Thread: Quick Canoe Sailing Potential - No such thing as bad questions

I'll jump in on this one

There is nothing wrong with putting the sails at either end in that dead space. It works well. Look at MIK's Beth.

Now, how you pay for that is more rigging, more spars, more possible points of failure. There is no free lunch. You do gain things though. More versatile options for reefing and more adjustment possibilities in the sail plan to balance under differing conditions.

Generally, when divided into multiple sails, they are not equal area sails though. Mainly because the weight and other foils are not equally distributed. They have to balance each other. There are also other options for things like the foils. Many boats have multiples. There have been some variations in position, shape, and size on these as well. Throw in is the differences between high aspect ratio sails and low aspect ratio sails to really complicate matters.

In a theoretical sense, the foils under the boat and the sails are the same things and work in conjunction. That whole equal and opposite reaction thing. The only reason they are different sizes is because of the difference of viscosity and density of the medium they are in.

The one other thing that has an impact is that the hull itself is a foil, though usually, a pretty poorly formed one in the plane of the foils and sails. It is designed to handle the interface between the upper and lower media. It takes advantage of the thick dense medium below and the light, fluffy medium above. The shape is modified in the same way that a supersonic fighter jet is different from soaring gliders. The hull that breaks the limit of hull speed and begins planing is exactly like the fighter just when it breaks the sound barrier. It moves into a speed where different physical rules apply.

The real science is balancing all these factors. To make it look good at the same time, we are into the realm of art.

Great reply, thanks!

Following your comment on rigging and stays... so, what are the advantages/disadvantages of rigging and stays over an unstayed mast?

Also, how do you work out the forces involved in a mast, and do the calculations on 'this is the force that needs to be braced' and relate that to your mast base and rigging attachments?

e.g. my hoop pine gunwale/inwale... what can be applied to this without ripping fittings out and/or deforming the hull shape... what do I need to account for when I do the next QC155 such as adding a ply brace on the hull where the rigging attaches??

Is there a 'for dummies' on carbon fibre so that I can work out weight/cost/strength of an unstayed mast fitting to put in the dead space under the decks?

Stayed vs. Unstayed mast on modern small boats:

Stays:

On a stayed mast, you can use a smaller mast diameter and hold it rigid with the stays which can potentially reduce weight aloft. Less windage. More control by being able to bend the mast with the stays to adjust sail shape. You can hang more sails on the stays such as a jib. You can possibly have a bit more reliable sail shape with less technical knowledge. You can potentially have higher aspect sails but that is pretty iffy. You don't need to as carefully engineer the spars. The strain loads are more distributed.

On the down side, there is the expense of all that rigging. More material to maintain. More concentrated loads on the chainplates. More through hull connections to have to maintain and support. More places for failure. Hard to inspect the upper rigging. Before newer synthetics, generally all metal rigging which is subject to fatigue. Sails can't go past shrouds. Chafe of sail on shrouds. Rigging is in the way of movement on deck.

Unstayed:

More flexibility to deal with gusts. Sails can rotate forward to create a more stable running configuration. Clear deck. Simple to maintain. Stress down low where you can engineer support easily. Less parts. No chafe on sails. On small boats, you can just lift the mast out of the step and lower. You can have a more balanced configuration by having part of the sail forward of the mast to lessen problems of gybes.

On the down side, you have to engineer the mast more carefully. You have a larger mast that is creating more windage. The mast has to be stronger as there is more leverage involved.

All that said, it really doesn't make that much difference overall. Both have very successful designs and can work very well. It really falls into a design decision.

As to the design specifics, there are two wildly different sets of design approaches. One is simple load and leverage calculations. This much pressure on this long of a lever produces a certain quantity of force. Add in a safety factor and you are good to go. Now, if you want to have a well designed one, it gets more complicated as you are dealing with fluid dynamics and dynamic loading that is moving in three dimensions with mobile loads in the boat and variable wind pressures. Lots of decisions to make. Some are designed to stay up regardless of what happens. Read some of the writings of George Bhuler. He likes masts that can survive an airplane hit. Then you have designs like John S. Letcher Jr's Aleutka that was designed so the top of the mast could break off and leave you a stub to continue sailing with. You get three yacht designers together and you will have three different opinions of designing the sail rig. They will probably all three be right too because both stayed and unstayed designs can be engineered to work wonderfully.

To figure out the bracing, that is pretty easy in a general way. The idea is that you want to distribute the loads. Focus a stress in one location, it will fail unless you make one small area strong enough to withstand the entire load. Distribute it and it becomes easy. That's why people can lay down on a bed of nails. Each nail only supports a fraction of the weight which is distributed over an area.

As far as how to engineer the loads, you have two choices. You can either go through all the calculations yourself or take an empirical approach. There are lots of designs in this category. Look at the successful designs and do what they did.

As to the carbon fiber, there are few places that synthetic carbon fiber makes sense over natural carbon fiber (wood). I was just reading over at woodgears.ca where Matthias has a new design for a shop built bandsaw. His wooden version had right at 1/2 the deflection of the cast iron saw when he hung off the top of each saw. Wood is not wimpy.

Now from the other side....

I am all for self designed boats. Everybody has different ideas of what they would like and unless a designer can get enough compensation to do a one off or it appeals enough to a broad audience to make it up in volume, there is not any way for a designer to make a living off single designs to make one person happy. If you want something designed special, you can always do it yourself. People have been doing it for thousands of years. Sometimes successfully, sometimes not. You take your chances.

If you want a sailing canoe and don't want to go through the entire design process, why wouldn't you choose Beth over the QC? All the design work has been done and tested. There are other designs such as Stephens with historical models of sailing canoes. William Gardner has some in his books. There are lots of existing designs.

If you look at MIK's quick canoe and you want to convert it to a sailing canoe, you have to ask yourself a few questions:

Did he design the hull to support a stay pulling on one place and keeping the hull from flexing?

Did he design it to withstand the stress risers from attaching a deck so you don't have a rigid bow and a rigid stern with a flexible center that will split open like a banana peeling?

Did he give it enough stability for the weight aloft of the mast, sail, and rigging not to flip over?

Shorter version: Are you trying to make the boat he designed into something else? Is his reputation going to suffer when someone takes his design and does something else with it and it doesn't perform or is unsafe?

I am not saying don't do it. I am saying, if you are going to do it, go all the way. It is a fun process. You will learn a lot along the way. If you are not interested in going through the whole design process and accepting the risks involved, get some plans from someone who knows what they are doing. They are free (Stephens) to dirt cheap (Beth from MIK, Gardner's Books) if your time has any value at all.

Just a few ideas if you decide to take the plunge and design a sailing solution based on the QC.

Traditional Sailing Canoe Approach:

Your first priority will be flotation. A long skinny sailing canoe with a sail up on top will tip over quite easily. You will need some method of being able to recover from it. This could be either internal flotation or external amas like a trimaran. The amas produce a nasty side effect. They will force you to build a much stronger rig because they have a lot of righting ability. (Read Mik's explanation on the Beth page)

The sailing rig will be small. Unless you plan on living hiked out, anything big will be a balancing act for experts. Beth would be up in the upper range of sail area that an expert could handle. For a beginner, you could work it kind of like a rodeo and see how many seconds you could last before getting dunked. It could be a fun game but it wouldn't be sailing. A nice comfortable sail area for us mortals would be half that size with reefing to go smaller. Keep it low to reduce heeling. Maybe a couple small lateen sails on short masts (a pretty traditional choice). You will want to be able to raise and lower sails from down inside boat. You really can't walk forward and lower in something that narrow. There were some really elaborate designs on the traditional canoes for reefing. The beautiful batwing sails are oh so sexy but not a simple build.

Then we are looking at foils. Do you want dagger board or a lee board? How are you going to steer it? If you are up hiking all the time, you could use a tiller. If you are looking for something to putt around in, a regular tiller will be miserable. Either something with rope steering or a linkage to the tiller.

You will want to beef up the middle gunwales with some amount of decking. A lot of racking will rip the boat apart otherwise. That is part of why they were traditionally decked. The other reason was that whole keep the water out thing.

Duck Punt Type Approach:

Another approach could be like the duck punts. They actually look like a lot of fun. duckpunt | Laid back sailing (There are others much more qualified to speak to those around here.) Very small sail, simple oar for paddling and steering. Would probably be a really cool adaptation and more in the spirit of the QC and much less reworking of the design required. If I were building a QC, this is the direction I would take. Small, simple and relaxed sailing.

Quick answers, 'cause I'm coming off an intense 16 hour day and my head hurts.
1. thanks... I'm going to take time to digest all that, which is a compliment to you... thanks, I understand and can work with your replies.

If you want a sailing canoe and don't want to go through the entire design process, why wouldn't you choose Beth over the QC?

2. Cause I have a QC, and my personal interest is in taking what I have and using it as a platform to understand. Call it the 'mad git' rule.

Is his reputation going to suffer when someone takes his design and does something else with it and it doesn't perform or is unsafe?

3. Nah, I am pretty free in saying that I'm the reason for the stupidity... call it the out and proud 'mad git'.

Originally Posted by Clinton1

Quick answers, 'cause I'm coming off an intense 16 hour day and my head hurts.
1. thanks... I'm going to take time to digest all that, which is a compliment to you... thanks, I understand and can work with your replies.



2. Cause I have a QC, and my personal interest is in taking what I have and using it as a platform to understand. Call it the 'mad git' rule.



3. Nah, I am pretty free in saying that I'm the reason for the stupidity... call it the out and proud 'mad git'.

Mr Kirtley has done a very nice job of answering the questions above. The only things I would like to emphasise in that exchange is that unstayed rigs are usually much, much cheaper than stayed ones and the sprit boomed and balance lugs are reasonably efficient without adding any extra gear beyond the basic.

With a stayed rig, which will usually have a conventional boom, you need to add a fair bit of extra gear to get the efficiency (from controlling sail twist and being able to control the downhaul tension) that you don't need to add with either the sprit boomed or balance lug rigs.

The smaller the boat, the simpler and easier the unstayed mast has to be. With much bigger boats engineering freestanding masts to keep the weight down (and keep the stability of the boat up) is the most difficult task.

Beth is a bit of a tricky boat to suggest to people - She is quite a specialist sailing machine requiring quite a bit of experience to sail her successfully when the wind gets up a bit. Not for everyone. You also pay for her good looks with some extra building time to get the deck looking good - cambered with coamings etc - so it looks "traditional"

I do think the Quick Canoe makes a lot of sense as a sailboat. It is simple and cheap and so a simple and cheap rig is the most appropriate.

Paul Helbert has already been sailing his prototype skinny quick canoe around for several months - all well reported in his thread about that. Note that he uses the simple drop in sailing rig plan which I sell - which is nice because it doesn't interfere with the other functions of the boat.
https://www.woodworkforums.com/f169/d...-canoe-121449/
He is also playing around with a larger sail (and his boat is 100mm narrower than yours!)

Oher sail configurations are possible, but this setup provides both lateral resistance and mast support with the whole lot coming out of the boat quite cleanly. Also a single sail keeps the work and budget down.

MIK

I've just changed the title of this thread.

Oh ... One thing to add ... is free standing masts on trailer sailer sized boats through to up to around the mid 30ft mark (11.5m) are tremendously cost effective

I've had to work out a couple of comparative quotes for a conventional rig vs a freestanding one and the freestanding rig has sometimes been 1/2 or a third of the cost of the conventional stayed and headsailed rig, built to a similar level of technology.

MIK

Mik,

A couple questions:

What are your thoughts of the Duck Punt type approach for sailing a Quick Canoe? Does the little keel lend enough lateral resistance to counter something like a little Opti sail with an oar for a rudder or would we be looking at downwind only? Maybe a bolt on keel like Bolger's Sweet Pea?

How far would you go with a little decking and a couple bulkheads to provide a bit of flotation but not compromise the open nature and simple building?

Originally Posted by dkirtley

Mik,

A couple questions:

What are your thoughts of the Duck Punt type approach for sailing a Quick Canoe? Does the little keel lend enough lateral resistance to counter something like a little Opti sail with an oar for a rudder or would we be looking at downwind only? Maybe a bolt on keel like Bolger's Sweet Pea?

I think it is good fun ever since Brian Pearson put the videos up of the Duck Punts on another thread on this forum. The Duck punts are relatively heavy construction (from what I've seen) and they might need some of that weight to sink them down till they start getting some lateral resistance. I do think a bigger wider version of the quick canoe family could match the Duck Punt type approach quite nicely as well as handle the Opti Rig - that would be quite a bit of sail on a Quick Canoe. With some bulkheading and some hiking straps it could be a lot of fun.

I am always suspicious of shallow keels that are claimed to have much lateral resistance. The duck punt in Brian's video is going upwind just fine but it is very flat water and a bit of a chop might mean it just starts pounding and going sideways.

It seems relatively simple to hang a leeboard off the end of the mast partner though.

How far would you go with a little decking and a couple bulkheads to provide a bit of flotation but not compromise the open nature and simple building?

Paul sails his with some quite big canoeing bags - I do think the buoyancy would have to be quite large to allow recovery from capsize ... hmm ... how to get back in the thing?

The swings and roundabouts are pretty dramatic. If you have enough buoyancy inside to make it stable enough when flooded to bail it out and get underway again - then it might be impossible to get back into from outside the boat when it is righted.

If it has less buoyancy it will be easy to get back aboard but might be hard to bail out without going over again.

Hmmmmmm

Probably not a big problem in light and moderate winds

Wonder if Paul has any thoughts about getting back aboard his after a capsize - I don't think he has capsized yet in sailing Mode. His son was Eskimo rolling the boat repeatedly in paddling mode.

And it is still warm weather there.

I might be overthinking the potential probs.

MIK

MIK,

Why did you and Paul bother with a 100mm narrower QC?
What benefits did the narrower hull give?

another.

Again, I'm coming from a position of complete ignorance.
Duckworks Boatbuilders Supply

I'm thinking the 'little' mast and sail in the pic of the canoe, compared to the bigger windsurfer sail in the background... come on! Surely bigger is better?

How much sail is suitable to the QC... from 'the largest able to be handled by the build without disintegration', to 'a reasonable sail for a canoe'?

in other words, "why not modify the QC to fit an unstayed mast that has the 'hardware/build' to handle a stupidly big (and only fun while it is not falling over) mast and sail, but also able to fit a 'sensible sail for 2 people plonking along'?

Thats my question, and I live on a bay that regularly sees 20cm chop on 50km/hr wind days, and who can drop the canoe in on the far end of the bay and get blown home, driven by the wind against the canoe body, faster than I can paddle home on a 'still' day.

Originally Posted by Clinton1

MIK,

Why did you and Paul bother with a 100mm narrower QC?
What benefits did the narrower hull give?

In practice, absolutely none except something that starts to be very pretty in a missile or torpedo type way. Paul gets lots of compliments on the boat. Extreme boats tend to collect compliments. If they are extreme on the minimal side.

The objective was to see about a Quick canoe for a single paddler.

I had been impressed by Rick Landreville's launching of the first Quick Canoe to see his daughter standing up with some degree of confidence. So I thought the beam might be possible to reduce for less drag. That's the biggest potential performance weakness of the Quick Canoe - the wide flat bottom. I've tweaked it as far as I dare.

The other strand was I was desperately trying to fit a smaller, what I thought was a singlehanded, boat onto two sheets of ply. Paul and his son Eli have canoeing in their blood - you can see that in any of the videos of either of them paddling anything. So when he said singlehanders never bother with short canoes, then the possibilities seemed obvious.

So the narrower boat was designed around a single paddler with a backpack type load.

Paul did point out that most single handers tend to use the whole capacity of a big canoe anyhow, just chucking more gear in, but I thought it was an interesting enough niche to think of a backpacker's canoe.

It turned out being pretty unstable. Paul can handle it fine but not a general market boat. He does tend to sit low inside when paddling and sits low in the middle when fishing.

I don't think it is a very practical boat. I think Paul likes it in the way that sailors like a hydrofoil moth or International Canoe or K1 Racing kayak. If they sail one it becomes a platform for them to use their high level of skills. The less practical the boat, the more you feel your skill as you push to make it work for you.

I know this because I really like doing it too. BETH is fun because she is extreme in some ways - not a boat for an average sailor.

So I think Paul loves the boat because of the psychology.

I am sure he will say something about that

MIK

Originally Posted by Clinton1

another.

Again, I'm coming from a position of complete ignorance.
Duckworks Boatbuilders Supply

I'm thinking the 'little' mast and sail in the pic of the canoe, compared to the bigger windsurfer sail in the background... come on! Surely bigger is better?

How much sail is suitable to the QC... from 'the largest able to be handled by the build without disintegration', to 'a reasonable sail for a canoe'?

in other words, "why not modify the QC to fit an unstayed mast that has the 'hardware/build' to handle a stupidly big (and only fun while it is not falling over) mast and sail, but also able to fit a 'sensible sail for 2 people plonking along'?

Thats my question, and I live on a bay that regularly sees 20cm chop on 50km/hr wind days, and who can drop the canoe in on the far end of the bay and get blown home, driven by the wind against the canoe body, faster than I can paddle home on a 'still' day.

Well Clinton ... it depends on how much you want to chew off. The more sail, the more everything above deck level ways and the more likely the canoe will turn over even when you are not sailing.

And even more when you ARE sailing.

So that's what you are up against.

When we drew up the OZ PDRacers - now the OZ Racer - we thought how much sail to put on them. We ended up putting a LOT of sail, mostly because we wanted to stir up the Yanks, most of whom were saying that 45 to 55 square feet of sail was plenty.

A great reason for an Australian to invoke our traditional roots and put 86 square feet on the Mk2 boats.



We found that the PDRacers had so much stability because of their squareness that they were pretty easy to sail with this sill amount of sail.

Something of a surprise.

However, what we do know of the Quick canoe is that it is stable enough, but not super stable. So would be a tricky, but possibly rewarding boat to sail with excessive sail area - see the notes about psychology in the post above.

What seems to make sense to me is to go the route Paul has gone with his canoe and make a bigger than standard sail. As a balance lug it can be reefed when the wind gets up. The rig is in the middlish part of the boat where you can raise and lower the sail ok.

The drop in canoe rig is about 25 square feet, but Paul has pushed it up to the mid 30s.

The problem with going higher is more of the boat gets devoted to the sailing function. With a modest rig the whole lot can be removed leaving very little inside the boat to clutter its use as a canoe.

Best wishes

MIK It also means