Newby building a Murray River Paddle Boat.

[vxquizit1]

Hi all.
I am building a Paddle Boat approx 1000x250x130mm.
Construction so far has been of recycled pine flooring, and some recycled pine wall panelling.
I haven't worked out the drive yet, but thinking along the lines of the insides of a cheapy rc truck. It has forward/reverse and servo steering. Will do for testing.

I need to work out the water displacement so I can work out my weights. @ 1000x250x130, I make it out to be 32ish kg`s ?

Cheers, All.

[derekwarner_decoy]

Hi PD's....& welcome quizit...that is a mouthfull....

Certainly 1000x250x130 is going to provide a 32 kg box  ...however depending on the fairing of the hull both FWD & AFT could take this down by 20% ....however this is arbitrary at this stage

As you have used 130 in the calculation ....this is the actual draft........& this dimension value concerns me

I have a set of Float a Boat plans for our Oscar W drawn @ 1:24
This provides overall hull length including rudder = 1400 mm x hull width of 250 mm and an actual draft of 50 mm

Remember our Murray River paddlers were and are still light draft

Anyway....please take some time to read the post threads...however very few paddlers had independent drive for each wheel

When you get a chance....post some digital images & if or when you have questions....just ask away....a PD member from around the world will offer constructive comment assistance

Derek

[Markds]

Welcome!!!! A lot of newbies like myself this week and good to see. Everyone here is great and very helpful. I am surprised how tight-knit this group is compared to other model followings. For every question you can pose there is someone here who has the experience to give you a qualified answer. Really! We are in good company here.

[PeeWee]

Welcome to our small corner of the web.  As Derek and Mark have said we are always willing to help and welcome all comers 

It will be interesting to see your Murry river evolve.  I always look forward to Roderick's reports from there on the coming and goings.

[vxquizit1]

Thanks all.
Derek. The draft is arbitrary as I haven't attached decks or anything. I can trim the sides down to a level. The only thing I worry about is the weight. The hull on its own is 5kg. This will come down a bit with more shaping to go. If I drop the draft to much, I might not have the buoyancy.
Is the available weight limit the product of volume displaced - boat weight ? Or is the natural buoyancy of the wood a plus factor. I would expect that it is minus, as redgum doesn't float and that is what they built them out of.

[vxquizit1]

I dropped th depth to 60mm.
So now have, at the base.
860 (length) * 220 (width, beam?) * 60 (depth, draft?)
I make that about 11.3kg * a bit for the flare fore and aft.

So if I work for max 13kg it should float, right?

Bloop,blopp. Shit. Was never good at maths: -)

[vxquizit1]

That would be 11kg.
So to the wheel. I know it workd on thirds, ie. The depth is 1 3rd of the width of the wheel, which is on third of the diameter.
So how much of the wheel, on average, is in the water?
Half would waste energy trying to lift rhe bows. Third again sounds the medium.

[mjt60a]

Welcome, it will be interesting to follow the construction of your model!
... all this 'thirds' buisiness is new to me - but then I haven't built or researched a sternwheeler, Looking at the only operational ships we have here I'd say one quarter of the diameter is about right with feathering floats, about one fifth (maybe less) for a wheel with fixed floats. An article about this in Paddle Wheels said if Waverley had fixed floats the wheels would have to be double the diameter of the existing feathering ones .....
probably not too much help but I think it's to do with the angle of the floats as they enter and leave the water and getting a balance between the load on the engine and how much is translated into forward motion....

[vxquizit1]

So I have done a fair bit more. Hull just needs finishing.
Front and rear decks are constructed, just have to look to mounting. I want them to be easy on/off for maintenance.
Was going to use a drum cut in half for the paddle covers, but have decided to do it in laminated 3ply strips over layered with a 3ply sheet. Keep the weight down.

Thinking a Stirling engine would be an awesome engine.
Anyone know of plans to build one. I guess it would have to be a reasonable size as I don't think they develop a lot of horses.

I have heaps of progrees photos stored on Dropbox.
Anyone point me to instructions to put them up here ?

Cheers, David

[Midge]

This is a Oscillating Steam Cylinder Engine. No drawing as yet but fully modelled up on CAD, Dawings just take a little bit longer....

[derekwarner_decoy]

Hi PD's....& welcome Midge

Your skills in the use of Inventor or what ever are great......  ....but the actual design as stated for an oscillating steam cylinder engine is marginally flawed

Think about this & stick with us on PD's...........you will get some help........Derek