New Folding Tender Design

[ConcertinaBoats]

Hi
For my school A Level project I recently designed a folding tender. It's called the concertina as it folds sideways becoming just 5 inches wide. I looked at many other designs before designing the concertina including the Origami and SeaHoppers but wanted to make it able to be folded in just a few seconds. It also had to be much simpler as I had to build it with limited tools at school.
The result was a tender that has no loose parts (other than oars) and can be folded and unfolded by one person very quickly. It has built in handles and can be carried by one person and easily attaches to a roof rack.
Some photos and more information are online at www.concertinaboats.com
I have created a set of detailed plans to help other people build their own.
I would love to hear your opinions on my design.

Clever!

Are you planning a career in boat / ship design?

[Squidly-Diddly]

single "pole", or a long bag of loose skin and frame roughly the length of the boat, and use some mechanism similar to an expanding umbrella to spread the stringers instead of the one piece "ribs".

I'd imagine you would have same number of Ribs, and they would be attached to a single center pole, with arms secured to the stringers. Moving the center pole fore or aft would either expand or collapse the frame.

The frame would always stay inside the skin, unless shipping.

I wouldn't break down into easily shippable pieces as easy, but would deploy almost instantly, in the dark, or other tricky situations, instead of the daunting 30min of careful and unforgiving assembly for a Klepper style.

[ancient kayaker]

Neat! any more information available like weight, dimensions, capacity, folding/unfolding sequence etc?

[ConcertinaBoats]

Apex1. Thanks. Ive not really considered careers much yet. I am starting a maths degree next year but intend to keep designing at least as a hobby.

Squidly-Diddly. I am actually working on a design for a collapsing canoe. It will not work in quite the same way as you described mostly because I wanted to reduce weight so the sides are not solid. It has several horizontal ribs which are held in place by three base sections.

Ancient Kayaker. There is more information on www.concertinaboats.com but I'll put some here too.
It is 180cm long, around 92cm wide (12cm when folded) and 35cm high. Its shape gives it around 500kgs of bouyancy (thats been calculated but not tested!) which means it sits around 6cm deep with a 70kilo adult rowing. Depending on the thickness of the plywood used (I suggest 9mm) the weight varies but is usually around 15kgs.
To fold the boat up, the base can be pulled up slightly by the handle holes in the bottom. The sides are then leant in slightly and the base is pulled up by the handle holes again. These handles are then at the top and can be used for carrying the tender.
To unfold the boat the sides are pulled apart. This means the base folds down on its own until it is completely flat. It then holds the sides firmly outwards so the do not tip in.

[Ad Hoc]

This is excellent.

I reckon this type of small portable boat would go down well in 3rd world countries that are flooded frequently. Its cheap, portable and should it break, probably very easy to repair. Could save many lives....could even be produced locally

Originally Posted by Ad Hoc

This is excellent.

I reckon this type of small portable boat would go down well in 3rd world countries that are flooded frequently. Its cheap, portable and should it break, probably very easy to repair. Could save many lives....could even be produced locally

Well thought mate. Ganges, Irrawaddy.....

Concertina.. I have the impression our new member is a female... am I right?

Ive not really considered careers much yet. I am starting a maths degree next year but intend to keep designing at least as a hobby.

Would be a loss if not! Do my peers agree?

[Ad Hoc]

Agreed

[ConcertinaBoats]

I have now put together a video of it in use.
http://www.youtube.com/watch?v=da7OzZOYBKk

[HMCH]

Wow...I have a recent post called "My One Man Fishing Boat", but yours is 10 times cooler!. I love this idea. It would fit all my needs even better than the crap I built. Great job!!!! I don't have a Pay Pal account, but man I am going to order some plans as soon as I get home.

[tinhorn]

Originally Posted by ConcertinaBoats

I have now put together a video of it in use.
http://www.youtube.com/watch?v=da7OzZOYBKk

Very clever!

[portacruise]

Great job with that design, Concertina. Here's more ideas:
http://www.youtube.com/watch?v=jQHTmEjuxGs
http://www.youtube.com/watch?v=QGtBkS17F0w

There's also the portabote which is resistant to impacts because of plastic material used, which is a plus.

http://www.youtube.com/watch?v=eYWPudtxE08

What they don't tell you about the potabote is that the flexing sides consume a great deal of energy to propel. Also that the sections are held together with staples which work themselves loose with the flexing, causing leaks. The seats are separate and not folded inside. The seat bracket holders were made of plastic which fractured after about 20 uses and had to be replaced at some $ and time consuming labor. At least that's what happened in my case.

Porta

[marshmat]

I am starting a maths degree next year but intend to keep designing at least as a hobby.

I do that too (studying medical physics, boats are a hobby)- it's fun, it's rewarding, and you don't have the "must get a commission this week" pressure that comes with being a full-time independent engineer. Keep it up, we could use more people like you with clever ideas like this.

I recently designed a folding tender. It's called the concertina as it folds sideways becoming just 5 inches wide

I like it. It's cool, it's clever, it's practical. As is, I think it would be a great thing to keep folded up on the top floor of houses in flood-prone areas, as well as being a good kids' boat for ponds, rivers and small lakes. I think a stretched version (maybe 240 cm long) would be quite a hit with the inland hunting/fishing crowd as well as with some cruising sailors.

PS- your "buy plans" button appears to be broken.

[portacruise]

Why would these folding type boats be good for flood conditions? Seems like you would need something more rugged that could take on adverse conditions. Wouldn't a low cost inflatable work just as well, after conditions stabilize to ideal? At least that seems the case for the several floods I've been through.

PFDs for everyone first, then wait for help to arrive?

Porta

[Jeremy Harris]

Originally Posted by portacruise

Why would these folding type boats be good for flood conditions? Seems like you would need something more rugged that could take on adverse conditions. Wouldn't a low cost inflatable work just as well, after conditions stabilize to ideal? At least that seems the case for the several floods I've been through.

PFDs for everyone first, then wait for help to arrive?

Porta

Depends where you live. Here is the UK major flooding seems to have become more prevalent in recent years and is primarily a problem for towns and villages built on river flood plains (which a lot are). Often what happens is that rivers just breach their banks and flood hundreds of acres of flat land on their alluvial plains.

When this happens the water is often slow moving, rather like a vast lake. A boat like this would be very effective as an emergency aid. At the moment, whenever there is a big flood we often see people getting about by canoe or paddled inflatable.

The major problem isn't drowning, its food, fresh water and protection from hypothermia for the vulnerable.

I understand that other areas around the world suffer different sorts of flooding, flash floods with high velocity water flow, for example. I doubt any small, portable boat is really going to be much practical help in those conditions. When a flash flood occurred here in the UK a few years ago (Boscastle, Cornwall, 2004) the only thing of any real use in saving lives were helicopters, boats weren't a practical means of rescuing anyone or providing aid.