A Houseboat that Sails?

[NolensVolens]

Is that a possibility? I believe that the answer is a definite maybe.

I am an engineer, and I have lived aboard with my family for over a decade, in a variety of circumstances and climatic conditions. I am also the instigator of a project to design and build comfortable, roomy houseboats that are also competent sailboats. The entire design process is detailed at http://quidnon.blogspot.com.

Our approach (there is an entire engineering team behind it) has been to combine the best of high-tech and the best of low-tech. The internal structure of the boat is plywood, intricately milled out using a numerically controlled robotic mill, then joined together by hand using mortise and tenon joinery and fiberglassed over on the outside. The design has been modeled in 3D software, tested out using hydrostatic and hydrodynamic analysis software and also using a 1:12 scale model. Everything works as designed.

Now we are getting ready to do the first build, aiming to launch Hull 1 in late 2017. After that we will be able to accept any number of orders for rapid assembly kits, to be built anywhere in the world.

At the moment, I am looking for opportunities to publicize this effort. I am a bit concerned that the fairly substantial blog following this project has acquired may be missing a critical angle or two because of the "cool-aid factor," and I welcome any and all constructive criticism.

Dmitry Orlov
S/V Prince Kropotkin, Pearson 365
Beaufort, SC

 

[Rurudyne]

Years ago Commodore Munroe designed a yacht called Savanilla that may be of somel interest you.

Here's a mention of her: https://books.google.com/books?id=r...=onepage&q=commodore munroe savanilla&f=false

Two things: says she exceeded expectations and seems to have gotten her length wrong (15'6" too high).

Here is what I believe is a picture of her underway: http://merrick.library.miami.edu/cdm/ref/collection/asm0015/id/283

 

[Angélique]

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Munroe's Savanilla​

We had an aside about the above boat in the thread Cargo Sharpie Design in the posts: #23 - #28 - #29 - #32 - #33 - #34 - and maybe in some posts I just missed . .

Good luck !

 

[Rurudyne]

We had an aside about the above boat in the thread Cargo Sharpie Design in the posts: #23 - #28 - #29 - #32 - #33 - #34

I remember now.

Forgot that her design was in 1905's Houseboats and Houseboating book.

 

[NolensVolens]

Yes, that's actually part of the thinking that went into QUIDNON. I have lived aboard and sailed a 32-foot sharpie for about 6 years. It was Chris Morejohn's HOGFISH. A great little boat, but it got too small for us. With QUIDNON, I took the basic sharpie hull shape and converted it into a scow. This made it much beamier (16 foot beam in a 36 foot LOD) and allowed it to function as a houseboat. The bow shape we came up with turned out to work well: the sides and the bottom have almost identical curvature all the way to a point directly at the bow, where all 3 join together into a tiny flat spot. The hull, being flat-bottomed and therefore very tender, is always heeling a bit, and presents a V to the water with gradually decreasing deadrise toward the bow that helps it bounce up and over the waves. I hope that this hull shape will also prove to be "surprisingly good."

 

[NolensVolens]

Hull shape

Here's an old screenshot from the 3D model (details have changed, but not the basic hull shape). Yes, it's a wide tub with plenty of living space inside. And yes, it sails well to windward and short-tacks rather well.

 

[Angélique]

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Halong Bay teaser

Sailing Houseboat Design

Garvey Houseboat ---> Christopher Cunningham's Garvey Houseboat

Dave Zeiger ---> Trilo Boats

SLACKTIDE - Sailing into the Lee​

The Sea People

---> Slacktide ^PDF​

Build a Houseboat ---> Building a Triloboat

 

[NolensVolens]

Ah, good old Triloboats! Dave Zeiger and I spent quite a while hashing out QUIDNON's hull shape. He is the one who gave me the courage to make the transom much wider than I would have. He said that the curves between the bottom and the sides have to match exactly at the bow, or the hull won't track, but the further aft the less this matters. So I made the aft section as wide as reasonable, and the result was that there are two aft cabins with queen-size beds in each.

 

[Squidly-Diddly]

Is that a possibility? I believe that the answer is a definite maybe.

I am an engineer, and I have lived aboard with my family for over a decade, in a variety of circumstances and climatic conditions. I am also the instigator of a project to design and build comfortable, roomy houseboats that are also competent sailboats. The entire design process is detailed at http://quidnon.blogspot.com.

Our approach (there is an entire engineering team behind it) has been to combine the best of high-tech and the best of low-tech. The internal structure of the boat is plywood, intricately milled out using a numerically controlled robotic mill, then joined together by hand using mortise and tenon joinery and fiberglassed over on the outside. The design has been modeled in 3D software, tested out using hydrostatic and hydrodynamic analysis software and also using a 1:12 scale model. Everything works as designed.
After that we will be able to accept any number of orders for rapid assembly kits, to be built anywhere in the world.


may be missing a critical angle or two because of the "cool-aid factor," and I welcome any and all constructive criticism.

I'd include a place and way to add an engine, especially if you plan on selling to others. Just use the space for storage or water tank otherwise, but don't make others do major heroic surgery (butchery) to add an engine AND BOW THRUSTERS...maybe even bow AND stern thrusters.

I'm guessing most of your customers will be houseboat types who mostly want a cool looking houseboat, and many wont know the 1st thing about sailing and will be happy to putt around with a motor.

They will also want good electrical and hot water when away from a deluxe marina berth.

Many will want it set up for 1,2 or 3 people, but with more office or shop space instead of bunks.

"room for a pony"? How about a wheelchair friendly version?

The wide bow would let you give it some traditional Junk adornment to complement the junk-rig.http://donhubbardseaeagle.com/wp-content/uploads/2013/05/Hai-Jung-Bow-on-the-ways-001-2-640x490.jpg


I've always wanted to design a boat where leeboards could also serve as gang planks, or planks to water's surface, or just extra seating space out over the water.

 

[NolensVolens]

Hi Squidly,

The engine is a 40hp outboard sliding up and down on a track in an inboard/outboard well just aft of the cockpit. There is a 50 gallon gas tank. Our simulations show that it motors at 7 knots with the engine at half-throttle. This is be a good canal boat, because the masts are tabernacle-stepped and are designed to be raised and lowered by a single-hander.

The design for the heat and hot water system is not quite finished, but it will feature a very flexible firebox and run on either electricity, propane or solid fuel. The fact that the shower stall in the head is huge and labeled "sauna" is not a joke. A steam room and sauna aboard are very good to have when overwintering aboard in the snowy north.

 

[brian eiland]

The engine is a 40hp outboard sliding up and down on a track in an inboard/outboard well just aft of the cockpit. There is a 50 gallon gas tank. Our simulations show that it motors at 7 knots with the engine at half-throttle. This is be a good canal boat, because the masts are tabernacle-stepped and are designed to be raised and lowered by a single-hander.

I think you will find that performance under power to be a bit optimistic considering that most outboards are not designed (propped & geared) to be real low range pushers.

The design for the heat and hot water system is not quite finished, but it will feature a very flexible firebox and run on either electricity, propane or solid fuel. The fact that the shower stall in the head is huge and labeled "sauna" is not a joke. A steam room and sauna aboard are very good to have when overwintering aboard in the snowy north.

Surprised there was no consideration for solar hot water? A black bag on the roof will create quite a bit of hot water, and it could gravity feed?

 

[NolensVolens]

The prop has to have the right pitch, and then everything works nicely. I had a 9.9hp on a 32-foot sailboat, and once I relocated it to from a transom bracket (bad idea) to an inboard well (good idea) it pushed the boat at 6kt on flat water and even motored upwind through big waves. So, outboards do work for this purpose.

More importantly, an inboard is simply not an option. Who would want to spend lots of money on an engine for a boat that hardly ever moves (because it's a houseboat)? And who would want to put up with the stink of diesel in their house? The downsides of inboard engines are endless.

An outboard may be less efficient, but then in this case better is the enemy of good enough.

 

[brian eiland]

Wasn't suggesting an inboard,...just making the observation that the 7 kts at half engine speed for that size and shape vessel was optimistic

 

[NolensVolens]

Here is the output from Orca 3D software we used. The 10t case is closest to normal ballast and loading.

 

[Angélique]

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The prop has to have the right pitch, and then everything works nicely. . . . . . . . . .

That's is only for ¹/₇ right as it only mentions 1 out of the 7 points you need to take care of to make everything work nicely for a particular boat:

1. - The chosen engine needs to produce the right amount of power.
2. - The chosen engine needs to produce the right amount of torque.
3. - The chosen transmision needs to have the right gear ratio for the choosen boat + engine + prop combination.*
4. - The chosen prop needs to have the right diameter.
5. - The chosen prop needs to have the right pitch.
6. - The chosen prop needs to have the right number of blades.
7. - The chosen prop needs to have the correct rotation direction in relation to the engine.
8. - Nothing is right if it ain't all together right. - So each point has to be right in relation to all other points.​

* For this boat a High Thrust outboard version would be the best choice I think.

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A High Thrust outboard version vs. a Standard outboard version has:

- In general¹ exact the same engine with exact the same specs, so the engine has exact the same power and torque output at exactly the same revs at the crankshaft.
- A higher gear ratio, this means lower revs and a higher torque available at the prop shaft.²
- Often the ability to house a larger prop diameter.³
- Often a more durable transmission.⁴
- Often a more durable leg.⁴
- Often a bit more weight.⁵
- With the right prop more thrust at low boat speeds⁶ compared to the Standard outboard version with also the right prop.

¹ Meaning: for most brands with High Thrust versions of outboards in their program.

² More torque delivery at the prop shaft means a higher force load on all components in the transmission and leg, especially on the bevel gears in the end.
- Therefore manufacturers often choose to use the next size up leg for High Thrust versions.

³ If the manufacturer has chosen to use the next size up leg for the High Thrust version then there's room for the next size up prop diameter.
- If the manufacturer choose to use the standard leg with only a different gearing for the High Thrust version then there's only room for the standard prop diameter, and then often a 4 blade prop instead of 3 blade is used for the High Thrust version, as often just more pitch on the small diameter 3 blade prop would be less effective for this application.

⁴ If the manufacturer has chosen to use the next size up leg for the High Thrust version then the force on all components in the transmission and leg will be lower than on its original design application. Hence less wear and thus more durability.
- If the manufacturer choose to use the standard leg with only a different gearing for the High Thrust version then the force on all components in the transmission and leg will be higher than on its original design application. Hence more wear and thus less durability. Plus the higher force increases the chance that some components will break even before they're worn.

⁵ If the manufacturer has chosen to use the next size up leg for the High Thrust version then this will add some weight.
- If the manufacturer choose to use the standard leg with only a different gearing for the High Thrust version then the weight will be almost the same as with the Standard outboard version.

⁶ With a low speed of the boat the prop grips better on the water when it has a low speed itself. To realize this the prop needs to produce more water displacement per rev. And to do so the prop needs lower revs and a higher torque at the prop shaft.<sup>7

7</sup> Note: the power at the prop shaft remains the same as with the Standard outboard version. This is only about the High Thrust version's more effective way to transfer the power to the water at low boat speeds.

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How to know if a High Thrust outboard has the next size up leg or the standard leg with only a different gearing:

First indication from the specs is weight:
- If the High Thrust version has more weight than the Standard version then this is an indication for the next size up leg.
- If the High Thrust version has almost the same weight as the Standard version then this is an indication for a standard size leg with only a different gearing.

Indication from the ability to house a larger prop diameter:
- If the High Thrust version has the ability to house a larger prop diameter than the Standard version then this is an indication for the next size up leg.
- If the High Thrust version only is able to house the same prop diameter as the Standard version then this is an indication for a standard size leg with only a different gearing.

Indication from the availability of props with a larger prop diameter as for the Standard version:
- If there are for the High Thrust version props available with a larger diameter than what fits in the Standard outboard version then this is an indication for the next size up leg.
- If there are for the High Thrust version only props available with the same diameter as for the Standard outboard version then this is an indication for a standard size leg with only a different gearing.

Visual indication from pictures and/or videos and/or seeing it IRL in the flesh:
- If the High Thrust outboard's leg looks and measures a little beefed up compared to the Standard version's leg, and/or there are other differences, then these are indications for the next size up leg.
- If the High Thrust outboard's leg looks and measures exactly the same as the Standard version's leg then this is an indication for a standard size leg with only a different gearing.

And just ask:
- Ask the dealer and/or the importer and/or the manufacturer etc. etc.. - And seek confirmation for the info they give . . :idea:

Good luck !