Loose footed main - boom attachment

damo

damo

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If I decide to get a loose-footed main, what are the options for attaching the clew to the boom?

My new boom (thanks Joe /forums/images/graemlins/smile.gif) has the usual bolt rope slot, and I presume that the clew slug on my present sail will be insufficiently strong.
 
This may not - for several reasons - suit 'Damo' exactly, but is known to work particularly well on numerous boats with loose-footed mainsails.

A strap of several layers of webbing is passed around the boom, making a not-tight loop. Six inches or so of Velcro is secured/stitched at the end - with the corresponding 'other part' stitched onto the webbing to mate with the above. A suitable snaplink or Wichard link like this.....

00001754.jpg


...is fitted onto the webbing loop, and used to secure the reef clew-eye. I've seen several variants on this theme e.g. - using a webbing 'spectacle' device, fitted through the reef clew-eye, such as is often used at the tack-eye to facilitate the clipping-on - and peeps 'tweak' according to their needs and spare kit.

This system works well, is reliable, and easily adjusted.

/forums/images/graemlins/wink.gif
 
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...I presume that the clew slug on my present sail will be insufficiently strong.

[/ QUOTE ]
I have a main with a bolt rope in the foot. When the main is filled I find I can move the bolt rope in the slot. So in my main at least the clew is taking all the strain.
 
Further reading seems to suggest that whether a main is loose footed or not, nearly all the stresses are through the tack and clew attachments and not along the foot.

So maybe the clew slide should be OK - but it just looks too flimsy! Maybe I needn't worry, though intuitively I feel I should /forums/images/graemlins/frown.gif
 
I have a loose-footed mainsail and a modern boom with a slot which is rectangular in cross section [roughly 3/4" x 1/2" from memory]. The slug is circular in cross section [about 5/8" diameter]. I am not worried about the s/s slug failing but I am concerned that the slug might just pull out of the slot if it's aluminium lips give way. It has never shown any signs of doing so but, in strong winds, I pass a lashing through the clew eye and around the boom a few times, just as a precaution.

When I get around to it I intend to make a slug out of a piece of s/s T-section so that the upward force on the lips of the slot is distributed over a greater area.

To tension the foot, I have a block shackled to the clew eye and the outhaul line is secured to the boom end. From there it passes through the block on the clew and back to one of the sheaves in the boom end and then forward along inside the boom to the jammer at the forward end. It is a simple arrangement that works well and gives a 2:1 purchase.
 
Thanks Alf - that an exact summary of my concerns, the new boom and the solutions I am considering /forums/images/graemlins/smile.gif

I have just been pondering while wandering the pontoons and decided that a fabricated s/s slug was the way to go - with a nylon pad on top which engages the underside of the T-slot lips. That way I can make it nice and long to spread the load.

I will also adapt the present outhaul tackle I have

I knew I wouldn't be working in a vacuum /forums/images/graemlins/grin.gif
 
My Kemps loose footed main came with a substantial slug.

Don't worry about it. When your current sail is reefed in a howling gale it is loose footed!
 
For cruising use a close fitting slug in the boom groove or a webbing strop. Problem with strops can be making keeping the clew close into the boom. For Racing use a track and ball bearing car. If you have a modernish boom contact the maker and see what they have for you or measure up the section and contact all the spar sellers and they may have a car arrangement that will fit. Z spars for example have a track which slides into the bolt rope groove with a ball bearing car to suit. It would fit quite a few other booms I reckon
 
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with a nylon pad on top which engages the underside of the T-slot lips.

[/ QUOTE ]

That's a good idea because it will cut down on the horrible noise of metal rattling against metal. Do you fancy making one for me whilst your about it?

Tip: if you use a block on the clew get one with plastic cheeks - less noise and marking of the boom.
 
Should be no harder to make one twice the length and cut it in half - send me the dims, and if they are the same we'll see about it /forums/images/graemlins/smile.gif

Regarding plastic cheeks - what I have done before is stitch a scrap of old neoprene wetsuit around a block or thimble to provide cushioning. The stuff is all over my boat - antichafe for cables, grommets in bulkhead holes, around the winch handle, across the top of the batteries in case I drop a spanner across the posts etc etc.
 
I'm not sure yet /forums/images/graemlins/confused.gif

It is s/h and little used and supposedly French, and looks like a z-spars extrusion and fittings. My job for the quiet wee small hours is to get some profiles and dimensions and see if I can ID it
 
My loose-footed main has a whacking great block built into the clew. The outhaul is attached to the boom, passes through the block and back down to a genoa car on a track on top of the boom and from there to the sheave in the end of the boom. I also have an inhaul line attached to the car so I can pull it forward to throw some draft into the sail in light winds.

My situation is a bit unusual in that the boom is at a fixed height but it should work for any boat as long as the extra few inches needed above the boom for the tackle doesn't result in the boom drooping too low.
 
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too much friction for adjusting tension with the outhaul?


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Not in my experience. A mate has exactly that setup on a 37' catamaran with a fully-battened main, and has raced and cruised offshore for more than a decade with it, without a problem. He's replaced the webbing once, just recently, with exactly the same thing. There's about a 35mm gap between the boom top surface and the underside of the Wichard clip, under load. Cheap, easy - and reliable.

Used on a lot of racing boats.... You can buy them here


clew-strap.jpg



Or pay lots of money for traveller cars......

/forums/images/graemlins/wink.gif
 
It is just possible that your new sail has a flattening reef. That is another eyelet about 20cms above the normal outhaul eyelet. Do not ignore this arrangement.
You attach a really powerful outhaul to this upper eyelet so that when the wind comes up you pull that down tight. It will waste a few cms of cloth but will flatten the sail beautifully for stronger winds. A bit like a cunningham but at the leach.

What this then means is that the normal outhaul is only used for light airs. Yes your old slug system should be perfectly strong enough. A bolt rope takes no load just closes the gap.

Now a while back I sailed on a 9 metre really hot racing boat. All it had at the clew of the mainsail was a what looked like webbing. What it was was ordinary velcro tape actually 2 pieces sewn together so hook was on one side and pile on the other.(an ordinary sewing machine will do it.) This was threaded through the eyelet and around the boom 3 times with all turns mating firmly with the other turns making a very strong hold down.
A tackle then pulled the eyelet back to adjust outhaul. The tape permitted enough fore and aft movement.

I have made many devices like in Billbobaggin's picture. They are great for holding in place all sorts of things from fire extinguishers
First Aid kit even a small battery. The tape is screwed to structure.All sewn on domestic sewing machine with just a SS ring. The ring makes a 2 purchase and puts the velcro only in shear where it is very strong.

good luck olewill
 
Thanks olewill - I don't have a new main yet, just the old one with a major tear through the leech /forums/images/graemlins/frown.gif (and it doesn't have a flattening reef anyway /forums/images/graemlins/smile.gif )
 
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