THE SQUARE SAIL

Running with the wind can be difficult, and on the Columbia river, the westerly wind can blow at your back all day. The main has to be brought out at ninety degrees or so to the boat, and the jib becomes useless unless it is forced on the opposite side with a pole. Add a mizzen to disrupt the wind and it’s a mess. Accidental jibing is frequent, and dangerous.

A spinnaker is one solution but somewhat out of character for an old style  gaffer. Spinnakers also require a long pole, are typically huge, and somewhat temperamental.

I came across a possible solution in an excellent article by Martin O’Scannall in Classic Boat (Feb. 2008, pp. 22-26) entitled ‘Squaring Up’. He goes over the advantages of a square sail and outlines a set up for a cruising sailboat, in his case a 5 ton gaff cutter, with a 28 foot length and 8 foot beam, namely, the beautiful Sauntress.

In his set up, the yard stays up permanently (for the length of the cruise at least) and the sail is hauled up or down as need be. He diagrams the rigging, with useful hints and comments, and provides dimensions.

O’Scannall also goes through the old literature, demonstrating how his rig is based on the practical wisdom of famous sailors who cruised with square sails, including my favorite, Conor O’Brien.

His sail is approximately 200 square feet on a 16 foot yard, 16 feet in height, and has a foot of 12 feet. That is clearly more than I need because my boat is much lighter at 1.5 tons.

I calculated the sail area needed to ‘push’ my boat at a desired speed using the formula:

A=(S/16)*(d^2/3)

A: area in sq. ft.

S: speed in knots

d: displacement in tons

For the Sauntress, I assumed a speed of 7 knots. The area comes out to 209 sq. ft., which is right on.

For the 20 foot Ann-Martin, I assumed an optimistic speed of 4-5 knots, requiring an area of 53-67 sq. ft. It surprised me how small the sail’s area had to be. Keeping a 16 foot yard, I cut the tarp to a height of 10 feet and a foot of 9 feet; the area comes out to roughly 120 sq. ft, which is more than enough. Esthetically, anything smaller looks like a toy. I might have a reef line put in if and when I have a cloth sail made.

The sail having a shorter height than on the Sauntress, the problem arose of estimating the width of the foot, which has to be wide enough to clear the halyards. On the Sauntress, the foot just clears the deck. With its 8 foot beam, there must therefore be about two feet of clearance on each side to get around the halyards. On the Ann-Martin, the foot is well above the deck, at a height where the halyards are closer together. I measured a clearance of  two feet on each side, so I think it will work out.

I made the yard from dimensional lumber. Rumaging through a pile of 2”x6”x16’, I found a straight one with desirable grain. I cut a 2” or so strip, let it dry, rounded it to a thickness of about 1.5 inches, and encased it in a biaxial fiberglass sleeve and epoxy. It’s quite stiff. I’ll apply a few coats of spar varnish when it warms up.

One objection that I read about on sailing forums is that a square sail adds too many lines. Well, get a motor boat – it has no lines at all. Yes, there are more lines, but I don’t see it as a valid objection unless it makes sailing more difficult.  With a square sail, you gain ease of handling going downwind, with no need to jibe. Besides, one sails for the pleasure of handling sails, and a square sail invokes history and tradition.

Another complaint is that square sails are only good for trade winds that blow in the same direction for days on end. I prefer to think of this square sail setup as a spinnaker, of which I see plenty on the Columbia river. O’Scannall’s rigging is easier and faster to put up than a spinnaker. The center of effort of a square sail is over the center of the boat rather than beyond the bowsprit, as with a sipnnaker. It is therefore safer and more comfortable.

Of course, I doubt that most forumites have ever deployed a square sail on a small boat. I’ll judge first hand and report back. At the very least, it will look cool sailing up to the dock at the wooden boat show this summer.

I’ve inserted some pics of an unfinished tarp sail, and minimal lines, with the boat on its trailer. I’ll try the sail out for this year to assess whether or not it’s worth having  a square sail, and then choose its final dimensions if so.