[UK-CONTEST] AUTOBRAKE WINCHES

[Doug Roberts]

Let me emphasise Paul's warning below - stainless steel wire ropes need pulleys with a larger running diameter than would be used for the same sized galvanised ropes.  For the same reason, the winch reel should also have a larger core diameter.  FOLLOW THE ADVICE OF THE ROPE SUPPLIER.

Please also be aware that "stainless" steel may not be the answer to everything - it can corrode if it is contaminated with dust or filings of ordinary steel.  This might occur, for instance, from using a grinder on or near the tower structure.  I've even worked on top quality stainless jobs (for oil platforms) where rusting started because the stainless was brushed up using a steel wire brush!

The core of smaller wire ropes (like those we use on towers) is often fibre, although steel may also be used (see British Standard BS302 if you want more details).  You can significantly delay any corrosion by making sure your rope is well lubricated before you fit it.  I coiled mine as large as would fit inside a clean plastic bag (a builder's merchant's bag for sand and gravel), and held the coils with a couple of cable ties.  Then, with the coil inside the bag, the rope was liberally sprayed with an aerosol of 'Liquid Grease' and laid flat, so that any excess was likely to be drawn into the rope by capillary action.  (That particular 'grease' basically ends up the consistency of thick treacle, rather than solidifying).  Instead of one heavy drenching, several lighter applications were made over the course of a week or three, laying the bag on alternate sides to help spread the capillary effect.  Finally, excess grease was wiped from the rope as it was fitted to the tower.

73, Doug G0WMW



----- Original Message -----
From: GW8IZR <paul at greenrover.demon.co.uk>
To: Don Beattie <g3ozf at btinternet.com>
Cc: 'UK CONTEST ' <uk-contest at contesting.com>
Sent: Sunday, May 18, 2003 6:15 PM
Subject: Re: [UK-CONTEST] AUTOBRAKE WINCHES


> In message <003201c31d55$29834400$81707ad5 at oemcomputer>, Don Beattie
> <g3ozf at btinternet.com> writes
>
> >a) Use stainless steel ropes (they are quite a bit more expensive, but
last
> >proportionately longer. Elliot-Strumech only say 5 years for galvanised
> >rope, but 15+ for stainless.
>
> Beware of the minimum bend radius for stainless steel wire.
>
> It pays to take advice from the rope manufacturer rather than the person
> who fabricates the tower and be particularly mindful of the diameter of
> the running surface of the pulley.. not the outside diameter.
>
> HTH
>
> --
>  73 de Paul GW8IZR IO73TI
>   http://www.gw8izr.com
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If there's one thing I can't stand, it's INTOLERANCE!
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