The purpose of this project is to design and mass-produce kits for a floating tiny house that can sail. It combines high-tech modeling and fabrication and low-tech assembly that can be carried out DIY-style on a riverbank or a beach. This boat is a four-bedroom with a kitchen, a bathroom/sauna, a dining room and a living room. The deck is big enough to throw dance parties. It can be used as a river boat, a canal boat or even a beach house. It's rugged and stable enough to take out on the ocean. Kits will start at around $50k (USD). The design has been tested in simulation and prototype; full-scale production will begin next year.

Monday, September 17, 2018

Quidnon 2.0

This boat design project started out by setting out some very ambitious requirements:

• A houseboat that makes a comfortable tiny house big enough for a family
• A competent, seaworthy sailboat, with masts that can be put up and taken down by a single-hander with the boat in the water
• A motor boat with an outboard motor for an engine that can be installed and removed easily, positioned in an engine well to prevent cavitation, collision damage and other problems with transom-mounted outboards
• Never needs a haulout: copper-surfaced bottom resists marine growth; settles upright and can be dried out and scrubbed at low tide
• Can be beached and relaunched by rolling over logs using anchor winch
• Can be assembled quickly from a kit on a beach or a riverbank by moderately skilled people
• Uses materials that are readily available almost everywhere: plywood, softwood lumber, bolts and screws, fiberglass and epoxy, galvanized mild steel, polypropylene three-strand rope
• Designed for all climates and seasons, from frigid to torrid
• Can be constructed and maintained at minimal expense

Over the past four years since I launched this project several people have made significant contributions to it: modeling, prototyping, contributing ideas and criticisms, helping spread word of it. Taking our sweet time with it has been very helpful in preventing us from building the wrong boat.

But what would be the right boat? How will we know when we have the right design? Well, one very basic indicator would be an empty list of unsolved problems—problems not in the sense of having every last detail worked out on paper (that’s largely a matter of grinding out mechanical drawings) but in the sense of not being sure what to do. And until very recently the list of unsolved problems contained the following big ones:

• No good, useful interior layout for the U-berth (the front section, normally called the V-berth, but Quidnon’s bow is semicircular, making a U). We went round and round on it, but the space was just too awkward.

• No reasonable procedure for installing and removing the keelboards or the rudder with the boat in the water.

• Complex joinery that required pieces of lumber to be milled to a variety of bevels, then steam-bent, adding expense and making the kit difficult to pack flat.

• The angled twin rudders, and the rudder linkage that went with them, gradually grew in complexity to include Ackermann geometry, a system of levers for amplifying the tiller angle and various other details, making it quite baroque.

• There was no straightforward way to construct the chain runners so that they would be neither too fragile nor too heavy and expensive.

• Rolling the hull over logs is made difficult because the bottom is curved throughout, causing the logs to squirm out from under it.

There were a couple of other, relatively minor problems as well. I will mention them later on.

And then something happened that broke this entire logjam: I consulted with a marine architect who raised certain criticisms of the design. They made perfect sense, and forced a rethink that made all of these problems go away.

• The hull doesn’t heel enough to make chine runners effective. They only work well at a considerable angle of heel, and with a hull as wide as Quidnon’s the heeling angle is insufficient to make them scoop up enough water to stop the sideways slide. Solution: get rid of them altogether.

• The hull doesn’t heel enough to make it necessary, or at all useful, to angle out the keelboards or the rudder blades. Solution: make them all vertical. It then begins to make sense to make the keelboard trunks into full double longitudinal bulkheads with a slot between them, leaving them open both at the bottom and at the deck. Keelboards can then be loaded into the trunks from the deck. An added bonus is that this creates a double baffle between the salon and each of the pilot berths, providing sound insulation. Another added bonus is that there are now two large deck drains, to quickly get rid of any seas that climb aboard.

• There is no reason to introduce the cost and complexity of twin rudders. Solution: have just one rudder, mount the rudder post on gudgeons and pintles along the aft wall of the engine well with the rudder blade nestled in a recess under the transom (which is already included in the design, to let through the stream from the prop). Instead of the baroque linkage, we can then have a simple tiller connected to the top of it. When at anchor or at the dock, the rudder can be pulled out to reduce noise and wear.

• There is no reason to curve the sides or to angle them out. It doesn’t improve sailing or motoring performance at all, but it complicates the joinery. It is better to simplify the construction, minimize the cost and maximize useful interior space by making them flat and vertical. This gets rid of most of the complex joinery and the need to steam-bend pieces.

• If the sides are flat, there is no reason to curve the bottom throughout. It has to have a curve at the bow, to help it move smoothly over the water, and it has to curve up gently toward the transom, to avoid dragging water behind it and to keep its center of buoyancy where the ballast is. Giving it a generous flat section in the middle makes it possible to roll it over logs while further simplifying the joinery.

• The fancy bow, where the sides sweep together to meet the bottom at a flat point, will not help performance. On the other hand, it is what makes the space in the bow so difficult to make any reasonable use of. The solution is to make a simple barge hull: at the bow, the bottom curves up to the deck with constant curvature while the sides are perfectly flat. This makes it possible to use the space as a comfortable livingroom of 114 sq. ft. (10 m^2).

What will the result look like? Well, my new motto is “Start your morning with a 3D model and get it over with.” Here is the 3D model, constructed out of highest-quality cardboard and scotch tape.



Yes, Quidnon looks like a barge. That’s because it is a barge. Efforts to make it look like something else—by slanting and curving the sides and giving it a fancy bow added complexity and expense while taking away useful internal space. Also, these little nods in the general direction of yacht design did nothing to appease people who like fancy yachts with curvy lines—there is no pleasing some people!

These major simplifications make it possible to produce the detailed plans over the course of the next few months. This is important, because the money with which to build the first Quidnon should be in hand over the course of the next year, allowing us to move on to the next phase: building and testing it.

24 comments:

  1. Yeah! Go Quidnon! I am too addicted to gardening, not to mention oldish, to want one for myself. But I just love the idea of an intrepid tribe of free people out there in the world.

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  2. Wow Dmitry, these are significant changes. I must say, I will miss the aesthetics of some of those gentle curves. It’s all for the best though it seems. Your fresh edit seems well thought out and I will get used to the new shape. Looks more like a Triloboat on the exterior now which isn't a bad thing. I’m wondering how these changes will affect the 3d software modeling with respect to self righting, stability, hull speed and such. On another note, the new “large” living room is a fantastic upgrade for a family.

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    1. Yes, the Triloboat concept does have certain merits. The perfectly flat bottom makes the boat easier to roll over logs and makes for easier joinery. And there is a lot less scrap, because everything is designed around whole 4x8' plywood sheets. These changes make 3D modeling pretty much unnecessary; everything can be worked out in plan, elevation and cross-section. And, yes, the living room is a major benefit.

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  3. I think you would please David Zeiger with the 2.0 re-design. It looks much like a Triloboat, now. The hull form has centuries of known behavior.

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    1. It looks like a Triloboat, but it isn't. It's ballasted (8 tonnes of water ballast) and is a great deal more stable.

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    2. So all the ballast is water now? Or is there still some steel and concrete?

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    3. Yes, with a few tweaks to the shape of the bottom and some other minor adjustments the solid ballast has been eliminated. Now it's just 8 tonnes of water in 2 tanks, and another headache gone.

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  4. Great changes totally appropriate to the simplistic hull. Dave Z. has a post on putting a roll-up bow on a triloboat. Dave also posted that slight overall rocker might add to performance but he didn't know if it was worth the trouble.

    A swedish guy posted a bunch of hull model test videos of various box hull types (in proa form): a Bolger AS type, a outright triloboat barge, with chine runners, without, and finally a trilo hull with a slightly rockered run. Unlike Quidnon these were long and lean but instructive as to performance differences. The rockered one was a lot faster and tracked really nicely. Vid link here: https://www.youtube.com/watch?v=OyyaOJWmZHU

    Always thought Triloboats could be made ocean worthy with a few tweaks. All your Quidnon mods just reinforce that speculation. Love the single rudder and tiller..... right on.

    From owning a rockered AS hull with copper plating I can attest that once dried out you can get to most of the bottom with a long handled paint scraper, which was our main method of raking off the slight beard we's get over time. I'm still not a fan of losing the bottom rocker: much stronger than that big flat. We all blaze our own paths though and in the end it's trivial. I will speculate that if you offer plans you'll sell a BUNCH.

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    1. In this case the flat bottom section is only 13' long out of 33-34' WLL, with rocker further aft. I hope that this is a good compromise. Dave Z's point is that rocker doesn't make the bottom all that much more rugged because it concentrates the stresses along a line instead of distributing them over an area. In the case of Quidnon, the flat section will be heavily reinforced: the chines, the keelboard trunks and then 2 more 4x4s running along the bottom which form part of the mast frame. Yes, I do want to offer plans as well as kits.

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  5. The design reminds me of a flat bottom or "platbodem" as we call them in Holland. They were barges which grew larger and stronger and sailed the big lakes and the North Sea to Germany, Denmark and England. Their flat bottom and single mast with just two large sails made them fast and reliable and much in use during the 19th and early 20th century. In the 70s they became popular as houseboats.

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    1. It's a barge, so it's reminiscent of every single barge ever. But the concept is different from others, in that it is first of all a houseboat—an affordable but comfortable tiny house for a family—and secondly has a long list of requirements listed above which make it cheap to own, operate and maintain.

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  6. At the bow, could the last remaining curve of the hull be replaced by a sloping plane? Could make it simpler, but would it take away from performance?

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    1. Yes, some scows do have a "forward transom" but I think a rounded bow profile has some advantages.

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  7. How much does this 'U' open space (living room) add bow buoyancy to reduce nose-diving / burying the bow / reduce greenwater on deck?

    How close is the chain locker to the Center-Of-Motion / Center-Of-Bouyancy?

    How much does the bowsprit and anchoring system compensate for excess bow buoyancy, the tendency to drag the transom? The tendency for following seas to side-slide our ride into a broach?

    How far can we move the mast(s) to maintain driving pointability?

    Do we have an estimated displacement? How much anchor to compensate for windage on the slab-sides? Are we going with a traditional 1:3 / 1:6 scope with most of a hundred meters of chain?

    Each change induces reciprocal changes. Newton's Third Law.

    I appreciate the simplified lines. Sooner or later, Nature gets a vote.

    PS:
    How much cash do we need for a scale to water-tank verify the V2?

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    1. The center of buoyancy is right at the center, as it should be. The chain locker is under the cockpit, not in the bow. It is aft of the center of buoyancy. There is no bowsprit. The transom is above the waterline, so following and quartering seas will drive the hull forward rather than sideways. We've already tank-tested and sailed a model and there were no surprises.

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  8. it appears that the design is now an enlarged version of the jon boat; a flat bottom boat common among hunters and fishers in the u.s. they are designed to ride on the chop rather than drive through it as a v hull would. as a result, they can be less comfortable in rough water and can be less stable. how would you compare the ride and stability of this design with that of the original concept?

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    1. A jon boat is not a houseboat, it is a dinghy, so the comparison is not accurate. As far as hull shape, Quidnon was always a barge, and its underwater surface has changed in ways that will not significantly affect performance but will greatly simplify construction, lowering the price of the kit and accelerating its construction schedule.

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  9. Congratulations on the new edition! So exciting to have this breakthrough. I'm not a boaty person but I continue to watch and support this project because Quindon might be perfect for me. It inspires me to become boaty enough when the time comes. Great stuff.

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    1. I've known some decidedly non-boaty people who lived happily aboard boats. The main inspiration behind the project is the fact that if you want to live right next to where the high-paying jobs are the rents are just too damn high. If you want to save up and retire early, living aboard a boat is an ultimate lifehack. Quidnon is designed for comfortable dockside living. There's no need to invest in an engine or masts and sails unless you are planning to go somewhere, but if you ever do they are easy to add.

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  10. Well, that pretty much eliminates any and all compromises. Except one. Maybe it't time to go back and lean the windows of the dodger foreward.

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    1. I think it makes sense to keep the dodger rectilinear. Leaning the windshield forward would cause complications with the companionway hatch. On the other hand, the deck arches are going to be rectilinear too (because T-track for the sheet blocks doesn't bend).

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  11. Can this lovely "Barge" sail upwind a little?

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  12. What will become of the old designs/ IP from the v1?

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  13. The 1.0 plans were not complete and will never be released, and there is no distinction between 1.0 and 2.0 as far as "intellecual property" (if that term even applies).

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