Model of Vertical Marine Steam Engines

Model of Vertical Marine Steam Engines

<< >>
Usage conditions apply
Downloads
Description
This is a model illustrating the details of three marine steam engine designs. At the left of the image of the model is a single cylinder steam engine. The middle engine model is a triple expansion, compound design. The left engine model is a double expansion, compound engine. Each model engine is highly detailed and shows the workings of the valves, crankshafts and other key elements.
A compound steam engine consists of a high pressure cylinder and one or more lower pressure cylinders. The steam exhausted from the high pressure cylinder is used as inlet steam for the next lower pressure cylinder. Each cylinder is sized in proportion to its inlet steam pressure so that each produces the same amount of work. Compounding was introduced in the early 19th century and widely used in many applications from steamship propulsion to powering large electrical generators.
The benefit gained from the increased complexity of compounding was efficiency. A single cylinder engine (other than those using uniflow valves) suffers from repetitive cooling and heating of the cylinder walls and piston at each stroke. These temperature differences create no work and consume fuel. A compound engine reduces this effect by having the same amount of steam expansion and cooling spread over multiple cylinders.
Object Name
Engine, Steam
ID Number
MC.310578
catalog number
310578
subject
Model
Steam Engines
Steamships
See more items in
Work and Industry: Mechanical and Civil Engineering
Engineering, Building, and Architecture
Exhibition
Power Machinery
Exhibition Location
National Museum of American History
Data Source
National Museum of American History
Nominate this object for photography.   

Our collection database is a work in progress. We may update this record based on further research and review. Learn more about our approach to sharing our collection online.

If you would like to know how you can use content on this page, see the Smithsonian's Terms of Use. If you need to request an image for publication or other use, please visit Rights and Reproductions.

Note: Comment submission is temporarily unavailable while we make improvements to the site. We apologize for the interruption. If you have a question relating to the museum's collections, please first check our Collections FAQ. If you require a personal response, please use our Contact page.