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 3-bedroom with a kitchen, a sauna and a dining 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. Oh, and 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.

Thursday, March 17, 2016

Deck Arches

QUIDNON has a large, flush deck, unencumbered by cabin tops, hand rails, vents and various other features that often makes sailboat decks far less useful. It can be used for lounging around in a chaise-longue or a hammock, for stacking bales of hay or cords of firewood, or for mounting various bits of equipment, such as plastic incinerators, digesters that produce gas for cooking or for running the engine, and biochar kilns. It can even be used to keep a few cages of chickens (for eggs and meat) and some small livestock (goats, for milk) tethered to the foremast. It is covered with aluminum diamond plate, for good traction, excellent wear resistance and to keep the boat cool by reflecting most of the sunlight.


The large expanse of QUIDNON's deck (measuring close to 550 square feet) is interrupted by two masts stepped in mast tabernacles, a large hatch in the center of the deck, and the dodger and cockpit aft. These elements are quite traditional; but there are also two more elements that are somewhat peculiar: there are two deck arches. They bear resemblance to boom gallows, but they are much more than that. In keeping with QUIDNON's overall design philosophy, they fulfill as many different functions as possible, to save space and to minimize costs.

The two deck arches are made up of three joined box sections—two feet and the arch itself—cold-molded out of plywood and fiberglassed on the outside. A thick plywood baffle runs along the centerline of the entire structure, to give it strength and to separate the airflows on the two sides. Along the front and the back of the arch there are openings, which can be closed and secured shut using internal sliders. On the bottom of each arch, in the center, is an eyelet for connecting a hoist. Where the arch joins the feet, there are diagonal reinforcements. At the tops of the arches are perforated aluminum angles (not shown) which can be used to attach an awning.

The arches serve the following functions:

1. Provide a point of attachment for a hoist. The front arch is used to hoist objects in and out of the cabin through the large mid-deck hatch. The aft arch is used to lift the engine out of the engine well.



2. Provide attachment points for the hammock or a swinging bench. This is an additional function of the two diagonal reinforcements in the inside corners.



3. Provide attachment points for an awning. The upper edges of the arches carry perforated aluminum angles.

4. Provide ventilation for the cabin. Front and rear sides of both arches have openings that let air either in or out, depending on wind direction. A baffle along the centerline of each arch keeps the two airflows separate until they reach the cabin, where they terminate in vents that direct the airflows in different directions, blowing air in and also sucking it out. They provide plenty of ventilation at anchor and on all points of sail except a beam reach. When sailing a beam reach in relatively calm conditions, the mid-deck hatch can be cracked on one side to cool the cabin.

5. Provide extra buoyancy up top in case of a capsize. The air openings on the front and back of each arch can be closed and secured using sliders, to create an airtight structure above deck level. Each arch encapsulates around 15 cubic feet of air. Both arches add around 2 tons of positive buoyancy 4 feet above deck level. This is very useful in case of a capsize, and enough to prevent QUIDNON, with its large, flat deck, from wallowing upside-down for any length of time.

6. Provide attachment points for sheet blocks (on top of each arch). A known problem with junk sails is that with most sheeting arrangements the sail tends to twist, losing efficiency, especially to windward. What typically happens is shown on the left; the optimal arrangement is what's shown on the right.



But in many cases this doesn't matter. For those who want to use QUIDNON primarily as a houseboat and prefer to keep things simple, a very simple sheeting arrangement will work fine, with a set of blocks mounted on top of each deck arch, while those who will want to make long passages to windward and would like an extra bit of speed can add a euphroe. I am also playing around with ideas for the ultimate solution: an automatic sheet traveler, but haven't tested it out yet. Here it is, shown schematically—not drawn to scale, and the final design will use tracks, sliders and blocks rather than rods and rings. But if you think hard enough, you should be able to puzzle out how it's supposed to work.


7. Provide places to mount navigation lights, red/green on the sides of the front arch, white aft light in the center, on the back of the rear arch.

8. Serve as boom gallows. When the sails are down, they can be made to rest on top of the arches.

9. Provide a support structure for the masts when they are down, for motoring down canals.

10. Provide an elevated place to sit or stand, to see a bit farther on the horizon and to be able to read the water better when sailing through shallows.

General progress update: There is now a full 3D model with most of the features drawn to scale, done in Sketchup. It has been moved to make a model in Delftship, which will be used for various calculations, and is in the process of being imported into SolidWorks, for creating a 1:12 scale model. There are plans to set up the model with radio control and sails, and to see how well QUIDNON sails.

23 comments:

  1. Your model will surprise you with how well it sails. I've built quite a few weird models that you wouldn't imagine sailing well at all yet they went quite well. I don't know how predictions are made with regard to the full scale versions of test models but I would imagine there are equations that naval architects apply to the results of model testing. Tank testing of hull shapes has been around a very long time. A suggestion - one I will apply to MY next model - is to make it bigger than an inch to a foot. Once it is out there on the lake it will look mighty small!

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    1. I hope you are right. Even if the performance of the model is not strictly representative of the performance of the full-scale hull, it will allow us to work out ballast, sheeting, etc. Also, we'll figure out the right size, angle and ballast for the centerboards and the rudder blades. All of that is hard to work out without a physical model.

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  2. I look forward to the sea trial report of the model. I agree with Alan; make the model bigger.

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  3. My New York apartment had 330 square feet.

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    1. My first house was 650 square feet. This is not a small boat.

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  4. Dmitri, using the arches as emergency floatation seems risky to me, with the high potential that the vents will leak or already be open on a capsize. Perhaps sealing up the inside of the upper mast section with Great Stuff foam after the internal power & antenna lines have been installed would work as well.

    Also, I'm curious how cargo heavy enough to require the winch over the cargo hold gets onto the boat deck. I'm sure you have a plan there too, I just haven't figured it out yet.

    Your mentioning of heavy gear on the deck made me think of this http://www.leafgenerator.com/ which would be a great fit for a small spark engine running at a level thrust for hours at a time, such as a boat motoring through doldrums or up a slow river.

    But how would storing so much mass on the deck, as opposed to in the hold, affect Quidnon's stability in a gale? Seems like that raising the center of gravity would increase capsize risk. I'm not shy of some risk, so long as I know how my actions might increase my risk.

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    1. I am not too concerned about the arches as emergency flotation, that's just an added bonus.

      The traditional way of getting cargo aboard is to use the boom as a crane.

      I doubt that anyone would be mad enough to take QUIDNON out on the open ocean with lots of heavy stuff on deck.

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    2. I thought that junk rigs didn't have a true boom.

      1) How much mass can the boom lift safely? Do you plan on over-building the boom for this purpose? Will a counter-weight on the other end of the boom be required?

      2) How much mass can I secure down to the deck before I'm too top heavy to venture out away from the coast?

      I guess I'm asking for safe use limits, but I'm sure you don't have those numbers this early.

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  5. Utilizing the arches as cabin ventilation is a good idea since they would provide a bit of chimney effect - but during times of dead air they would only likely work well as evacuation of stale (warm) air from the cabin without allowing much fresh (cool) air to enter since the ingress/egress vents are at the same level above the deck. Perhaps a few of the ports could be made operable to allow fresh (cooler) air to enter below as the warmer air is evacuated.

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    1. No, the arch vents should work fine as is. They are fancy wind scoops. So long as there is an apparent wind across the arches from front to back, any chimney effect would be negligible.

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    2. In a perfect calm the chimney effect would draw air out of the cabin through the arches and in through open hatches. Open ports don't sound good to me: they are expensive and unreliable.

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  6. Corner corbels need to go away (design vise).

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    1. They shouldn't be corbels, just pieces of pipe welded to L-brackets. Then they'll look entirely unobtrusive and traditional.

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  7. If you want to be able to swing items from below onto the deck you might consider having additional pad eyes for your hoist(s) plumb to the deck on each side of the hatch so that as the lift clears the combing you can take up on the outer tackle while slacking the one plumb to the hatch until the lift is over the deck. This would mimic the way cargo was handled with union purchase derricks for decades on traditional cargo ships.

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    1. Rob,

      I think you're right that you need a method to transfer the items onto the hoist over the hatch that leads below deck from the sides. Personally I'd be nervous about the setup you suggested being that I lack the skills of an ironworker and wouldn't likely be able to transfer suspended loads without incident indefinitely.

      Assuming that the loading process may need to be single-handed, or done by inexperienced people, and that there's wake from passing boats, possibly wave action, wind forces on suspended load, boat heeling, corrosion/fraying on the cables, etc. I think you'd eventually be facing a situation where the load got loose on you and then you've got a swinging load bashing anyone/thing in its path.

      A more idiot proof alternative might be having the deck hatches fold so that you can clear the coaming plus hatches in a straight lift and fold them flat to allow you to put the load back down on the hatch. Or a dolly/roller system which would let you then winch or push the load around on the deck in a controlled manner.

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  8. When I look at this layout and deck, I'm seeing the basic design of a light salvage barge. It might need to be slightly larger, 50 to 60 feet, and have a crane, but the basic layout wouldn't change that much. Perhaps I'm anticipating jmg's "Age of Salvage Industrialism" a little early...

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    1. It's a sailing scow. Barges are a bit different: vertical, flat sides, flat bottom instead of rockered, etc. Scow hulls win races; barges - not so much.

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  9. Dmitry,
    I like the boat design a lot. One thing I noticed, you frequently talk about fiberglass coating and epoxy. From a book by John Guzzwell (cold moulding boats) I understand that Dynel cloth with special resins is better to protect a wooden hull. Dynel flexes, fiberglass does not, so if the wood moves, cracks could open up. That problem seems solved with Dynel.
    Best wishes to you, family and that your plans may succeed.

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    1. Dynel works well for covering wooden hulls, made of lumber, because the sticks aren't dimensionally stable and tend to flex in various ways. With plywood hulls, the material is dimensionally stable, isometric, and fiberglass has been proven to work extremely well, with no cracks after over 30 years. There is no problem, and nothing to fix.

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  10. Slight quibble. Aluminum diamond plate or other silver material is reflective, but not radiative, this is why Airstream trailers get so much hotter than more conventional ones, which are white. A low cost white paint(after all, it is the deck, not the hull) purely for reflective/radiative purposes would improve that aspect.

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    1. The diamond plate is mostly for durability and abrasion resistance. Yes, aluminum conducts heat well and radiates it poorly, but here it is backed by fiberglass and an inch of plywood, which insulate the hull's internal space. Judging from a sailboat that has aluminum diamond plate on its deck, this works quite well. The glare is tolerable (white paint produces too much glare, which doesn't work) it's fine to walk on barefoot even when it's in full sunlight, and, most importantly, it's zero maintenance. But if somebody wants to paint it, who's to stop them?

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  11. I finally took the time to look at that "sheet traveler" diagram you put up here, and I must say that I think that it's brilliant, if I am understanding it correctly. Am I right in believing that the travelers are range bound so that when you tack, the top & bottom most sheet blocks switch places and the other two also just switch places? Where would it be mounted? On the arch, perhaps?

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    1. Yes, that's the idea. And the travelers will be mounted on top of the deck arches. I need to test out the concept on a prototype, which I now have all the mechanical parts for, just haven't put it together yet.

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