Marine steam engines and boilers

[Dave Stevens (Lumberyard)]

There is a vast field of marine subjects that have not been explored by model builders such as merchant ships, work boats and steam boats these are general subject topics and they are broken down into all sorts of ships.

This topic is all about the world of steam engines what they look like and how they work.

the forum is dominated by kit builders of wooden sailing war ships but that to me is no reason not to create a reference subject on something totally different.

When you look at the mechanical aspects of the workings of steam power there is a sublime beauty in it. Cross sections of these ships and boats from a simple steam launch to the biggest of merchant and passenger ships give us all an endless array of models that can be built and challenges to meet.

 

[Moxis]

Very interesting subject. We have just started a project to build a model of a steam powered launch/tugboat "Lempi" (Love in English) made on 1877 at Ahlstrom shipwright in Varkaus, Finland. Original plans can still be found in internet, and are already copied into the size that equals a scale of 1/15, which will produce a 1200 mm long model.

To power the ship I have thought to use a steam engine of my own fabrication. After having searched information about suitable engines, I have come to conclusion to build a two cylinder slide valve engine Marcher, for which a set of plans and castings has been ordered, and work can be started when the parts arrive.
My intention is to start a build log of this project in the near future, after there is something to show. Most probably the hull will be made with POB method, first of wood, of which molds will be made to produce final hulls from glassfibre/epoxy.

 

[Dave Stevens (Lumberyard)]

As this topic progresses it is my hope it will include all types of marine steam engines but to kick thing off I will start with the engine of the steam frigate Mississippi. After searching the National Archives in Washington D.C. I found a number of drawings. What ran through my head was Oh happy days I got the drawings, well that was short lived! reviewing the drawings more and more questions arose and NO instructions, NO isometric drawing of the complete engine and worst of all a total lack of knowledge on my part as to building such a thing. It makes you want to give up the idea like trying to assemble a jig saw puzzle with the picture facing down on the table and you trying to assemble it from the back side. What are all these parts and where do they go? and if that is not enough how about actually building it so it can move. The original plans are not a set of "kit plans" by no stretch of the imagination, these are plans for an engineer.

this is also serves as an example for any modeling project when you are faced with a lack of information, where do you get it? how do you apply it to the project?

air pump etc



back sink

bars


bed plate plan elevation


blocking for propeller shaft

 

[Dave Stevens (Lumberyard)]

blow valves



unknown parts


bottom inspection lock


bunkers on berth deck


bunkers


columns frame


connect rod main strap


cranks


crosstails crank wrot iron

 

[Dave Stevens (Lumberyard)]

crosstail crank


cylinder rod ends


cylinder side rod


cylinders


engine corp


engine room floor

 

[Dave Stevens (Lumberyard)]

engine sections


excentric hook


excentric shaft rock shaft bearings


excentric air


exhaust and steam rods parallel shaft


feed safety valve

 

[Dave Stevens (Lumberyard)]

frame section


frame1

frame2


framing for engine


friction rim for water wheels

 

[Dave Stevens (Lumberyard)]

front of boiler steam pipe


furnace doors


outboard delivery valve


parallel steam and exhaust shafts



piston and rod

 

[Dave Stevens (Lumberyard)]

present pipe


pumps bolts


pumps


ratchet and spring catch


radius rods

 

[Dave Stevens (Lumberyard)]

regulating screw


reservoir


unknown

 

[Dave Stevens (Lumberyard)]

safety valve


section of columns


shafts

 

[Dave Stevens (Lumberyard)]

side pipes with valves


side stop cocks


side stop lock


side wheel


sir? chamber


smoke chimney and parts


smoke chimney with parts

 

[Dave Stevens (Lumberyard)]

unknown


water wheels

 

[Dave Stevens (Lumberyard)]

the next 15 images were one drawing but badly damaged so the drawing was photographed in sections

 

[Dave Stevens (Lumberyard)]

starting the CAD drawings for the engine first will be the main frame structure then everything else will fit to it.

I am not using the drawing posted on the forum, they have been reduced to a lower resolution., I will be tracing the original drawings which are bigger in size and higher in resolution so I can zoom in close.

first is to scale the original so working in 3/8 inch = I foot the green arrow on the left is 17 feet 11 inches to scale that is 6 3/4 inches now I know how tall the model will be so I can be sure it can be printed.




starting with the green arrow that line is 132 inches according to the drawing see above there are lines with 66 inches from center. look right and you can see the red line falls short because the blue arrow is showing a rip in the original. Move the rip together and the CAD line is exact.

orange arrow and the magenta line it is level but the original drawing shows it above the magenta line. look at the arch below the right side is distorted because of the rip.

Finally the short red line above the magenta line plan says the bed is 75 inches to the right it falls short of the side to the right, once again the rip is to blame.

This gives you an idea what it takes to draw out a set of plans of a stream engine or a ship or anything going from a paper plan to a working set of plans for model engineering.

 

[Moxis]

I too have always been interested about the paddle wheelers powered with steam engines. Some time ago I was going to start building a model of such a ship, and bought a documentation package from Seawatch Books for USS Susquehanna. My original idea was to make a rc model of her, but with an electrical drive. I thought to build a working steam engine which however does not work with steam, but be powered with electric motor situated so that it cannot be seen.
There are very nice drawings of the steam engine which eventually has been used in USS Susquehanna, at the drawings and book included into documentation package. The author of the book has made a model of the engine out of wood, which he descibes nicely at the book, so it might be possible to follow his footsteps to build a working engine which looks natural enough, without making all the details exactly as with original engine.

 

[Dave Stevens (Lumberyard)]

Moxis I am doing the same thing I am building the Mississippi engine to run off an air pump and not steam.

most all drawings and plans of early steam engines are in England, Germany and Norway few are here in North America
as a matter of fact you can find steam engines in parks around Europe



and models in marine and science museums London England



getting drawings is another story those are in archives and difficult to locate and get copies

 

[Dave Stevens (Lumberyard)]

here are some of the books in my collection on steam. The books are quite useful on how steam engines work and how they are built

I can ask Author if he would upload the PDF files on the Navy Board site so you can look at the books

 

[Dave Stevens (Lumberyard)]

drawing the column



when I zoom in close there is not enough clear details at the base



there is a drawing in the collection of the column base that was sharp enough to get details
first I drew a center line and then drew the left side, next I mirrored the left side to the right. You can see how much the original drawing has distorted. also an interesting thing is it looks like a pipe that runs up the center of the column



I scaled the drawing and placed it on the main frame drawing you can see here the original drawing is way off. I also removed the inner pipe on the drawing. I knew the correct size because on the main frame drawing is a measurement of 18 inches at the base of the column those are the short outer lines on top of the base drawing.

 

[Dave Stevens (Lumberyard)]

as for the column itself there is a cross section drawing, I imported the drawing and on the right I traced it


I will take the file and change the view



I will now lift the shape of the column right off the drawing



For the old school guys who say they rather draw with pen and ink on paper Well you can not do this. From here I can take the column scale it, make it any length and set it into the main frame drawing. I can also export this drawing to a 3D print format and print out an exact detailed column.

The columns are hollow so either a pipe runs up the column or the column is being used as a pipe line.