This is a model of a “fore and aft” type compound steam engine. It is the kind of engine that had marine applications in powering tug boats, trawlers, and similar craft. A compound steam engine has two cylinders of different sizes. The smaller is the high pressure (HP) cylinder into which high pressure steam is introduced from the boiler. After expansion, its pressure reduces and its passed through the receiver to the low pressure (LP) cylinder. There it undergoes further expansion and is finally expelled through the exhaust pipes.
This engine also includes a fully working Stephenson link motion for reversing and controlling the point of cutoff for both cylinders. Detailed plans for this engine can be found in the first volume of The Shop Wisdom of Rudy Kouhoupt. Rudy’s original construction series on building this fore and aft compound ran in Live Steam magazine, in the issues from March through November 1988. The engine can be seen running in the video below.
One of the first large donations to the Miniature Engineering Craftsmanship Museum was the collection of famed model engine builder Rudy Kouhoupt. Rudy’s niece, Susan Alvaro, was kind enough to donate his entire lifetime engine collection for display at the grand opening of the museum in 2006. After retiring as a chemist, Rudy had a second career building engines and writing magazine articles documenting the process. Many people have built his models, but we have the honor of displaying all of his original prototypes. Rudy’s collection includes scale model engines, locomotives, tractors and more. Additionally, thirteen of Rudy’s model steam engines are hooked up to run on compressed air to demonstrate their function.
