Mizzen sail - orientation?

[Metaspace]

Hi model making experts,

 

my son and me are building a remote controlled version of the Papegojan (1623, scale 1:26.6).

All sails will be contolled as in the original, with the help of bracing winches (I hope this it the correct English term).

 

Currently, we are configuring these winches, to correctly position the sails for any course in relation to the wind.

What I am not sure about (as I never have sailed on a comparable ship), how is the mizzen sail positioned, braced, depending on the course, and the position of the other sails?

Or, in detail, when the yard sails are braced 10°, 20°, 30°, 40°, ...., in which position would the mizzen rod be, and how tight or loose would the mizzen sheet be?

 

Can anyone help here?
Thank you in advance.

[popeye2sea]

Are we speaking of a square mizzen or a fore and aft or lateen mizzen?

 

Regards,

[Dr PR]

Lateen. You can see pictures of his build in the llink he posted. I have no idea how the lateen sail was used.

[Metaspace]

Indeed, lateen, yes 🙂

[Baker]

The mizzen sail (and spritsail) actually serves to make adjustments while sailing.

I read this somewhere in one of my books. I don't know how it actually works.

Maybe this explanation already helps a little.

This is from a modern boat. But the explanation is probably also correct for older ships

https://www.riggingdoctor.com/life-aboard/2019/5/22/mizzen-staysail

 

I'll see if I can still find the explanation in the book.

Edited September 22, 2022 by Baker

[popeye2sea]

Lateen mizzen sails, drivers, spankers, etc. are all what are known as steering sails.  They work by increasing or decreasing pressure on the after part of the rig. This in turn helps to keep the ship pointing into the wind in the right direction.  By hauling in the sheet (bringing the sail closer to the centerline, you increase the pressure on the aft part of the rig which will pushes the stern more downwind and the bow up further into the wind.  The fore sails and jibs work in the same manner but in the opposite direction, helping to push the bow off the wind.

 

So the answer to your question is. Set it however you find looks pleasing to you.  It is more than likely to have been put in any position and adjusted depending on steering orders and fine tuning of the sail trim.

 

Regards,

[Metaspace]

Thank you, yes, I'm aware of this.

The mizzen sail on square riggers is mostly used to create traction on the rudder (by creating additional lateral pressure at the aft of the ship), as well as for trimming the weather helm of the ship.

 

Unfortunately, form this I still cannot derive the supposed position of the sail...

[Metaspace]

4 minutes ago, popeye2sea said:

[...]

So the answer to your question is. Set it however you find looks pleasing to you.  It is more than likely to have been put in any position and adjusted depending on steering orders and fine tuning of the sail trim.

 

Regards,

 

That makes a lot of sense, thank you!

[popeye2sea]

There is no set position.  The trim of the sail would be determined by conditions of the moment. ie. direction of the wind, wind speed, position of the rudder, etc.

 

It would be analogous to flying a plane. You get the plane going at the correct pitch angle then you set the trim tabs (your ships mizzen) to relieve back pressure on the control stick or yoke (your ships helm). It is a constant or at least frequent adjustment.

 

Regards,

Edited September 22, 2022 by popeye2sea

[Lieste]

The driver is rarely set, and tends to be most useful in wearing or tacking, where it can outhaul to push the tail end around.

From what I have gathered, the foresails and mainsail would more or less balance the rig on most broad reach and beam seas, the mizzen topsail and topgallant might only be reefed, or left unset to give a fairly neutral helm. On other points of sail (or in different conditions of trim) more of the mizzen stack might be needed to have a neutral or slight tendency to fall off the wind.

To bring the head smartly around setting more of the mizzen sails, and hauling the driver to windward will help the rudder drive the stern to the leeward and the head into the wind, with the pivot in forward motion being something like the 1/3rd of the WL length from the head - if the ship loses head-way during the tack, the helm is sent over, and the pivot shifts to closer to 1/3rd the way from the stern, which slightly reduces the effort the rear sails can impart to aid turning - if not already set the driver will be needed now if the vessel is not to miss stays.

For maximum lift the sail should take an angle of attack of 'around' 20 degrees, if you can set it to closer to 90 degrees it will provide a greater force, but as a 'drag' force (which is strictly limited to zero when running at the wind speed) - the driver can be used in either mode to push or pull the stern as needed and as the angles of the wind and hull allow. I would start seeing how the sailing performance is without it, and the ability to hold a course with trimming the other yards, and reefing/clewing the other sails. Then try various strategies to drive the stern or pull the stern the way it needs to go for each planned point of sail it struggles to hold or attain.

You also need to consider the sheeting strategy for the headsails to ease tacking and wearing, especially with lower speeds and lighter airs.

 

[Metaspace]

Thank you for all your input.

 

Just for clarification:

 

The thing is, as the mizzen sail cannot be fine tuned based on current conditions (due to remote control limitations), I am forced to preset mizzen rod position and sheet bracing based on the angle of the aft yard sails (one servo driving all of them).

 

As it is considerable effort to define, build, and integrate the relevant brass winches, I hope to not need to have several iterations in order to get them right 🙂

 

I therefore will go with what looks right. I'm fairly confident the model will sail well enough (as it has a rudder with increased size, as necessary for scale models).

[Baker]

4 hours ago, Baker said:

The mizzen sail (and spritsail) actually serves to make adjustments while sailing.

I read this somewhere in one of my books. I don't know how it actually works.

Maybe this explanation already helps a little.

This is from a modern boat. But the explanation is probably also correct for older ships

https://www.riggingdoctor.com/life-aboard/2019/5/22/mizzen-staysail

 

I'll see if I can still find the explanation in the book.

From the book "galleon by Peter Kirsch".

[amateur]

I have seen e youtube of a fairly large RCmodel of Prins Willem (same period, slightly latger) and it looks ad if the mizzen is set more or less just to please the eye.

It just goes with the wind. Not sure about the spritsails…

Jan
 

 

[Metaspace]

Yes, thank you, I know that video - here, the mizzen can move freely with it's bounds, it's edges also stiffend by - assumedly - wire.

For our ship, we are actually using a sheet on the bottom corner of the sail, allowing for more options.