folding boats

[Alan]

Seeing Tim's article in Watercraft reminds me that I've been there and done that. When I lived in a flat I felt that I needed a boat which folds so, instead of just buying one I designed and built one. I'll dig out some photos in due course but am busy at the moment due to christmas and unretirement.
The boat is pirogue shaped (flat bottom, flat sides, double ended and open) 3.3m/11ft long and made of a pvc skin over rigid pvc frames and plastic tubes and struts. The first version, which is fully backpackable in one bag, had cams to tension the skin longitudinally and loose struts to hold the top and bottom tubes together. The next version had captive struts to prevent them from getting lost and the final version had twinwall polypropylene sheets in place of the struts, and screwjacks to tension the skin.
I tried to sell the idea at an invention exhibition at the NEC without success although the public were very interested.
Anyway, pictures after christmas.

[Timmo]

I'll certainly be interested in seeing them!

Merry Christmas to one and all in the meantime.

Tim.

On 21 Dec 2012, at 21:45, Alan [via UK HBBR Forum] wrote:

Anyway, pictures after christmas.

[Alan]

Luckily I found the photos of my folding canoe, which saved me from dragging the boat from the loft and assembling it. The images here are rephotographed from prints.

above, early prototype.

above, truly back-packable, 15kg, bag made by Barbara Farr who used to make hot air balloons and accessories.

above, partial frame showing captive struts, aluminium floor struts and stem frame with tension device.

above, interior view; seat is also backpack frame.

above, at Cuckmere Haven.

above, in the sea at Christchurch.

So I am a home boatbuilder! The boat also got on tv in a children's programme called "It'll never work" I think the presenter was Sally Gray.

[Port-Na-Storm]

That looks like a very neat arrangement Alan. Well Done.

Graham.

[Timmo]

That's very impressive. Looks very robust with the trangulation along the sides.

Tim.


On 30 Dec 2012, at 17:52, Alan [via UK HBBR Forum] wrote:

> Luckily I found the photos of my folding canoe, which saved me from dragging the boat from the loft and assembling it. The images here are rephotographed from prints.

[Alan]

Thanks for the comments. As I look at the pictures I can remember a few more facts about it. The skins were made to my drawings in both pvc on nylon and polyurethane on polyester (very expensive and impossible to stretch) by a firm on the Isle of Wight who made hovercraft skirts. An article about it was published in Canoeist magazine. And I was suckered into paying money to an invention company who claim to present your idea to industry and only take commission after a sale. What they actually do is to "evaluate" your idea, and tell you that it's absolutely marvellous - and then try to sell you expensive services such as professional draughting. The evaluation cost me £250 - I didn't spend any more with them - and overall I spent about £3000, in ca. 1991, far more than the cost of a commercial folding boat.

[Alan]

Two years later..... I dragged the folding canoe from the loft to assemble it and remind myself how it looks, I'm adding a few pictures here:

Above, plan view of the longitudinal tensioning.

Above, shoulder straps also position backrest, "new" seat never really resolved, twinwall PP makes neater stiffer sides.

Overall, looks quite reasonable.