Jensen Steam Engines is a manufacturer of
model/toy steam engines, located in
Jeannette, PA USA. Established in 1932 by Tom Jensen Sr. They are still making steam engines using traditional technology and methods.
History
Tom Jensen Sr (1901–1992) was born and educated in Denmark and was interested in
steam engine
A steam engine is a heat engine that performs mechanical work using steam as its working fluid. The steam engine uses the force produced by steam pressure to push a piston back and forth inside a cylinder. This pushing force can be ...
s from an early age. In 1923 he made a large model steam engine which is still in working order and is now unofficially known as the Jensen #1. As a young man, he moved to the United States looking for work as an engineer. While waiting for a "proper" job to come along, he made a few samples of steam engines, hoping to sell them in a local department store. These were seen by a buyer from the F.A.O. Schwarz Toy Store in NY, who placed an order. The first batch of engines created much interest from other stores and catalogues and Jensen Steam Engines Inc. came into being in 1932.
The factory temporarily closed at the start of
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...
but soon reopened to make equipment for the army. In 1992,
George Bush wrote to Jensen, thanking him for his "...unique contribution to America".
On his death in 1992, Tom Jensen Sr. passed on the business to his son Tom Jr., who has continued the business until the present. Jensen Steam Engines is still a small family-owned business making steam engines using the same traditional technology as used by Tom Sr.
Of historical significance:
The world's first nuclear power generated electricity was produced in September 1948 with the
X-10 Graphite Reactor at
Oak Ridge National Laboratory
Oak Ridge National Laboratory (ORNL) is a U.S. multiprogram science and technology national laboratory sponsored by the U.S. Department of Energy (DOE) and administered, managed, and operated by UT–Battelle as a federally funded research an ...
, Oak Ridge, Tennessee, where among other firsts, this first ever electricity generated by nuclear power occurred utilizing a Jensen #50 steam engine and generator. A miniature atomic power plant was operating and generating electricity on September 3, 1948 per records at ORNL.gov. The #50 was the largest model engine and generator made by Jensen Manufacturing Co of Jeannette, PA. That Jensen #50 and generator are still there in the Graphite Reactor building and still on the same shelf they were mounted on in 1948. That shelf with the engine is now part of a kiosk display in the visitor area in front of the loading face of the X-10 Graphite Reactor. While the power generated here was only about 3 volts, enough to light a flashlight bulb, it did occur in Oak Ridge in 1948 with a Jensen Steam Engine and generator. The makeshift boiling water reactor that these engineers built also became the test bed for the light water reactors used today.
Models
The current range of models are divided into the Hobby/Educational series and the Collector/Commercial series; the latter being more substantial and "up-market". Some models are electrically heated and some are
solid fuel
Solid fuel refers to various forms of solid material that can be burnt to release energy, providing heat and light through the process of combustion. Solid fuels can be contrasted with liquid fuels and gaseous fuels. Common examples of solid fuel ...
fired; some on pressed steel bases and some on wooden bases.
Current range
Hobby

* #25
* #25G
* #60
* #65
* #70
* #70G
* #75
* #76
* #85
Collector
* #20
* #20G
* #55
* #55G
* #95G
* #50 returned to production 2015-2016
Discontinued models
* #5 1932-1960s
* #10 1932–1979
* #30 1954–1982
* #35 1934–1960
* #40 1960-1965
* #45 1949-1959
* #50 1930s-2011
[Jensen Steam Engines]
* #51
* #78 1981?
* #80 1980s
* #90 1961 and 1988
One-offs and Specials
* #1 1923
* #20S 1984
* #51 1973-1996
* #55S 1984
* #85G 1996
Accessories
* #15 1935 current
* #15BL 2004
* #15D 1990
* #15E 2004
* #100 1948–1985
See also
*
Mamod
Mamod is a British toy manufacturer that specializes in manufacturing live steam models. The company was founded in Birmingham by Geoffrey Malins in 1937. The name is a portmanteau of Malins Models. The first models produced were of stationary ...
*
WilescoMiniSteam
References
{{Reflist 4.^ http://www.indianarog.com/jensenchronologyvarieties.htm
External links
Jensen Steam Engines web siteMiniSteam
Toy steam engine manufacturers