Paddle wheel construction for ship

[Zubair Pk]

Good day
I hope I am in right place to get some special guide in subject matter
we have a cargo motor barge, powered by 600 x 2 diesel engines in river, now it is not in use any more and we wanted to convert it to classical passenger ship driven by paddle wheels.
the sip size is 100 feet long x 30 feet wide x 10 feet high and 2 feet draft.
weight approx. 400 tone.
need advise what size of stern paddle wheel required to be constructed and what is the best way to make it stronger and to maintain the speed of 15 knots against the river flow, were the velocity of water is 5 - 7 knots.
do the chain (mechanical drive) system is better or the hydraulic pump and motors will be a better choice with the same engines.

looking for best practical guide.
best regards

Zubair

 

[SwinnyGG]

No one here is going to design something like this for you. Designing a system which will drive a 400 ton ship at 22 knots using paddle wheels is a highly non-trivial exercise.

You may want to investigate installing a free-wheeling 'cosmetic' paddle wheel on the stern if you need it that much.

 

[LittleInch]

Zubair,

there's a reason that paddle wheel ships died our in place of propeller driven ones and this is why. The move the amount of water in the opposite direction to the direction of travel is actually quite difficult when you get to sizes and speeds that you mention.

But 100ft long by 30 ft wide is a big vessel for something like this and needs a good design. You're not going to get that from an internet forum.

See

https://www.eng-tips.com/viewthread.cfm?qid=252396

http://www.americansternwheel.org/Boats/articles/the_paddlewheel.pdf

https://www.boatdesign.net/threads/how-can-i-calculate-the-size-of-paddle-wheel.59717/

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[crshears]

Hmmm...

Classic formula for hull speed in knots is square root of waterline length in feet x 1.34, which in your case yields 13.4 knots.

You want to drive your vessel, which weighs ~ 400 metric tonnes, at 15 knots ground speed plus an opposing river flow of 5-7 knots = 20 - 22 knots.

Which is well into planing speed for your vessel.

With a paddle wheel.

I don't think so.

Somebody, anybody, please correct me if I'm wrong.

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

 

[LittleInch]

I'm sure your right.

Old zubair is so interested be hasn't bothered to log in since losing the question.....

Paddle wheels suited the initial steam engines which operated at low pressure and large cylinders. As soon as higher speed engines / turbines appeared with propellers paddle wheels were seen no more.

And I don't think they ever did 20+ knots.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[crshears]

It is my understanding that paddle wheel propulsion still has a place for lower speed vessels operating in waters heavily choked with vegetation; unless I'm mistaken there are a good number of these in use on the Mississippi, albeit without the low pressure boilers and steam engines and firewood for fuel.

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

 

[btrueblood]

Paddle wheel steamboats on the Mississippi river are a tourist draw for casino operators, most of them run the paddlewheel for show and hide the propellers/thrusters underwater that do the real work (more efficiently than a paddlewheel ever could). Guarding the props, or using waterjet thrusters (with suitable screens to keep the veggies out of the pumps, or macerators to chop said veggies to pulp), or fan-driven airboats, are how modern boats go through swampy/weed choked canals.

Paddlewheels had one unique advantage for the old riverboats, as mentioned by Mark Twain in Life On the Mississipi: a paddlewheeer could repeatedly ram the bank separating the river in a narrow section of an oxbow bend, and use the paddle to claw its way through the mud, opening a channel that would cut off the oxbow. Since the river also formed the boundary for many states back then, and erosion of the new channel would eventually strand the oxbow into a lake, that practice also affected the livelihoods of a lot of farmers and politicians, to name a few.