Spreader setup for a hog-stepped ali mast

04/06/2010 21:48:03
Mags
I don't know if this topic is any more interesting than the spam that has recently been appearing on the forum, but I have been meaning to ask for ages...

How do I set up the spreaders on a hog-stepped mast? Magazine articles this century all concentrate on deck-stepped arrangments of course!

My spreaders don't seem to have a very variable adjustment, but I do fear something might be wrong; the mast bends like crazy with even a little rig tension. I wouldn't like to feel the setup is making my life harder in strong winds (I'm less concerned about power in medium winds).

Thanks.

14/06/2010 09:59:03
Mags
Nobody knows? Has no-one else adjusted their spreaders since the 80s?

14/06/2010 10:24:48
Barry D
Sounds like the mast needs some chocking at deck level, or adjust your spreaders forward if possible. If you cant put more chocks in at deck level then try putting the foot forward.

14/06/2010 10:56:37
Rob
1 inch forward and 1 inch out was always a good starting point

14/06/2010 12:56:48
Mags
I can pull on the mast ram/lever to straighten the mast, but it only affects the section below the hounds (and gets close to S-bending it!). The top part still bends over dramatically.

My mast foot is at the front of the step already - can move it backwards 1" or 2" only.

14/06/2010 13:52:44
david Henshall
Hi Mags,

Is the boat anywhere near the Hamble? Although deck stepped carbon masts are not my 'thing' I'm using an hog stepped alloy rig on 3025. Having kept 'pretty much in touch' with alloy masts, if you are local then either come and look at how 3025 is set up, we can look at your rig or better still - let's 'yot' in the same place at the same time and compare

Dougal

14/06/2010 14:06:19
Mags
My boat came from the Hamble actually! Not that far away now either, in Guildford.

Having had a closer look at the spreaders I can see a concealed screw that wasn't obvious before. I assume it allows finer control of angle, so thats good news.

14/06/2010 15:00:16
Andrew M
HI Mags.  Do you know what section it is?  Most masts of that generation were pretty stiff but you might have a Proctor C or a Needlespar if it is really bendy.  The physics - the load is on the windward shroud which will go as near straight as it can (the lee shroud can be ignored in a hiking boat as there is never much tension in it, particularly older Merlins, it will be loose when sailing)  The middle of the mast below the hounds is pushed out of column by the pull of the kicker on the topmast and the thrust of the boom.  Both push to windward and forward, the spreader resists this in the middle of the mast the ram, strut or lowers at the gooseneck.  You are aiming therefore to start with the spreader pushing the mast back a bit and to leeward a bit so deflecting the shroud out and forward.  An inch each is a good starting point but a soft mast may need a bit more.  If the mast can twist in the slot there is no point trying to get the spreaders right.  You need some restriction at deck/gooseneck height as you really want the mast to bend evenly or if anything a bit more towards the top.

14/06/2010 15:10:11
Mags
It's a Proctor, but no idea what section. Leeward shroud VERY floppy!

When you say "an inch out and an inch back", do you mean the spreader tip's action? So I could undo the shrouds from the spreaders, and set the mast up to see where the shrouds sit if unaffected? Right!

14/06/2010 16:07:43
Rod & Jo Sceptical
I remember I followed GGG's guide to how to set up spreaders when it was in the magazine some years ago, but found that my old boat and lower rig tensions meant that I needed much more deflection than was recommended to achieve the same result.

14/06/2010 17:07:37
Andrew M
Yup, that's the idea, or you can (if you can't detach spreader from shroud) run tight string from hounds to deck to see what the deflection is.  Rod and Jo's observation useful to you also as your rig is likely similar to theirs.

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