The Hohenzollern Locomotive Works (Aktiengesellschaft für Lokomotivbau Hohenzollern) was a German

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

 locomotive

Locomotive

A locomotive is a railway vehicle that provides the motive power for a train. The word originates from the Latin loco – "from a place", ablative of locus, "place" + Medieval Latin motivus, "causing motion", and is a shortened form of the term locomotive engine, first used in the early 19th...

-building company which operated from 1872 to 1929. As well as conventional steam locomotive

Steam locomotive

A steam locomotive is a railway locomotive that produces its power through a steam engine. These locomotives are fueled by burning some combustible material, usually coal, wood or oil, to produce steam in a boiler, which drives the steam engine...

s the company also built fireless steam locomotives

Fireless locomotive

A fireless locomotive is a type of locomotive designed for use under conditions restricted by either the presence of flammable material or the need for cleanliness...

 and diesel locomotive

Diesel locomotive

A diesel locomotive is a type of railroad locomotive in which the prime mover is a diesel engine, a reciprocating engine operating on the Diesel cycle as invented by Dr. Rudolf Diesel...

s.

Fireless steam locomotives

Hohenzollern built a large number of fireless locomotives, including some articulated

Articulated locomotive

Articulated locomotive usually means a steam locomotive with one or more engine units which can move independent of the main frame. This is done to allow a longer locomotive to negotiate tighter curves...

 fireless locomotives with a cab at each end. Hohenzollern's fireless locomotives were unusual in having inside cylinders. The German for fireless steam locomotive is Dampfspeicherlokomotive, meaning steam storage locomotive.

Hohenzollern articulated fireless locomotives

Each locomotive had two 2-axle bogies. On no. 1685 only one axle was powered but, on the others, two axles were powered. For an explanation of wheel arrangements see: AAR wheel arrangement

AAR wheel arrangement

The AAR wheel arrangement system is a method of classifying locomotive wheel arrangements that was developed by the Association of American Railroads. It is essentially a simplification of the European UIC classification, and it is widely used in North America to describe diesel and electric...

. Nos. 1685 and 2107 (which were designed for use in mines) had air-cooled condensers

Steam locomotive condensing apparatus

A steam locomotive condensing apparatus differs in purpose from the usual closed cycle steam engine condenser, in that its function is primarily either to recover water, or to avoid excessive emissions to the atmosphere, rather than maintaining a vacuum to improve both efficiency and power...

 to condense the exhaust steam.

Works no.	Date built	Gauge	Wheel arrgt	Name	Condenser
1685	1904	840 mm	1A-2	BERGMANN	Yes
2107	1907	840 mm	B-2	GNOM	Yes
2483	1909	780 mm	B-2	-	No

Diesel locomotives

Hohenzollern supplied a 1,200 horsepower

Horsepower

Horsepower is the name of several units of measurement of power. The most common definitions equal between 735.5 and 750 watts.Horsepower was originally defined to compare the output of steam engines with the power of draft horses in continuous operation. The unit was widely adopted to measure the...

 diesel-mechanical locomotive to the Russian State Railways

Russian Railways

The Russian Railways , is the government owned national rail carrier of the Russian Federation, headquartered in Moscow. The Russian Railways operate over of common carrier routes as well as a few hundred kilometers of industrial routes, making it the second largest network in the world exceeded...

 in the 1920s. This had a constant-mesh gearbox with an individual electromagnetic clutch

Electromagnetic clutch

Electromagnetic clutches operate electrically, but transmit torque mechanically. This is why they used to be referred to as electro-mechanical clutches. Over the years, EM became known as electromagnetic versus electro mechanical, referring more about their actuation method versus physical operation...

 to engage each gear.

Around the same time, Russian State Railways also took delivery of a 1,200 hp diesel-electric locomotive, designed in Russia by Professor Lomonosov

Iurii Vladimirovich Lomonosov

Yury Vladimirovich Lomonosov was a Russian railway engineer and a leading figure in the development of Russian Railways in the early 20th century. He was best known for design and construction of the world's first operationally successful mainline diesel locomotive, which was completed in 1924 and...

. There is some dispute as to whether this was also built by Hohenzollern or by Esslingen Machine Works. Ref: http://home.att.net/~berliner-Ultrasonics/boxcabs5.html#odderbox

Sources

• German Wikipedia article
• The Locomotive Engineers' Pocket Book 1934, (UK), publisher unknown, page 286
• The Industrial Railway Record, published by the Industrial Railway Society
  Industrial Railway Society
  The Industrial Railway Society was founded in the United Kingdom in 1949 as the "Birmingham Locomotive Club - Industrial Locomotive Information Section"....
  
  , ISSN 0537-5347, no. 166 (2001), page 10 and no. 170 (2002), pp 216-218

External links

• German Wikipedia article
• List of preserved Hohenzollern locomotives
• Photo of Hohenzollern fireless locomotive at Keilehaven Gas Works, Rotterdam