French Beam Engine
As machined and constructed by Rich Carlstedt
Brief history written by Ardyth Carlstedt
This is a prototype model of one of thousands of similar engines used to pump water in France from the mid 1700's to mid 1800's. There are no plans for this model.
Due to improving technology, and war, most all Beam Engines were scraped for material. Today there are less than 75 in the world. This model was scaled at an inch to a foot. Its' cast brass flywheel is 15" in diameter. The Beam Engine gets its name from the rocking beam developed for double-acting cylinders.
This engine is unique because James Watt controlled steam development in England until his patents on the kinematic linkage (Watt'Parallel Motion) shown here, expired about 1805.
The expiration of Watt's patents allowed extensive development and construction in other countries to begin and this French version was developed.
To start the engine, the engineer would disconnect the valve drive from the crankshaft and manually set the valve on the cylinder with his hand lever. After eliminating condensation in the cylinder, he would lock (latch up) the valve linkage.
Beam Engines were of great size, and, although outdated by 1820, they were built until the 1890's. Eventually, they were made obsolete by horizontal mill engines.
John Grant of Palo Alto, California found engravings of this steam engine in a French encyclopedia residing in the library at Stanford University. Because no drawings were available, John scaled the engravings to approximately 1-inch to the foot. Major components were then drawn for the model, and casting patterns made.
The patterns were loaned to Rich Carlstedt and were used to cast the engine frame, beam, valve chest, cylinder and fly-wheel. Rich then proceeded to make pencil drawings for other components which were subsequently machined in his shop in Green Bay. The only purchased items on this model are 0-80 screws and governor springs. Since these pictures were taken the French Beam Engine has been mounted on a tile floor (machined) as the original engine probably was.
If you have any questions about the above model you can contact Rich
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Richard Carlstedt All rights reserved.
Model Steam Engines