I/12th scale Pendulous Engine

[Coxy]

Here are some pictures of a 1/12th scale model of a Pendulous Steam Engine, the full size of which was designed by Dr. Ernst Alban from Plau in Saxony, in about 1840. There is one preserved in a Museum in Germany, although I did not know this when I made the model (pre-internet!).
I was inspired to make it by a short article about it in the "Model Engineer' in the mid sixties. I got the details form a translated book about the work of Dr. Alban, that is held in the Science Museum Library in South Kensington, London, England.
The engine is called "pendulous" because the cylinder is suspended from a pivot at its top end, and swings like a pendulum when in motion. The steam ports are located on top of the top cylinder cover, and move under the slide valve which remains stationary, held by links to the frame work.
There are no castings in the model. All the parts have been cut from solid or fabricated. The fly wheel for instance has fifteen pieces in it. The most problematical part of the whole thing was the governor drive belt. It passes through the governor frame, and therefor has to be joined in situ. No rubber bands here, I'm afraid. I finally thought i had found a workable solution by using two layers of brown paper parcel tape, glued face to face, with a staggered joint. It is surprisingly strong. However, over time, something in the paper or glue caused corrosion on the pulleys. I then managed to make one from thin leather, with a scarfed joint stuck with woodworking impact adhesive. More corrosion! The belt has to be slipped off while the engine is not in use. I do have something else in mind, but I will tell you once I have tried it. Any suggestion would be welcome.
Glad to answer any questions you may Have.

Regards  Maurice

[Coxy]

Sorry, the picture of the old Stuart number one included by mistake. That's another story!
regards   Maurice

[vcutajar]

That is a fine model.

Vince

[Jasonb]

Now I know what you wanted the photos for When I first saw them I thought I've seen those somewhere before, only twigged when I saw Maurice at the end. Lovely job and a lot nicer finish that the other one I know of which has a bit too much bling for my liking

http://www.eckartkercher.de/Dr.Alban01.htm

BTW did you ever see my Easton and Anderson that you help me with the photos for?
http://www.modelenginemaker.com/index.php?topic=705.0

J

[Coxy]

Hi Jasonb; I've just seen your grasshopper beam engine on you thread. What a wonderful job. You have the finish just right. I am so glad that the pictures were of some help. Is it completely finished now?

Regards      Maurice

[b.lindsey]

That's some beautiful work Maurice!!  Thanks for finding and sharing the photos !!

Bill

[mklotz]

What a beautiful model.

Were such engines ever built in full scale and used for real work?  Somehow the idea of a steam engine with a moving cylinder seems like a nightmare to seal effectively enough to provide for economical operation.

[Roger B]

Excellent model   

It appears to be halfway between an oscillating engine and a conventional one?

[BillTodd]

What a beautiful model.

Where such engines ever built in full scale and used for real work?  Somehow the idea of a steam engine with a moving cylinder seems like a nightmare to seal effectively enough to provide for economical operation.

Yes a beautiful model

There is video (on youtube?) of a three cylinder oscilating engine on board a paddle steamer (low revs so wobbling cylinders not a problem)

Dampfmaschine der Marie  (1878) / Oscillating Ste…: <a href="https://www.youtube.com/watch?v=Q3WF0EY0cvY" target="_blank">http://www.youtube.com/watch?v=Q3WF0EY0cvY</a>

[fumopuc]

Hi Maurice, that is a beautiful engine you have build there. I like your interpretation of the Alban.

[fumopuc]

What a beautiful model.

Where such engines ever built in full scale and used for real work?  Somehow the idea of a steam engine with a moving cylinder seems like a nightmare to seal effectively enough to provide for economical operation.

Hi Marv, may I offer some pictures of the full scale Alban. Made by myself  at the "Deutsches Museum" in Munich.

[Coxy]

Thanks for all the nice feedback gents. The point raised by" mklotz" about sealing is not really a problem. The steam and exhaust pipe centres are coincident with the axis of oscillation of the cylinder. They just have to twist, and have glands such as you will find on a piston rod. There is a wedge behind an elbow in the steam pipe to stop the pressure blowing the joint apart. I like the pictures of the model by 'fumopuc", very nice! There are obvious differences between our models. If you read the book I was working from, you will see quite a lot of detail variations, obviously Dr.Alban was an innovator and his designs changed, I suspect, quite quickly.
There was one drawback to the engine, highlighted by the translator of the book I used. The engine could not be reversed. If the customer required one to rotate the other way, a mirror image version would have to be built.

Regards    Maurice

[mklotz]

OK, I'm convinced.  Next question...What advantage(s) were claimed for this engine over more conventional designs?  Actually, I suppose that question applies to any oscillating cylinder design.

[Coxy]

Hi Merv, good question. There were lots, according to Dr.Alban in his book. I have never read a book of this nature before, that is written in the first person. He was very fond of his own opinion. There are sentences starting "My method is superior...." and so on. In the section on his boilers, he speaks of "the dangerous English steam exploders'', actually with some justification, as his boilers were inherently very strong, but they had a low water capacity. I don't think this engine has any particular advantage over a conventional one, and several drawbacks, including the non-reversability. I just thought it was interesting, and a bit of a challenge.

Regards     Maurice

[mklotz]

I'm not suggesting that you shouldn't have modeled it, Maurice.  It makes a fine model and you did a splendid job building it.

But, in the world of real engines, there were all sorts of off-the-wall designs, most of which never went anywhere, presumably because they were inefficient or hard-to-maintain.  Admittedly, technological designs evolve over time.  Still, it's hard to understand what the designers of the odd-balls felt made their engines special.

BTW, my name is Marv, not Merv.