Packable Sailing Boat

[daniel aus 300]

Hey guys,
first post here, I am a 4th year Industrial design student and have been sailing and racing all my life from international cadets to i14's and 470's.

For my final year project my intention is to target the recreational sailing market with a unique dinghy design that is capable of compacting to a smaller size for easy transportation and storage purposes (hopefully into the boot of a car!) I am currently looking at something which is about 10feet long, most likely single handed boat and light weight for easy transportation.

I am focussing on recreational sailors specifically but I feel it should be a suitable alternative to a racing dinghy aswell such as a laser, moth, 420, 470 etc. without the price tag.

There are currently a few designs already out there, but most look really cheap and lack a certain level of performance.

Some of the requirements I hope to achieve are:
low-mid cost range relative to other sailing dinghies
compact light weight design
ease of assembly
maintain safety and stability
integrated launching trolley system

Would like to hear your thoughts on the idea good or bad

Have attached an initial concept aswell

look forward to hearing from you all

Happy Sailing

Daniel

[rwatson]

Have a look in the DESIGN forum under the heading 11' nesting pram

You may be interested in
http://www.abc.net.au/tv/newinventors/txt/s1883861.htm

for a dismountable Kyak that uses a webbing belt with rachet tension to hold a boat together, doing away with the bolts.

There are two other threads with foldable boat discussions in them I can remember.

My first take on your idea, is that the word 'inflatable' creates a lot of problems - maybe 'dismountable' is the way to go.

Some racing dinghys have a lot of space frame triangulation to hold rudders, centreboards, masts and seats etc in place.

Perhaps a few key modules, that are all held together with some sort of fastening system using smallish diameter aluminium strut assemblies would be the key to a dissasembleable performance dinghy ?

[Guest625101138]

Why not a cat using 4 identical 2m long roto moulded hull parts that slide onto a folding frame. Faster and more stable than a dinghy.

Rick W.

[Chris Ostlind]

While I absolutely love multihulls in just about all their variant flavors, there's still a very big reality check when it comes to what the buying pubic views as "a boat"

Daniel's ideas are very much in keeping with that pragmatic reality, whether they are based on research or just simple gut intuition.

With the right material choices and fundamental design applications, a boat of this type could be made at an effective price point and it could sail well... along with all the obvious benefits to a more low-key, boat buying public of the future.

One doesn't have to look too far into the stats of all boat sales over the last couple of years to get the idea that the marketplace is tanking in some very big and dramatic ways. Yes, the high end rages-on, mostly because rich folk do not dance to the same tune as do you and I.

I'd, personally, like to see him develop this idea further and see where it can go.

[tspeer]

...dinghy design that is capable of compacting to a smaller size for easy transportation and storage purposes (hopefully into the boot of a car!) ...

This may not have the performance you're looking for, but the Klepper kayak (http://www.klepper.com/images/sailkit1.gif) is eminently packable and can sail:
http://www.klepper.com/images/sailkit1.gif
http://www.klepper.com/images/segel2.jpg
(Although why they are sailing with the windward leeboard down and the lee one retracted is a mystery to me!)

The Aerolite boats (http://gaboats.com/boats/) are not packable, but they are light weight and may give you some ideas to pursue.

[TeddyDiver]

TS Think it's their anticapsize strategy. More wind.. less lee board.

[daniel aus 300]

hi all
thanks for your replies so far, i am still very much conceptualizing this design I had thought about doing a cat as it would be much easier, but as Chris said there is a greater market for a monohull rather than a multihull. Also being a student I have to back up all my claims with stats so if anyone knows any good places for finding relevant info on the boating industry it would be very much appreciated.

Cheers

Daniel

[Petros]

Great idea. I think that a skin-on-frame design would be best suited (like a folding kayak), folds smaller and lighter than an inflatable. I have built many of them. See the free "on-line" folding kayak builder's manual at the following site to get ideas:

http://www.yostwerks.com/MainMenu.html

A similar concept would work just fine for a dingy shaped hull, just make the stringers and frames stiff enough for the extra weight and the sail loads. It could also be done in wood rather than the aluminum and plastic as shown on the website. I would also suggest keeping the rig as simple as possible, a boomless cat rig, with full length battens. It would be a fast set-up and sail pretty well too.

I have sailed a similar klepper as the one pictured above, it was rather disappointing. My basic rule is do not sail in a kayak, and do not kayak in a sailboat. The design if very ill suited for sailing, it was not a pleasant experience. I think it would be a waste of money to buy the sailing rig for this rather heavy and expensive klepper. I have many hours of both sailing and sea kayaking.

Good luck with the concept.

[Meanz Beanz]

Although why they are sailing with the windward leeboard down and the lee one retracted is a mystery to me!

If they heel to far the leeboard will lift higher reducing resistance and hopefully prevent a capsize... they are probably just trying to stay upright as apposed to going faster.

Just a guess.

MBz

Edit: Yeah what Ted said in the next post :D

[rwatson]

.... but as Chris said there is a greater market for a monohull rather than a multihull.

There may be more monohull sales for *recognised classes* but I would think that there are more catamarans sold for the leisure market.

Certainly, for a new starter who might be looking at 5 boats a year, the type of boat isnt going to matter so much because they are such a small percentage of the overall market.

The philosophy I am using is to build the boat I want, and hope like blazes that there are a few other people who also like it. That seems to be the secret of success for the well known brands these days. Enthusiasm creates success.

[rrhal]

I like the idea of a foldable boat. Google the Klepper Master (trade wind and Passat also) and you'll see that Klepper did do something like this years ago.

I'd like to implement something like a Raid boat that used a frame similar to the Aerolite concept but have the hull be several pieces joined together. Have a skin that goes over it all - like a big klepper. I think you could build the hull to be about 100 lbs. Make some soft side water bags that attach to the frame for water ballast. These would have to be integrated fairly well so they couldn't shift.

A balanced Lug Rig with Mizzen so the Masts can be short and unstayed and the rigging simple.

[ancient kayaker]

A folding boat may make a good intro for a new boatbuilder if that's your plan (you used the word "market"): the skin can be subcontracted and the other parts are easy to make in a small shop.

Referring to your concept file, I can't see how the inflatable ribs can make the hull rigid enough for sailing although it's an interesting idea that I personally haven't seen before that might work well for a folding canoe. The
more usual folding boat method using rigid ribs should work, and the idea of a fabric skin definitely works in the sailing area, see last post at http://www.boatdesign.net/forums/showthread.php?t=12176&page=7

The challenge with a folding boat. other than its effectiveness when assembled, is getting it assembled. Most manufacturers claim 10-15 minutes and are lying in their teeth, I have not yet seen one that took less than an hour the first time and only a very practised and organized person could get the ones I have seen together in less than 20 minutes. The same things apply to the cat format and that will involve twice as many hulls to assemble plus the crossbeametc. Cats aren't as popular as they were, probably because people appreciate their disadvantages and some small monohulls can give them a run for the money. In my favorite boating lake there are hundreds of power boats, a few dozen sailboats including 2 cats, neither of which I've seen in the water. Oh, and one sailing kayak when I'm there. Think about market size if you this is a commercial project.

Remember the folding boat has two main advantages: it will travel on a plane (assembly time no object), and it can be taken by car to a lake and assembled for a sail then disassembled and taken home (assembly time and ease critical to satisfaction and enjoyment). One format that should be mentioned in this thread is the folding canoe with outrigger floats; the floats need not collapse since they are small.

How much performance are you looking for? The Klepper is a good boat, but I'm assuming you don't want to produce yet another folding canoe here; there are a lot of them around. For a dinghy you need more beam and for a sparkling rather than merely adequate performance in a small boat you probably need a planing hull (I hope this don't trigger a swarm of protests that are irrelevant to this post) and decent sail area. All of that will need a seriously stiff hull and an extra strong mast mount. I'm not sure if it's been achieved yet in a folding boat.

If it turns out that a folding boat cannot be made with the requisite performance, rrhal's idea of the raid boat is a good one although I would aim at less weight. A ketch rig would reduce mast height further. Other ideas might include a self-bailing cockpit and provision for oars and/or small outboard.

[rrhal]

I like Petros' boat in the under $100 thread a lot.

It seems to me one could implement an 18' - 20' boat in the same vane with oarlocks. The trick would be finding a way to cut and rejoin that Aerolite like frame so it would be stiff enough.

The third advantage of a folding boat is that moorage in your closet is much cheaper than moorage at the marina.

[grob]

Have you seen these boats

http://www.porta-bote.com/

Gareth

[Petros]

I like Petros' boat in the under $100 thread a lot.

It seems to me one could implement an 18' - 20' boat in the same vane with oarlocks. The trick would be finding a way to cut and rejoin that Aerolite like frame so it would be stiff enough.

The third advantage of a folding boat is that moorage in your closet is much cheaper than moorage at the marina.


Thanks, it was a lot of fun to build with the creative challenge of staying within budget.


It is not that difficult to make the frame stiff on something like a folding kayak or row boat. There are two methods used: On the older all wood frames, the gunwale is the main structural element and it uses metal hinges or connectors, as well as on all the stringers to transfer the bending loads. These connectors are tedious to make by hand and it adds a lot of weight, but it works. On most of the newer designs, the same as I have used on one I built, is to use aluminum tubing with sleeve connectors, the same as used on modern backpacking tents (but using larger dia. tubing). The tubes could also be carbon graphite composite, and they can be connected with shock cord (also like the backpacking tent poless) to speed assembly.

I have used a number of different folding kayaks, and have built several (one was for backpacking and weighs only about 14 lbs see here: http://www.pouchboats.com/chopelas.html. I have also thought about a folding sailboat along similar design concepts, aluminum poles with either aluminum or composite frames, and a small sail and rudder. It could be light enough for backpacking if made small (like 7 or 8 feet).

I have also thought about a larger one, as long as 16 feet LOA x 5 foot beam, (20 feet would be a pretty large folding boat!) even with a little cabin up in the prow. It is possible, but the frame would be fairly heavy to take the much larger hull and mast loads, and it would take a number of large duffels or trunks to pack it up. I would guess in the 300-400 pound range. So hauling it around would take several people, a very large car trunk/boot or a pick-up truck, and it would take as much as an hour to assemble. It is possible, but I am not sure there would be much of a market for it, if it is not easy to use, it will not get used much. It would be an interesting design exercise. You can ship it to a vacation location, use it on a mulit-day sailing trip, and then pack it up and ship it back home. Cheaper than renting a boat.

I think one in the 10 to 12 ft size would be more practical and appeal to more buyers. It would fit in almost any car when packed into a duffel bag, and into an apartment closet or storage locker, be faster to assemble and easier to sail single handed. Assebly time I would guess would be in the 10-15 min ranger for one person. This would appeal to a much larger market, both as a packable tender for people with smaller yachts and for people who have no place to store a boat but want to own one. Think of all the apartment or condo owners near the waterfront that have no place to keep even a small sailboat.

Skin-on-frame would be the only way to go for a folding boat, it is the lightest and simplest way to make a packable boat. I even thought about a folding catamaran along the same lines: two skin-on-frame hulls, a trampoline "deck", and all tubular frame, 16' loa, 8' beam, 20' mast, and it all fits in two large duffel bags at about 50lbs each. Though it too would take as much as an hour to assemble, too much trouble I think.

[ancient kayaker]

I tried the pouchboat link but nothing was there. As the boat gets larger it rapidly passes the point where it can be carried by hand or packed onto a car trunk.

There are a lot of SUVs and minivans around however. A boat that broke up into sections to fit such a vehicle might have a future; these are often called nesting boats since the sections can be designed to nest. This reduces the weight of the individual parts that must be carried and also reduces the overall length, but assembly time is kept minimal.

I have seen some that date back a hundred years. They have never been common and I have not seen a recent one. Back then they were all wood and the sections were sealed to one another. It seems to me that sealing is an unnecessary complication; one can have bulkheads on the ends of each mating part that is a bit higher than the fully loaded waterline. If the gap between the bulkheads of 2 mated parts were kept small the water would not slosh around enough to reach the top edge and spill into the boat, and a seal at the top for extra security would be simpler to make than a seal all around the hull edge.

Bulkheads can be placed under seats, decks and mast supports. No reason why such a boat could not match the performance of a regular boat of the same size, and its total weight would not be much more either.

There is another thread showing such a boat that was implemented as a skin boat, but a hardshell boat is practical.

[Voyageur]

Hi, this is my first post also. I am no expert, just an interested by-stander really.

Steven Callahan has designed a folding rib which fits in a car. It is about ten feet long, so maybe the pictures on the linked page will gve you some more things to think about. http://www.landlpardey.com/Tips/Tips_2003_January.html


I think with enough time expenditure etc. it would be possible to build a fully inflatable hull (which doesn't resemble a rib). There are inflatable surfboards in production up to 11 feet in length. http://www.uliboards.com/index.php


Good luck with your project!


Wes

[Petros]

I fixed the link to my folding kayak essay, there was an extra ")" at the end of the address. so it works now.

A pure inflatable, as it gets bigger, will need higher pressures to keep from folding. The air takes the "compression" and the fabric the tension in an inflatable "beam". As they get bigger they become impractical without some kind of a rigid frame, otherwise they get heavy and are difficult to inflate, and they do not have as much interior room.

Also I agree, as the boat gets bigger it also get more difficult to launch. Consider a 16 ft boat. You assemble it on the beach, and than have to somehow launch it without doing damage to the skin. It will also weigh perhaps 400 lbs without your gear in it. A wheeled dolly might allow the loaded boat to launch, but that means more junk to haul along.

[NordicFolkboat]

How about an inflatable catamaran? Two inflatable pontoons fixed to a collapsible aluminium frame.

Edit: This guy beat me to the idea: http://www.youtube.com/watch?v=BlzRDvfGs2c