# paddlewheeler recuction drive

Discussion in 'Propulsion' started by xxdroom, Oct 30, 2014.

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### xxdroomJunior Member

most of the paddlewheeler boats I`ve seen have a max of 60 rpm wheel/s.
hell I don`t know ......I guess I will just build & run the thing & adjust the wheel/s rpm to fit ?

unless you can give me the math calculator you use to get what you got on the 60 rpm wheel/s.......... can you give me the formula to compute the problem please....... I reall need that one !
thanks, al.

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### xxdroomJunior Member

4000 rpm

the 4000 rpm is max h.p. rpm live 250 hp @ 4000 rpm .
with a v-6 or v-8 I guess I wouldn't need quite that much hp..... because the 100ft is truly feather light,,,,,,,,,, very light weight .

the thing is after 60 rpm the paddles do not produce anymore thrust because the paddles don`t pick-up anymore water from the hole in the water that they produce .
I would of course like to calculate the max hp I can attain to the wheel paddles......... at a reasonable rpm .
its a sort of tough question......... but you have put me much farther up the road on the 60 rpm ordeal......... no way will 60 rpm work as an operating wheel speed for my side paddle wheelers . period.

I need to find out what will work though ....... with your equasion formula I should be able to find many wheel rpm settings that WILL work ..... please sell me the formula !

al.

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### AndySGraySenior Member

You need to supply a bit more information.

Lake, river, inshore, offshore.
Cruise speed
proposed dimensions (beam, draft, air draft)
Hull shape
proposed use, passengers, cargo, fuel, duration...

A naval architect will surely be needed for a project this size?

If you are building a 100 foot boat out of carbon fibre, going bargain basement on the motor is not going to make sense?

-----------------------

You seem not to understand the magnitude of the forces involved - it's not about horsepower.

have a look at the recent posts on the 'random picture' thread. page 412 has some paddlewheelers.

There is a sternwheeler pictured

http://www.boatdesign.net/forums/at...15021158-random-picture-thread-whitehorse.jpg

with a wheel somewhere in the 15 -20 foot range. It is powered by a crank - look at the con-rod size - the bearing end is steel and around a foot thick! The push and pull forces on it are going to be several tons.

----------------------------------------------------

Now as to horsepower

Back in the 18th century they hauled 30 tons of coal in canal barges pulled by a horse walking alongside the canal - so a 70 foot by 6 foot boat with a 30 ton displacement needed only 1 Hp (literally).

Max speed was only 3 or 4 miles an hour, the barges had no windage as they sat low in the water, the canals have no current and no waves.

There is a navy patrol boat which is only 50% longer, 3x wider and 4x the displacement - it is fitted with TWIN V20 (yes 20 cylinders) MTU's with a power output of 2,500Hp EACH - 5000Hp total but she'll do 44 knots.

There are many boats with a 600 to 800 Hp main engine to move forward but the bow thruster that moves it sideways is only 30-40 Hp and it is harder to push a boat sideways than forward...:?:

Google the Waverley Paddle Steamer
Twice the size your talking but over 2100 horsepower from a steam engine - I have been on her - Awesome.

The weight is only one factor - the wet area of the hull is much more important.

-------------------

That said I may have been hasty with the calcs. (Much, much too low on slip - in my defence, on props, slip of 20-30% is the usual ballpark).

The slip appears to be between 55% and 60% on the Waverley - 18 foot feathering paddles would give about 32 knots theoretical but the actual is more like 14.
So your 16 foot at 60 rpm is looking like a top speed of 12knots -providing you have a good hull shape.

So there is one reason that propellors replaced wheels.

------------------------------------------------

Lets have a think about the torque while we're here.

your little V6 will produce a max 200 pound feet (probably nearer 175 but for ease of maths as an example....)

i.e it could lift a 200 pound weight with a 1 foot pulley or a 20 pound weight on a 10 foot pulley (i.e both are 200 pound feet)

Ah but it is geared 66:1 (your 4000:60 ratio) so it will move with 66 times more force but 66 times slower - so at your paddle it is 13,333 pound feet of torque!

i.e. 6.6 TONS at 1 foot

in my example the chain is on an 8 foot diameter sprocket - i.e. 4 foot radius

so the tension on the drive chain is 1.6 TONS

similarly at the outer edge (8' radius) it would move about 0.8 tons...

Sounds impressive?

Less than you'd think.

1600 pounds of fresh water is 26.75 cubic feet or just under a cubic yard.

if your wheel is 16 foot giving a 50 foot circumference and a quarter of the wheel is submerged even a 1 foot square blade would sweep about 13 cubic feet so with a wheel on each side your engine would stall.

Now of course we could use a big diesel - 600 pound feet - no problem as we have three times the torque.

but the tension on the chain is now over 4.8 tons so stuff would be VERY heavy duty if breakage were to be avoided...

This is another reason why the propeller replaced paddle wheels - the transmission is much smaller, lighter and simpler.

The Drivetrain for a 100' prop driven boat would go in a pickup truck - for a 100' wheeler 4 to 6!

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### xxdroomJunior Member

?

back to thr drawing board .

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### Dave TSenior Member

Gearing down from 4000 to 60 RPM is not a big problem. You need a total gear reduction of about 66 to 1 therefore with a double chain reduction with a 12 tooth drive gear and a 96 tooth driven gear to give an 8 to 1 reduction will give you 500 RPM at the jack shaft then another 12 tooth gear on the jack shaft and a 96 tooth on paddle wheel would give you a total gear reduction of 64 to 1 so at 4000 RPM the paddle wheel would turn 62.5 RPM. A double no. 80 chain would probably be heavy enough if the boat wasn't too heavy and the paddle wheels weren't too big or wide. The main problem is getting the the thing moving. With a gas or diesel engine you must have some kind of a clutch to disengage the motor to start it. The problem then is that a gas or diesel engine wouldn't produce enough torque at low RPM to get the paddle wheel to turn. With a steam engine this wasn't a problem because a steam engine produces almost as much torque at zero RPM as it does at full speed and doesn't need any clutch and can rotate in either direction for reverse. That is why steam engines worked well with paddle wheel boats and trains. You could use gas or diesel electric like in modern diesel electric trains or possibly a hydraulic drive system from a large skid loader.

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### xxdroomJunior Member

well thanks for the work that you have done !
what do I owe you ?
name a price .
I do trade work......... I am a fiberglas mold maker.
I first go started in the garage at home & went to work at hallett ski boats in Irwindale, ca. in 1976.
I do it all now with 35+ years in the biz.
carbon fiber.
epoxy.
etc.

one thing I don`t do is any kind of foam boat or yacht mfg.
never have & never will.
the laminates I do are old school 2 layers of 3 oz. mat & 1 of woven roving W/maybe a finish laminate od fine woven roving on special projects .

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### xxdroomJunior Member

as far as final drive I was planning to use an automobile automatic transmission, w/the 12 tooth gear & chain to the jackshaft from there......... attached to the transmission output shaft .
low gear would get the wheels moving don`t you think ?

62 rpm at 4000 rpm on the overall final drive ......NOT BAD when you consider that the high rpm of 4000 would rarely be used....... that would leave ALLLLLLLL kinds of crusing speedrpm to play with ! actually the 4000 rpm is a little slow....... the v-12 jaguar engine I plan to use reaches top output at over 5000 rpm.
but I plan to use a verity of power sorces......... ford , chevy etc.
I`m thinking that with the hull as light as I am planning & the very strong side paddles I plan to make ........ I should not have any problems with an failure .
the jag v-12 puts out less than 300 hp....... but it purrssssssssssss !

A V-12 JAGUAR SIDE PADDLE WHEELER .

I also think that the gear drive you presented could hook right up to any power plant & work .
I would like to tinker with the math on other rpm equasions though.....just for my own mind ..... I`m stickler for that kind of perfectionist action .

I seen a complete v-12 jag engine on ebay just a few days ago the was selling for a measlily 1700.00 usd !

thanks this is valuable information .

how did you do the equasion ?

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### xxdroomJunior Member

the reason I would like to know how you do the math is because I would like to do the math for a varity of rpm equasions .

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### xxdroomJunior Member

general info

I would like to know how you did the math .....
because I would like to do the math on different rpm equasions .

you know the side paddles I am talking about only have a 2 1/2' width.
& draft in the water only 1 ft.

the 16ft. paddle can be changed to 8.10,12, 16 etc .

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### Dave TSenior Member

The math is very simple. If the motor turns 4000 and you want the paddles to turn 60 RPM just divide 4000 by 60 this will give you the total gear reduction which is 66.6 so 66 or 67 to one would be close enough. To achieve this with out having a monstrous driven gear you would need a double reduction by using two shafts. To figure this you just divide the number of teeth on the driven gear by the number of teeth on the drive gear 96 divided by 12 is 8 so the second shaft RPM would be 4000 divided by 8 would give you 500 RPM. Now using another 12 tooth on this shaft and another 96 tooth on the paddle wheel will give 500 RPM divided by 8 or 62.5 RPM by adjusting the number of teeth on the driven gears slightly you can obtain the exact RPM you want.

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### xxdroomJunior Member

Cvt

of course if I could find a huge cvt beltdrive unit to attach all the drive power & the paddle wheels that would be the way to go....... always in the perfect gear whan the power is turned on .

it would have to be a pretty good sized belt drive though .

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### xxdroomJunior Member

eliminating the chain drive.

of course a heavy duty steel welded gear case (home made) with the same gear ratio would be far more better .

what I mean is;
instead of the chain & sprockets ......... a well made gear drive with a jack shaft still in place to reduce the rpm`s & then a final gear drive to the paddle wheels.
this I like `very much better !
I am a class c- machinist so I know a little about heavy duty welded steel casings for gear drives .

[what do you think about the following] ?

I`m thinking that a direct drive from the small drive shaft installed in a bearing case, from the automatic transmission that has a 5+rubber belt drive (in case the paddles get stopped by debree) on the end of the belt drive shaft..... the 1st. drive gear sits, it drives the jack shaft, than another gear from the jackshaft drives the main wheels gear ( a huge gear ! ) .
there are ways of making huge gears ....................

again;

a small 1ft. (shaft) protrudes out of the automotive transmission & is mounted in a bearing case (heavy duty truck axel bearings)..... on the end of this output shaft is the 1st. drive gear, it connectes to the 1st. gear on the jack shaft ...... then it drives the jackshaft 2nd. gear to the main wheel/s main drive gear which spins the wheels ......... simple really .
after one can get the correct gear ratios down pat........ the rest is easy !

of course the case housings would be a work of art (e`specially for a class act like a JAGUAR V-12 POWER SORCE ).......AND VERY WELL MADE CASINGS FOR THE DRIVE UNIT OUTFITS .

HEY THIS HAS BEEN GREAT !
SO FAR I AM GETTING CLOSER TO EXACTLY WHAT I AM LOOKING FOR !
THE GEAR DRIVE IS THE ONLY WAY TO GO .

I KNOW THE GEARS WOULD BE A PROBLEM TO ATTAIN , I HAVE SOME IDEAS ON MAKING MY OWN THOUGH........ THE LARGE ONE FOR THE ACTUAL FINAL DRIVE ........ FOR THE WHEELS .

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### xxdroomJunior Member

the only other problem is ratio-ing the auto transmission .......
for the correct rpm at the 1st. gear .

reducing the the automatic transmission with the wheel safety overall drive from damage with the belt drive......... after the correct rpm from the automatic transmission to the first drive gear............ all is ........... well lookin good !!!!!!

you see with the auto transmission not only do you have 4 forward gears (ford AOD ) you also have reverse .

got to have the automatic transmission with a JAGUAR V-12 paddle wheeler !

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### xxdroomJunior Member

the beltdrive attached to the automatic transmission shaft ....... is only for a cushion against damage to the drive line/s .
the rpm output shaft of the transmission needs to be known to calculate the correct size of the pulleys for the 2-5+ belt drives V-belts that will slip ....... so as to give the overall drive a way to make up for any blunt stop of the wheels ........ could even put a stop switch sensor on the belt safety connect to stop automatically ?.

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### xxdroomJunior Member

just thinking that a 3/4" steel bearing housing for the gear drive would do it for the paddlewheeler I have in mind .

I doubt if it could ever be broken .

& actually this super heavy duty bearing housing would only house the jackshaft anyway .

the output gear would attach to the main drive gear ( the oversized one ) on the axel drive of the wheels .

narrowing it all down .......

here are the problems that are left to complete the drive for the side paddle wheeler;

rpm of the output shaft of the automotive automatic transmission .
actuall gear size of all the gears .

I`ll have to do all the math & go from there .

what diameter would a 96 tooth #80 chain sprocket be ?

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