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[3838Derrick]

Hi all,
I'm in the process of  building my first steam powered launch. I've read somewhere that it's a good idea to be able to remove the entire drive train in one piece (engine & boiler), for test running and ease of maintenance.
To this end, I've made a sort of ladder rack to which I'm bolting the engine & boiler.  Now, I'm assuming the boiler should be as horizontal as possible, but in order to line up the engine with the propshaft, the rack would have to be inclined!
Would it be ok to have the rack level and use a universal  (or even a double universal) joint between engine and propshaft?
The boat is the "River Queen" a 34" open launch with a TVR11abb. Any ideas as to what propeller size I would need?
Thankyou,
Derrick.

[hammer]

Derrick, could you use gears to drop down to align with the prop shaft?( see Irene in Yachts R&D) Or could you pack the front of the engine on the frame, to incline it. If not use a universal joint.
As for props, just doing my first one, so can't help. All my boats have been sail or paddles.

[Baldrick]

I would  keep the propshaft and engine crankshaft in true alignment to minimise vibration and wear . By all means fit your ladder rack level but make a wedge shaped spacer to go below the engine to give it the correct inclination, a bit of trial and error involved here.
 A thought for you, it is usual to form a tray (sheet brass ) under the boiler and engine partly to shield the hull from heat but also catch the secretions of oil and gunge which will occur , this could go on top of your ladder.

[rhavrane]

Bonjour Derrick,
Based on my experience, it is VERY practical to have all the steam plant on a single platform, example : https://www.youtube.com/watch?v=2rliYY448XQ And on this launch, I have 2 single gimballs as there is 4 cm of difference : https://www.youtube.com/watch?v=gIoFeZV-MhM
Example on Eric's puffer : https://www.youtube.com/watch?v=qrtFh6a15qU

You can also use toothed belts or gears : https://www.youtube.com/watch?v=UOjylZzQyeA

About propellers, for my 7-8 cm3 steam machines, I like 90 mm 3 or 4 blades propellers to slow down the speed rotation and save autonomy, examples : https://www.youtube.com/watch?v=QIbGjiD36xU or https://photos.google.com/share/AF1QipPGuZKl0AiA3oBG2NPavgdW0eN_1idDdRwtY6qnn5xOcoC51UDTOp6qk2SsIdL7Hw/photo/AF1QipN1q37wj-NY2CkqcTxrWAmV7cHXDk-5W1EcKJEY?key=X2JKcEJuUEdSMVNOcEdUckotVk1YYW5GZW1zU29n

[Jerry C]

I can't repost the picture for some reason but have a look on steam, Jerrys steam launch wear, about page 9. I don't even bother inserting the pins through the yoke holes.  Since new in 2012, no wear or problems in use. The plant is in a tray. Angle between crankshaft and propeller shaft approx 20°.
Jerry.

[3838Derrick]

Thanks for all the advise chaps. I'll have a fiddle and get the engine in line with the propshaft.  I was pretty sure that was what you would recommend anyway.  I've built lots of boats and this is my first foray into Steam.  I'm finding it quite a challenge, (not to mention, b****y expensive). but I like a challenge!!!!
Regards,
Derrick.