3-Rings and Risers

[skyymooner]

In light of the (few and far between) apparent cases of risers cutting away at inopportune times, I have a few questions. Please keep in mind that I am a new guy, and in no way would second guess Bill Booth or the manufactuters.

I have read through most of the threads on this topic, and have seen a few logical ways to lock off the 3 rings in the event that one wouldn't need to chop. It seems that the method of using a big rapide link in lieu of the teflon coated cable is a pretty sure-fire way to lock the system. However, to me, this would make the locking loop that is, I presume, sewn into the riser, the weak link.

My question, I guess, is that given the fact that we really shouldn't need to cut away a highly loaded canopy, and in the rare case that we would need to cut away while loaded (skydive, tree maybe), the canopy should still be loaded lightly compared to say a small stilletto, couldn't we come up with a more bulky, reinforced system of rigging the 3 ring, even if it lessens the mechanical advantage a little? This seems to be one of the places that BASE gear might could go a different way from skydiving gear. I doubt this is an original idea, but I hadn't seen any thoughts on it. Maybe a thicker kevlar (or something) loop? Am I way off BASE :9 ?

Mike

[imported_Tom Aiello]

>Couldn't we come up with a more bulky, reinforced system of rigging the 3 ring, even if it lessens the mechanical advantage a little?

YES. This is an idea who's time has come.

Our needs are not the same as those of skydivers, and I don't see why we use a skydiving cutaway system in a jumping environment it is not designed for.

>Maybe a thicker kevlar (or something) loop?

Has anyone re-visited any of the old pre-3 ring systems? I don't know anything about them, but as I recall, the big problems with them were that they were inconsistent in cutting away. Maybe a modernized variation on some old system would be a good starting place. Does anyone who knows about those systems have any thoughts?

--Tom Aiello
tbaiello@mac.com

[346]

Assuming the riser is built, assembled and maintained correctly, the loop on the riser is not the weakest link.

I think the primary failure points on a Type VIII riser system are the front or rear leg of the riser (most likely near a joint), the hole through the riser (for the grommet) and the location where the ring on the harness meets the webbing for the riser.

These problems were addressed for Tandem systems by simply using stronger webbing (Type VII). If I was looking to over-build my risers some more, I'd start there. You'll notice the material used for the loop on Tandem risers is the same as used on your sport rig / BASE rig. In fact, it's one of the few things that did not change. The loads placed on the loop are relatively small and a change was not needed there.

Can't wait to see those new reversed large-ring Type VII risers....

Mark &-)
BASE 346

[skyymooner]

>Assuming the riser is built, assembled and
>maintained correctly, the loop on the riser is
>not the weakest link.

There I go again, showing my ignorance. :D
>
>Can't wait to see those new reversed large-ring
>Type VII risers....

Who's making those?

I appreciate the schooling. I am not overly concerned about riser release, just theorizing on ways to possibly improve.

Mike

[Tree]

If you are concerned about un-intentional release of the 3 ring system, L bars and a hook knife would be 100% effective. If you need to "cut" away, you would need new risers, but there is no chance of release.

The loop part of the 3 ring takes very little force, somthing to the effect of 15 to 20 lbs of force. THe loop material is typically made of hollow braided line that is rated to at least 200 lbs (more like 500 lbs). The failure of a 3 ring system is almost certain to be assembly errors, or human errors such as grabbing the cable at the loop under pressure.

I've heard of old shcoolers putting zip tyes around the risers and through the small ring in the early 80's, but back then the system was much less tested.

I'm sure my point of view would be different if it was my riser that released. :D

[Dapper Snapper]

I'm with you Mike. I would like to see a new release design for base rigs. The 3-ring cuttaway loop/pillow is a bit too easy to dislodge on accident (climbing to the exit point on a tight "A" or something), and there have been a few too many mystery releases in my opinion. I use rapid links to ease my mind when not jumping near water.
The 3 ring system is outdated for base. If any manufacture designed a system that would be very difficult to release on accident and yet very easy to rig and inspect I would love to retire my 3-rings.
C'mon all you manufacturers this looks like a great way to make some easy cash!

cheers

[space]

The only time I needed to cut away on a BASE jump was on an aborted landing target and I took the water downwind was being drug face down across the surface, the release was not so easy to find in this situation (loop type, under the liftweb).
As for mechanical advantage loss, we already have that using mini "ring" risers and/or main harness rings.
I have already inspected a skydiving failure of a typeVIII riser that was miniringed but not reversed.
The Mechanical advantage of a large 3 ring system lies in a touted 10/10/2 reduction in force, example; a 1000lbs load would be reduced by the middle ring to 100, then to 10 by the small ring, and 5lbs by the loop. This is of course assuming the were properly inline at the time of loading, Miniring systems are around 7/7/2 if I remember correctly(correct me if I´m wrong please), RW7 main (mini)harness rings suck bigtime because of their thinness and was (I think) a major factor in the guillotine failure of miniring systems, not the grommet.
food for thought,
take care,
space