HB16 No Cabin

[bklake]

So, my 10 year old was looking over my shoulder while I was looking at the study plans for this boat. I saw a little spark in her eye and could see the wheels turning in her head, dreaming of what she could do with it. I'm so proud of her. I also had just read the entire thread about the RB14 father/daughter boat.

I had an idea for a landing craft style boat but there really isn't anything out there. The HB16 with a door/ramp on the front looks about as close as one can get. A lot of the places we go are sand bars and beaches in protected waters. It will have to live outside on a drive up floating dock. I have a 25HP outboard on my Carolina Skiff that would get repurposed for this boat.

I've read all the previous posts and have a few questions I couldn't find an answer for.

-How fast will it go with 25HP? Just on plane is fine with me, it's for the kids.
-Weight of the bare hull?
-Weight savings by deleting the cabin? Questions about deleting the cabin were asked. Keep the framing, delete the roof.
-Flat sole (no cabin step down) front to back? Asked before and sort of answered but seemed to be some confusion about what was being asked.
-Bracket for engine. Shows in study plan. Is that a commercial unit or is it in the plans? I know the designer's stance on home made brackets. That's why I'm curious.

[bklake]

Bought the plans today. Most of my questions are answered in the plans. Still not sure what kind of performance to expect from 25HP and what the hull weighs. I have a floating drive on dock and need an estimate of how much the hull weighs.

[gstanfield]

Bought the plans today. Most of my questions are answered in the plans. Still not sure what kind of performance to expect from 25HP and what the hull weighs. I have a floating drive on dock and need an estimate of how much the hull weighs.

The study plans call out 1,100 pounds as built. Experience says that is with a minimal outboard and perfectly built without any excess or added stuff. I'd say most of us on a boat that size would land about 15-20% over on weight, but then you're removing a bit and adding a bit. Maybe Jaques will see this thread and post a calculation for bare hull, but keep in mind that adding batteries, fuel, etc. is all weight that adds up very quickly.

[bklake]

I have a habit of asking a question and finding the answer clearly printed right after I ask it. The weight is listed as displacement but doesn't say if that is max or empty. Later on, the trailer weight is listed as 1100lbs. So, there we go.

The cabin looks like at least 4 sheets of ply. So, not that much. It is not going to be that much in it. I run the Suzuki outboard off a smaller battery and a 5 gallon portable tank, that's it. That amount of fuel gets me through a month of summer use. It is mostly no wake everywhere I go.

The HP range is 10-45 and top speed is listed as 25mph. I'm guessing that is with the largest engine. One build had a 9.9, I think, and listed 8-10 kts max. If 25hp isn't going to get it on plane, no sense using it and I should get something smaller.

When I was building my kayaks, I had the chance to spend an hour or two in the Chesapeake Light Craft shop. I picked up a lot of tricks and techniques for keeping it light. Mind the ounces and the pounds will take care of themselves. My kayak came out just under the listed weight. Their head builder said he usually came in several pounds under the listed weight. I still have a few things to learn.

[jonnymac]

don't forget that without the cabin, you just removed a lot of wind resistance especially for a boxy cabin. So you might be surprised what a 25 hp will do. Probably will need to try it to know for sure.

[bklake]

New question. Study plan for HB18 says engine bracket in the plans is only for displacement speeds. Same for HB16?

[Cowbro]

The study plans for the HB16 say the same thing, displacement speed only.

[jacquesmm]

Correct, those are not fast planing boats. You can get them on plane but it will be uncomfortable if not dangerous.
The ideal engine is around 10HP and that is what the bracket is designed for.

[Cowbro]

I can completely understand why a 16' long 8' wide brick would not be a good planing boat. But to answer the OPs question or provide a solution for his intended motor, what about foregoing the bracket and mounting the engine directly to the transom? Without the cabin he is probably not going to be as concerned about the slight loss of deck space.

[bklake]

The thrifty route is to use the engine I have. Prop it to keep the max speed at 15 or so. Should make it a strong puller. A concern is the weight of the engine. 168 pounds vs. 120ish for a 9.9. Not too worried about going fast. Mostly no wake where I go. In the areas where I can go fast, will add about 10-15 minutes max to the journey.

Making the floor flat and keeping the frames is not that straight forward but I'm working it out. Deleting the cabin not that troublesome. Will probably change the shear lines a little. Maybe favor a Higgans boat?

I have a flat bottom skiff now. Not a fan of going fast in it. Everything is fine if perfectly flat and no need to turn. It gets interesting crossing a wake or turning with any speed. Wind chop and boat traffic are constant and unavoidable.