Small Sternwheel Design

[PADDLEGUY]

I Am New On This Forum, As You Will See. I Have Searched Best I Know How To See If Anyone Has Got Into Sternwheel Boats On Your Fine Forum..no Luck Yet, So Here Goes.... I Have An Idea To Build A Small One ( 28` X 9` X 3` ) To Check Out My Designs. She Will Have A Welded Steel Hull, Small Diesel, Hydraulic Pump Running Twin Wheel Type Motors, Turning Twin Five Ft. X Two Ft. Sternwheels. The Wheels Will Be In "cut Outs" At The Stern, Giving In Effect Twin Engine Control. All This Looks Good To Me On Paper, But I Need Sound Advice On The Wheel Sizes, Horsepower Required, Number Of Buckets, And Wheel Dip.. Anyone Available To Offer Some Advice.

[Sean Herron]

Hello...

See http://modelplans.steamboats.org/paddlewheelers.html ...

http://hometown.aol.com/polysail/HTML/showboat.htm...

http://gemort.wirefire.com/Contents.htm

http://home.att.net/~aaron.j.richard...nks/links.html

http://www2.cemr.wvu.edu/~venable/asa/padlboat.htm


Also http://www.copernic.com/en/products/agent/choose.html - still free basic - multiple search engine...

SH.

[jehardiman]

Go to you library and have them get a copy (all 3 volumes) of "Hydrodynamics of Ship Design" by Saunders publushed by SNAME. He covers paddlewheel design right alongside convential ship dersign and devotes a whole chapter to wheel and float (you say bucket) design.

[PADDLEGUY]

Thanks You Guys, Some New Links I Didn`t Have, Some I Did. Like Bob Keims Sternwheel Forum, Excelent, And Gary Morton`s Also Fine Site On Sternwheel Construction.. ( I Keep Gary`s Site On My Desktop For The Great Music, You Just Can`t Be Unhappy When You Hear That Banjo.) I Will See If I Can Find That Set Of Books. I`m Having A Really Hard Time Finding The Expert Advice I Need For The Builders. I Have Send E`mails To Three Naval Architects With No Replys Yet.. One I Even Gave A Small Retainer To And Never Heard From Him Again...!! The Welding Shops Don`t Want To Build A Boat That Doesn`t "work" And Neither Do I.. Thanks Again...

[Sean Herron]

Hello...

NEVER dole out a retainer without a contract and some research into the person or organization being represented - other wise it is just that - some scribbler on the dole...

Anyway - sternwheelers are crazy things and very much things of the past - but therein is an answer...

These things were being built at a time when everyone was mad for patents and their industrial protection at a time when the USA was enjoying some of its best boom times...

Perhaps a patent search will afford a good muse - at least some great illustrations and technical proposal drawings...

Try https://www2.delphion.com/cgi-bin/nc...al=freetrial55 - for a bit...

I believe that Copernic Pro has a specific patent search engine...

Also - I can design the sternwheeler in question - but I would require a retainer of $2680.00 CDN - good for a new Honda 9.9 pull start -

Yup...

[PADDLEGUY]

Like I Stated, I`m New To This Forum. Are You A Naval Architect? My Builders Say They Need More Than My Simple Delta Cad Drawings. Their Reputations Are At Stake I Guess..

[Sean Herron]

Hello...

It was a tongue in cheek joke - but if you have 3 grand you don't need - I do need a new motor...

SH.

[artemis]

A few simple rules:
1. The top of the paddle bucket should be immersed 50% of the bucket height.
2. The width of the wheel should be 5/6 the width of the hull.
3. The transom should "just kiss" the water.
4. The underwater buttock lines approaching the transom should move sharply up.
5. You should have two rudders forward of the wheel (contoured on their after ends like the wheel) and three rudders aft of the wheel. Failure to have rudders aft of the wheel will result in POOR steering.
6. I suggest you check out the specs on Al Dunlap's Cheng Tse at: http://www.pcez.com/~artemis/NWSSBchg.htm The owner would be happy to answer questions - he designed and built the entire boat himself over the course of nearly 20+ years. But he doesn't have rudders aft of the wheel and "pays the price" in poor handling, particularly at slow speeds. Another sternwheeler is at http://www.pcez.com/~artemis/NWSSBolm.htm
7. Not sure why you want two wheels. If you're thinking of manuevering, it doesn't work that well. A better way to go is to install "quarter wheels". The after end of the wheel is even with the transom - sort of a sidewheeler with the side wheels moved aft and set into the hull somewhat. This configuration was much used in Australia, and a few still survive there. You might have to "play" with rudder location.
8. The hull is not a critical factor 'cause you're gonna be lucky if you get 6 knots! Flat bottomed barge with a "pointey" bow. Keel if desired (but not necessary).

[tom28571]

Artemis,

Good points but I gotta couple of thing thats I saw differently from a few weeks experience driving a twin stern wheeler.

I found the forward rudders to be nearly useless. Part of the reason might have been because the hull bottom did not have enough rise at the stern causing the rudders to be partly hidden behind the hull..

In an occasion when I had to hold upstream of a drawbridge for quite a while, the only method of control was the twin wheels. Nether set of rudders are responsive when almost stationary. The current, aided by suction from the reversed wheels, did a did allow some control but still needed correction from the wheels to maintain position. The boat was not maneuverable enough to allow circling in the space available.

I found the twin wheel control to be very useful around docks and locks, especially if there was a crosswind. In any case, maneuverability is certainly not a strong suit of a shallow, flat bottom, high windage riverboat. I would surely want some form of low speed steering assistance other than rudders.

The wheels on this boat were driven by chains. High maintenance requiring constant atention and messy repair put this at the bottom of my list. Hydraulic drive is very inefficent if you plan to go very far. How about crank or rocker arm drive? I've no experience with these.

[PADDLEGUY]

I Thank You All For Your Inputs. Maybe What I Need To Do Is Include Some Sketches Of What I Have In Mind To Help Clear This Up... I Have Twin Wheels Located In "cutouts" At The Stern. I Call This A Side Sternwheel. I Have Been Told By Two Hydraulic Engineers That I Should Have Excellant Control, Down To A 10th Of One Rpm Or Less, Using Wheel Motors. Wheel Motors Are Low Speed-high Torque Motors That Are Used For Powering Forklift Front Wheels With Very Substancial Internal Bearings.. I Understand The Problem With Not Having Good "feed" Water In Front Of Each Wheel, And Not Having Flow Over A Rudder. I Am Glad To Hear Someone Had Good Luck With Twin Wheels For Low Speed Control. I Am Sorry, I Fail To See Why Only 50% Of A Bucket Should Be In The Water.. What Is The Other 50% For?? How Was The 5/6th Of Beam Determined?? I Know Very Successful Sternwheel And Sidewheel Boats That Don`t Come Near That Width. Now I`ll Attempt To Attach A Drawing... Thanks Again All. Keep Coming Up With Ideas.

[artemis]

1. "The top of the paddle bucket should be immersed 50% of the bucket height"; i.e., from bottom of bucket to water level is 150% height of bucket. This is from a very old rule developed for best efficiency in the 1830s and never changed (see: Tredgold, "Propulsion Machinery for Steam Propelled Vessels", 1838, vol. 1, which has some really neat plates on determination of wheel travel through water and efficiency - usually about 53%, which falls way below a properly selected propeller).
2. The 5/6s rule is based on maximizing bucket area. If you've read some of the URLs noted, I'm sure you've found that there are a whole series of inter-related formulas for determining wheel and bucket sizes based of speed, hp, angle of bucket entrance, etc. The 5/6s rule is a "rule of thumb" that assumes you want maximum bucket width proportional to hull beam.
3. The "side sternwheel" concept you're talking about is essentially a quarter wheel. If you move the wheels as far out as possible - leaving just enough room for the outboard sponsons that support the wheel - and mount the hydraulic motors on the inboard, it should work well (has over the past 150 years in Australia where they have narrow, shallow rivers). Plus, you get the extra deck space between the two wheels.
4. Manueverability with any paddlewheel boat is "tricky" if you don't know how. You need passage of water (generated by the wheel) over the rudder(s) to do this, and the forward rudders are only useful(?) when going astern. In the drawbridge case tom28571 mentions, experienced river pilots would have known of the probability, turned the vessel so her bow was upstream and "backed" down to the bridge. The wheel would then be turning in the best rotation direction to give control. Of note is the fact that in 1946 the tugboat operators in Portland, Oregon - at that time there were a LOT of cargo vessels using this port - demanded that the tugboat the City's Port Authority was contemplating building be a STERNWHEEL. Now this was before such things as Kort nozzles, etc. and today's tugs can and do better the Portland's performance, but she remained a working tugboat until the 1970s (she is preserved and operated today by the Oregon Maritime Historical Society). The "old time" river pilots say she could "outpush" any three propeller tugs of the period.
5. Looking forward to seeing any drawings you post.

[Vern Ledbetter]

Hi there. I'm like PADDLEGUY and new to this forum. I'm curious where artemis got the information he presented and where can I find the formulas for calculating paddlewheel parameters that he refered to.

[Gilbert]

Hi,
Someone gave me a reprint of a Frisco Standard chart. For their two cylinder 16 brake hp engine they recommended a sternwheeler 51 feet long overall, 40 foot hull with 13 foot beam, cargo capacity of 6 tons. Speed would be 7 mph light and 6.2 mph loaded. They insisted that the vessel trim with the bow down whether light or loaded for maneuverability. For what it's worth.

[Vern Ledbetter]

I'm new to forums and I posted a question for you there not knowing that I should reply directly to you. I was curious as to where to find the formulas for calculating paddlewheel perameters that you refered to. Thanks.

[jehardiman]

Originally Posted by Vern Ledbetter

I was curious as to where to find the formulas for calculating paddlewheel perameters that you refered to. Thanks.

Saunders, who I refered to earlier has all that stuff. There may be other texts out there, as it is pretty straightforward.