American Propeller and Manufacturing Company, in
Baltimore
Baltimore ( , locally: or ) is the List of municipalities in Maryland, most populous city in the U.S. state of Maryland, fourth most populous city in the Mid-Atlantic (United States), Mid-Atlantic, and List of United States cities by popula ...
manufactured 75 percent of all
propellers
A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon ...
used by America in World War I.
History
APMC was founded by a
patent lawyer and engineering
consultant Spencer Heath
Spencer Heath (January 3, 1876, Vienna, Virginia – October 6, 1963, Leesburg, Virginia) was an American engineer, attorney, inventor, manufacturer, horticulturist, poet, philosopher of science and social thinker.Spencer Heath MacCallum"The Qu ...
. His clients included
Simon Lake
Simon Lake (September 4, 1866 – June 23, 1945) was a Quaker American mechanical engineer and naval architect who obtained over two hundred patents for advances in naval design and competed with John Philip Holland to build the first submarines f ...
, inventor of the even-keel-submerging submarine, and
Emile Berliner
Emile Berliner (May 20, 1851 – August 3, 1929) originally Emil Berliner, was a German-American inventor. He is best known for inventing the lateral-cut flat disc record (called a "gramophone record" in British and American English) used with a ...
, inventor of the flat-disk phonograph record. Heath helped Berliner design and build the first
rotary engine
The rotary engine is an early type of internal combustion engine, usually designed with an odd number of cylinders per row in a radial configuration. The engine's crankshaft remained stationary in operation, while the entire crankcase and its ...
blades used in
helicopters
A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes ...
while working in Washington as general manager of the
Gyro Motor Company
Gyro Motor Company was an American aircraft engine manufacturer.
History
In 1901, inventor Emile Berliner (1851-1929) began building experimental helicopters that used Addams-Farwell rotary engine.
The Gyro Motor Company was formed in 1909 by ...
.
[Alvin Lowi, Jr., P.E.]
The Legacy of Spencer Heath
July 13, 2006. Heath developed and first mass-produced
airplane
An airplane or aeroplane (informally plane) is a fixed-wing aircraft that is propelled forward by thrust from a jet engine, Propeller (aircraft), propeller, or rocket engine. Airplanes come in a variety of sizes, shapes, and wing configurat ...
propellers at APMC. In 1922 he founded Paragon Engineers inc, and demonstrated the first engine-powered and
controlled, variable and reversible pitch propeller.
AMPC was initially founded in Washington D.C to build low-production experimental and custom propellers under the name Paragon. In 1912 the company moved to Baltimore, Maryland. Initial propellers were built with Mahogany wood, followed by Oak with sprucewood cores, and by 1915 APMC converted to solid oak construction. With the onset of World War I, AMPC became the largest manufacturer of wooden aircraft propellers in America by 1918. Four manufacturing plants operated in Baltimore to meet World War I production contracts . The 95,000 sq foot plant number four was constructed in 1918 specifically for propeller production with a capacity of 300-500 propellers per day. An additional 90 propellers a day were produced at the other three plants. The plants used 158,000 sqft of dry kilns to process wood and custom duplicating machines that reduce the number of lathes required for the construction process. Over 25,000 propellers were produced in World War I with 8000 delivered to the
Royal Flying Corps Canada
The Royal Flying Corps Canada (RFC Canada) was a training organization of the British Royal Flying Corps located in Canada during the First World War. It began operating in 1917.
Background
As the war progressed, Great Britain found that i ...
.
In 1937, the company took a case to the United States Supreme court. The company stated it was owed income from contracts ending in 1918, the government counterclaimed several years later that it was overcharged. The difference between the amounts was roughly $12,000 in favor of APMC. While each side litigated who owed each other for over a decade, both sides charged interest, changing the amount to be payment to a penalty of over $36,000. The court ruled in favor of APMC, stating the counter claim failed to provide adequate evidence initially, so accrued interest could not be charged
On display
An example of a Paragon propeller is on display at the
EAA Airventure Museum
The EAA Aviation Museum, formerly the EAA AirVenture Museum (or Air Adventure Museum), is a museum dedicated to the preservation and display of historic and experimental aircraft as well as antiques, classics, and warbirds. The museum is lo ...
in
Oshkosh, Wisconsin.
See also
*
List of aircraft propeller manufacturers
References
{{Reflist
External links
Basic Propeller Construction - Materials
Aviation in Washington, D.C.
Aviation in Maryland
Aircraft propeller manufacturers
Bendix Corporation