a silly idea on a hot day.

[hansp77]

A bit of a long tale...

The other day (thursday oct 12)
we had our hottest October day since 1914.

After waking up late and enjoying a coffee in the sun with a dear freind that is staying (she's just back from round the world), I dedided that I would not go into university and instead would drag the new (old) 9 ft tinnie down to the Yarra river (100 meters down hill) to float around in the heat drinking white wine, eating fruit and catching up.
It was a really windy day, with areas in the state battling fires in up to 100km winds.
We paddled north upriver against the wind in the cover of the bank(so that we could lazilly drift back) , stopped to tie up and picnic and then kept going. Where there was a bank or rocks to walk along I would get out and tow the boat along.
Eventually we turned around.

It was at this point that I tried something I had been thinking of for the last hour or so.
I had brought a big golf umbrella along for some shade.
I got one of the odd oars I had brought, a short large wide blade wooden oar, and with some rope tied off the two loops on the corners of the transom rigged it up as a rudder.
I then got my freind to sit up the bow of the boat facing me and open the umbrella.
I am not sure of how windy it was on the river, it was pretty sheltered. Maybe 10-15 knots generally, and then gusts of up to 30-35(?) knots, or something like that.
After popping the umbrella in a relatively sheltered area and catching the right angle of wind we started cruising off. I took the tiller at first before taking over the umbrella.

After this we rounded a slight corner and started to catch some real wind.
I lay right back into it holding the umbrella up and towards to catch the most of it.
We started flying along, the bow digging over a foot down into the water so that I had a momentary worry that I was going to get water down my back. After I didn't get wet, I settled in and started to check out our sailing performance. My freind was sitting up the back laughing wildly and I could see the fairly decent wake that we were leaving.
I really don't know how fast we were going but it was fast enough to be quite a surprise.

Along this windy straight I took the tiller again and started to see what sort of angles we could sail at. It was all downwind but we could easily tack back and forwards across the river at 45 degree angles.
After an hour and a half paddling and walking up river, we were back home in about ten minutes.
After a quick jog up the hill to get another bottle of wine I found my freinds boyfreind had come home, and with the prospect of fresh paddling and towing power, got him to come down and we did it all over again with three of us.
By the time we were sailing back, the wind had dropped, and heaps of private school kids were rowing up and down the river (hogging;) ).
Thought we didn't get the same speed we could easily navigate and dodge our way through the rowers (and their giggles or blank eyed stares).


So, this all got me thinking about how to improve upon the situation.
Now this would not be pretty, so bear with me if you can.

The aim would be to make a very cheap, lite and easily transportable/stowable sailing conversion kit for a tinnie (or other suitable lite dinghy).
Aside from sailing up and down a river in the sun drinking wine and other such fun, other possible uses would be for fishing, to silently troll or drift, etc.

The first picture I was getting of this umbrella-franken-tinne, was first, to get more power.
Two umbrellas would be good.
I thought of laying a sheath along the vertical side of a seat to step a small mast in. One on the front seat, or off the front flotation chamber, and one off the back seat. The height of the mast would have to be high enough to give just enough room for movement around the boat underneath the umbrella's.
Onto the top of the masts one would atach horizontal umbrellas that rotate on a bearing or something. I don't know if these would be sheeted, or just allowed to free rotate.
The next thing that I thought of was to get some more lateral resistance by adding two simple ply dagger boards that would slot and lock into the holes for the oarlocks and and drop off into the water.
For the umbrella, which is just a cheap $2 shop one, even though it showed no signs of popping inside out, it could be supported by fine nylon lines that would run from the outer (eye poking) rim of the umbrella and in to the center. But considering that cheap is the goal here, and cheap umbrellas would be used, it might be better to allow them to pop inside out rather than tear. Also a slightly flexible mast would probably help here.

So apart from raising a few laughs, what do you think?
I am certainly no boat designer,
but with her freestanding masts and rotating square rigs
she is not unlike a little open deck tin can Maltese Falcon:D

If anyone wants to play with idea,
chip in,
If you think it sounds absolutely ridiculous,
maybe it was just the wine and the sun;)

Nevertheless it was really fun, with surprisingly good performance.
I have no idea, but I doubt it could ever get far (if at all) to windward (shape of umbrella?),
but for the purposes mentioned it could be a fun, and very very cheap self buildable and easily replacable sailing kit.

Take your shots, or add your thoughts.:cool:

Hans.

[timgoz]

Hey Hans,

How about a real fat chick (my apoligies to any who may read this) with an oversized Mumu in the bow seat? You could trim the boat with an equivelent amount of wine aft with you. As the wine is consumed and your bow settles the alchohol should provide enough artificial bravery to deal with the situation. Worst comes to worst you could ride her to shore :)

Take care.

TGoz

[MikeJohns]

If you added a simple unstayed cat rig (mast at the bow) and a drop over lee board you could go upwind as well, much better in my view than the multi sunshade aproach. Far simpler overall and tried and true.

The mast sits in a simple step and through a hole in a cross-board at gunnel height . The lee board just hangs on the leeward side for upwind work the water pressure keeps it there.

Sounds like fun though, as a youngster I used to have a small square sail on my bicycle on windy days, visibility was tricky at times but.

cheers

[timgoz]

Hans,

I hope you did not take the above as being sarcastic or demeaning of your unique thoughts. It was more an attempt at stupid humor & maybe should have been kept in my cranium.

Hope all is well.

TGoz

[hansp77]

Mike, No doubt you are right, and the tried and true alternatives are probably the way to go... but
there was just something so simple, unique, (funny) and so easily replacable with the sunshade. A trip to the two dollar shop for a replacement sail, or a fancy new colour, won't exactly burn a hole in your pocket.
I am still a amatuer with a lot of the terminology, but I think that a leeboard was what I had in mind (attatched to the side amidship yes?) rather than what i called a dagger board.
I was imagining that the whole rig, one mast or two, with umbrella's and leeboard would easily break down into a very compact and light bundle, and probably take less that a minute or two to set up. The easy instantaneous opening and closing of the sail is of course a bonus.
It was a laugh, and unbelievably at the time, WE WERE MOVING!
But we had a lot of wind, thus the thought that two 'sails' may be needed for light airs.

A question- is the idea with leeboards, that you only have the leeward board down at one time, rather than both?

The only advantage that I could see from this idea- apart from being CHEAP and unique(ugly), and easily home buildable- is the potential of the square rig for comfortable and relaxing down wind sailing.

I would be interested to hear what potential for even slight upwind sailing might be had with a rotating umbrella (or two) rig and leeboards.

No doubt this is just a silly idea, but it was a very fun one.



P.S. TGoz,
no harm mate,
for a moment I felt like I was the fat chick...:D
then I had another wine and got over it.

P.S.S.
Last thought, once you've sailed out into the bay or lake to do a little fishing and find a good spot to throw the anchor, then want to rest back with a cool drink in the shade,
a simple hinged mechanism on the mast where the umbrella handle attachtes would swing them up right-ways, to provide a canopy.

Hans.

[gggGuest]

Or, of course, you could just have one of those two string steerable kites on board and use that... If you could get enough lateral resitance it would even be able to go upwind, but messing about with leeboards and things really defeats the object of the exercise...

[MikeJohns]

Here's the general idea.
The leboard just hooks loosely on the side

Use a poly tarp and bamboo if you want super cheap.

cheers

[hansp77]

Thanks Mike,
that's a really good explanatory picture.
And a lot prettier than any umbrella boat.
Though I may of course one day experiment with the umbrella;) (no harm in having one on board- like popping the spinnaker)
I am tempted to make a up a simple rig like that.

As a rough guide, would it be right to make each part of the mast aproximately as long as the boat? (as it appears in the scale in the picture)
(this is a nine foot tinnie)
I have some nice beams of oregon and western red cedar that I could use for the mast (I like wood).
How thick would this need to be (approx)?
also, would it be better solid, or laminated? (oregon could probably be solid)

I have a big torn jib available, and ply for the leeboard, enough epoxy,
then I would put some styro flotation under the seats..

Should be pretty easy.

Thanks.
Hans.

[MikeJohns]

No hard and fast rules on the size. Bamboo , alloy poles Teatree trunks whatever. Note that there are two loop positions on the yard to keep decent sail shape when using the reef.

cheers