paddlewheel

[ssphb1]

Originally Posted by troy2000

If you joined this forum hoping people will listen to what you have to say, you probably shouldn't have started by getting snotty with respected, long-standing members whose worth has been proven time after time. We have a surprising large number of experienced, knowledgable (and yes, educated) professionals contributing their time here.

If global intelligence has indeed fallen in the last few years, it's probably due to the proliferation of self-anointed internet experts drowning out science and facts with their arrogance and pseudo-knowledge....

i am here to share my insights, and hoping to learn, grow. i did, do not mean to be insulting. or snotty.

i apologize to all, i may have mistook his good will and misplaced emphasis in the writing.

global intelligence was out of place, off subject, frustration.

for reference, my boating knowledge is self taught, it is mealy a hobby that has become over grown. i am by no means an expert, the only reason i wrote my patent was to see if i could, to grow. i was amazed at the lack of prior art and i saw potential. my forte is in efficiency, layering of systems and time management.

[PAR]

Two identical hulls have the same resistance to propulsion, the same frictional resistance, the same wave making resistance, the same parasitic resistance, so it goes to reason that having only the drive method difference would surely make a reasonable comparison.

Do you honestly think the paddle wheel builders walked away, happily embracing the screw? They tried everything and still got handed their businesses and concepts. This occurs frequently in industry. We don't see many biplanes around any more either, even though they are much more efficient and generate more lift which is the fundamental thing you'd desire from a good wing design. Yep a Fokker tri wing could easily out maneuver a FA-18, but the FA-18 would shred the tri-plane on it's first pass, making the extra maneuverability and higher efficiency numbers a bit of a moot point, particularly if you're the pilot.

You're not the first to try what you are attempting, but you've made assumsions that don't add up and more study on your part would relieve you of this burden.

BTW, screws where not adopted because they"fit the evolution of steam power". They were adopted because they didn't roll or pitch out underway in 30' swells on large vessels like wheels do. It doesn't matter how efficient the big wheel is, if it's not immersed and this was the crux of the problem for merchant vessel and wheels.

[ssphb1]

thank you PAR

granted screws have distinct advantages, as do paddle wheels.

i see the greatest disadvantages of a screw is the direction of rotation and the angel or pitch of the screw from which the thrust is applied, so that thrust is not fully in line and also causing twist on vessel, (which is solved by counter rotating screws.)

further when submerged both the leading and pushing surfaces are producing friction. on surface piercing screws, the leading surfaces contact much less water because the water is positively displaced by the pushing surface = less friction allowing the pushing surface more power because of increased efficiency. however thrust is still not in line and there is the problem of splash (entry) and lift (exiting) caused by surface piercing.

where a properly designed PW, (be it simple, articulated paddles, or multi axle (endless line-belt)), passes the energy from the prop directly in the desired direction, and because it is a surface reactor there is very little drag from the leading surface because the water is displaced by the pushing surface.

because a PW have high traction and low relative speed (as do larger screws) splash is much easer to control (by design of the wheel(s) and/or paddles) and lift can be almost be eliminated while efficiency is increased by directing the lifting water to the desired direction with a trailing fin which is also highly effective in controlling trim by the lifting (or lack there of ) effect produced by directing the water.

splash and lift are much harder to control on surface piercing screws because of the inherent increased surface area caused by there pitch to produce the screw, centripetal reaction, and turning in the wrong direction.

your stance for the move away from PW is highly valid, my self trimming technology greatly reduces these disadvantages however. i have incorporated articulation for steering (nothing new), and automated trimming with consideration of the seas (controlling dig and allowing twist).

this was not easily possible in the past, but with modern materials and control is, can be very viable and reliable. it further enables great reduction in size and weight, while retaining simplicity and effect.

[ssphb1]

Originally Posted by PAR

You're not the first to try what you are attempting, but you've made assumsions that don't add up and more study on your part would relieve you of this burden.

No, I have read also, I understand that the conversion to screws was highly controversial and initially regected and then resisted. Much as my work is often put down, usually until people actually see it work.

I do not think that automated trimming of PW was practical in the day, and is why there was so little prior art on the subject, along with people gradually accepting being screwed (joke) and turning away from PW.

I strive not to assume, but... I beleive I have basicly explained my premises in my prior post.

You are correct it is a burden. Is why i am here. Direction is requested.

thanks.

[tinhorn]

Originally Posted by ssphb1

...along with people gradually accepting being screwed (joke) and turning away from PW.

Hahahahahahaha!

[zebinuk]

Greetings from Brisbane river, Australia.
We have a number of grand paddle wheelers plying the waters here, however of all the house boats in the area none seem to have picked up on the romance of slap, slap , slap.
Being a novice in all things paddle wheel i was wondering how would one work out the size of drive (Diesel kw) required compared to wheel size and boat weight?

I am thinking of building a 15mtr house boat and paddle power appeals.

Cheers Zeb

[Pericles]

Screw propulsion had some obvious potential advantages for warships over paddle propulsion. Firstly, paddlewheels were exposed to enemy fire in combat, whereas a propeller and its machinery were tucked away safely well below deck.

Secondly, the space taken up by paddlewheels restricted the number of guns a warship could carry, thus reducing its broadside. These potential advantages were well understood by the British Admiralty, but it was not convinced that the propeller was an effective propulsion system.

It was only in 1840, when the world's first propeller-driven steamship, SS Archimedes, successfully completed a series of trials against fast paddle-wheelers, that the Royal Navy decided to conduct further tests of the technology. For this purpose, the Royal Navy built Rattler.


http://en.wikipedia.org/wiki/HMS_Rattler_%281843%29

http://en.wikipedia.org/wiki/Paddle_steamer