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.

Saturday, February 29, 2020

Custom Hardware

Three years ago I bravely published a post titled “The Final Sheeting Arrangement.” I was filled with optimism at the time. After much experimentation I had discovered a simple way to keep Quidnon’s Junk sails sheeted perfectly flat. I had tested it out on a 1:12 scale model and verified that it worked very well indeed. But soon after I published it my friend and very experienced Junk rig operator Dave Zeiger blew my boat straight out of the water by pointing out a major problem with my design: it would not keep the sails anywhere near flat once they have been reefed. I accepted his critique with equanimity and, since I had no solution to offer, kept quiet about it for three years, during which, luckily, not a single person endeavored to build a single Quidnon, and so this unsolved problem hasn’t hurt anyone.

But now I believe I have finally found a solution. With this problem solved, the Quidnon project can finally move past the head-scratching phase and on to the next phase, which will involve grinding out a large number of mechanical drawings, assembly diagrams and other documentation without which no boat can ever get built. Here, then, is my plan, which I will call “The Final-Final Sheeting Arrangement.”

The previous, “final” sheeting arrangement involved attaching the sheet to a padeye on the deck arch near the centerline of the boat, sending it through a block on the boom, down through a block some distance out on the deck arch, up to the first batten, down to another block a bit further out, up to the second batten, and so on. The blocks on the deck arch are mounted on a T-track, allowing their positions to be fine-tuned. Likewise, the blocks hanging from the boom and the battens can be repositioned closer or further away from the leach of the sail for optimum performance on all points of sail. Here is what that looked liked on the scale model, in quite a stiff breeze.

The reason this arrangement works so well is that each block on the sail receives exactly 1/5 of the overall tension on the sheet.

However, this only works on the full sail, all 50 sq.ft (4.6 m2) of it. But if it’s reefed (lowered part way, that is) to compensate for stiffer breezes, more force is concentrated at the bottom, warping the sail and ruining its efficiency. This effect is only slight for the first reef, and gets progressively worse, so that by the time the sail is on its third reef it wouldn’t work as a sail at all because all of the wind would simply be spilled out of it.

As I mentioned, I have now found a way to solve this problem, using a custom piece of hardware.

But before I explain my solution, I’d like to mention another custom piece of hardware, which was already part of the plan: the take-up spool. It solves a number of problems. First, it eliminates cockpit clutter: all loose line magically disappears. Second, it makes a simple winch into a self-tailing one: just take a few turns on the capstan and crank; the take-up reel maintains the tension for you. Third, by automatically taking up slack, it reduces the chance that a loose sheet will get caught on the roach of the sail, requiring a trip out of the cockpit to free it.

Quidnon’s cockpit layout provides an ideal place to hide all of this loose line: directly under the cockpit floor, at the top of the anchor chain locker, where there is plenty of room. The details of the take-up reel are not particularly interesting. It is a sealed metal box bolted to a bulkhead that has a shaft sticking out of it. Inside it is the sort of mechanism found in every wind-up toy or mechanical watch: a constant-force spring and a gear reduction mechanism. The shaft goes through a shaft seal to keep water out and grease in, and the entire mechanism is designed to never require any maintenance. A spool is splined to the shaft and a fairlead some distance away from the spool makes the turns wrap onto the spool tidily.

There will be a total of 12 take-up spools hiding under the cockpit floor, 6 for each sail:
• Halyard (to raise the sail)
• Reefing line (to pull the battens down when reefed)
• Port and starboard sheets – tension end
• Port and starboard sheets – slack end

Why do the sheets have a slack end, and why does it need a take-up reel? That’s what I will explain next. The key element in my cunning plan is a custom piece of hardware that is probably something I invented, because in all of my years of perusing sailing gear catalogs I have never come across such a thing. It is a remote-operated locking sheet block.

In its unlocked state it is just like any sheet block: the sheet goes in one side, around a pulley and out the other side. The pulley is on a bearing and spins freely to minimize friction. In its locked state, the sheet is firmly clamped between the pulley and a shoe. The shoe has a dog that matches a recess in a pulley, preventing it from turning. The shoe has a channel with diagonal serrations similar those on a jam cleat which grab the sheet tighter when it tries to slip in one particular direction. That is, the locking action is unidirectional.

The block is switched between its free state and its locked state by means of a control line which goes through it. On the control line is mounted a very specifically shaped plug. It is prevented from slipping along the line by a ferrule which is crimped onto the line. The ends of the plug are tapered to reduce the amount of tension on the control line needed to move the plug into position by compressing a very strong spring whose job is to clamp the sheet in place. There is also a much weaker tension spring whose job is to keep the shoe away from the sheet when the block is in its free state.

The locking sheet blocks are mounted on the T-track on top of each side of each deck arch, observing correct orientation, so that the locking action is when the sheet is pulled to outboard. There are four signal lines which are sent through four cascades of five locking blocks each. A fairlead at each end of each cascade prevents the plug from escaping. Each of the four control lines is led to the cockpit, forming a loop.

When the sail is fully raised, the inboard-most block is locked. When the sail is at first reef, the next block to outboard is locked; and so on. As each reef is taken in, the sheet purchase is reduced from x10 to x8, x6 and so on down to x2, at which point only the topmost panel is showing (to use the mainsail as a riding sail when at anchor, or to use on the foresail for scudding off with a drogue in extremely heavy weather). Note that there are two control line adjustments to be made: one for the port sheet and one for the starboard sheet.

The steps to take in or to let out a reef (or two or three or four) are as follows:

• Open the sheet clutch to depower the sail
• Open the reefing line clutch
• Open the halyard clutch, pay out/haul in the required amount of halyard, close the halyard clutch
• Haul in the reefing line, close the reefing line clutch
• Move the starboard control line the required number of clicks; repeat for the port line
• Haul in the sheet to power up the sail, close the sheet clutch

Importantly, all sail evolutions can now be done without leaving the cockpit. This has been a requirement all along. Quidnon is designed for easy single-handed operation.

There are a couple more changes to the design which are small but important. Previously, the two pilot berths, which are on both sides of the salon and on top of the water/ballast tanks, were accessed by climbing up on the settees and going through a door in the two bulkheads that make up the keelboard trunk.

This plan raised several objections. First, this method of ingress seemed rather undignified, required rather excellent range of movement in the hips and wasn’t at all convenient if attempted in the course of a dinner party, during which the settees in the salon would be occupied. Second, cutting a door through the keelboard trunk resulted in some significant structural complications, Third, it wasn’t clear how to provide good sound insulation, which would be important if pilot berth occupants wished to sleep while a dinner party was in progress.

For all of these reasons, the pilot berths will now open to the stateroom, which is in the bow, with a small two-step ladder leading into each and with the opening fitted with a sliding door. This makes the layout of the pilot berths much more convenient, with some free space at the entrance, then the berth, and some cabinetry at the head.

Finally, the decision to eliminate one of the keelboards has been reversed. The reason is that a single keelboard positioned off-center would give Quidnon a different turning radius depending on which direction it was turning. If the keelboard were mounted to starboard, the boat would turn tighter to port; and vice versa. This seems like a very bad feature. With such a wide hull, it is important to be able to reliably execute the tightest possible turns when maneuvering in and out of marinas. Another advantage of having two keelboards is that they can be made smaller, easier to manage and less likely to damage the hull if they hit something underwater.

As I already mentioned, this completes the head-scratching phase of the project. The next phase will involve producing detailed construction plans and cost estimates.


  1. Sounds great! For your next book, assuming you're looking to write one, might I suggest one on the ins & outs of sailing this vessel? Is there any plan to make a smaller Quidnon?

    1. I wonder if a "dinghy-non" would make a good test platform for sail design. A lot of dinghies or "cat boats" are small, but will have a main and a jib, and a boat like that set up with a Quidnon-type sail system could give you some valuable experience.

      I'd like to mention that keeping sails flat generally isn't a goal of modern sail designs. Just keeping them to a shape that viewed from the top, looks like the top surface of an airplane wing. In a sailing class I learned that if you have to make use of the smallest whiff of wind, you lean the boat purposefully to get the sail to "belly" out a bit, and it works far better than sitting straight up with a flat sail.

    2. I'd like to build a dinghy to test out the kick-up appendages and the sailing rig, mostly.

      The usual modern sails are stitched or laminated out of nonstretch materials such as Dacron and carbon fibre to have a certain aerodynamic shape. In racing, there are also certain adjustments, such as the Cunningham, which can reduce the belly of the sail in stronger winds. Quidnon's rig is different. It is best viewed as a stack of Lateen sails. The panels between the boom, the battens and the gaff all form conic sections, which make perfectly good airfoils and create plenty of lift. The equivalent of belly can be adjusted by tightening or loosening the leach of the sail. In the case of Quidnon, this can be fine-tuned using the reefing line and the halyard.

      What I meant by "flat" is not that, though, but the avoidance of twist, which simply spills the wind out the top of the sail, generating no lift. That's the problem I believe I have solved.

    3. Aha yes, an advantage of a lateen sail as opposed to a marconi is you don't get twist, due to the top boom. An especially visually pretty rig, the schooner rig, seems me to be an attempt to get the best of both worlds, large sails that are a hybrid lateen/marconi.

      You could probably buy any old tub of a catboat to test sail rigs etc with .... cheap.

  2. Woohoo, Quidnon! I am too old and landlubberish myself but I love the idea. Beef on borscht? Never thought of that. I make the Kootenay Doukhobor version which is strictly vegetarian. It is a staple in my freezer. I will miss that freezer if or rather when collapse happens.

    I have expressed the impolite opinion that an epidemic that mostly kills old people might be a welcome development, and if that includes yours truly, so be it. I would love another decade but at 76 will not feel cheated if this is it. What I fear is not death but discomfort.
    After a lifetime of sort of prepping on an acreage I plan to move into the village this summer. My main selfish worry right now is: will the interruption in supply chains interfere with the delivery of the modular home I have ordered?

    Meanwhile the political landscape in the West has gone bonkers with extreme political correctness. If you want to have a laugh, google Yaniv. It does look like the gods wish to destroy us. Merry prepping everyone.

  3. Your locking sheet block is ingenious, and could solve a lot of other problems than just the one you created it to solve. I suspect that the idea, if not the exact method, will outlive us all. On that note, I've noticed that with your design requirement that Quidnon be sail-able entirely from the cockpit, that it's also going to be ideal for autonomous/computer controlled sailing. Replace your locking sheet block control line with a pneumatic break pin, the take up spools with electric winches, and your sheet clutches with pneumatic cleats/clutches; and it becomes possible (not trivial) to program a Raspberry Pi as an autopilot that can sail Quidnon in changing winds for hours at a time, or sheet back the sails and wake the "watch". Combined with your controllable tiller mounted autopilot, it might even be able to sail a pre-programmed path "zero-handed" in some predictable waters.

  4. Hi Dmitry, I have been sailing a Paradox with a junk rig from a few years now. I did all sorts of sheeting experiments. I was not willing to invest in expensive blocks and found that one continuous sheet had too much friction. Then I tried a separate sheet for each batten. That gave a lot of control but a bit too cumbersome. So I settled on tow sheets, one for the boom and first batten up and then another for the next tow battens. I can then control twist by tightening one or the other. This has worked very well, not perfect but very good. Cheers, Roselt

  5. The dual keel boards make sense. And I was wondering.., doesn't' the reefing problem described above affect all junk rigs? How does Dave Zeiger deal with the "uneven" tension on the sail.

    Just looking at it (and I have no experience with sail design.., what if you move the attachment point of the upper block farther forward on each batten. Wouldn't that increase the tension on that portion of the sheet and help balance the increased force when reefed?

    I'm asking "cause" I want to learn something. I hope I'm not coming off as critical..., thanks

  6. Hi Dmitry,
    I'm a big fan of this Quidnon project. I probably count for no less than 50 to 75 of the hits on this page over the years. I talk about it all the time to my wife. Trying to get her buy in is a hard sell, but this is my favourite daydream, so I may have to leave her to live my golden years as a sailor or marina rat. I've never owned a boat before and barely know how to sail, but this sounds great to me.

    My questions and comments are coming from the nautical novice fringe, but are informed by my experience as a carpenter and architect. BTW I'm pretty good with CAD software, maybe I could help the project along? You don't need to post this or even reply. I just wanted to get these ideas into your mental hopper in case they'd hadn't been considered, which isn't very likely.

    I just love reading and rereading all the Quidon design development posts and have great faith in your dream Dmitry. I'm ready to sell my big house and downsize on almost any provocation, when that happens the first $50K is being set aside for my Quidnon HouseBoat.

    My questions:

    1. The chimneys for the stoves, where are they mounted on the exterior? Do they penetrate the side wall or the deck? Will they have a protective heat shroud like the exhaust pipe on an 18 wheeler? What is to stop water from coming down the pipe during a storm at sea? Is there an escape vent for that water?

    2. The railings around the deck, what sort of hardware detail or railing system is planned? For maximum flexibility you'd want a sectional system where the wire ropes between the posts are easily removed for loading of gear/ freight to the deck, right? Are the posts surface mounted or is there a metal sleeve drilled into the deck that receives the post and fixes it with a twist lock action? If water gets into the sleeve is there a drain vent path for water to escape? It would be joint/ penetration prone to damage and an infiltration point to unprotected plywood. It could be a weak spot in the design if not well considered.

    3. If the boat were to take on significant water for a short time the walls and built in furniture should be detailed to allow for ventilation without disassembly, and treated to prevent the plywood from swelling up like oatmeal at the first hint of water. Are the interior deck/ floor boards removable in a systematic fashion with just a screw gun?

    4. Thinking about the floor, I'm wondering if long term storage items, for emergencies, could be stored under the floor while still maintaining air flow for heating in the the underfloor plenum? Things like extra keel boards and rudder, extra rope, chain & anchor, another propeller, that don't care if they get flooded.
    5. How does the companion way door seal out stormwater? Or how does it manage the water that will inevitably spill down the stair? Will there be a recess in the floor there, or gaps in the floor boards with a drip collection pan underneath and a pump?

    6. I'm 6'-3" and would like to have 6'-5" clear in most spaces. Is there an option to order 12' long plywood for the side walls and suffer a bit of waste to gain an extra foot of height for headroom, ceiling cavity, and increased underfloor storage/ plenum? It shouldn't be too hard to stretch the height in the software, but would we be able to make good use of the cut offs for interior furniture or other parts?

    I think that's it for me and my bright ideas. This is what you get when your dream catches fire with other dreamers. Love your work Dmitry, and I hope you and your family are able to ride out this pandemic in splendid isolation in a lovely little marina or lagoon somewhere.
    Sincerely, Jake


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