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
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Beam Engines were of great size, and, although outdated by 1820, they were built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.
The Model 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 questions concerning this model E-mail Rich here.
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R. Carlstedt All rights reserved.