Reserve Ripcord - Cleaning?

[dgw 8]

There were a number of posts a while back relating to hard cutaways. One of the possible reasons for a cutaway handle being hard to pull appears to be dirt/third party material on the yellow cables, and the advice seems to be that cleaning the yellow cables regularly (every 30 days) will mitigate this particular mode of hard pull occurring.

I was wondering if such a mechanism could also affect the reserve ripcord: i.e. dirt/material on the cable or in the housing being solely responsible for a hard reserve pull. It would seem reasonable that if it can affect the cutaway cables, it could also affect the reserve ripcord. However, it doesn't seem possible that a jumper could clean the reserve cable every thirty days. Some repack regimen would not allow a cleaning operation to be carried out for a year.

Thoughts appreciated

Darren

[billvon 2,400]

> i.e. dirt/material on the cable or in the housing being
>solely responsible for a hard reserve pull.

Definitely! Gravel in the cable housing can jam reserve ripcords. If you have a hard landing and manage to drag the area near the reserve pin near the ground, make sure to inspect the area near the cable housing entry. Also, you can wiggle the cable back and forth a few inches (there should always be some slack between the swage and the handle) to verify that it moves freely.

The primary problem with cutaway cables is that they get dirty/sticky, and then it gets hard to pull that area through the white loop. That's not too much of a problem with reserve ripcords unless the pin itself is damaged or bent. That's another thing to check whenever you have a hard landing, or when you're checking your gear in the morning - make sure your pin is straight, there are no nicks/scratches on it and the pin looks clean.

[dgw 8]

Right! I get it now. I was thinking about the yellow cable in the housing 'before' the white loop, rather than the portion 'after', in the (hard) housings.

Thank you.

[crazydiver 0]

Quote

The primary problem with cutaway cables is that they get dirty/sticky, and then it gets hard to pull that area through the white loop. That's not too much of a problem with reserve ripcords unless the pin itself is damaged or bent. That's another thing to check whenever you have a hard landing, or when you're checking your gear in the morning - make sure your pin is straight, there are no nicks/scratches on it and the pin looks clean.

I would argue that its the legnth of cable INSIDE the housing coming from the handle that creates the most drag/pull force on the cable due to grime buildup.

Cheers,
Travis

[billvon 2,400]

>I would argue that its the legnth of cable INSIDE the housing coming
> from the handle that creates the most drag/pull force on the cable
> due to grime buildup.

Hmm. I have seen several hard ripcord pulls caused by bent/damaged pins, but have never seen a hard pull caused by a dirty cable.

[bob.dino 0]

Quote

>I would argue that its the legnth of cable INSIDE the housing coming
> from the handle that creates the most drag/pull force on the cable
> due to grime buildup.

Hmm. I have seen several hard ripcord pulls caused by bent/damaged pins, but have never seen a hard pull caused by a dirty cable.

When referencing a dirty cable are you talking about reserve deployment or main cutaway?

[crazydiver 0]

I was referring to cutaway cables as you were speaking about in that post. I agree that the bent/damaged pin will create a hard pull, but when it comes to cutaway cables, In my opinion, I dont think the excess cable being dirty/grimey will cause a hard cutaway. Sure, physically, the grime on the excess could create more friction, but most of the hard cutaways come from inside the housing.

Cheers,
Travis

[riggerrob 558]

A dirty cutaway cable has far more surface area - in contact with the inside of the housing - than a ripcord cable. An awful lot more dirt can hide in the grooves of a ripcord cable, than a smooth cutaway cable.
By the same logic, most firearms are built with tight clearances on a few components, while the rest of the components are loose fits, to allow for soot, grime, grit, gunpowder residue, etc.

It requires a genius of an engineer to decide which which components need tight tolerances and which other components need loose clearances.

[billvon 2,400]

>When referencing a dirty cable are you talking about reserve deployment
>or main cutaway?

Reserve.

When it comes to cutaway cables, dirt inside the housing is more of a factor because of the greater distance/direction changes the cable to the left riser makes. Is it more than the force caused by the friction between the cable and white loop? I don't know. I would suspect that the friction between cable and white loop is still the primary factor, though, since the white loop is pretty heavily loaded during some cutaways.

[riggermick 6]

Quote

>When referencing a dirty cable are you talking about reserve deployment
>or main cutaway?

Reserve.

When it comes to cutaway cables, dirt inside the housing is more of a factor because of the greater distance/direction changes the cable to the left riser makes. Is it more than the force caused by the friction between the cable and white loop? I don't know. I would suspect that the friction between cable and white loop is still the primary factor, though, since the white loop is pretty heavily loaded during some cutaways.

Bill,

If, I understand it correctly, Bill (the other one) Has always stated that the load on the the T2-a loop will remain constant regardless of the load under which it is subject to at any given time. What say you?



Mick.

[billvon 2,400]

>Bill (the other one) Has always stated that the load on the the T2-a
> loop will remain constant regardless of the load under which it is
> subject to at any given time. What say you?

Hmm! I seem to recall a test in which at certain high riser loadings, the cutaway cable got "sucked through" the grommet by the force on the type-2 loop. That, to me, implies that the force on the loop increases as the force on the riser increases.

This seems to be supported in theory. The 3-ring system is basically a lever system, where a very large force (the suspended weight of the jumper) is reduced to a very small holding force (the force on the cable.) In an ideal world it's reduced by a ratio, so that a 200 lb force is reduced by a factor of 100 at the end of the lever system.

But I would certainly defer to Bill B's experience with that, since he has far more experience with it than I do.

[RMURRAY 1]

Quote

>I don't know. I would suspect that the friction between cable and white loop is still the primary factor, though, since the white loop is pretty heavily loaded during some cutaways.

that is what I was told by John Sherman. most of the effort is to overcome the friction of the white loop and the cutaway cable. since most people do not clean and lub their yellow cable regularly JumpShack came out with the red maintenence free (red) cable. They do not offer hard housings in risers because even when severely twisted (Jumpshack) risers, cutaway effort is low.

rm