Building a sailing Dory...

I am building a Banks Dory,and would like to add a sail...small but a sail..thinking about 15 ft mast...but my plan has nothing about a sail plan...Her is a pic of my boat under construction,if any advice please share,thanks Willie ...also will need a dagger board..

 

Looks like a hell for strong build you have there. Depending on what you will be doing with it, it appears to be unnecessarily heavy.

My first impression is that the seats are too high. Might be OK for rowing but not for sailing a skinny bottomed boat like this one. On a boat like this you will need to sit near the bottom, or even on the bottom, for sailing. The Banks style dory is stable when loaded with 500 to 1000 pounds of Cod fish. Not so much so when lightly loaded.

The dagger board will need to be put in the right place so that it lives well with the sail. Of course you will also need a rudder unless you are thinking of a sweep oar.

Keep up the good work and tell us more about the project.

 

Thanks Messabout....The boat is lighter than you think...its made of cypress,and whit oak frames...I have owned many sail boatsmbut not a sailiong dory...this is a "Banks Dory" that will be rowed and sailed...ballast is not a problem...but the placement of the dagger well is...I was hoping for some one to post that has some experience with what I'm doing...Thanks for your input...

 

Have a look at John Gardener's book "Building Classic Small Craft", as it'll have a few plans that will show the traditional ways to do this on your Banks.

 

I trust that you have taken Pars advice by consulting John Gardners book. The Banks dory is capable of sailing fairly well but it can not tolerate too much sail or too high a sail. A lug rig or a peak sprit rig will likely be the best choice. The general idea is to keep the center of area low.

The dory that you have built has the advantage of easy adjustment of fore/aft mast position. Once you put the centerboard case or the dagger board case in place it becomes a fixed entity. Luckily the mast is movable with only minor modifications.

The location of the sailing rig parts are subject to experimentation but you can get into the ball park by using some fairly simple calculations. First make your best estimate of the location of the sail center of effort. That'll be somewhere aft of the mast of course. Now make an informed estimate of the center of lateral resistance of the hull and board. You may want to fiddle the locationof the board in the process of these calculations. Let the center of lateral resistance, the CLR, fall somewhere in the neighborhood of five to eight percent of the waterline forward, not aft, of the center of sail effort (CE). That is counter intuitive but that is the way that it usually works out.

After you try the boat under sail, you will have determined whether weather helm or lee helm is in effect. You will want some weather helm, not much but enough to feel in the tiller when going to windward. Lee helm is a no no. Now you will know whether to move the mast or not. Keep in mind that the Banks type is cranky when heeled. Very much heel and the boat will want to steer itself despite rudder input. As a matter of fact you can steer one of these boats by merely heeling it one way or the other.

The cypress boat is going to be heavy by todays standards. Cypress is a magnificent wood but it is a thirsty wood. It will "take up" some weight if you leave the boat in the water for any but the shortest time intervals. I suggest that you epoxy saturate the cypress to keep it from taking up more water that you'd like. If left in the water for long periods of time, it can easily take up half its weight in water soakage unless you head that soakage off at the pass.

Keep us informed about your progress. Your dory is an interesting project.

 

Heres the latest....

 

Pwillie where are you? Have you made progress on the dory build? Tell us more.

 

Messabout: I have been stalled some what in the build...but look at this..

 

Lookin' good. Have you been stalled on account of Alabama and/or Auburn football or something? In any case for the boat, so far so good.

For a boat like that you must be close to some big water.....like....Mobile or Gulf Shores or somewhere that will do justice for a boat of that type.. Here's hoping that you can splash the boat soon.

 

...most any project becomes slow when trying to finish up! Weather,materials, and tools brought on some of the slowdown......But, hope to resume soon....got oars and oar locks last week.....Yes, I live close to Mobile Bay....thanks for you asking....will post some new pics when the project moves along...

 

pwillie,
Dorys make good motorsailers too. A small 10hp (or so) engine w a shaft going through the 12" (or so) keel would give better lateral resistance for sailing and/or make the size requirements for the CB or drop keel less. Five or 10hp air cooled engines are readily available for cheap.

I once put a fixed keel (alum plate) on a 16' sailboat (sloop) and put the center of area of the sails the same w the area of the keel. It worked well but perhaps I just got lucky.