Modern paddlewheels

[yipster]

great movie WillJones and agree it can be even better. max surface area also counts, giant wheels or caterpillar?

[WillJones]

Yes, Yipster, I am seem to be having more luck in tracking down these water-riding cars this time around.

Here is another link to a similar picture. It clearly says that the water is deep and the car is doing 80mph! What amazes me is how little spray there is (compared with what I expected) and very little sinking in the water surface.

http://www.sonypictures.com/tv/shows...e/ep_318b.html

By thw way, BBC World is supposed to be broadcasting a special feature on precisely these cars tomorrow on their car programme "Top Gear". It is on several times during the day (at least on USA chanels). I may be able to get a clip later.

These cars are to be found in Iceland - which sounds like a very nice place, by the way. Free education free medical, all organic foods, very healthy people and good looking girls (too bad it is too late for me). Anyway, I plan on visiting soon. Maybe I can get a ride in one of these things!

[WillJones]

Here is an update on water-riding cars:
Today (5 Nov 05) I saw the BBC segment referred to in my last post. The Icelandic water-riding "cars" are relatively crude, home-made vehicles built from Jeep chassis and equipped with supercharged V-8 engines delivering 800 horsepower. They are very heavy and weigh in at 1.5 tonnes (3,400 pounds). This is nor surprising because they are designed to survive recurring rollovers during horribly dangerous-looking, near-vertical, hill-climbing attempts (cliff-climbing would be a better description!).

The segment showed a young (and brave) BBC correspondent getting into one of these vehicles as a passenger and being accelerated along a shallow beach and then launched across a deep lake at high speed. It didn't say how fast they were going but it looked like 50 to 60mph. There was a lot of spray, including lateral spray, which is to be expected considering the knobbly tires. I couldn't see what the wake was like, but I doubt if there was much of one, given the principle involved (ie: no wave drag and no skin friction).

After a successful first run, they then did the same thing again, but this time they "raced" against a snowmobile. The snowmobile won handily, including inital acceleration on land. However, I doubt if the hill-climb car was geared properly for high speed runs so it was not a perfect comparison. Anyway, we got an excellent demonstration that both wheel-driven and track-driven propulsion work very well - and obviously have much room for technical development.

So, after this BBC publicity, I hope we see some serious technical development in boats propelled and lifted by wheels or tracks. Do I see a 25 foot Subaru-powered boat in my future, cruising along comfortably through light chop at 50mph on its long-travel suspension and doing well over 10 miles per gallon. It could happen!

[JonathanCole]

If the "tires" were made of rotomoulded HDPE, let's say, two of them, steamroller style, with molded in treads (although a rough surface might be just as good) then the "tires" also become the flotation when the vessel is at rest. On flat water it could go fast. With four "floatwheels" and a long travel suspension this thing might go fast in moderate chop.

Wetted surface might not count as drag when the surface is rotating in the direction of movement. It would also probably stand the concept of long, thin hull efficiency on its head.

[cyclops]

Lorsail. Forget the foils! We are switching to wheels! More efficent.

[yipster]

dont over rush things guy's, saw on tv a quad ( not ozzy ) hitting the water fast with his little wheels crashing making a ugly free fly almost getting the quad on his head

[tom kane]

Originally Posted by JonathanCole

If the "tires" were made of rotomoulded HDPE, let's say, two of them, steamroller style, with molded in treads (although a rough surface might be just as good) then the "tires" also become the flotation when the vessel is at rest. On flat water it could go fast. With four "floatwheels" and a long travel suspension this thing might go fast in moderate chop.

Wetted surface might not count as drag when the surface is rotating in the direction of movement. It would also probably stand the concept of long, thin hull efficiency on its head.

A UK World water speed attempt had two wheels at the front of the hull,I do not recall seeing any glowing reports or any other boat trying the same,there does not seem to be many boats with wheels except www.sealegs.com.

[tom kane]

Anphibian Turbo Racer.Drive direct from land into water,rear wheels convert to stern engine system.Ready- to- run incliding all batteries.$98.

[yipster]

turning rear rims with prop spokes?
to ride the water we need a 4 wheel drive model

[Cliff Pope]

Instead of the original analogy of the back axle, what about an analogy with tank or tractor tracks? A flexible belt running along each side, with paddle blades attached at right angles. The boat would then "crawl" through the water with maximum grip and minimum losses as each blade entered or left the water.
If the rollers or sprockets were mounted on pivots, the whole assembly could stay on the water as the boat gathered speed and started to lift.

[cyclops]

Sounds like a new Catamaran design coming?

[tom kane]

Wheeled boat,a tom kane experimental boat to drive into the water and back up the beach,over the tidal flats and sand dunes.Great for old lazy wrinklies with sore bones,you can still get out and about.A great mobility scooter.

[amascia]

OK, the Dyson water car... sorry, "wheel boat" works, thanks WillJones. And while Dyson's cumbersome beast is (I assume) buoyant and won't sink when not moving (vs "floats like a rock" like the snowmobiles and Ripley photo in Will's earlier post), a new bouyant version could be very fast with modern materials, suspension system, & lots of money (WillJones sketch Pg2, 3rd down -- think "Off Road" PS: the wheels might not need to power the "thing." A jet pump might be simpler than all-wheel drive, eh?). Unfortunately, it will have to be very large for the suspension system to handle any significant wavelengths / height... something a hydrofoil can do relatively easily.

Is this a "modern paddlewheel" application? I wouldn't say so. Personally, I can't imagine genuine paddlewheel propulsion for high speed applications. The point of a paddlewheel would be maximum propulsion area in low draft situation yielding high efficiency... usually dealt with using a tunnel for a large propeller these days. An articulated wheel becomes complex requiring the ingenuity of MC Escher to design. I'll try to build one of these small scale some day. If it turns out to be extremely efficient -- questionable considering the number of moving parts compared to a propeller -- maybe it could have some application.

Link to animation of articulated wheel above on YouTube

Regards to all, very neat forum.
Anthony

[Nolen]

This thread seems to have died, however, it seems to be the appropriate location to post photos of my drive. This particular idea (my patent) was discussed earlier by SamSam in post #45. If any wish to discuss, I welcome the interest.
Thanks
http://nolentechnicalservices.com/blog/

[sharpii2]

Originally Posted by amascia

OK, the Dyson water car... sorry, "wheel boat" works, thanks WillJones. And while Dyson's cumbersome beast is (I assume) buoyant and won't sink when not moving (vs "floats like a rock" like the snowmobiles and Ripley photo in Will's earlier post), a new bouyant version could be very fast with modern materials, suspension system, & lots of money (WillJones sketch Pg2, 3rd down -- think "Off Road" PS: the wheels might not need to power the "thing." A jet pump might be simpler than all-wheel drive, eh?). Unfortunately, it will have to be very large for the suspension system to handle any significant wavelengths / height... something a hydrofoil can do relatively easily.

Is this a "modern paddlewheel" application? I wouldn't say so. Personally, I can't imagine genuine paddlewheel propulsion for high speed applications. The point of a paddlewheel would be maximum propulsion area in low draft situation yielding high efficiency... usually dealt with using a tunnel for a large propeller these days. An articulated wheel becomes complex Attachment 15665 requiring the ingenuity of MC Escher to design. I'll try to build one of these small scale some day. If it turns out to be extremely efficient -- questionable considering the number of moving parts compared to a propeller -- maybe it could have some application.

Link to animation of articulated wheel above on YouTube

Regards to all, very neat forum.
Anthony

What you show here, I have seen in a book called "The Lore of Ships". I really have to wonder if the efficiency gains are worth all that complexity.

I would almost think that the blade size, shape and proportion would be more effective at gaining efficiency.

The problem with propellers is they are quite compact for the amount of thrust they offer.

The other problem with propellers is that, when they are not in use, as on a sailboat, they are a real drag.

But it seems every problem they present has a solution, such as feathering propeller blades on a sailboat, that is, though costly, less expensive than moving to another propulsive technology.

I have thought of a paddle wheel on a sailing catamaran, where allowing the paddle wheel to freely rotate would require less energy than letting the faster turning propeller do the same.

But then I could just get an outboard engine.

I imagine, as the realities of the 21st century wear on, more and more outboard engines will become available for non planing boats.

Really, the biggest advantage of a paddle wheel is that its a rather low tech way of turning circular motion into forward thrust.

Making it fancy, just to gain, a little efficiency kills its main advantage.

It would be interesting to give a bunch of college engineering students the challenge of a hand cranked paddle boat race, where design complexity would be restricted and the boats would have identical hulls.