Small square lug

I'm looking to rig up a small (12'x4') rowboat I built last year. I don't sail often, don't want to spend a lot of money, and don't care about performance really at all. I just want to be able to sail around a bit when the wind is good.

I'm wondering about using a rectangular lug. I can order them in the exact size I want, no sewing, no grommets, pretty durable.

I'm imagining rigging it like a lug with a yard on the top and bottom edge, fixing it to the mast towards the front edge of the sail so I only need a single sheet (unlike a normally-rigged squaresail)

Anything simple I should to do improve on this plan? Tape a dart into the bottom maybe? Is this going to be a total disaster (who cares anyways, disaster is fun?)

Things that are already obvious to me:
1) I could pretty easily make it peaked like a regular lug. True, but I'm lazy.
2) There's lots of ways to make cheap sails in any old shape. True, but I'm lazy.

 

It's doable. Maybe simplify by omitting the boom, which allows you to lower the rig (since your head would be safer). Also, a rudder is going to be necessary, and you might consider a leeboard so that you can sail against the wind if necessary.

 

The usual working boat lug rig in UK in years past had a rope or iron traveler, consisting of simply a large ring sliding up the mast with an attached small ring the halyard went through. When hoisted this kept the yard to the mast, when hoisting or lowering there was good control. It goes up and down with the sail and is wonderfully simple.

 

lug sails, espically a loose footed one with only a boom at the top, are simple but not really the easierst to control I have found. I would consider a simple cat rig, or even a junk rig. A junk rig almost sails itself and is easy to control (it will not flog or flutter).

You might make one with duck tape and tyvek and see how you like it, easy and fast to change shape. You can use it for years and once you have it sorted out make a sail cloth one using the tyvek one as a pattern. I have made a junk rig with tyveck and 3/8" x 1.5" battens I cut from a 2x4 for a dingy in about an hour, put it on a short cvantalver mast and found it easy to use almost hands free.

I also agree with Alen, you might rig up a lee board and you will need a rudder. Keep It Simple (KISS), and have fun.

 

A sprit rig is easier to live with than a lug. A sprit rig It is as simple as it gets. A lug is a bear to raise or lower when the wind has piped up.because the yard becomes a liability.

 

How is a sprit any less of a liability? At least the lug yard will just drop straight into the boat if you release the halyard. A sprit wont do that.

 

NoEye, the yard, in the process of raising or lowering is subject to whatever pressure the wind exerts on the upper part of the sail. This can get pretty dicey in strong gusty weather. The sprit however, can simply be yanked from the peak of the sail without much difficulty or excessive expletives. With the sprit removed, the sail will flap around until you roll the sail onto the mast. A sprit boomed sail, as opposed to a peak sprit, is even easier to rig and unrig in spite of the weather. The sprit boomed sail is, unfortuneately, taller for a given area...Oh well, you can't have it all.

Confession: I have been painfully bashed by a damned lug yard during a sudden squall. I should have gotten the thing down five minutes earlier. That said, I know that a well designed lug is powerful rig. Your famous GIS dinghy uses that rig to advantage. But the OP just wants to sail a little bit. SImple is better.

 

I know you Yanks are enamoured of your sprit rigs for small boats, but I wouldn't have one if you paid me, not even for simple messing around. I'd prefer a lug under any circumstances.

 

NoEye it is not so much that we are enamored of such a simple rig, it is just that we are a bit lazy. My personal choice is full battened square tops but they are just too complex and demanding of attention for liesure cruising

To each his own.

 

A sprit rig can be can be remarkably easy to smother.

It often doesn't have a halyard, as the sail is often lashed directly to the mast.

Usually such a sail has no boom.

By rigging a line through a pulley the top of the mast to the sprit, at that height, the sail can be quickly furled by relieving the sheet line, pulling the top of the sprit up against the mast, then wrapping the tail end of that line around the sail a few times. This makes a somewhat dirty bundle, but effectively furls the sail with little or no drama.

Unfurling the sail happens just as quickly.

For this reason, this rig was used on boats that could be a bit tippy, or couldn't afford to have their decks cluttered with spars.

The disadvantage of this rig is that it is difficult to reef.

Yeah. You could take the top end of the sprit out of the eye at the top, aft corner of the sail, then pull that corner down to leeward, Leaving a much smaller three cornered sail standing. But getting the top end of that sprit back into that eye, with any kind of wind blowing could be a bit dicey.

In the case of an auxiliary sail for a rowboat, I don't think this rig is easy to beat.

By its very definition, such a sail is going to be small in relation to the boat it is set on, so there should be little or no need for reefing.

A standing lug might be a good 2nd choice. It too would have no boom. It would have a yard, a halyard and a tack hook at the lower front corner of the sail. This tack hook would be on the mast and would hold the said corner of the sail to it.

The lower aft corner of the sail would have the sheet line attached to it.

This sail would be easier to reef than the sprit sail mentioned above. It would have to have a parallel, to hold the yard up against the mast, at a lower height, and it would have to have a new tack hook eye and a new sheet line eye higher up on the sail.

When reefed, the lower, now unused, portion of the sail is bundled and lashed to the new foot created by the new tack hook eye and the new sheet line eye.

The disadvantage of this rig is the yard tends to go up the mast vertically rather than horizontally, as one might expect. This may cause it to end up on the wrong side of the mast when the sail is raised. It can also flail about in windy conditions, when it's being raised and lowered.

A dipping lug would be more weatherly than the two rigs mentioned above, but its yard must always be on the down wind side of the mast. This means the lower front corner of the sail must be hauled around the back of the mast, then re attached to the bow, every time the boat changes tacks. When this is done, the forward end of the yard is often 'dipped' back behind the mast to the new down wind side, hence the rig's name.

For sailing one one tack, for long stretches, this rig is hard to beat. it is reefed pretty much the same way the standing lug is.

 

Balance lug. Simple, effective, self vanging, so good downwind. Easy to drop and to reef. In smallish sizes, easy to hoist too. Less likely to give you death rolls off the wind. Lower sheet loads than a loose foot. Need I go on?

 

Lazy Yanks? Well, maybe a few.

 

Now that I've read this more carefully, I can see what you really want. Sorry for going off on a tangent.

Basically, you want to make a simple sail out of a polytarp, or something like it, using the existing eyelets and edge reinforcements.

Your plan could work quite well if you simply fix the upper and lower edges to your boom and yard, have your halyard attached about 40% of the yard length aft the front end of the yard, and have the hold down attached about 20% of the boom length, aft the front of the boom.

Cutting darts into this tarp is going to add the labor you seem keen on avoiding. If you do that, you will need reinforcement patches and maybe a bit of sewing.

The biggest problem I see, is not so much the rig, but the rig in relation to the boat.

If you want to sail any direction but down wind, the rig is going to have to be placed so it's Horizontal Center of Area (HCA) is roughly above the boat's Center of Lateral Area (CLA). The further these two areas are apart, lengthwise, the more likely there is to be trouble.

You never described your rowboat.

Does it have hard chines, or is it mostly a round bottom?

Does it have a long keel under it?

Does it have a transom?

If your rowboat has a flat bottom and deep chines, like a sharpie, you may be able to get away with using them as lateral area. You will have to keep the boat heeled to leeward to do this. Your upwind performance may not be spectacular but it may be adequate.

If your boat has a long, shallow keel, as some traditional rowboats do, you can use that. Again, since it wasn't intended to have a sail over it, your windward performance may be just adequate. In this case, you will want to keep the boat as level as possible while sailing.

A good guess as to where the sail's HCA should go, in both these cases, is about 3/8ths the boat's actual waterline length aft the beginning of the waterline.

If you resort to using a leeboard or dagger board of some kind, its fore and aft placement (and its LCA) in relation to the sail's HCA becomes more important than where it ends up on the boat.

A rudder of some kind would be a big help, but you may be able to get away with steering with an oar. If your boat has a transom, it will be much easier to mount a rudder of some kind.

 

Actually, if the boat has no keel and does not have a deep fore foot, it is best to place the HCA (Horizontal Center of Area) of the sail at about half the Water Line length back from the front of the waterline.

It is always better to have it a bit too far aft than it is to have it a bit too far forward.

The 3/8ths rule is best for long keels that are level on their bottom edge and have a nearly vertical leading edge. If the keel has a sloped leading edge, take your 'waterline' measurement at half the depth of the keel.

A deep fore foot and a deep skeg, which many traditional rowboats have, act pretty much like a long keel. Such boats were built this way when long distance directional stability was considered more important than maneuverability. 'Pea Pods' and 'Whitehalls' are good examples.

Some 'Pea Pods' had slightly deeper keels (a few inches deeper) when they were expected to carry sail. A slightly deeper long keel (or one added to a deep fore foot and skeg), requires no case and only slightly degrades rowing performance, while allowing the boat to sail upwind at least as well as a close reach.