"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