Split Paddle Wheel propulsion design

[Kermath]

Hello new to the site. After a 25 year hiatus from boats I have decided to jump back in. I have always wanted to build a stern wheel paddle boat. I am trying to make it as visually and mechanically complex as is reasonably possible. For example if I was looking at doing this the easy way for me I would drive the wheel(s) with a hydraulic motor(s). My plan is to to have a split rear wheel boat w/ 2 relatively small gas engines w/ For/Rev transmissions (10-20hp ea) powering them. My biggest question at this point is having a split rear wheel worth it? It looks cooler. Twice the amount of mechanical stuff going on. Spare engine if one conks out. Better steering. There is no boat yet. The boat will be built to suit the propulsion system. But in general about 10'w and 30'L. I realize that the split rear will cost about double what the single would. The labor is close to double also. Is the split rear functionally better enough to make it worthwhile? This is something that I don't have a lot of real life examples or experience to draw on for reference. I have driven boats with twin I/Os and used differential speed and direction for maneuvering but don't know how that equates to paddle wheels. Thoughts?

 

[gonzo]

Well, paddle wheels are like having mules pulling a cart. However, many of us do silly things as a hobby. You will need significant reduction gears for a gas engine. The wheel usually turns 75 to 100 rpms. That can be acomplished with a chain drive with double or triple reduction stages. Worm drives are an option too. How much complexity do you want? There are all kind of crazy gears, square to round, heart shaped, etc. that wuold definitely qualify as complex. Most paddle wheels you see nowadays are fake and are driven by propellers.

 

[montero]

I know guys using stern wheel paddle boat to make excursions on shallow river and the lake. They have convince me that they have big tug power when compare to propeller .
Already exist researches of high speed boats also , but power demands are much higher.

 

[BlueBell]

Kermath,

Welcome to the Forum.

Did you consider a side wheeler?

Where are you in the States?

My biggest question at this point is having a split rear wheel worth it?

No.

Is the split rear functionally better enough to make it worthwhile?

No.

I'll post a picture of a paddle wheeler near here. It is impressively visually and very mechanically complex.

Thoughts?

Outboards have directable thrust, a divided stern wheeler doesn't.

Why are you designing and building this boat, may I ask?
What's the purpose (SOR)?

 

[seasquirt]

I'd do a historical search of river / lake boats going back 150 or so years. I'm sure someone would have built one to try. They were used all over the world, and in some unlikely places, like in asia. You may be more successful, since not carrying tons of coal and wood to burn in a heavy steam engine, also carrying tons of water, and then cargo. It seems to me to work in theory. Redundancy is good too. I'd like to say "keep it simple", but you probably won't by the sound of it. Will you go the whole hog, with smoke stacks and musical whistles like the old boats. Got a name in mind ? Makes me think of Tom Sawyer and Huck Finn, or Mark Twain = mark 2.
A paddle steamer I rode on a few times was a side wheeler, where the toilet was a long drop to the down rotating side of the paddle wheels, and if something fell in it was gone forever. Illegal now, but in the 70's it was still 'normal'. Complicated - you could have the engines drive big polished brass wheels and levers for effect, which actually do nothing but look 'ye olde time'. Have fun.

 

[rangebowdrie]

I have always wanted to build a stern wheel paddle boat.
I am trying to make it as visually and mechanically complex as is reasonably possible.
My biggest question at this point is having a split rear wheel worth it?
Is the split rear functionally better enough to make it worthwhile?

I couldn't begin to add-up all the hours spent in thinking, drawing, research, and even designing and building my own steam engine, all because of wanting to build a sternwheel boat, (I'm not past that, I'm just too old to do it now. lol).
Do a search for "Atkin boat plans", he designed 2>3 sternwheel boats in the size range you're considering.
Go on YouTube, lots of sternwheel boats.
Split wheels? Up here in the PNW we've a rich history of sternwheel boats and from all the books I've read and research I've learned that split wheels were quite rare, two main reasons, but with IC engines instead of steam one of those reasons is moot.
The reason left is cost.
You'll find that there is no need whatsoever to try and add mechanical complexity, you'll have more than enough of that
without even trying.
Unless you absolutely require the Nth degree of turning area reduction split wheels on a sternwheeler don't add much.
If the rudder arrangement is proper, (the Atkin boats were not,) you'll have little trouble being able to "back-and-fill" in a tight area.
When I said "proper", you need rudders both ahead of and behind the wheel, (usually three, with split wheels you need at least four,) and you should have a way to operate them independently, (inner and outer steering wheels,) and have simple cable/rope operated rudder position indicators.
Propulsion? Hydraulics are a nightmare and noisy beyond belief, everybody will wear earplugs. Listening to a couple of little gas engines screaming away running hydraulic pumps will ruin any peaceful enjoyment.
Use mechanical drive, don't use worm gears, with an IC engine you need LOTS of reduction. That brings me to a point I almost forgot: Welding, learn how to do it, you're going to have to fab and weld all kinds of things.
Anyway, you want a fairly good-sized engine that will be able to produce some torque at an easy speed, partly to reduce the need for heavy/complicated/power robbing reduction stages. A relatively easy way to get part of your reduction is using a vehicle differential with welded spider gears, (in the old days we called that a Lincoln Locker,) but weight and its distribution is a constant reality in a small sternwheel boat, you need to use a pick-up truck unit so you can get 4:11, 4:56, 4:89 gearing.
And then you cut off the axle housings and all the brake stuff and use pillow blocks outboard to support the axles, now you've got a reduction unit with a U-joint input that you can connect up a transmission/engine to that and have industrial V-belts/pulleys, (or chain/sprockets,) at each end of the axles to run out to the wheel shaft.
If you can stand the weight, just get rid of the brake stuff, you'd also save on pillow blocks, mounts, and having to fab inner oil seals at the differntial.
Multiple chain reductions are fairly lightweight but require bearing blocks, shafts, supports, and GUARDS so no one gets an arm cut off, also chain is expensive and a maintenance hog.
Start looking around at old industrial drives, even old rusty farm equipment, stuff that was used to run conveyor systems and mow fields, you got to get inventive if you don't have a fortune to blow.
The wheel? There is only one way to get propulsive efficiency out of a sternwheel, DIAMETER, as much as you dare.
You need it big enough so that you can have lots of floats without them being too close to one another.
Only in a fairly small section of their travel are they doing much work to move the boat, much of their effort is either pushing water down at some angle or lifting water up, neither of which add productive thrust., a larger diameter helps to alleviate some of that.
Me? I would forget about split wheels unless I was going to use a sound-enclosed marine generator set and electric drive.
But 15>20 hp motors are not cheap, neither are speed controllers. And keeping water out and away from high voltages and currents is not cheap or easy at all.
Well, for now I'm tired of typing, but look at the Atkin boats, look at some YouTube, you'll get some ideas to run thru your mind.

 

[jehardiman]

Kermath,
I assume this is for Lake Winnebago and environs...given that that is zip code 54937...
So in that case, as rangebowdrie states, a split wheel was for maneuvering in small rivers, something you may not need. On larger rivers, especially after the ACE got done with them, split wheels and side wheels were no longer necessary...dying out in the early 1900's.
Is it just the aesthetic? Many "stern wheelers" today are just push boats with an unpowered stern wheel that rotates in the wake. This is because of the onerous requirements that are demanded of a single/double acting steam system (which are ideally suited for this form of propulsion BTW). A steam plant today is ALL about the boiler...unfortunately it is literally viewed as a bomb, ... as many boiler accidents in paddle boats from the 1820's onward will attest.
The problem with hydraulics is that they lose so much in heat and flow losses that, again as rangebowdrie states, they become noisy.
Electric is viable with modern motors and proper gearing, so you just run a small generator to top up.
So as Bluebell asks...what is the statement of requirements (SoR)...for something that small (30x10 ft) evening sundown cruising, electric might just be fine.
But whatever you do, first read the sections on paddle wheels in Hydrodynamics of Ship Design (Saunders, SNAME) Vol 2, Sec 59.6 (references) and Chapt 71 (design). There is no need to reinvent the wheel....

 

[Kermath]

Thanks for all of the responses so far. A bit of explanation. I am not building a boat because I need / want a boat. I do like boats. I like building stuff. I built a sawmill last winter because it looked like a fun fabrication project. I don't need it or use it. I may use it in the future or sell it. So, back to the boat. I will not debate how noisy hydraulics are. I am not using them. It seems so far the split wheel concept hasn't been met with open arms. I have researched it in the past but it is kind of a unicorn so I'll let that rest for now. My favored engine choice is and engine from the teens or 20's with exposed moving parts. It is way easier to find a cool engine if I only need one and not a matching pair. Electric is tempting. More so if I go split wheel. They did have electric boats in the early 1900's. But that is drifting to the easier route and not mechanical. The cost of this project isn't a primary concern. When thinking about how this boat might work you need to set aside those common things we always think about. Cost and labor. Just working on the concept for now. More later.

 

[alan craig]

It seems that you want complexity and good manoeuvrability so I suggest making a single steerable stern wheel. As far as I know no one else has done it. I can think of a couple of mechanisms right now. But no rudder needed so maybe too easy!

 

[Will Gilmore]

Have you considered a single engine mounted sideways with speed and direction controlled with port and starboard transmissions? Keep the engine running a optimal speed and torque, but control the pto for each wheel individually. It would be a little lighter and roomier for a 30 footer like you described. On a lake, you could get away with a 2:1 length to beam and gain a little more steerage by setting the paddlewheels farther apart.

It is always fascinating to watch those piston connecting rods rotate the wheels instead of a shaft or chain. Maybe a transmission can be designed that moves the connecting rods in or out closer or farther from the center of the drive wheels and/or paddlewheels.

-Will

 

[BlueBell]

Kermath,

I see you're not keen on answering questions.
I won't bother with the stern wheeler photo.
Build what you invision.
Best of luck, post pictures of your progress.

BB

 

[rangebowdrie]

It is always fascinating to watch those piston connecting rods rotate the wheels instead of a shaft or chain.
-Will

That is where you could make use of an automotive differential with welded spider gears.
With such you can have connecting rods.
Some kind of center-to-center adjustment is needed to allow the rods to be exactly the same length, and they and the crank throws on both the wheel and the inner ends need to be phased at 90 to each other.
The rods must be phased at 90, in the original stem engines this prevents the wheel/engine from getting hung-up on dead center, on IC drive it keeps a rod from getting "crossed", especially when shifting from fwd. to rev.
Forgot to say before: various garden tractors might furnish some parts as they are closer to the hp ratings needed without so much weight as auto stuff.
This guy talks about torque, Hp, and wheels/buckets.

 

[messabout]

More than a few paddle wheeler enthusiasts in this video.

If you are serious about this project, you might be able to contact some of the Ohio River owners. They will have the benefit of lots of experience with those woefully inefficient propulsion systems.

 

[Kermath]

Kermath,

I see you're not keen on answering questions.
I won't bother with the stern wheeler photo.
Build what you invision.
Best of luck, post pictures of your progress.

BB

I think the only question I didn't answer was did I consider a side wheeler. So, considered it but don't want it. My zip code is posted but I guess that's not enough. 54937 is Fond du Lac , WI. I have explained in the posts that I am considering building this because I want to. There is no sor. Your answers of no and no were highly informative.

 

[Kermath]

I will continue to digest the info that has been brought forward so far. A steerable sternwheel is something I hadn't thought of. Maybe for good reason. We'll see. The other configurations I'll have to look into. Thanks. Ron