Steam powered sternwheeler ( first boat build ever )

[apointofview]

Here I go into uncharted waters !
I have never built a boat of any kind so why not start out over my head.  I wanted to build a boat that looks similar to the sternwheeler down in Disney.  It was built to represent the look and feel of the riverboats of long ago.  I figure it would make a good subject to use as a pattern for my attempt.  Another benefit is my wife is more supportive of it because it means a ' research trip ' to go see the details. 

I started off with a little drawing on my custom graphite 2D design system.

Once I got a rough outline of what I wanted I scaled it up to the size needed to support the weight I anticipate it will be.  I am just making a wild stab at the 50lb mark but who knows. I never did this before.  I need a weight to figure a waterline to set the paddle depth which will determine the deck height !!  If I guess wrong I can ballast it if I am too light.  If its to heavy then it will be surgery I guess.  After the big drawing I started cutting foam for a mock up.  I use the 1/4 inch blue fan fold stuff from Lowes.  Its a lot cheaper that wood and easier to make changes.  The first build up looked short and fat, so I added some length to the hull in the middle.  That helped but it was still funny lookin.  I added more to the bow, but that takes it to a length that wont fit sideways in the back of the minivan ( ugg now its either haul out the truck to go float this thing or pull a seat out of the van )   



Anyway the look was still not right but looking at images of the real boat closer showed me that the sides of the upper decks lean inboard.  I cut down the floors of each deck to get the right lean and now its getting better.  I have a lot more adjusting to do, but progress is being made, I think.  The top deck in these shots hasnt been cut down yet.  I want to finalize almost everything in foam before going to wood and fiberglass.  I think it will take awhile.


I should have built a smaller steam engine.  It will be way way out of scale for the hull, but I doubt anyone will care, I know I dont.  I just want it to float and propel itself with steam and not catch fire, explode, and or sink !! 


Looks like my dining room table workbench is about outlasted its welcome too, so I will have to clear off the work bench to continue.

Pete

[derekwarner_decoy]

Hi PD's....& welcome 'APOV'    so lets start with a few basics

We see you have the hull completed...so you must first calculate the internal volume of the hull from the water line down

eg.,  lets say your hull is 1000 mm long x 200 mm wide and sits 50 mm deep in the water

1000x200x50 ..so in cubic mm ~~ so this is approximately 10 litres of water or 10 kg of mass required to get the vessel down to it's 50 mm draft line ~ well that is for a plain pontoon shape.........you will need to make some estimations of the reduction in volume with the pointed bow & stern...so depending on the form of the hull......this same 100 x200x50 may be reduced in volume by say 1.2 kg?

So from there...you need to estimate/weigh and add the weight of the complete hull plus the weight of all of the steam components = the vessels total displacement

BTW...those mirror reversed steam cylinder & drive assemblies look  ...please tell more about the engine & the build

This is not a difficult task....you just need to be methodical and all will be OK...

Come back & tell us more ...... Derek

[apointofview]

Derek,
Thanks for the info on what I need to do to figure out my waterline.  I think the hull size is getting closer to its final size.  I will be building the real hull out of plywood and the superstructure with something to keep it light.  Its tall so I dont want it to be tipsy.  Guessing the weight of the unbuilt ship seems like it will be hard.

As far as the steam engines and boiler build, here is a link to the thread that I used to show the steps I have taken to get where it is now. http://www.homemodelenginemachinist.com/showthread.php?t=22191

This is an early run on compressed air - https://www.youtube.com/watch?v=0lkgsXzCYoM
there are several more videos on my youtube channel showing the engine.

It has been several years in the making, a little here and a little there when I have time to work on it.  I am to the point where I need the boat to be built to get all the support equipment built and positioned correctly.

Lots of work but sure is fun,
Pete

[derekwarner_decoy]

Goodness Pete...that is some engine build....congratulations ....& the video link confirmed a few things

1. from the image below, it is a twin engine build ...not a twin cylinder engine as there is no interconnecting crankshaft between each engine
2. so with respect to timing the engines @ 90 degrees,  [and maintaining the timing] does this rely on the mechanical rigidity of the Pullman arms, linkages, the paddle wheel axle and all?

By reading your WEB thread it appears that the vessel hull selection is not yet set in stone  ....so from this point it would seem criminal to install such an engine hidden behind a deckhouse superstructure

One alternate here could be to consider a smaller sized vessel with open engine casing walls but build her to a larger scale & hence the same~~~physical model size & displacement

Naturally this could also be used to display the boiler and ancillary components etc

In one of your WEB images we see cotton string lagging on the steam tubes.......these as is will get oily & dirty

For my long time engine assembly, I copied a concept from a member of Model Boats Mayhem in UK .......

1. Superglue a 1/8" ID white nylon washer at each end of the pipe spool
2. wrap with cotton string as you have....& secure at each end with superglue
3. apply a Polyfiller [wall & ceiling paste] over the string
4. allow to dry & carefully sand the OD  to a uniform diameter & straightness
5. paint with enamel undercoat & enamel  gloss top coat

Any oily marks  or splashes simply wipe away 

Best of luck with your build & certainly keep us posted......... Derek

[apointofview]

Goodness Pete...that is some engine build....congratulations ....& the video link confirmed a few things

1. from the image below, it is a twin engine build ...not a twin cylinder engine as there is no interconnecting crankshaft between each engine
2. so with respect to timing the engines @ 90 degrees,  [and maintaining the timing] does this rely on the mechanical rigidity of the Pullman arms, linkages, the paddle wheel axle and all?

Derek,
I have always looked at my power plant as one engine.  Each cylinder is double acting and the paddle shaft is the crank shaft.  I am not sure what a Pullman arm is but my guess is the wood beams that connect the piston rod to the paddle shaft arms.  I have called those connecting rods ( guess that's wrong ).  The whole system does rely on the ships deck to hold it all together and keep the timing correct, so I guess it acts like the frame of the engine.  So far the whole assembly has kept time really well on the particle board test bed.  That board has even warped a little over the years and the engine has been quite tolerant of the movement.  I plan on building a very strong structure for that area of the boat.

By reading your WEB thread it appears that the vessel hull selection is not yet set in stone  ....so from this point it would seem criminal to install such an engine hidden behind a deckhouse superstructure

One alternate here could be to consider a smaller sized vessel with open engine casing walls but build her to a larger scale & hence the same~~~physical model size & displacement

You are right the vessel is not set in stone.  That is why I am using that blue foam and hot glue right now.  What I have built is just a full size mock-up of what I want to build and it is all subject to change.  I am a very visual kind of guy so I needed to design using this method rather than just drawings. 

I am attaching a couple of pictures of what I am trying to make my vessel look like.  My engines are not even close to scale with the size I am building but thats fine by me.  The open design of the decks should show off the engine and boiler well.  What do you think ?

In one of your WEB images we see cotton string lagging on the steam tubes.......these as is will get oily & dirty

For my long time engine assembly, I copied a concept from a member of Model Boats Mayhem in UK .......

1. Superglue a 1/8" ID white nylon washer at each end of the pipe spool
2. wrap with cotton string as you have....& secure at each end with superglue
3. apply a Polyfiller [wall & ceiling paste] over the string
4. allow to dry & carefully sand the OD  to a uniform diameter & straightness
5. paint with enamel undercoat & enamel  gloss top coat

Any oily marks  or splashes simply wipe away 

Thats a great idea!! My cotton has gotten quite dirty already ( some of it has charred near the boiler burner door, turns out you shouldnt leave that open for any length of time  )

Thanks for all the thoughtful comments !!!!!
Pete

[apointofview]

Ok this displacement and balance calculation task has been a real head scratcher.  I understand the idea that I need to have a good idea of what my boat will weigh and how big the hull is to figure out how low into the water the hull will go.  What has been a challenge to figure out is the balancing of all the various heavy items in the boat.  The paddle alone weighs 4lbs 4oz and its center shaft hangs over the water 6 inches behind the hull.  The total weight of the propulsion system weighs 23 lbs, but most of it is concentrated on the aft side of the ship.   I tried to use a program recommended by Dave ( delftship ) but I am way too stupid to come close to getting my hull shape into that program.  I really dont have the time it would take to understand that program.  So I went with using a board with all the heavy items placed on it at the distances they will sit in the hull.  Using a nice round battery to balance all that on, I found the overall center of gravity of all the propulsion components.  I marked that distance on the mockup hull and it looked bad.
It took forever to try to get a similar lifting center out of the hull.  My guess is that the lifting ability of the hull should have a center point and if the center of the equipment in the boat matches the center point of the lifting ability of the hull I should be good.  ( hopefully thats right ) I used geometry to get the area of the hull.  I broke the length of the hull up into three parts, the curved area of the bow, the rectangular area of the bulk of the hull, and the part of the stern that tapers up to the surface to allow water to flow to the paddle more smoothly.  I think the numbers I came up with are pretty close.  Since I have just a flat bottom barge like hull the numbers are easier to calculate than if it had a curvy v shape.  ( I would be toast if I had to come up with a volume on something like that.)   After getting those three volumes and their lifting center locations figured I used a formula I found on the web that figures out the center of gravity of a 3 axle truck.  I know that sounds really wrong but I hope that the three lifting volume centers can be looked at like the three axles on a truck.  Each has to support some of the total weight  depending on their location.  The formula was here - http://www.bendpak.com/support/balancing-safety/
That gave me a lifting center point and I had the equipment center of gravity, so I lined them up on the floor and re-balanced the board with all the equipment on it to have it balance at the same point as the results of the lifting calculation on the hull.  It took 5lbs of steel at the very front of the bow to get the two points to match up !!  Seems like a lot.  That brings to total weight of the balanced equipment to 28 lbs 4 oz  The super structure is fairly symmetrical so it shouldn't change the CG much.  It will make the boat go lower into the water, which will effect paddle height,  so I wont be able to set the stern height in stone till I get closer to done.

The other Idea I had to deal with the heavy stern would be to make the hull deeper towards the rear of the ship to offset the weight, yet still have the boat appear level above the waterline.  It would look odd out of the water though.  Would that be better than ballast in the bow ? Would that even work, and would it make it more unstable ?

Thats a lot of word out of me, I hope it makes sense, it does in my head.  I just want to see if you guys think I am totally lost and did this all wrong.  Feel free to point out my mistakes, I have never built a boat other than a milk carton sailboat as a kid !!!

Pete

A couple of pick to help out - I dont want to have my boat look like the first picture !!!!

[derekwarner_decoy]

Pete....if we could go back a few steps 

1. the machinery is built ...so set in stone 
2. the hull is still an open semi filled canvas
3. you are going on the water so forget any centre of gravity of a 3 axle truck concept  ...your vessel [displacement] should be considered as a single flat level plank
4. rather than be concerned with ballast up FWD to overcome the waterline levelling issue, consider moving the boiler and make up water tank up FWD
5. the only downside here is the length of the steam lines to the engines which can be adequately catered for with lagging 
6. there are plenty of American early stern paddle wheelers with exposed boiler & engine spaces 

Just one more question....[may sound silly] if you orientated the engine & wheels with the boiler into the hull as shown in image 0091, do they all fit?

Derek

[apointofview]

Derek,
Well the hull needs to be as close to the Disney design as I can make it, no real reason why except I want to see if I can do it and my wife loves that place and wants to go to the park for "research".  So it is set in stone as far as the outside appearance.

With the single flat plank method how do I figure out the weight distribution without building a watertight hull and testing ?

I thought items such as water and fuel had to be close to center so as they are consumed the trim of the hull remains steady.

I cant move the boiler fwd much  more than an inch, but your question on does it all fit got me thinking.  I am not sure if you meant it but with a few gas line changes the boiler might be able to fit in the hull 90 degrees to the way I planed and therefore move more of the weight fwd. Hmmm a couple of problems will be the exhaust stack of the boiler and my current feed water pump design.  I will have to think about that for awhile.

Everything fits easily, I just have all the parts set on the skinny board in those orientations so they would not fall off.

Pete

[Gerhardvienna]

I thought items such as water and fuel had to be close to center so as they are consumed the trim of the hull remains steady.
Pete

Hi Pete
Dont forget, the engine will have some weight too. So it may be better, to place the boiler and the gas tank a bit forward out of the center.
Regards
Gerhard

[apointofview]

Thanks Gerhard I will keep it in mind.

I measured and measured and ended up with more numbers that looked good.  It was time to see if I ended up with a reasonable setup for weight distribution in real life.  Instead of trying to build a watertight hull , I went with reinforcing the foamy mockup to support the bottom of the hull so when the propulsion components were place on the foam they would deflect the foam only a small amount so as not to mess with my displacement calculations.  Then I skinned the bottom of the hull with foam and then water proofed it with a piece of plastic sheet that was just taped to the boat above the waterline.  I also marked some depth lines measured from the bottom of the foam

I built a ' dry dock' and lined it with more plastic and put the boat and all its hardware in it along with the 5 lbs of ballast that my calculations said I would need.  Threw in the garden hose and started filling. 

The  hull floated right about where the math said it should and was only about a 1/4 in off from bow to stern.  That was most likely due to the fact that the bow sides have a curve to them and my geometry layout just made nice triangles with no curves so the real area was a little bigger.  I am thrilled !! The hull weighs 28 pounds with the ballast and the displacement calcs said it should sink 1.5 inches into the water.  I added 14oz to the bow in the form of a bowl and water to make the hull level.  With everthing balanced the hull sank about 1 3/8 inches !! Not bad   I loaded the hull down with another 12 pounds to bring the hull 2 inches down into the water.  At that level the paddle sits just where it should in the water, one bucket will be almost all the way in the water and the leading and lagging buckets are partially in the water and the buckets leading and lagging those are dry.  From what I have read thats what I am to shoot for. 
So with a 2 inch draft the hull, as is, it can support 41 pounds !!!  Thats not light.  I dont know if the boat will be that weight when its made of wood and glass but at least I can predict fairly accurately what will happen and where the paddle will have to sit.  I also know right where the balance point of the hull is so I learned a lot.   The shots of the paddle in the water are at the 1 3/8 depth not the 2 inches I will shoot for on the final wood hull.

Lots of fun today
Pete

[apointofview]

A little more mock-up progress.  I keep fiddling with the curve of the decks, I think its getting closer to what I like.
Pete

[derekwarner_decoy]

Pete.......that mock-up is starting to show promise.....& plenty of viewing of the important bits....... ...

In OZ...we would use the family bath tub for such displacement and inclination tests  .......

Dependent on the cleanliness or quality of the water you intend to steam on, you may need to make allowance for a make up water tank on board

As a ball park figure, the equivalent of the boiler volume is a useful volume....however being mindful that the same litre of volume is that same kilogram of displacement....

So every 30 minutes or so you dock the vessel to fill the gas tank & top up the make up water tank at the same time...........Derek

[apointofview]

Derek

Yep I am planning to have a clean supply of water on board for the boiler.  The ponds around me are no where close to clean enough.  I also have to capture the oil contaminated waste steam condensation to keep it out of the pond. 
I sure will have a lot of equipment in this hull.

Pete

[apointofview]

Just a little progress.  A couple of details, just to think things out. 
Looks like I am going to add lights like the Disney boat has.  I had a small strip of LED lights left over from the under cabinet lighting I put in our kitchen just to test it out.   It should look good. 
I bought some thin plywood from the lumber yard, so the cutting of the real thing will start soon --- I hope. 

The last pic shows where most of my spare time is going.

Pete

[apointofview]

Not much to show, but wood has been cut !!
Pete