Sternwheel paddle construction

[brian freegard]

Hello List,
I'm making a Simpson,Strickland Type 39 'Colonial' sternwheeler. Has anyone any suggestions as to how they built the wheel? It is 10 feet diameter and 9 feet wide and was probably constructed from steel sections. Are the front faces of the floats truly radial to the rim or offset, or does it matter? Model is 1:32 and will be 32"X7 1/2" X 3/4" draught! Like a tin tray on a puddle.

Motive power - steam I hope but weight will be critical so might have to be galvanic trickery.

Regards,
Brian Freegard

[brian freegard]

No replies, so, here's how I did it.
Cut hub and spokes from 18g. brass (X2). Roll two rims from 18g. brass. Bend spokes to the correct angle 22 degrees and silver solder the rims to the spokes. Bend the end of the spokes to be in line with the hubs. Fit ss shaft with brass tube spacer for correct distance between bearing surfaces.

Soft solder brass angles to spoke ends after jig drilling for the float fixings. Make and fit floats. Should be wood but styrene will stand immersion better?

Paint. Overall it is 3.6" dia X 2.8" wide with 12 floats.

[Harold H. Duncan]

Hi Brian,
Sounds like you have it done right, but how about a few photos of not only your paddlewheels but your hull and superstructure as well.
Keep up the good work
kiwi

[R.G.Y.]

Brian, We would very much like to see a photo R.G.Y.

[kiwimodeller]

Also keen to hear how you intend to drive the wheel Brian, that question seems to be one of the hardest to get a consensus on. Stick to steam, it will be well worth the extra effort. Cheers, Ian.

[brian freegard]

Photos to follow when the Olympics are done
Driving the wheel? I think that weight of the ship and freeboard will be a problem. I would like to use steam as I dislike this modern galvanic trickery, but... The options are -
Oscillating cylinders eugh!
Slide valve cylinders. Where does the reversing gear go? The A6 catalogue drawing, which is all that I've got, doesn't show anything at all.
Piston valve cylinders with reversing valve for inlet/exhaust seems to be feasible.

thanks for your interest,
Brian

[kiwimodeller]

I must admit Brian that in the size you are building it might be difficult to find enough displacement to carry a steam plant. It is not uncommon with model paddlers to increase the depth of the hull to give a bit more load carrying capacity and some more freeboard so you might consider adding a little to the hull. Cheers, Ian.

[R.G.Y.]

Brian. Oscillating cylinders eugh. Well they do have a lot of advantages, easy to regulate & revers, but most important  in you case they can be lighter. Ok there are disadvantages but any design has to be a compromise. R.G.Y.

[brian freegard]

Bit of a haitus here chaps! I looked at the wheel and didn't like the run-out of the rims. You may remember that I rolled them up out of brass strip. They weren't truly round and not well centred.

So, I stripped it all back to bare metal and took the rims off. Then happening to have a scrap of 3" dia brass bar I trepanned two 1/8 square X 3" diameter rings from it.  Now re-assembled and it looks much nicer.

Did some calcs. about the weight today and I reckon that it should displace about 2 kg. The bare hull and the wheel together weigh 620 g. So the false keel option looks almost a certainty.

Regards,
Brian

[brian freegard]

Hello again,

Pictures of the wheel construction attached. things have moved on a bit since they were taken. The hull has a bottom and has been planked with balsa. The main and promenade decks cut and drilled. The sanchions will be 1/8" square brass tube. The cabin sides are CAD prints glued to 1/16" balsa sheet.

Regards,
Brian

[Harold H. Duncan]

lookin' very nice.
love your wheels
kiwi