Dory Questions

[andrewmct]

Well, I have posted on here a few times about dories and now I have bought the plans. Since it was my first boat project ever, I have gone simple, simple. i purchased the plans for a Labrador 24' banks dory from Spira International. The plans are simple and concise but there are a couple of design related questions that I would like to ask some experienced builders.

1) The motor well is situated quite far aft and is only a box that is 2feet long and 16" high. It doesn't appear to be big enough to pull the engine up. Would a dory be better with a long shaft or a short shaft and does anyone know of an easy design that would allow the motor to tilt up for beaching.

2) The frames are designed from 2x6 and 2x4 fir. Does it have to be vertical grain clear fir for millions of dollars, or can I get away with a less expensive variety. I'm not iterested in bright work etc for now since it's going to be the winnebago of the sea.

3) Lastly, is it easy to change the shear line to give it a bit more of and elegant line than the plan suggests. I don't think it looks bad, I just think that if I used a batten to re-do the shear it might be a little prettier. Would that work? Or would it be a disaster waiting to happen?

I know it's a few questions but I appreciate the insight.

Regards,

Andrew

[TerryLL]

Good questions, and easily answered.

A long shaft motor will serve you better because it allows a taller outboard well, and less chance that you will get sloshing over the well. A well long enough to tilt up the motor is a must for a boat you plan to beach. Feel free to lengthen the well as needed. John Gardner's Dory Book has a design for a tilt-up well.

You can use construction grade fir for the framing in this boat as long as you high-grade it to avoid major knots and other defects.

The sheer on this boat does indeed need to be adjusted. Feel free to change it to please your eye. This will require redrawing the lines in plan and profile in order to determine the new sheer offsets. Not a difficult thing to do, and something well worth knowing how. The Dory Book will show you how. You might try redrawing the lines at either 1/8 or 1/4 scale, as these are convenient scales when working in inches and feet. And let use evaluate your redraw before you start whacking wood.

[Steve Paskey]

The Banks Dory is not the first hull I think of when I'd be planning to power it with an outboard motor. There are better Dory Variants for power. I have not seen the Spira International Bank Dory that being said.

It's probably a misnomer to call the Labrador a "banks dory" -- the proportions are wrong. It's a large boat, with a length of 24 feet and a beam of 8 feet -- that's a ratio of 3:1. The Labrador is almost the size of a St. Pierre dory ... the beam of the two is about the same, but the Labrador is a few feet shorter.

For comparison, a 23-foot-long dory from the Lunenburg Dory Shop in Nova Scotia is more narrow, with a beam of just under 7 feet. And a typical banks-style rowing dory is even more narrow, with a length to beam ratio of 4:1 or better. (Bolger's Light Dory, for instance, has a beam of 4 feet on a length of 15'6".) Some rowing dories, like Sam Devlin's Fairhaven Flyer, are around 5:1.

Given the beam and length of the Labrador, there's plenty of room forward of the outboard well. It should be fine with an outboard as long as he doesn't try to power it past hull speed ... it's purely a displacement boat.

[Thorne]

Has anyone used a swing-down / adjustable outboard motor bracket in a well, or is the space needed for the swing-down so close to that of the space needed to just tilt the motor up?

http://images.cabelas.com/is/image/cabelas/s7_017511_imageset_01?$main-Large$

[TerryLL]

I haven't seen a swing-down bracket in a well, but there are some vertical crank-up-and-down designs out there. I think the larger NIS boats use that system.

[perldog007]

AndrewMCT, I don't know much. I am the skipper of a packing crate with oars.



But I do treasure my copy of John Gardner's 'Dory Book'. I also really enjoy 'Building Classic Small Craft' by Mr. Gardner. I have looked at the study plans for the Labrador many times, and am currently building a Bolger Gloucester Light Dory.


You might like both of those titles. I like to have a lot of information, due to lack of experience I guess. I am wearing both of those out currently along with some titles more specific to the GLD.

[Venchka]

That's a big boat, Paw-Paw.
That's a big boat for a first time build, Paw-Paw.
Did I mention that's a big boat, Paw-Paw?
John Gardner's library is the Bible of the dory clan.
That big boat will need a lot of cargo to keep it down on her lines.
That's a seriously big boat. Will you be hauling freight?

Take a look and a read of this page. Especially the last 3 boats. Then peruse all of the pages. Well worth the time.
http://www.doryshop.com/dory_types.html

[TerryLL]

That's a big boat, Paw-Paw.
That's a big boat for a first time build, Paw-Paw.
Did I mention that's a big boat, Paw-Paw?
John Gardner's library is the Bible of the dory clan.
That big boat will need a lot of cargo to keep it down on her lines.
That's a seriously big boat. Will you be hauling freight?

Take a look and a read of this page. Especially the last 3 boats. Then peruse all of the pages. Well worth the time.
http://www.doryshop.com/dory_types.html

Wayne,
It's about the same size boat I cruised to Alaska. These double-ended dories are not as big inside as you might expect for a 24' boat.

[andrewmct]

Thank you for the replies. I know this is not a banks dory in the traditional sense but I do like the look of dories and want a double ended design with a flat bottom for west coast beaches. Terry has helped me through this one ad-nauseum. I may move the well forward then. I think I can do that without too much difficulty. I have read the dory book but I should go back to it and review the well stuff. Thanks Terry for the shot of confidence on adjusting the sheer line. I think a couple of inches adjustment can make a much nicer looking boat. At 7'6'' wide, it is a little wider than the traditional dory shape but Jeff Spira assured me it works just fine. it still looks like a boat to me and if it's even a little more stable than an original, then my family will ride in comfort and safety. I'll look for the highest quality construction grade I can. I may lap the frames and gusset them with ply too.

[Thorne]

You'll save a lot of confusion and typing if you list your location -- we have members from all over the world, so products and materials recommended often vary depending on your location.

Go to the USER CP link near the top left of this page. At the top of the listing on the left side under YOUR PROFILE select EDIT YOUR DETAILS.

In the second section down, called ADDITIONAL INFORMATION, fill out the Location field. Scroll to the bottom of the page and click the SAVE CHANGES button.

While in the USER CP section, I recommend updating the option that allows you to easily post photos in Forum pages.

Click the “Edit Options” link about halfway down the left column.

In the “Misc Options” at the bottom of the next page, select “Enhanced Interface” from the pulldown list.

Once this interface has been selected, in any “Reply” window you can click the “insert photo” icon --> a little yellow square icon with the stamp in the upper right corner, the mountains in the lower center. http://woodenboat.com/forum/images/editor/insertimage.gif

[jerry bark]

I would suggest that you contact Jeff Spira about moving the motor well, there is more to that perhaps then meets the eye. he should be able to guide you toward making a well that allows tilting up the engine. I suspect that he will be willing to help, he seemed nice enough when I had an email exchange with him.

good luck
jerry

[Venchka]

24'X8'x3' or 4' is still a lot of boat.

[jclays]

Contact Jeff Spira before design changes. He is easy to get a hold of. Im sure his motor well was designed to accomodate a motor that will properly propel his design. If you have a larger motor it could be too much for this design. Moving the well forward could change how the boat handles.

[Bradley]

I love dorys. Back in '91 i designed and built a 19 ft dory. Since then i have logged over 70,000nm of open seas in that skiff. If you want a seaworthy design, you can't beat a true flatbottom. Here is a link to some pictures of the skiff:

http://lovesthesea.com/category.asp?category=Skiff

In the center of that page there is a link to pictures of the build process.

I don't understand the advantage of having the engine in a well as opposed to the transom. If it is for weight distribution there is a better way to solve that problem, one that does not carry such a penalty in performance. What i did to get the desired weight distribution was to place the fuel (54 gallons) way up to the bow. I use portable fuel tanks so i can further redistribute the weight as the voyage progresses.

[TerryLL]

I don't understand the advantage of having the engine in a well as opposed to the transom.

The dory that Andrew is considering is a double-ended dory, which has a very narrow and sharply raked tombstone transom. A well is the only option for this type of dory.

For a dory-skiff like yours, a transom mount does offer same advantages over a well.

[andrewmct]

Amazing pictures and boat, Bradley. So you ventured 100 miles offshore in your Dory-skiff? I will have a look at your website in more detail later but it looks as if you really enjoy your boat. Have you ever had doubts about where you were with you little boat? I am choosing a double ended design so that beaching and follwing seas are a little easier. Any ideas on that?

Andrew

[Venchka]

Beaching may be easier, but getting off the beach and into deep enough water to drop the motor may be interesting.

[Bradley]

That submerged mountain top (Cortes Bank) is my favorite destination here in Southern California. There is a wreck out there that i like to swim on when the weather is just right. I have been out there 34 times and have spent 33 nights anchored right where that huge wave breaks. Right now it is treacherous out there--13ft @ 9, gusting to 35kts.

Following seas are to be avoided-- granted, sometimes you can't. I have no experience in a double-ender so i couldn't say how well they work in seas. I like being as far offshore as the weather allows, so for my needs i had to have a planing hull built like a brick house. (actually like an airplane..) I usually go for 2-3 nights at a time, so i spend more time being there than getting there. Being there is where the flatbottom outshines any other hull configuration imo.

There have been a few occasions where i was caught in severe seas and my dory took them very well from the transome. I wrote about one such experience on my web site.

Everyone has their own needs-- no doubt you have thought this out and chosing a double ender was the best choice for you~

One thing about wood...

You get the piece that you choose, so choose well. Take the time to sort through the selection before deciding on any individual plank. (people who choose string beans one at a time at the Farmers Market drive me nuts, but when it comes to wood, it is perfectly acceptable to sort thru the stack.

Is there a picture of your skiff out there?

(PS, you are going to love building your boat! Life spend dedicated to a project fills you with anticipation.. Anticipation is a very healthy state of being~)

Brad

[andrewmct]

http://build-a-dory.blogspot.com

This a link for a nice guy who has decided to help boat builders build a dory. He is building the 19' Spira alaskan. I bought the plans for the 24'. Terry, if you're still reading this, what size of motor was in your Cape Ann for your trip? The advice on the lumber is good. Fortunately on the west coast of Canada, Douglas Fir is plentiful.

Andrew

[Hal Forsen]

Bradley,
I've followed your adventures for years;
Would you mind giving the dimensions and scantlings of your skiff and tell us how you installed the "window" ?

[TerryLL]

Andrew,
The motor I used was a 9.9 4-stroke Honda, 1982 model. It did not have reduced gearing or a large prop, but was nonetheless entirely adequate, pushing the boat at hull speed at half throttle.

Today's motors are much superior, offering better gearing, a large prop, and better fuel economy. Unless you're planning to really load the boat down, a 10HP high-thrust will serve nicely, and a 15 would be the max I'd consider.

[Bradley]

Hal.

The width of the bottom and two internal bulkheads were determined by the width and length of 3 nesting fuel tanks (two 12 gallon low profile poly tanks with a wedged shape 6 gal. in the middle)

Here is a link to a picture of the fuel tanks:

http://lovesthesea.com/large%20photo.asp?id=247


The bottom length was determined by the 6" scarf splice of two 5'X9'X 3/4" sheets of marine plywood, end to end = 17.5'. The width of the transom was determined by the amount of give and lift i wanted in the hull--it was a wild guess @ 8" narrower than the widest point of the bottom which is 1/3 hull length from the bow. Lucky guess. The angle of the bow stem was determined by making the overall length precisely 19'. The flair at the widest point was determined by the natural bend of the mahogany rail logs from the bowstem to the transom which was set at 10 degrees, 12.5 at the widest point and 20 degrees at the bow.

One dimension follows another...

[Bradley]

The window--

I designed a two piece SST housing that screws together with a 1' flange clamping the hole circumferentually. When you cut a big ol' hole in a planing hull, you want to make sure that you do not create a stress riser--you want all the harmonics to transition past the hole rather than ending up right there....

The window is a 6" Dia X 3/4" thick slug of bullet resistant, optically pure glass. The window is flush on the bottom and has an inspection cover finish in the cockpit.

It was very expensive to have machined, but you wouldn't believe all of the cool things i have seen through it! I take video thru the window also.