Sea Sled madness. It’s in my brain.

On a boat this slow and heavy, relatively speaking, wind resistance is a small part of the total. I raised the roof 3", or 75mm, to give myself a bit of head room.

 

You will need it. 6'4" needs clearance for the ol' punkin'.

 

Man, that thing looks like it's being built to withstand major surf rollovers.

The boat I'm working on is being built to maybe withstand surfers, rolling over on it.

 

Hahahahaha! CR, THAT is funny, thanks for the laugh!

In all seriousness, I put my little boat in some rough conditions yesterday. (Now what I consider rough is some 1 foot chop) she handled just fine. These boats are stronger than you would think. At least I thought mine did anyway. I had to take it slow, the convex front end is quite the pounder.

 

It's such a matter of perspective. I build houses. By that standard it feels almost flimsy. But I'm glad you're not worried I'm building it too weak.

 

Mr Efficiency warned me I was building it too heavy. Bluebell always says "don't worry, it's just gas money"

 

Yeah, "too heavy" is tough to call. I don't know much of anything about the necessary immersion of Hickmans so I can't really speak to how light or heavy they should be. Mass is one of the factors in ride softness on a conventional hull; a heavier hull has a gentler motion, all else being equal. But your hull is not very conventional so nothing else being equal is a better descriptor here.

Is there a design displacement you are trying to hit, or are you building by feel? At any rate as long as the structure will handle the loads exerted in strange directions, and the weight doesn't get so great that the centre of mass is too high, it seems to me that the fuel bill will be the main indicator.

But I'm not a naval architect or anything, I just build boats when I want to have a new boat, and my handful of designs have been so conventional that there's not really a huge advantage in working out a ton of detail when I can ballpark the requirements by eye and I know I'm going to use the materials I already have on hand. As such I'm totally incapable of working out what should or shouldn't be in this boat. But it doesn't look like it's going to be blown all over in every gust, that's for sure. There would be some point at which the superstructure weight would concern me but then the hull is so massive and rectangular that I don't think it'll be overly tender unless you want to mount a Transat sail on the roof.

But I'm not in a great position to advise on design. The biggest boat I ever designed is a 17' skiff for my own use. This is totally out of my league.

 

I like your approach. I'm trying to build the superstructure so that it's proportional in strength to the hull.

 

Great photos John, thanks.

And it rides on a cushion of air (at speed).

Agreed. However, I did say "nothing bigger than 2x2's above the gunwales"

For the record, I think this a mistake.
Your hull is not underbuilt, and may be overbuilt.

In your best interest, John, I'd like to remind everybody all this is going to be epoxy-fibered, inside and out.

My 2 cents and no more.

Cheers

...

 

Your advice is always gratefully recieved, Bluebell, as is your sense of humor. Certainly my superstructure has nothing less than twice your recommended scantling. Part of my intransigence is the fact that with COVID-19, decent wood is hard to find. The smaller sizes are all garbage.

 

Moving right along I see!

 

Frames under construction.

 

I would avoid building as heavy. What will you feel like if the boat is two inches low astern?

I should talk.

I installed engines that are 100# heavier and a 22 pound bracket on the stern. On each side or 244 pounds aft. I built the console with 3/4" ply. And I built the helm riser much higher than designed.

Anyhow, I would not use 2x4s in the superstructure for a different reason. I have seen like 95% of them twist.

I understand the ship has sailed aspect here. But I would have laminated 2x2s with 1/2" build ups, which would not twist on you. Or using a half rabbet joint and epoxy can help.

But building heavy is not always best. The roof, for example, if built heavy will want to sag under its own weight.

Now, if you build light enough, you ought to have room for a wine locker. It will be a fitting surprise for the lady friend who helps you. My wife generally only helps with advice, and demands wine.

Not sure how you intent to build the roof, but laminating timbers makes them pretty strong.

 

Well, this is a work boat. 2" deeper astern means I have 2000# of paying cargo aboard. It's about 1000# per inch of immersion.

But I take your point. Gasoline is expensive, and load in the superstructure is weight I have to pay for, but can't bill anyone else for.

To maintain perspective, the framing as built is about 120#, windows will be about 240. Roof about 350. Beams about 90. The only component I can lighten are the frames. Halfing them saves 7.5% weight of the superstructure, at the cost of making them really annoyingly fussy and weak until they are finished. Math is cool. Also dungeons and dragons. My other high school interest...