Bermuda sail rigged as sliding gunter?

[JimD]

I'm sure its been talked about a million times before but I wasn't paying attention. Can it be done? I have a small bermuda sail, about 83 square feet, from our Glen-L Minuet. But I need short spars. Is it feasable to use the sail without recutting it only bend it on gunter spars?

Here's a Duckworks article on the sliding gunter. The sail shape in the illustration is very similar to the actual sail: http://images.google.ca/imgres?imgurl=http://www.duckworksmagazine.com/05/vintage/sbj/2/sgr.jpg&imgrefurl=http://www.duckworksmagazine.com/05/vintage/sbj/2/index.cfm&usg=__vP2CoHLVExowFga0EOEedUJWHRg=&h=629&w=450&sz=37&hl=en&start=3&tbnid=SkIFKNGWmPQHCM:&tbnh=137&tbnw=98&prev=/images%3Fq%3Dgunter%2Brig%26gbv%3D2%26hl%3Den
http://www.duckworksmagazine.com/05/vintage/sbj/2/sgr.jpg

http://www.duckworksmagazine.com/05/vintage/sbj/2/ssg.gif


Minuet: http://www.glen-l.com/designs/sailboat/sailboat-images/dsn-minl.jpg

Edited to add: There would be no jib. Just the main. With or without shrouds, pivoting in a raised tabernacle.

Option #2: Lop the top of the sail off and turn it into a gaff rig. This sounds less promising. Is there any point to discussing it or would it just be a foolish way to ruin an other wise perfectly good sail? :o

[Thorne]

Sure seems like it could be made to work, although you'd have quite a gap between the mast and luff for the bottom half of the sail. You could probably also do a folding gunter if you could get the top spar upright enough.

Let's see what Todd and other say...

[JimD]

Sure seems like it could be made to work, although you'd have quite a gap between the mast and luff for the bottom half of the sail. You could probably also do a folding gunter if you could get the top spar upright enough.

Let's see what Todd and other say...

Folding gunter sounds promising. But I don't really know what it is. A mast that folds in the middle, presumably. I googled for a pic but couldn't find anything.

[Hwyl]

Yes, but getting the gunter upright enough could prove difficult <insert joke about drunk Germans>.

As you mentioned, you'd also have to have the tack a long way from the mast.

I bet Todd would suggest recutting the sail, and I'll suggest you give it a go yourself. Are you going to have the top part with a luff rope?

[JimD]

Are you going to have the top part with a luff rope?

Don't know. I'm quite ignorant on these matters. But I have the sail and don't want to invest in a new one. I've added a little pilot house affair to the top of our Minuet. I understand I've effectively ruined her as a sailboat but still would like some auxiliary sail assist The original sailplan has a jib of 46 sq ft and the main of 83. So I've moved the mast step forward to allow for a single sail, no jib. Either I find a way to use the mains'l I already have or I stitch together a polytarp junk. That would be fun, but its more time I don't want to invest. So I really would prefer to find a way to use the sail I already have without recutting.

Edited to add. I can always use the aluminum mast I have and rig it as designed if need be.

[Hwyl]

83 sq feet is just a bit bigger than a Laser full rig. Which spawns a couple of points. A laser and crew 120 lbs for the hull, 180 lbs for the driver and maybe another 20 lbs for the rest of the bits of the rig and blades. How many more multiples of 320 lbs, will Minuet and crew weigh?

2nd point, use a laser mast, it's already in two parts.

[JimD]

83 sq feet is just a bit bigger than a Laser full rig. Which spawns a couple of points. A laser and crew 120 lbs for the hull, 180 lbs for the driver and maybe another 20 lbs for the rest of the bits of the rig and blades. How many more multiples of 320 lbs, will Minuet and crew weigh?

2nd point, use a laser mast, it's already in two parts.

I'm a little concerned about the weight and windage factor of the wheel house I've just plunked on top of the cabin. I don't expect to get very far under sail alone. I've effectively turned this into a motor boat with sail assist when a soldier's breeze allows. The sail plan will be about 2/3 of the original. Frankly, I think the boat might now be much better off with a low aspect squarish sprit or similar rig - ie:
http://www.boat-links.com/Atkinco/Cruisers/images/Periwinkl-1.gif

[Hwyl]

I'm a little concerned about the weight and windage factor of the wheel house I've just plunked on top of the cabin.


You don't want my opinion do you?

[Thorne]

Jim - the folding gunter has a spar that pivots up to run (roughly) parallel to the mast, whereas the sliding gunter has a spar that, not surprisingly, slides up the mast. Todd has made this distinction clear even when other authors haven't (like Nichols' book on small boat trad sails). But I don't know if the folding rig gets the upper spar upright enough...
http://www.woodenboat.com/forum/showthread.php?t=79114
http://books.google.com/books?id=axf0LZBU-goC&pg=PA49&lpg=PA49&dq=folding+gunter&source=bl&ots=ozallNkPXU&sig=w6mISm5B_SIszVHyb_0ipMBFc2c&hl=en&ei=Fg3ASca7N8yJngf-pcgl&sa=X&oi=book_result&resnum=1&ct=result

Why not rig up something strong but temporary and see how she sails with the mast and sail in that location? If you like, you build a folding/sliding rig =--= otherwise back to the drawin' board...

And remember there are lots of used sails kicking about, some for sale online and others free from racing clubs, no need for polytarp.

[Paul Pless]

You don't want my opinion do you?> :D

[JimD]

You don't want my opinion do you?

Yes, I do. I value your opinion above most others. But I'm having trouble seeing the comparison between a Laser and this:

http://www.glen-l.com/picboards/picboard4/pic323e.jpg

This is how the boat was first built rigged with the mains'l and jib from Glen-L. Cathy on the fore deck. The 'wheel house' such as it is is about half the size of the cabin again, sitting on top to about the height where the boom is in this pic. The top of the wheelhouse is over 5 feet above the waterline on a 15 foot long boat. Boat and crew about 1,000 lbs.

[ChaseKenyon]

Go with the sliding gunter.

Go to Wall Mart get a $70 Brother sewing machine and some of their lightweight "Lawn Furniture Canvas" Sunbrella subsititute.

Make yourself a nice easy to sew long rectangular filler panel for below the top mast. Get a brass grommet kit from sewing dept too . Install grommets in the the panel and the lower tack of the sail to match so they overlap. Lace the panel to the tack before hoisting and you will have a fitted two piece sail. Not as clean as a custom cut one but still better than a big gap. This will leave your present sail still usable in its original form if you ever choose to.

Best possible efficiency with least possible un-reversable changes.

Chase

[Les Schuldt]

Jim,

You might want to study a couple things at the Dutch Drascombe Site. My wooden Drascombe Lugger has a sliding gunter rig and the luff is pretty straight (maybe a little curve built in to accommodate slight curve in the gaff when under load).

http://www.drascombe.nl/download/handbooklugger.pdf

Because the head of the gaff sags away from the mast and also because both ends are tapered, the maximum gap between the luff and mast is just below the gaff jaws, gradually tapering to the tack which is right against the mast.

You will also note some useful details of parrel beads, the correct marlin hitch for bending the sail to the gaff, an unusual way to lace the sail to the mast, etc. (My boat uses 3 releasable toggles instead of lacing around the mast between the gaff jaws and the tack.)

Additional information is provided by the designer, John Watkinson, in his "Know Your Lugger" document.

http://www.drascombe.nl/download/knowyourlugger.pdf

My guess is that you can convert a marconi to a gunter with minimal isues. The Drascombe Lugger is loose footed. Assuming that you have a boom, the resulting raking of the luff angle (because of the gaff) my require a slight recut of the foot of the sail, to keep the foot and boom "level".

Les

[Thorne]

Les! Good to see you back, man.

I didn't think of the Drascombe info as a resource, good stuff.

[JimD]

Thank you all for your suggestions.

[Woxbox]

Jim -- I did exactly what you're thinking of on an 18' pocket cruiser some years back. It had an aluminium mast with a slot in it, too.

So I cut 4' off the top of the mast. Then I got a length of aluminum tube about 8' long and slid a length of dowel in it to stiffen it up.

Then I got an extra gooseneck that fit the mast slot and fabricated a gate sort of mechanism so I could pin the aluminum tube at its center into the gooseneck with a quick release pin. The halyard ran from the top of this modified gooseneck.

I didn't have to modify the sail at all. I just lashed the slides to the sail with about 1 1/2" lengths of line. The gap had no discernable affect on performance whatsoever. The top 8' of sail was secured directly to the aluminum tube.

So now I had a sliding gunter with a mast that was very easy to lift up and drop down by hand. Plus, when reefed I had an effectively shorter mast. Plus, the flex in the tube allowed the sail to shrug off gusts.

The only thing I didn't think of ahead of time was that a conventional topping lift doesn't work in a rig like this. So I rigged lines that doubled as a topping lift and lazy jack to support the boom when I dropped the sail.

It worked like a charm. One other benefit -- when trailering the mast was hardly any longer than the boat.

[Todd Bradshaw]

Ahhhhh, the old sliding vs folding thing rears its ugly head again. It is fairly difficult and uncommon (but not impossible if you use enough hardware) to peak up a folding gunter's top section to plumb. It tends to make the butt of the topmast (yard, gunter or whatever you want to call it) want to wander around. That little bit of head angle (5-10 degrees or so) that one normally sees on most gunters helps push the topmast's heel forward, where it becomes somewhat more stable.

A true "Sliding Gunter" is a different animal. The topmast is plumb and stays that way at all times (even when furled). It has a ring or fitting attached to the topmast heel that surrounds or rides up and down the lower mast section and another one higher up on the topmast (near the lower masthead area when the sail is at full hoist). It literally is a vertical spar that doesn't hinge like a gaff. It climbs straight up and down the back of the mast when raised or lowered. With a Bermuda sail in that size range, you could probably rig it as a real sliding gunter without much trouble. There would be a 2"-3" gap between the lower luff and the lower mast, but it could be stabilized with lacing or a few hoops (and adequate luff tension) and I doubt you would really lose much performance. You would want to account for the gap by making sure that your tack fitting on the boom (if you have one) is set back far enough from the mast to match the gap between luff and mast.

The middle drawing in Jim's first post is pretty interesting as it makes a folding gunter act more like a sliding gunter. The topmast heel is stabilized by the track on the mast and the "ears" on the masthead help stabilize the upper section. These should allow more topmast control that many folding gunters have, and a more vertical topmast angle. It would need to be a strong track system though, as there would be a lot of strain on it in use. By contrast, the more typical folding gunter type (without the track and ears) would probably work best by re-cutting the top of the sail to give the upper luff that 5-10 degree rake - rather than trying to pull the topmast all the way to vertical.

The Laser mast idea is a can of worms that you probably wouldn't want to open. Lasers have very well designed rigs, but both the sail and its mast are built for a lot of bend in use and matched to work together. Taking either just the sail, or just the mast from a Laser and trying to use it in a different system usually doesn't work well at all.

[Craic]

I have a folding Gunter mainsail like sketched in the Duckworks article, with a track, but minus the 'ears'.
The ears are superfluous, through using Dyneema halyard material the topmast is held absolutely vertical at all times, never a heel or wobble. Sails like a Bermuda, folds like a lugsail. Mainsail area is approx. 12 sq mtrs. .

[Tomcat]

Craic, so would you figure something like this could actually work?

http://www.ikarus342000.com/KD650page.htm

Some are skeptical. I would like it to work, because it looks like a great option to get around the heavy lifting required to raise most spars on trailerable boats. The gaff has carbon, but it is a lot easier to build something where carbon is applied than a tube as with an all carbon spar.

[Craic]

Craic, so would you figure something like this could actually work? http://www.ikarus342000.com/KD650page.htm ...


What is the question? Will the boat work, or the sliding gunter gaff thing?

A sliding gunter gaff sail with full length battens, I have my doubts.
C.

[Craic]

Andrew,
there is no question that a well-done sliding gunter can and will perform like a Bermuda rig, but on that boat Tomcat proposes there are a few details of the gaff and especially of the sail that look odd to me.

[Woxbox]

Tomcat -- I like the look of that catamaran a lot, and I'm pretty certain from my experience with a home-made sliding gunter that you can make it work.

The trick will be to lock the attachment points into the mast track or slot so there's no slop whatsoever. The sail I rigged was 100 sq. feet if I remember right, and adapting a standard gooseneck fitting and bending up some stainless pieces was plenty strong. I used it for 5 or 6 years without any problems.

But as Todd noted earlier, there are gunters that are hauled up more like a high-peaked gaff, and then there are those that are fixed more rigidly to create a mast that essentially telescopes. You'll have to do the latter to have any success with getting such a sail to set properly. You may be needing some expensive hardware to put it all together with the strengthneeded. The only downside I see is that you are designing a pretty expensive rig, but done right the performance will be stellar.

A note on that jib--you'll have a very hard time maintaining luff tension. I see more issues there than with the main.

[bucheron]

.

I didn't have to modify the sail at all. I just lashed the slides to the sail with about 1 1/2" lengths of line. The gap had no discernable affect on performance whatsoever.

True, I had a Heron for a while and an Aus olympic sailing coach who was very keen on the class wrote that one of the commonest mistakes beginners made was to lash the lower part of the sail too close to the mast.

It does not really need to be lashed to the mast. The lashing keeps the sail under control when raising and lowering.

I think it was John Leather pointed out that a gaff sail does not need to be held to the mast at all, it would work quite well just stretched out by the four corners. It would be hard to keep in the boat when raising and lowering but.

If I were JimD, I would start by making as little change to the sail as possible.

cheers buchie.

[Carlsboats]

It's tricky to fit the sail to a rig like this, and in the only two cases I know about, the owners ditched the rig in favor a a marconi main. Herreshoff's put that rig into Alerion, the boat he designed and built for his own use in Bermuda -- then switched to Marconi. And recently a Maine boat builder built a near duplicate for a customer -- abnd told me the customer switched to Marconi within a year or two. So it seems to be a problematical proposition. But if spar length is a problem, you have options: Gaff rig, or a take-apart mast. The latter has been used successfully, in both wood and aluminum, in numerous designs for boats with sails in the 50-80 square foot range.

[CK 17]

4 or 5 years ago woodenboat had a building series on the riverside dinghy. That boat had a folding gunter rig. As i recall, there was a lot of detail in one of the issues in that series.

i made a saddle out of a section on 4" copper pipe. The saddle attached to the bottom of the yard; the halyard attached about a third of the way up.

It was my first sailboat build. It worked great. The sail was laced on the yard and rope hoops were used on the mast. The short sections of spars made rigging quick and easy. For trailering, the yard folded down, the boom folded up and the sail stayed attached. I tossed the whole thing in the hull and drove around like that all summer. I wonder why we don't see more of these.

I only have pictures of the saddle. To answer your original question--will the sail fit--there are a lot of adjustments to this rig. My guess is you will see the sail tight up against the yard and about 3 or 4 inches away from the mast. playing with the halyard, rope hoops on the lower half of the sail around the mast and the hold down or boom vang will make the sail fit.

http://im1.shutterfly.com/media/47b7d737b3127ccec275aa320ac600000010O00QZt3DFs5bsQ e3nwo/cC/f%3D0/ps%3D50/r%3D0/rx%3D550/ry%3D400/

http://im1.shutterfly.com/media/47b7d737b3127ccec275f558cb2b00000010O00QZt3DFs5bsQ e3nwo/cC/f%3D0/ps%3D50/r%3D0/rx%3D550/ry%3D400/

http://im1.shutterfly.com/media/47b7d737b3127ccec274195b6a2200000010O00QZt3DFs5bsQ e3nwo/cC/f%3D0/ps%3D50/r%3D0/rx%3D550/ry%3D400/

[donald branscom]

Andrew,
there is no question that a well-done sliding gunter can and will perform like a Bermuda rig, but on that boat Tomcat proposes there are a few details of the gaff and especially of the sail that look odd to me.

And if it looks odd,even if it works great- you may not be allowed into the yacht club for a beverage. LOL....

That is what ice chests are for.

[Dan St Gean]

Check out the Mirror dingy as it uses a luff rope in the upper mast section and laces the bottom portion.

Dan