Paddleducks
Other Marine Models => Live steam => Topic started by: Hankwilliams on April 23, 2020, 08:49:23 PM
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Some weeks ago I bought in the net an old riveted copper boiler for wood and coal. The boiler misses water gauge, safety valve and manometer - this parts I ordered. On monday I made a pressure test with warm water until 6,5 bar - absolute tightness! The riveted copper parts are sealed with a alloying of tin and plumet.
Yesterday I made a steam test with gas burner until 4 bar, at first the safety valve was a little leaking, but was no problem to seal.
Tomorrow I will heat with wood - we will see the result. I think, this will give an interesting steam plant in combination with an steeple engine like Stuart`s James Coombes.
Thomas
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True an old treasure :trophy ....will make a superb smoky source of steam for a stationary steam plant with spinning governer
There are many examples on the WEB and always seem to attract a gathering at displays ...
Does the boiler shell have any reference marking or registration numbering?
Derek :beer
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Hi Derek,
I don`t know anything about the history of the boiler. There is no reference marking. The kind, like fire- and ashdoor and also the rounded ashpan are made, leads to the the conjecture, that the boiler was manufacted and is not a singular built. At first I supposed, that the boiler was made in England, but the threads were metric - thread of water gauge is M 8 x 0,75.
Perhaps one of our members knows more about this discovery?
Thomas
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Today afternoon the first steam up with scrap - plywood. In the beginning I had to take care, that the fire don`t extinct - there should be some small holes in the firedoor for the air. After some pressure was availiable, one can use the steam blower, what was very effective. After 20 minutes 4,5 bar pressure was reached. The blower gives a strong draught, without it would be difficult to reach higher pressure. Unfortunately I didn`t have any anthracite coal - probably the the fire will be much stronger.
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So I suspect the copper outer is a decorative shell, and the actual boiler is contained within
The boiler itself is also probably of riveted and caulked construction
Depending on the age/year period of manufacture, the boiler may have been lagged with an asbestos material or even with wood lathes over the asbestos
Do not be concerned with the word asbestos, as it is contained/dormant and of no consequence or harm
In one of the images we see a different red/purple patina on the outer shell, so little children must be aware :ranting
When you turn the boiler on its side or upside down and remove the ash pan, do you see the actual boiler shell endplate and vertical fire tubes?...are there signs of silver soldering of the tubes to the tubeplate?
Another feature of such model vertical boilers was a reinforcement ring plate, riveted to the actual boiler shell approx mid position. This plate also had the mirror image of the tube bank pattern, so provided additional shell reinforcement against diameter expansion ballooning and also maintained the boiler tubes straightness
This form of construction would have been the only way to clean the boiler tubes of the build-up of carbon black together with bituminous crud that held the carbon & set like tar......or clinker
You are certainly correct that the calorific value of 'coal' is near x 2 of 'timber'
Would suggest you don't plan on doing a boiler tube de-coke on the loungroom bone carpet :nono
Derek
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The boiler is a crosstube one with a wet firebox, only two strong crosstubes (ca. 25 mm diameter) one upon another and the smoke tube with 2 further small crosstubes, it goes into the funnel like in the sketch.
When I got the boiler, I looked at the riveted joints, I don`t found silver solder but a soft alloy of - like I suppose - tin and lead metal. As far I know in former times the riveted joints were tighten with this soft and low melting alloy. As far there is enough water in the boiler, this alloy can`t be overheated. If not, the tighten alloy will melt and it must be difficult to repair this joints. But the strengthening of the boiler obviously is made by the rivets.
Today I made a further heating up with wood and charcoal. But charcoal is difficult to inflame, nearly no flames but only glowing fire gives no sufficient heat for the rather high firebox. I will try to get some anthracite, which for the 5 " and 7,5 " locos is used.
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Yesterday I got this nice steeple engine via ebay. All threats are metric, bore and stroke are 19 by 38 mm. Height of the engine is 300 mm, weight 9 kg. Together with the vertical boiler this will be a nice steamplant. The compression of cylinder and piston seems strong when I turn the flywheel. Like the boiler also history of the engine is unknown. The combination engine and boiler will take some time because I`m busy with drawing the exact plan of the "Presto" steamer and a lot of further sketches for my book about steam driven ship models.
Thomas
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First test run of the steeple engine today - with steam from the big Regner boiler. The engine was running, but there were some leaks at the gasket between slide box and cylinder. After tighten with a new home made gastet the engine was running as good as soundless for a while, but after 15 minutes the piston nearly stucks. Obviously there was too less clearance between piston and cylinder and with the expansion through heat the piston stucks. Another reason could be, that too less oil comes to the cylinder.
We will see. I have polish the piston on my lathe - now it seems better. Tomorrow will be a further day...
Thomas
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Great success! I altered the steam tubes to and from the oiler to the slide box. Now slide valve and piston gets oil enough - the engine is running well and there isn`t any leak. Minimum pressure is needed by 0,7 - 0,8 bar, this seems relative high for turning - but I think, it`s ok.
Next job will be to arrange the vertical boiler with the engine to a nice and suitable steamplant. A feed pump and a water tank also will be required.
Thomas
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You make great finds on ebay Thomas. I look there from time to time but I have only seen Wilesco engines or multi K euro ones.
This engine looks great.
Jurgen
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Because I have to draw some illustrations, plan sketches of boilers and engines for my book, I can`t continue to built up the steam plant in the moment.
But the pictures should imagine, how the lay out could be. There must be a hotwell, feed punp, water tank - may be a little water tower like the railway ones - and also a coal bunker.
Thomas
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Dear friends and neighbors,
book manuscript with many illustrations is finished - last week I send it to the VTH publications.
Now another project becomes topical: The steam plant with coal fired boiler and steeple engine. I now made the foundation from wood with pine fillets and dark stain. The engine is now dismantled, the pieces gets a coloring in dark green, red and purple for the cylinder and inner flywheel. The whole installation will get a coal bunker and boiler feed pump. May be, a small water tower will complete the whole model.
Thomas
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Congrats for the book. When will it be published?
This a very strange engine. I have been looking at the pictures for a while, but don't seem to understand the mechanism of all the levers.
The barrel is a nice detail. Did it come with engine?
Jurgen
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I hope, the book will be published in this year, may be in autumn. The crosshead or steeple engine was used in early American paddlers before walking beam engines were common.
No, the barrel wasn`t part of the engine, it`s a China made stainless steel container for strong alcoholic drinks - but the scale, about 1 : 10 seems quite correct for the water tank.
Thomas
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Some progress was archieved in the meantime, engine was painted and fixed with hotwell and boiler. The coal bunker will be beside the boiler, the water barrel behind. May be, the engine will connected with a generator to produce illumination of the whole steam plant - this must be nice at warm summer evenings?
Thomas
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Thanks for the explanation Thomas. I looked up Steeple Engine in Google and found plenty of help to understand the mechanism.
Nice idea to use a generator for the "warm summer evenings". Somewhere I saw an article where a guy modified a standard DC motor to look like an old generator. If I can find it again I'll let you know.
Jurgen
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Today I hat the first steam up of boiler with engine. I don`t fire with anthracite coal but with kindling and wood pellets. As long as there is no pressure, one must give attention, that the fire don`t goes out. As soon there was a pressure of 1,5 bar, I started the engine. With the draught of the exhaust steam it was no problem to reach 3 bar in short time, engine was runnig well. There is still no feed pump, but the engine could run 45 minutes, until I stopped to avoide scarcity of water. Minimum pressure for running engine this time was 0,5 bar.
With wood pellets it`s very easy to control the fire, after a while of burning the pellets became a glowing pile on the grate. Hotwell was leaking, but this became repaired in the meantime. May be tomorrow I will make an attempt with anthracite coal.
Thomas
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The steam plant with water barrel and feed pump now is finished and working well. I`m looking now for a generator for electric light. Steam pressure raised with draught of exhaust steam up to 4 bar. It`s best to fire with kinding wood in the beginnig and then with wood pellets. I also made a trial with anthazithe coal, but this must have very high temparature to lit. The engine was running 50 minutes, without any use of the feed pump.
There would be also a possibility to use the steam plant for a rather big òpen model boat a la`"African Queen"
Thomas
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