Furled
(Please note that the following entry reflects my pitiful lack of understanding. See tomorrow’s blog entry for details.)
I know I said that I intended to make this a “full speed ahead” build, but some things are just beyond my ability to tolerate. I know I can tolerate a lot, including abominable plastic shrouds and sails, but, in the immortal words of Meatloaf, I won’t do THAT.
Here is an image to illustrate the problem. The direction of wind is indicated by the arrows. The main sail is bulged outward due to the wind moving into it from the, um, port side of the ship. But notice the lateen sail “abaft” of the main sail. Blimey! The wind is blowing in a different direction entirely on the poop deck!
Leaving aside my almost irresistible urge to make a poop joke, I’ll just say that the wind doesn’t act like that, unless a tornado is approaching. So there’s a problem. Due to the laws of chirality (what? you never heard of those laws?) I can’t make that main sail and that lateen sail work together unless I attach the yards at a different angle, and even then it would be “questionable.”
To me, this is big deal. It may seem silly to some folks, but the beauty of model building is that I get to set the agenda–and this had to be fixed. So I decided to create a “furled” sail to replace the vac-formed lateen sail. I could not figure out another solution.
This is a paper napkin.
I cut out a piece that was the same size and shape as the sail, then dirtied it up with pastels, then rolled it into a…thing…and tied it to the yard.
It will have to do. I’m happy that I’ve been able to develop enough confidence in my rigging “knowledge” to do this one little modification. I should point out that I practically dismantled the mizzen mast during this effort, trying to make that darned sail “look right.” Then it dawned on me. It just wasn’t going to work. So, this is my solution. I actually think that this will work out better for showing off the crew figures on the poop deck.
What? I’ve taken a solemn vow of the sea not to make poop deck jokes. Must…resist…
The mizzen sail (called either a spanker or lateen on your ship) is never a “pushing” sail, but is a balancing sail…notice how small it is by comparison to the hull/keel/square sails.
It was also used more like a “wing” works today on an aircraft. The air flows across the lateen sail (wing) and its shape causes lower pressure on the outside (port as it’s supposed to be rigged on your model) and higher pressure on the inside. That pressure difference causes the rear end to “pull” a bit left (on your model) and is adjusted to minimize “weather helm” and “lee helm”. Weather helm is where the tiller is held to weather (into the wind) to steer a straight line, and lee helm is where the tiller is held to lee (with the wind). They didn’t know the physics/theory, but they understood what worked.
If you furl that lateen sail, then you should move that tiller to the extreme left (and rudder to the right), because your model has lots of weather helm. Which means your Captain can’t turn the ship left because he has no room to do so.
Since you want to avoid a poop deck joke, how about the old sailor’s saying of, “always pee to lee”?
If I’m understanding you correctly, the sail’s purpose is the creation of a lateral force which helps the rudder to keep the ship on course without adding additional drag in the water (which is major drag). It acts like an “air rudder.” The other sails push the ship forward, in most cases the wind is not precisely going in the desired direction, so something has to keep the ship going in a direction other than that of the wind. This occurs because the force of the wind is harnessed by the pushing sails, and the rudder and the mizzen sail pull the stern around and force the ship along in a way that is not strictly in the direction of the wind. As the wind shifts, the pushing sails are adjusted to improve efficiency, and the “steering” sail is adjusted to provide that force swinging the stern around.
The limited research I did on this did not provide me with this information. But I did learn that these sails might not be as “mobile” as they appear. From my research I’m wondering if this type of sail is a “one way” device. It can push the stern to port, so the ship goes to starboard, but it can’t do the opposite because it’s not (generally) swung around and repositioned? Could it be rotated on the mast to the other side, putting the sail “front to back” and making it look backwards but still useful to provide a lateral force in the other direction? Does the ship have a built in “twist” that tends to push it to port so that the mizzen sail off-sets this twist, in the way that certain aircraft have an offset rudder to counter torque?
So much to learn…fortunately, I haven’t done any more on the sail. I can still change it.