Swivel On Winch Cable

[John Sp]

Tost's cable handling notes prohibet the use of a swivel between the cable
and winch parachute They say it destroys the multistrand cable.- Swivel is
only to be used for towing out.
THis is counter intuitive - can anyone offer an explanation why this is so?


Thanks

John Spargo

[Stephen]

"John Sp" > wrote in message
...
> Tost's cable handling notes prohibet the use of a swivel between the cable
> and winch parachute They say it destroys the multistrand cable.- Swivel is
> only to be used for towing out.
> THis is counter intuitive - can anyone offer an explanation why this is
> so?
>
>
> Thanks
>
> John Spargo
>

If you use a swivel the cable will untwist when under tension and then turn
itself into a rats nest when the tension is removed. My club uses a swivel
that doesn't work when under tension. I'm not sure it would twist during
towing out either. As far as I can see the only purpose of the swivel is to
prevent the cable twisting as the parachute spins on the way down after a
launch.

Stephen

[Phil Jeffery]

"John Sp" > wrote in message
...
> Tost's cable handling notes prohibet the use of a swivel between the cable
> and winch parachute They say it destroys the multistrand cable.- Swivel is
> only to be used for towing out.
> THis is counter intuitive - can anyone offer an explanation why this is
> so?
>
>
> Thanks
>
> John Spargo
>

It is normal to use a swivel that locks when launching to prevent the cable
un-twisting whilst under load which would destroy its structure. However,
it is desirable to then permit swivelling whilst the cable is retrieved
after glider release to prevent the parachute from winding-up the cable.
This is normally achieved by having the two sections of the swivel joined by
a plain bolt without any form of bearing incorporated.

The only use for a freely operating swivel is when retrieving the cable once
or twice under a fairly light load when it has been newly fitted and prior
to launching any gliders. It is considered by some that this helps to bed
the strands in and reduce the springiness in a new cable making it less
prone to cause loops at the winch in the event of a glider release under
tension.

Phil Jeffery