action” going on – the mechanical advantage is merely to reduce this frictional force and ensure that the yellow cord can be removed easily, regardless of how heavy the human is.
How to do my 3-ring system maintenance?
Most manufacturers recommend servicing the 3-ring release once a month. Make sure to check your manufacturer’s manual for a definitive time frame.
Pull your cutaway handle and safely set your risers aside under a weight or rubber-banded together. You will need a paper towel and a lubricant spray like silicone or Teflon. Spray about a quarter-sized area of your spray onto the paper towel and draw your cutaway cables through the lubricant. You will probably see a black residue left on your paper towel.
We usually give two or three pulls through, then find a clean spot on the paper towel, and do one or two pulls to clean off excess dirt. After that, you can feed your cables back into your rig (make sure to thread it properly if you have a Skyhook/Collins lanyard). Once that is in place, it is time to massage your rings.
Grip the rings on your risers in turn between your thumb and pointer finger and wiggle the ring around in as many directions as possible. We are trying to break the memory of the fabric that has it held in position for how it usually rests.
In a low-speed partial malfunction, your risers may not release if they are too set in their shape. Get the end of the riser straightened so that the middle ring lies flat out. Reattach your risers and then do a full line continuity check to make sure that you put them back on straight.
Keep coming back
Learning about our gear will help to keep our community safer. I’m sure you will spot something weird in someone else’s gear and at some point, someone will spot something in yours. Being ready for the day that person needs you is the best you can do to keep people around you safer.
If you like this article, please let me know, leave me a message or send me a DM on Instagram. I want to know more about your experience and thoughts!
Follow me on Instagram: @augustobartelle
Like the Fan Page on Facebook!
Support this blog by wearing our Colorful Jersey. Find more at our Online Store – www.ColorfulJerseys.com