1928 gaff schooner sail construction?

[John Howland]

Thad,
Thank for the insights. I can use all the help I can get. One can kind of get lost in these drawing after a while and lose sight of what is what and every thing is just so dam small. I have started a 30"x50" of America and Titania. Maybe keep me from going blind.
I spiffed her up a little bit.

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John

According to Plato, art is false knowledge of reality.

[mohsart]

Nice with drawings.
Here's an old one of mine, Swedish Training Ship "Gladan" 1954, near Gibraltar I believe.
1 Gladan 1954 mindre.jpg

/Mats

[John Howland]

Yours too,
It looked so easy in till I started drawing them. Now If I just could get some paint to stick.

[John B]

A couple more Nina sail photos for you, John.
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In another photo the jib is mitre cut as well as the staysail shown above.
Can't quite fully make out the main staysail, but it appears cross cut to me from what I can see.

[John Howland]

John B.
Great photos!
Olin Stephens, once said that Nina was the only yacht that looks great from any angle.
I would agree that NIÑA'S main staysail was cross cut. I think I had been looking at Starling's fathers Edward Burgess American Cup designs Titania, Purita, and Mayflower. Just got lost in the my own head, a newbie mistake.

nina Spinker.jpg

[Nicholas Carey]

I have found newer photo with broad seams.

Cotton sails were sewn from narrow cloth. Selvedges were kept intact as they add strength and stretch resistance.

"Broadseaming" is a construction technique used to put shape in the sail whilst keeping each panel uniform in width.

You impart shape to the sail by altering the seam allowance. If you seamed up 2 rectangular strips of fabric with a uniform seam allowance, you'd wind up with a flat, wider rectangle of fabric.

But if you make the seam allowance wider at each end and narrower in the center, and spring a fair curve, you wind up three-dimensional panel with a curved belly - the width of the panel is narrower at each end and wider in the center.

Do that across the many panels in a sail, and you have a lot of control over sail shape without cutting fabric.

[Todd Bradshaw]

But if you make the seam allowance wider at each end and narrower in the center, and spring a fair curve,

In reality, it is not a fair curve. Most broadseaming on cross-cut sails is done with straight tapers, not curves. A "broadseam curve" is an imaginary line established on the plan and/or lofting on the floor. This is a mark made to show where the seam width will start to get wider as you approach the luff. It is determined by eye and the experience of the sailmaker. The rate of seam width increase will vary with the bias stability of the chosen fabric. Stiffer, more stable fabrics need more aggressive broadseaming. An awful lot of natural fiber fabrics may need little or none, due to their stretchiness. On something with as many seams as most of those old sails had, and at the scale shown in these drawings you wouldn't be able to see any broadseams.

Cross-cut sail (Dacron): The red line is the broadseam curve. They start there and increase seam width at a rate of about 1/2" per 30" of seam length as the seam approaches the luff - in a straight line taper. Once you get within a few inches of the luff the overlap rate is increased to give a little width flair to the broadseam's forward end. The amount (or not) of flair will help to determine the sail's entry angle as it comes back from the mast. A fairly full round (plenty of flair) entry is generally more forgiving of sail trimming errors than a flatter entry (less flair) though the flatter one may be faster. The seam closest to the tack corner is usually broadseamed at about twice the typical rate.

Aft of the broadseam curve the panel-to-panel seam width is kept constant to the leech with a couple of very minor exceptions. One or two tiny (like 1/8") overlap increases, maybe 18"-24" long with no flare are often put into the leech end of a couple of seams to help keep the leech firm as the sail ages. As I said though, on those old boats with natural fiber, narrow-paneled sails you would be hard-pressed to see any broadseams.

dinghy.jpg

[Bruce Keefauver]

There is a very nice and clear period photo of Advance (Burgess's slightly earlier staysail schooner) flying all her rags with sail seams clearly visible on page 230 of his bio.

[mohsart]

Nobody has, as far as I'm aware, claimed that seams are impossible to see.
It's whether it's possible to see if broadseaming has been used that that has been disputed.

/Mats

[Todd Bradshaw]

There is no way in hell that you would be able to see whether or not the sails were broadseamed at the scale of this sort of drawing. Combine both the stretch of natural fiber cloth (which very often was not broadseamed at all, because it didn't need it) and the fact that even with modern Dacron, typical broadseam rates are usually in the range of one half inch of seam overlap increase per 30" or so of seam length in the broadseaming zones. If you are trying to make accurate drawings of old sails, it is more about getting the panel layouts and corner patch styles correct, leech hollows and draft locations right than anything having to do with broadseaming - especially on old sails, which probably had little to none of it in the first place.l

[mohsart]

That's what I said. More often than not, you may see the seams - width of the panels - but not even see that there are two seams that connects one panel to another. How would anyone be able to see if those two seams are a tad bit further apart close to the edge? I often find it hard to see if a sail is broadseamed when looking at the actual sail, without measuring. /Mats

[mohsart]

For a drawing, broadseaming is uninteresting.
One needs to think of whether the seams are visible, which they may or may not be due to the sunlight and whatnot.
Drawing over-detailed drawings is a mayor paux pas.
For lines, or seams, that are thinner than the tip of my pen/pencil I like to make gaps when drawing them. That creates an illusion of the drawn line being thinner than what it actually is.

/Mats

[John Howland]

Your descriptions are most helpful but the more I read the less I know. I had assumed so much about how sails shape were created and what they were from the little experience I have. But what I do know is they don't stay that way very long, most of my sails are soft as sheets.

Tood,
So the corner patch styles have a period that they were used in. Huh newbie mistake.
I knew that there was more to sails than what meets the eye. I made a Spreadsheet to calculate the center of effect and square footage but the shape and how they react with the other sails is where it is at.
The problem with sails technology is that no one gives up their magic for free. People talk about NACA foils but I don't really see much of that oversimplified in a sails shape any more. It's a good place to start to understand what a sails shape is but falls short of being useful information after that.
The sail maker craft seems to be 2 parts science and 1 part art.

Mohsart,
I have been using a .2 lead mechanical pencil for the thin lines, it helps but I love my old clutch pencils and I have a sharpener that was my dads. You know it's not just the process, it the history that we carry in our head that makes it our art and a good eraser.
I made 3 different scale set of copenhagen ship curves 1:1, 1:2, and 1:3. These curves can be found on every part of a sailboat and they make me a better artist than I am.
In my drawings I try to give a area of detail that the viewer can see and then carry that detail to other similar parts of the drawing in their mind but are not really on the drawing, save on graphite.

Thanks
John

[Lima33]

OK, I have a question. "Gaff rigged stay sail schooner" ? I have never heard of or seen a picture of such a thing.


Thanks

Lima

Semper Fi

[John Howland]

OK, I have a question. "Gaff rigged stay sail schooner" ? I have never heard of or seen a picture of such a thing.


Thanks

Lima

Semper Fi

Lima33,

Welcome to the forum.

John Howland

[peter radclyffe]

i think he used a similar midsection on a j class

[Todd Bradshaw]

John,
Corner patching on old sails could be simple triangles, or sections of circles, usually on smallish sails. Throat patches on four-sided sails might be round or some sort of four-sided or rectangular-ish/parallelogram-ish shape. Examples:

These are on Dacron, which tends to need larger patches than cotton due to its increased stability and lack of give. It spreads the strain out better. If, for example you were drawing an old dinghy with a cotton sail, the patches might only be four or five inches across. Panels might be as little a maybe eight inches wide, but it would depend on the price. Narrow-paneled dinghy sails would be substantially more expensive than sails with full-width cloth.

corners-1.jpg

Larger boats with traditional sails would most likely have been equipped with tongue patches. Rather than actually being a larger boat, this is my old Mini 12 Meter - half model boat, half high-performance real keelboat. I built it a set of Kevlar radials and this set of Egyptian Dacron traditionally styled narrow paneled sails with big boat-style tongue patches. The long clew and tack patches running up the leech and luff, connecting the other patches are typical of the old styles. I put little red dots next to the broadseams on the photo, so that you can see the flare in the seam widths near the edges. Since these are small sails, the cloth is proportionally quite stiff and stiff cloth needs wider broadseams, so these are pretty big overlap increases, visible to those who know what they're looking for.

mini.jpg

For bigger traditional boats, the tongue patches would usually look more like these. Note the four-sided mainsail throat patch as well. There are no hard and fast rules for patching, but these would be acceptable in almost any context. The worst offenders for those in the know are modern radial corner patches on what is supposed to look like a traditional sail. They tend to be overly common on "traditional" sails cranked out by the big modern sail lofts.

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[John Howland]

Tood,

Thanks for the information things are starting to make sense.
I was reading about the Schooner AMERICA and how she put on a set of cotton sails for the first AMERICA Cup race and how the US navy started using cotton right after that giving up the flax sails. High technology for the day but history has a way of weaving it own web.
By the way that is that is top topnotch seam work on your sails that I have seen of yours and the creative colors are very handsome.
John

[Todd Bradshaw]

Thanks John. There is a lot about sailmaking that can get pretty tedious and/or boring, while you grind up your knees crawling around on a hardwood floor. I always vowed that if I was going to do it, then the sails would need to be mostly one-offs and individually interesting enough that I wanted to see how they would turn out. I told my customers that from 100' away, the work I did for their boat would probably show up more than all the hard work they put into building it - so I had better do a good job. My knees and back are much happier since I retired, but I can certainly say that it never got boring. Sails for small boats are quite often built as cheaply as possible in terms of the quality of the materials used, the design and the construction details and reinforcements. That doesn't have to be the case.

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