Steam powered sternwheeler ( first boat build ever )

[DamienG]

A real masterpiece Pete. 

[derekwarner_decoy]

Morning Pete.....when you get time, could you please tell us more about the gas shut off valve & the means of actuating it...

Is it a 90 degree steam valve?
How do you achieve positive shut off?
Are you using a spring controlled servo saver?

With respect to your question on smoke from the stack, oil spray apart from being messy, has the potential to leave a carbon build up on the cross tubes...& this in time becomes an insulator & retards heat transfer from the gas flame

Having said this, all of our club members with 5" gauge steam engines use a coal dust type compressed material termed as char....it also has a small % of clay dust in the mix as a binder.....and we see the cross tubes in the fire box caked with a soot build up however this does not appear to have any serious consequences with heating

So, I have a collection of 1:20 scale timber splits representing boiler feed which is stored on deck, however also have a collection of non split logs which will trial poking 1 or 2 down the chimney ...these will lodge on the cross tubes in the exhaust gas path & hopefully will smoke until they are consumed as or to ash....the logs will actually sit below the height of the condenser steam outlet which is higher up in the chimney stack.....my relief valve discharge tube is also external to the chimney ....so there is little chance if any of the log being subjected to wet soggy steam........

I hope to do a trial steam up this weekend, in preparation for one of our Club boiler inspectors to recertify my boiler in accordance with the Australian Model Boiler code.... Derek

[apointofview]

 I havent had a chance to get a few pictures to show what I did to give you guys a good reply.  But I just used a DuBro smoke shutoff valve.
http://shop.dubro.com/p/super-smoker-valve-qty-pkg-1
The propane feed line to the burner is silicon fuel tubing from the regulator to the burner adjusting valves.  I just put the dubro valve inline and it just pinches the tubing and stops the flow of gas with little effort.  I am going to setup the travel limits of the servo to match the valve. 
My son asked ' what happens if you have a leak or break before the valve ' good question, anybody have any experience with gas leaks and or fires and the subsequent loss of the boat ?  How do I add a level of safety to this potential disaster ?
Pete

[derekwarner_decoy]

Hi Pete

I have gone down the path of our European colleagues and used soft sealing [O-rings] for my gas connections on brass tubing

Gas regulations seem to vary greatly ...I remember using one of those stainless steel woven reinforced over nylon tube hoses with crimped fittings on my gas BBQ....& found the hose fitting leaking at the crimp   

Since then...we seem to be able to purchase gas flash back arresters for bottled gas just like the full scale arresters used with oxy-acet gear

I have experienced Stauff Minimess Test hoses on hydraulic fluid systems from -1 Bar to +320 Bar with total integrity and ZERO decay, however using the same Test hoses on nitrogen accumulators provides totally unacceptable results due to the permeability of gas or gas leakage at the crimped fittings ...

You have the Stauff Corporation in Walderick [USA] pen an e-mail to them enquiring about their recommendations on Stauff 1215 or 1620 Test hoses for use with gas  .....the Stauff publications are misleading...as the actual Test Fittings themselves are approved for gas application's, however the hoses themselves are not capable of maintaining that constant gas pressure without de-pressurisation decay  

Remember high school or early university science?....permeability of gas?........

http://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&cad=rja&uact=8&ved=0CDUQFjADahUKEwiYmdTNjY7IAhWLFpQKHSnzBPE&url=http%3A%2F%2Fencyclopedia2.thefreedictionary.com%2FGas%2BPermeability&usg=AFQjCNHl-v415uGuu5Ae-mlIwS8Lby4LHw

Look at the value for Nylon…..P = 0.7 x 10⁸ cm²/second to atmosphere = 

[I question if that table is correct...should it not be 10^-8 ......?]

Accordingly I would be most reluctant in using any synthetic hose with crimped fittings on gas..... Derek

[apointofview]

Derek,

Thanks for the info that gave me more to think about and more work to do.   

The silicon tubing is going to have to stay because it solves a major problem of connecting the tank to the burners.  The supply is located in a very tight space and rigid lines wont work.  Because of your cautions I will shroud the feed line in a second flexable tube.  I will have to look around at whats availiable locally, mabey fuel line from the auto parts store....Whatever I use will be sealed at each end of the supply line and then have a vent tied into the shroud that will vent overboard away from the burners.  I may have the vent line go over the railing on the lowest deck and the end below the water line.  That way if it begins to leak I should see bubbles at the vent outlet.
 
The aircraft that I work on have similiar setups for the fuel lines that run through the fuselage.  If there is a leak in the supply line the shroud directs it to a drain line that runs to a mast on the belly.  That keeps the fuel out of the plane and makes it easy to discover a leak.

I dont know if this project will ever get done !

Does anyone know much about bilge pumps ??

Pete

[DamienG]

At a guess a windscreen washer pump activated by lever switch  with a cork float on the end of the lever would work ok.

Damien.

[apointofview]

Damien, that's a good idea, but I have been staring at my hull for awhile and it seems the water level inside the hull would have to get pretty deep before I could start pumping.  Since the hull is dead flat I have no place to setup a sump for the pump. There are also several bulkheads that divide up the bottom, water could end up in any one of them. Might have to skip that idea and just float on very calm days only.

I had to make a new valve for the control of the whistle.  The original was not good enough.  Getting it to shutoff all the way was hard and it didnt have much control over the amount of steam it let by.  This valve is exactly like the two throttle valves I made for the engine.  It works great with no leakage and good control.  I mounted the whistles in the only place they fit.  The exhaust of the whistles will soak down the first deck, but there is plenty of airflow inside the boat and it wont be blown too many times, because it eats lots and lots of steam.

Here is a link to the test of the valve https://youtu.be/eDe0KgAoWwI

I also got around to cladding the boiler.  There are two layers of ceramic insulation under the wood.  It will be secured with stainless wire. 

I also added another layer of metal under the boiler.  It has a air gap above and below it just to add more protection to the hull.

No pictures of the gas shutoff for now since a design change is in the works

Pete

[DamienG]

If you're worried about water ingress perhaps filling unused spaces with expandable foam?

[apointofview]

well since this is my first boat maybe I should ask, does a lot of water get in a scale boat very often ?  Does sinking happen much ?  I have flow model airplanes for a long time and crashing is pretty much a guarantee at one point or another.

[DamienG]

While far from an expert on this matter my observation is the difference between Paddle boats and paddle ships greatly influences the free board of the vessels, on a river boat the deck is close to the water (low free board) due to relatively stable water surface where as a paddle ship has considerable free board so it can handle rough seas.

Anyone who disagrees feel free to pick my ideas to bits.

Damien.

[derekwarner_decoy]

Pete....to consider a worst case scenario of wave height that an old OZ paddler would have been exposed to is on Lake Alexandrina near the Murray mouth in South Australia

The following WEB link suggests wave heights of 5 ft......however the shallowness of water experience dictates that the pitch between wave crests would be relatively short....& hence rough & choppy for any vessel plying the Lake

So 5 ft is 60 inches multiplied by the scale of 1:20 equates to scale wave height of 3" and I am guessing at a crest to crest pitch of 5 ft

So if the scale paddler is the same 5 ft in length, a vessel even with a relatively low freeboard will tend to ride the swell adequately [I am sure we touched on this subject briefly early on in the thread]

So from your build, the obvious areas for concern would be around the pair of horizontal Pitman arms attached to the stern wheel, and where they exit the above deck superstructure

1. So from this we could conclude that it is possible that a small amount of splashed water could enter the hull
2. If this were the case, every internal surface of the hull and superstructure should be adequately painted, varnished or epoxied with sufficient completeness to withstand an ingress of water

My intended build @ 1:20 scale will only have ~~ 2" of freeboard which represents 3' 4" of the actual vessel

Being a river paddler, I would never expect to sail in rough weather beyond the scale scenario above. Further I do not propose to install any form of bilge pump

The only thing that I have done here is to install a 6" wide x 2" long foam sponge in the oil drip tray under the engine, however this is for oil or condensation, and not intended to cope with any water ingress............ Derek




http://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CBwQFjAAahUKEwj4za2ytpbIAhUh3KYKHbyPDkY&url=http%3A%2F%2Fwww.ace.net.au%2Fschooner%2Fmlakes.htm&usg=AFQjCNFXBg_XbUNrZPuh76n47H_421h2ag&bvm=bv.103388427,d.dGY

[apointofview]

Thanks for the replies, it seems like if I just excercise patience and wait for calm waters, then sinking due to water splashing in should not be a concern. I am going to scrap the added weight and complexity of bilge pumps

Derek, you are right, the pitman arms, cam pushrods, and rudder linkage holes in the aft bulkhead will have to be addressed to eliminate water getting in.  There is a beautiful model sternwheeler being built by a guy in washington state here - http://www.rcgroups.com/forums/showthread.php?t=1497645. He is in the process of testing his model.  Those tests have shown that the paddle kicks up a lot of water in reverse and quickly puts a lot of water in the hull thru those openings.

[apointofview]

I have been working on little stuff lately.  Its really nice to only make one or two of something instead of 100's of the same thing like the railing was.

I am going to have a working fixed flood light on the mast/crane rig and a spot light on the top of the bridge so I went work on those.  I cut up a flashlight for the led and lens for the wood boxed flood light.  I used the reflector and led end part of another light for the spot light.  I turned down the spot light to remove the knurling and made a thread on plug to cover the opening left by the rest of the flashlight.  I will make a bracket to support the spot light and then mount it on the roof of the bridge.  Both lights will be run on 3v dc.  They originally used 4.5vdc but that was way too bright.  I dont want to be blinded by the boat.

I worked out a way to quickly disconnect the steam exhaust lines for the two engines to allow removal of the super structure.  I used silicon tubing and a piece of brass tube that fits inside another tube.

I ran steel cable for the bracing that runs from the paddle to the bow over the superstructure.  I used model airplane control line cable and eyelets.  One end slips over a 4-40 bolt at the paddle end and the other hooks a spring from a clothes pin to keep it under tension.  I figure with temperature and humidity changes I wouldn't be able to get the length perfect all the time.  I don't want saggy cables.  Those also have to be quickly removed to pull the superstructure.

Last on the built list is the crane.  It isn't functional but it adds a lot to the look of the boat.  It also has to be easily removed for access to the boiler and engines.

[apointofview]

I have started designing an electric recovery option for my boat.  The pond that I have access to cannot have a kayak on it and casting a tennis ball from a fishing pole seems like a great way to knock holes in the boat I would be trying to save.  I don’t want to build another boat to keep on standby, so adding an electric motor and prop to the hull seems like the best option.  During the testing of my engines things went well, but a couple of times the system stopped.  I have corrected the problems but since I make my living fixing reliable machines that occasionally fail I am paranoid about this boat getting stranded in the water due to a mechanical issue.  The water I will run in is free from weeds so getting hung up on something is not that likely. To add to the recovery problem, the soil here is clay and the bottom of the pond is several feet thick of sticky gooey mud.  I made the mistake of stepping into it one time teaching my dog to play in the water and I just about lost my shoes and had a miserable time getting out of the water.
All that said I don’t want a prop hanging out of the nice smooth bottom so a jet drive type setup is in the works.  I found a pvc pipe for kitchen sinks that makes a nice 45 degree bend at the end.  The plan is to put that in the hull and have it exit at the back of the boat where the bottom slopes up to meet the back bulkhead.  I found a three blade plastic prop that just needed a little turning down to fit in the pipe.  I plan on using a 'speed 400' type motor to drive the prop. I don’t know if it will be just an on/off control or add a speed control.  The addition of a speed control would have the added benefit of a BEC to power the rest of the radio gear on the same battery that will power the lights eliminating a second receiver battery.
since this is for emergency only operations I don’t plan on cooling the motor and use just plain bearings for the stuffing tube.
Any thoughts or experience with something like this ?
Pete

[pete]

That is one very impressive model. I think your idea of a water jet for emergencies is good. I have a 1/48 scale side paddler which, in addition to a normal paddle drive, has a commercially made water jet fitted. I split the outlets such that it pumps water out just aft of the paddles, but still under the sponsons. It has proved extremely useful not only for emergency recovery but for avoiding impending collisions or dealing with inclement conditions.  Downsides? - on full chat the scale speed is around 70 knots!!
Regards,
Pete.