I need a naval architect please

[Geno67]

I'm wanting to combine elements of two different designs and modify the bottom. I can get the frames worked out fine and the two outside panels (side and anti trip chine) but the inside bottom panels that make up the inverted vee will need to be worked out by someone who knows what they're doing ( I do not). Is there someone the fine folks here can recommend to do this work?

I have plans for the 1950's version of the 18' Hickman Sea Sled and the more modern 18' Texas sled. The beam on the Hickman Sea Sled (HS-18) is too narrow for my needs, the freeboard on the Texas Sled (TX-18) is too short and I wish to carry the inverted v all the way through the hull as seen on the Laguna Tiger produced by Duckmaster, Inc.


I will begin building in September of this year as my wife has accepted a job in another state and we will be moved by then. Thank you in advance for your assistance.

 

[DogCavalry]

If you have the time and inclination, pick up a copy of Elements of Boat Strength by Dave Gerr. It is invaluable in almost any situation from long flight to zombie apocalypse. Based on his recommendation I chose strip plank composite. As a result of which I did not need to develop 2D panels to fit a 3D structure. However, in your size range plywood composite is mighty appealing.

Are you looking for the configuration in the tunnel, or just the panel shapes to make the configuration you have already determined?

 

[Geno67]

Why thank you DC, I will do that. I have read some of Dave's articles and poked around on his naval architect site but have not read his book(s).

This will be a stitch and glue ply composite with all seams taped and glass sheathing on outside and inside of the hull. All frames, stringers and sole will have 3 coats of epoxy, will be taped at all joins and tabbed as called for in the TX-18 plans. They have some of the frames as temporary and replaced with just sole support and gunnel knees in the plans but I will change that up to keep all the frames.

The configuration has already been determined, I just need the two inboard bottom panel shapes.

 

[bajansailor]

@Geno67 you could perhaps let this thread develop into a group design exercise, where the considerable talent and expertise on here could help you to design what you (think) you need.

How about posting some sketches of what you have in mind, and see where it goes from there?

@DogCavalry received a lot of useful help and advice on his iconic Seasled thread by doing just this.

 

[Geno67]

After some soul searching, I'm pretty sure my back will prevent me from finishing it.

My absolutely wonderful wife claims she'll help as she knows I want one last small boat. She's the reason I own the old McKee Craft as she made me sell a perfectly good 1993 16' ski boat I had used for a decade before that but only a few years offshore in it. Had one of those hot bite days when I could see the weather coming but wasn't leaving while they were biting. Pretty good squall popped me, lost one anchor pretty quickly and the other two over a few hours after a nasty wave over the stern drowned out the inboard engine. I was just going to get a plb but she cornered me up and asked me point blank if a different boat would be safer.

My absolutely wonderful son suggested we build the strong back on wheels up a couple feet off the floor with hinges on both sides so I can tilt and whirl it and work on it standing up.

I'll get on the drawing board tomorrow and get something drawn up best I can. Maybe.

 

[DogCavalry]

I'd be glad to help, but the commute is too much to be practical.

 

[Geno67]

LOL. You are entirely too kind. You get unsore and quit falling off roofs. That would have killed me. I'm going to install another suspension seat and get some beanbags for the McKee. Also going to open her fuel tank cover and see if we can tell how bad the foam is.

My fishing buddy.

A couple pictures of the engine.

 

[Geno67]

This is an HS18 that came as a bonus plan with the TX18 plans. I've kept the side and the chine the same, pushed the sides out to the TX18 width (more or less) and carried the inverted v through the transom. The bottom panels will change of course due to the widening and carrying the inverted vee through the transom.

 

[DogCavalry]

This is an HS18 that came as a bonus plan with the TX18 plans. I've kept the side and the chine the same, pushed the sides out to the TX18 width (more or less) and carried the inverted v through the transom. The bottom panels will change of course due to the widening and carrying the inverted vee through the transom.

This is great!

 

[Geno67]

Thanks. I can do the frames, sides and chines at this point. I'm unable to work out how the bottom panels should be shaped due to ignorance of boat design techniques.

I plan to use the wood type, thickness and glassing called for in the TX18 construction notes. I'll need to move the sole up to accommodate a fuel tank underneath. I can do the frame adjustments for the higher sole as it's all flat planes and the baseline appears to be the sole. I figure I can measure for the taller stringer curves once the bottom panels are in place - that being a wild guess as I know nothing about boat design.

 

[Geno67]

Is anyone able to help with the bottom panels or maybe explain the math to me so I can?

 

[bajansailor]

The easiest way might be to build everything else, and then use stiff cardboard to make templates for the panels?

I've kept the side and the chine the same, pushed the sides out to the TX18 width (more or less) and carried the inverted v through the transom.

Are you sure that everything re your lines plan is still fair, after you pushed the sides out?

 

[Geno67]

I had not thought of the cardboard panels. That is a good idea.

I have not the faintest idea if she is still fair.

 

[bajansailor]

I have not the faintest idea if she is still fair.

In this case you should try re-drawing your lines plan, using the new dimensions shown on the 6 sections above, and see if the lines are fair.
Put all the sections together in what is called the body plan, and then use a curve to get a best fit through the chines - if it is a nice curve, you are off to a good start. If it is not, then you need to do some fairing and adjusting of your sections.
Also draw a side profile view, and put the chines and keel in this as well - do you still have fair curves?
And a plan view, as if you are looking down from above.
All of the curves should be fair, and all of the intersection points should correspond in the three different views that you will sketch out.
Don't try doing this on your computer - just try it on paper with a pencil first. It will help to give you an appreciation for what the lines plan represents.
If you do not have any curves, then a standard set of three plastic French Curves (obtainable from anywhere that sells stationery items) should cover most curve shapes you will need, especially if you are drawing it to a small scale (like on a standard A4 or A3 sheet of paper).
If you need to draw a more shallow curve, you could try making a timber or plastic batten and use this to try to fit the points to the curve.

PS what type of fish are these in your photos above?
And what is the dog's name? I guess he is the chief mate / look out?

 

[Geno67]

I am watching freeship tutorials now. This changes everything. I'm familiar with cad, gis and bim software. Once I have the hull input, I'll have a better idea of whether or not it's fair.

Those are striped bass, red snapper and gag grouper. They are all from the Gulf of Mexico although I often catch the striped bass in freshwater as they make their spawning run.

The first mate's name is Boudreaux. The poor guy was kidnapped in South Georgia and needed a home. One of our Long Island friends was travelling to Atlanta to fly home to NY and she came across a dog walking down the road by himself. Being from NYC, she was certain no one would allow a pup out unaccompanied so she "rescued" him and brought him back to FL. He was neutered, had no fleas or ticks and was extremely well behaved. We tried to find his owners but without success so he's been a fixture here for the last year. He was heartworm positive for a year. Treatment fixed the heartworms up but he still suffers from shortness of breath quite often.