Rigging Geometry

[abindoff]

Hi all, is there a rule of thumb for positioning the chainplates for the shrouds on a boat without a backstay?

My shrouds interfere with my main excessively, to my eye. Plus, I worry about gybing and damaging the rigging.

The boat is an 18' trailer sailer with an old Hartley rig retrofitted to it. This boat carries it's maximum beam further aft than the Hartley. It looks like the builder has just fixed the Hartley rig directly to the boat without shortening the shrouds.

I used to own a Hartley TS18, and if I recall correctly, the shrouds were positioned only about 1' aft of the mast. This is more like 2-3'

Any thoughts?

Regards,
Aidan

[sharpii2]

I would go 1ft back for every 6 ft up.

Also, you might consider running back stays as well (which are tightened on the windward side and slackened on the leeward side with each tack), unless you plan on dropping the jib as soon as the wind freshens (my usual practice).

Bob

[Brent B]

Around 24" would be right for your rig if you fly a spinnaker. Otherwise you might go down to around 20".

Putting them too far forward could lead to much greater rig damage than having them too far aft.

That boom is pretty long, so an uncontrolled jibe could be pretty dangerous. Using a good boom vang to keep sail shape while running downwind helps prevent jibes. There are also boom brakes and other devices that can be used.

Brent
Benson Sails

[bhnautika]

Abindoff On boats without a backstay the shrouds have to do three jobs the usual athwart staying plus fore and aft and tensioning the fore stay. Look at it as tripod; if you move two legs forward too much it falls over. All boats with sweptback spreaders have trouble with the main hitting them, its part of the breed. It’s also important to get the fore stay tensioned for upwind work.

[abindoff]

Thanks everyone for your advice. Sounds like they are already in the right place, I could probably move them forward another half a foot. If I were racing I probably would. Given the difficulty, I think I'll leave them.

I like to be able to single-hand this boat, so I would try to avoid running rigging for that reason.

I'm putting a vang on shortly, got most of the parts required. A boom brake would be a good idea, are they readily available? I didn't know there was such a thing.

Accidental gybes are one thing, I'm having difficulties with intentional gybes! That is probably just inexperience, though. I haven't got a traveller, might make it a little easier. It's a lot of sheet to bring in and pay out quickly and smoothly whilst steering the boat.

I lost my starboard gunwhale in a storm recently, thought it would be a good time to move the chainplates. I'm actually kind of glad I really only need to repair the 1 gunwhale now. Moving chainplates is a lot of extra work and I already have plans to rebuild the rudder and possibly the centreboard too.

Thanks again!

Regards,
Aidan