Sliding Paddle Propulsor (SPP)

I am a marine engineer and lecturer in maritime school. A couple of years ago I have carried out a “theoretical and experimental study of a SPP device” a patented design of marine propulsor inspired from paddle wheel system. following an abstract submission, I have been invited to submit an article to the Symposium on Marine Propulsors however the article is still lacking to draw the basic characteristics of this particular device.You can see the summary of this study in the link below.

Therefore, I am seeking any opportunity to carry out more research and experiment on the Sliding Paddle Propulsor, as well as to build solution if any to better waterproofing.

Best Regards

watched the video and think the whole thing looks quite STOOPID…whatever is the point of this?

sorry to burst your bubble but are you seriously a lecturer in marine engineering? I would think such a contraption as this would be more akin to a junior high school science project…

Thanks for watching. I 'd be very grateful to you if you could explain what is STOOPID in this work, especially the scientific meaning of STOOPID. regards

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I would also suggest you might make a query at, where many naval architects, hydrodynamicists and the like are in attendance.



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I think the Romans beat you to it by a couple of thousand years and theirs was probably more efficient because they didn’t have a bunch of moving parts to retract the blades to what? Reduce air drag?

Besides, hauling enough extension cord to go anywhere might be beyond the capabilities of paddle wheel boat.

The question I have is why? I’m trying to think of situations where this would be superior to currently available propulsion systems. Your post seems to be fishing for research dollars so that you can investigate a solution to a problem that you haven’t defined.

I don’t see advantages for a sliding paddle vs a fixed paddle other than a more compact unit at the expense of increased complexity. I understand why you would want to water proof the unit, however keep in mind that any seals you add are going to inhibit the operation of the paddles. I think you’d be better off opening the ends of the drum and just giving the water an easy way to get out, or, just forgoing the housing and sliding part altogether and making a fixed paddle.

The sliding paddle is because the blade is going to be most efficient at the bottom of the cycle, when the force vector applied is 100% horizontally and aft. As the cycle continues around the vertical force vector increases while horizontal decreases.


Not sure what the advantage would be over a prop. Maybe shallow water?

Need a HMS Rattler.

Rattler was pitted against a number of paddlewheelers from 1843 to 1845. These extended trials were to prove conclusively that the screw propeller was as good as, indeed superior to, the paddlewheel as a propulsion system. The most famous of these trials took place in March 1845, with Rattler conclusively beating HMS Alecto in a series of races, followed by a tug-of-war contest in which Rattler towed Alecto backwards at a speed of 2 knots (3.7 km/h)

Thanks Earl for your advice!

I do see how the sliding paddle would increase efficiency, but my question is for what purpose? How important is efficiency if you’re in water shallow enough that you’ve gone with a paddle wheel vs a prop? You lose a lot of efficiency when the hull is constantly touching the bottom. If you’re running in that shallow of water then it’s also very likely that you’re going to be kicking up crap that increases the chances of a paddle jamming. In this case, a fixed paddle wheel makes more sense.

I’m just not seeing any reason for this. The OP hasn’t shed any further light on the subject either.

I couldn’t help but notice the extension cord dragging in the water during the “sea trials”. Has anyone informed the OP that water conducts electricity?

I don’t know, I was answering the narrow question of the purpose the sliding blades, not rejecting or endorsing anything.

One advantage of a paddle wheel is no gear box needed. Like those paddle wheel boats people rent at the lake.

People sit in them and peddle which turns the paddle wheel, presumably connected with a belt or bicycle-type chain. If a prop was used in this application some kind of gear box would be needed.

I’ll try to be more clear with regard to my request for research, I do appreciate discussion and questions about this propulsor. Actually, this particular design is intended to improving feathering and immersion which are cited as shortcomings of the classic paddlewheel device (J.S.Carlton). with regard to our study, we have tried the complete immersion of this wheel which is obviously effective with more driving torque.I do beleive that the progress in marine propulsion has always been an experiment based process, and I do not pretend to question the Tug-of-war experiment, but still there some advantages of the paddlewheel that would deserve attention.

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The Port of Portland hung onto the paddle wheel tug Portland for a long time, the pilots in Portland used it for ship assist and swore it was more effective then prop boats in some situations.


“Normal” blade feathering was like this

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Only if you have a very very slow speed high torque prime mover … electric or recip steam.

Only because it has flanking rudders … rudders ahead and astern of the paddle wheel.

By the way, I rebuilt one of the feed pumps on the Portland just before we took it on its first post-refit run up the river.

Isambard Kingdom Brunel!

(I’ve always thought that his name would make a good explicative. Now I can’t pass up the opportunity to use it)

Yes, my post was poorly worded, I didn’t intend to make sweeping generalizations about naval architecture. I meant to say, in some applications, the paddle wheel has the advantage of not needing a gear box to make a 90 degree change in rotation direction.

An example being the paddle boat used on lakes. Instead the simpler and cheaper belt or bicycle type chain is used.


And the background music is terrible. Not even suitable for low-budget blue movies.

The feathering paddle wheel was greatly utilized in the UK on side wheelers, most of whom were excursion boats. These represented the ACME of paddle wheel designs. Unfortunately difficult / near impossible to fit to stern wheelers so neve take up in the NA AFAIN.