Maudslay/Fellows Twin Cylinder Marine Engine

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Well-Known Member
Dec 5, 2011
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After doing drawings for the single cylinder Maudslay, it was inevitable that a twin cylinder version would be next. By the time the drawings were finished for the single, I had already had the initial drawings of the twin complete & Chuck had a chance to have a look at them.

For those unfamiliar with this engine, it was designed & built by Mr. Chuck Fellows & based on Henry Maudslays oscillating marine steam engine. Most of the parts are identical to the single cylinders design with obvious additions. The baseplate is going to be tricky, it's a manifold type of porting & will require some extended length drills, but certainly possible. Study the drawings carefully & you will see how I went about it. Not a beginners engine...

George Britnell built a .7 scale model of the single cylinder engine, added some braces to stiffen up the uprights & added a beautiful little govenor to it. After seeing Georges Engine, I knew I just had to incorporate those items into this design. After contacting George, he was more than happy to contribute his knowledge & CAD files to this design. Thanks very much George!!!

Files can be found here as one PDF file containing 29 drawings:

Hope you all enjoy these,




Junior Member
Sep 11, 2010
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Hi John,
I am a model maker with a lot of mechanical experience, having worked for 40 years as a mechanical expert. I have carefully seen your engine drawings in pdf format and I congratulate you for the attention to detail. Being Italian, I use the decimal metric system for the drawings, so I would like to transport the dimensions and adapt them to this type of unit. So I ask you if it was possible to have the Cad files of both the single cylinder and the twin cylinder engine. I am available to provide all the guarantees that the drawings just transferred with the decimal metric system will be made available to you.
I await your response, and for the moment I send you best regards.

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