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.
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?
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)
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’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.
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.
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.