Unwarranted Concern?

[daniel_owen_uk 0]

So after its stripped stopper from the end of the cable, and tore that cable up at about 120MPH, what happens to the other end of the cable, that presumably it's still attached to?

__________________

BOOM Headshot

[mr2mk1g 10]

What's "it"?

Are you asking about what happens after the RSL pulls on the reserve cable?

Remember most RSL lanyards simply terminate in a ring through which the reserve cable passes rather than actually being attached to anything.

If the RSL lanyard pulls on a cable which has one end through the reserve loop and the other end is free floating and attached to nothing (because you've pulled the end off the cable)... it's possible the whole cable will simply come out of the housing and trail behind you as the ring on the end of the RSL lanyard slides up the cable.

What you're hoping for is that the resistance of the cable being pulled through the housing is greater than the resistance the reserve loop exerts on the reserve pin. I wouldn't want to hang my hopes on that alone.

But then... that swadge is not exactly likely to come off the end in the first place... so I hope this whole thing is just theoretical for us.

[ZigZagMarquis 8]

Daniel_Owen_UK,

Mr2mk1g beat me to it, but he said basically what I whould have.

Thinking about it more... now I can think of a reason where Bill Booth's RSL set-up on the V3 makes some sense in this scenario... the Reserve Pin is on the end of the RSL, not on the end of the Reserve Rip Cord cable, effectively, the V3 Reserve Rip Cord is just a pin puller, instead of the other way around, where the RSL is a pin puller.

In this secnario, where the ball comes off of the Reserve Rip Cord cable, the V3 RSL would pull the pin straight away since the pin is on the end of the RSL. I don't know if that was part of Mr. Booth's thinking when he set-up his V3 RSLs that way, but maybe...

[daniel_owen_uk 0]

Of course! That makes sense, I was thinking that the RSL was directly attached to the reserve cable, although of course that would mean you would have to drag your main along by the reserve line. Makes sense now, knew I should have looked harder for a diagram before I posted

V3 does sound like a much better idea.

__________________

BOOM Headshot

[mjosparky 3]

Quote

Quote

Yet another reason for RSL

Ya know, I thought about that too... in the scenario where the ball comes off the end of the Reserve Rip Cord... an RSL may pull the reserve... but then I did a double take thinking it just may strip the cable through the housing and leave the pin in place... hmmmm... guess the only way to know would be to do some sort of test drops... MJO! You up for it???

Hey Zig,

That is some good thinking. (you engineer types do too much of that) That does present an interesting "what if". You know me, if the money is right I will test what ever you got. You could rig it with a dummy ripcord system and do an intentional cutaway. You build it and I will jump it.

Sparky

My idea of a fair fight is clubbing baby seals

[JerryBaumchen 1,064]

You don't even have to spend any money to find out. Just get an old ripcord (almost any kind), cut off whatever to get it to a 1-pin/no ball configuration, then stick into a rig with a ringed RSL (what a non-Vector would be like), bench test/pull the RSL & see what happens.

My money is on the cable merely stripping out of the housing and the pin staying place.

I think PdeF had some type of pillow ripcord at this year's Symposium that used two RW-4 rings (I think RW-4, the smallest rings in a mini-3-ring setup) that were interlaced through each other. The cable was looped around one ring & nico-swaged onto itself. I wish that I had taken a pix of it. If anyone has a photo of it, I would like to see it posted.

And lastly (maybe ???), you do not need to use Mil-Spec cable. You do need to use the cable that the item is/was TSO'd with. If mfr's were stuck with only Mil-Spec stuff we would never see rigs like we have today with all of the composite/plastic/Delran/Lexan/etc in use. It's called progress. And be damn glad of it.

Anybody remember the GripCord?

[daniel_owen_uk 0]

Bench testing wouldn't replicate the forces for the main pulling the RSL though would it?

__________________

BOOM Headshot

[mjosparky 3]

Quote

You don't even have to spend any money to find out.

You could put in on a torso dummy and throw it off a building and static line the rsl. That might give you a pretty good idea. You could even get fancy and rig a load link in and find out what the pull forces would be.

Quote

If mfr's were stuck with only Mil-Spec

I have heard that Mil-Spec has been abandoned for the most part. What have you heard?

Sparky

My idea of a fair fight is clubbing baby seals

[tbrown 26]

Quote

I did wonder about this, they taught me to check it as part of my gear check, make sure the ball doesn't come off the end of the cable.

But how would you do that ? If you tug hard enough on the ball you'd pull the pin and pop your reserve. I suppose you could try to get a grip on the cable and try to rip the ball off by hand. As there's no way you could do that with 300 lbs force, you shouldn't be able to rip the ball off, but that's not going to tell you it's holding at 300 lbs either.

If you're really concerned, you could probably ask your rigger to set up a test with a bunch of barbell weights or something. But only do it ONCE and then stop worrying about it. Ultimately we have to trust our gear, as our sport is entirely gear dependent - can't jump without a rig, not more than once anyway. This is a sport where no matter how we love it, that little voice reminds us every time we open the door that, "this could be the last time", so try not to let EVERY detail prey on your mind.

Your humble servant.....Professor Gravity !

[riggerrob 558]

I manufactured and tested hundreds of ripcords while working for Butler, Rigging Innovations and Para-Phernalia. All of them use manual swaging tools (like over-grown Nciopress) originally designed for swaging aircraft control cables.
I pull-tested all the PEP (Pilot emergency parachute) ripcords to 300 pounds for 3 seconds and I pull-tested all the RSL-compatible ripcords to 600 pounds for 3 seconds.

Flying High uses two ball swages on the end of their RSL-compatible ripcords.
Oddly, Strong Enterprises uses copper Nico Press sleeves on the ends of their tandem reserve ripcords.

When R.I. first started installing RSLs, they pull-tested several different ripcord end configurations. Some simple ball ends passed the 600 pound test, but not enough for Sandy Reid's liking, so R.I. standardized on ball-and-shank for all their RSL-compatible ripcords.
Jump Shack stuck with a simple ball because it consistently passed all their 600 pound tests. Jump Shack has their own custom-made swaging tool and John Sherman will tell you why it is better, just ask him!
Hee!
Hee!
Jump Shack also builds ripcords for dozens of other manufacturers (hint, they are stamped: date of manufacture and "PL").

[JerryBaumchen 1,064]

Hi Sparky,

"I have heard that Mil-Spec has been abandoned . . ."

What I understand it that it is on the way out but that you can still get Mil-Spec webbing, tapes, etc.; for now.

The PIA has taken over the control of the documents, rewriting them into their letterhead and format.

I think that it is only a matter of time and the term 'Mil-Spec' will disappear within this industry.

Just my thoughts . . .

[matthewcline 0]

I don't think a bare handed check could adequatly measure the strenth of the "steel swaged ball".

Maybe he is confusing checking that the cable is freely moving and intact from the handle to the pin.

You know the old school JM skill of holding the cable at the pin with one hand and pullling gently on the "steel swaged ball" with the other. During the old school gear check that I rarely ever see any more.

An Instructors first concern is student safety.
So, start being safe, first!!!

[FrogNog 1]

Quote

You know the old school JM skill of holding the cable at the pin with one hand and pullling gently on the "steel swaged ball" with the other. During the old school gear check that I rarely ever see any more.
Matt

You rarely ever see anyone doing this on gear at all, or rarely ever see instructors do it on students' gear?

At my DZ they taught us this as part of the gear checks, and it's near the end of my packing ritual. (Although, I don't actually pull on the cable, I push it up inside the (D-ring) handle and watch it flow out the housing end by the pin. Then I let the cable go and cable flex returns it to its normal position, and I call it good.)

-=-=-=-=-
Pull.

[daniel_owen_uk 0]

Quote

Quote

I did wonder about this, they taught me to check it as part of my gear check, make sure the ball doesn't come off the end of the cable.

But how would you do that ? If you tug hard enough on the ball you'd pull the pin and pop your reserve. I suppose you could try to get a grip on the cable and try to rip the ball off by hand. As there's no way you could do that with 300 lbs force, you shouldn't be able to rip the ball off, but that's not going to tell you it's holding at 300 lbs either.

If you're really concerned, you could probably ask your rigger to set up a test with a bunch of barbell weights or something. But only do it ONCE and then stop worrying about it. Ultimately we have to trust our gear, as our sport is entirely gear dependent - can't jump without a rig, not more than once anyway. This is a sport where no matter how we love it, that little voice reminds us every time we open the door that, "this could be the last time", so try not to let EVERY detail prey on your mind.

I am pretty sure it doesn't take 300lbs of force to pull the pin through the closing loop, so do I really need to test it to that degree when doing my gear check? If I make sure that the stress the ball can take is greater than the pin can take then that's enough for me to be confident it will hold in an emergency.

Oh and yes the test I was taugh was to hold the cable and pull on the ball.

__________________

BOOM Headshot

[nitrochute 2]

supposedly EVERY ripcord is subjected to the 300 pound pull test.but my experience in the industry is that aint so!even WASLEY PRODUCTS(ssuccessor to capewell)only did a sampleling.when i worked at para flite/sse inc , i rejected a batch of ripcords,around 300,because the ball swages were cracked (yes they were cracked. we examined them under a microscope)apparently from over swaging them.(so people were scrutinizing things a little more)this was around the time that that there was a fatality involving a homemade ripcord were the ball swage did in fact come off the cable.i was doing a 100% inspection.we found out at that time that waasley was only doing about 10% sampleing.

[mjosparky 3]

Quote

supposedly EVERY ripcord is subjected to the 300 pound pull test.but my experience in the industry is that aint so

Every ripcord is supposed to be marked with the following information but the recent problem with Capewell pins brought out the fact that they are not. Had they been marked as required, it would have been an easy matter to identify those that were manufacture using the suspect batch.

From AS801-B

4.2.2 Primary Actuation Device/Ripcord: The following information shall be marked on the primary
actuation device/ripcord:
a. Part number, including dash number
b. Manufacturer’s identification
c. TSO-C23( )
d. Batch, serial number, or date of manufacture (month and year)

Sparky

My idea of a fair fight is clubbing baby seals

[Zoter 0]

Quote

So does anyone have a picture/diagram of the 'internals' of a pillow type reserve handle...?

If not I'll Xray mine and post a pic after the weekend.....

This whole thread got me curious so I xrayed my Wings cutaway and pillow reserve handles.....thought I would share.
(Pillow is highlighted in red)