The Prussian S 9 was an express steam locomotive with the

Prussian state railways The term Prussian state railways (German: ''Preußische Staatseisenbahnen'') encompasses those railway organisations that were owned or managed by the State of Prussia. The words "state railways" are not capitalized because Prussia did not have a ...

, first built in 1908. It had a 4-4-2 (''Atlantic'')

wheel arrangement In rail transport, a wheel arrangement or wheel configuration is a system of classifying the way in which wheels are distributed under a locomotive. Several notations exist to describe the wheel assemblies of a locomotive by type, position, and c ...

and a four-

cylinder A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base. A cylinder may also be defined as an infin ...

compound engine A compound engine is an engine that has more than one stage for recovering energy from the same working fluid, with the exhaust from the first stage passing through the second stage, and in some cases then on to another subsequent stage or even st ...

. It was developed by the firm of

Hanomag Hanomag (Hannoversche Maschinenbau AG, ) was a German producer of steam locomotives, tractors, trucks and military vehicles in Hanover. Hanomag first achieved international fame by delivering numerous steam locomotives to Finland, Romania and ...

Hanover Hanover (; german: Hannover ; nds, Hannober) is the capital and largest city of the German state of Lower Saxony. Its 535,932 (2021) inhabitants make it the 13th-largest city in Germany as well as the fourth-largest city in Northern Germany ...

who delivered a total of 99 engines of this class. There were also some high-speed trials locomotives which were classified as S 9s, but did not belong to this particular class. These included two cab-forward 4-4-4 locomotives Altona 561 and 562. Although at the time

superheated A superheater is a device used to convert saturated steam or wet steam into superheated steam or dry steam. Superheated steam is used in steam turbines for electricity generation, steam engines, and in processes such as steam reforming. There are ...

technology was widespread, the state of

Prussia Prussia, , Old Prussian: ''Prūsa'' or ''Prūsija'' was a German state on the southeast coast of the Baltic Sea. It formed the German Empire under Prussian rule when it united the German states in 1871. It was ''de facto'' dissolved by an ...

still wanted to have saturated steam engines delivered by Hanomag. The locomotives procured as a result had a very powerful

boiler A boiler is a closed vessel in which fluid (generally water) is heated. The fluid does not necessarily boil. The heated or vaporized fluid exits the boiler for use in various processes or heating applications, including water heating, centr ...

and, at 4 m², the largest grate area of any Prussian steam locomotive. The quantity of steam generated was however more than the high-pressure cylinders could cope with. As a result, the performance of the S 9 was little better than the considerably smaller superheated locomotive, the

Prussian S 6 The Prussian S 6 (later DRG Class 13.10–12) was a class of German steam locomotive with a 4-4-0 wheel arrangement operated by the Prussian state railways for express train services. Development After the Prussian steam locomotive classes S 4 ...

. Nevertheless, the S 9 initially formed the backbone of

express train An express train is a type of passenger train that makes a small number of stops between its origin and destination stations, usually major destinations, allowing faster service than local trains that stop at most or all of the stations alo ...

services from

Berlin Berlin ( , ) is the capital and List of cities in Germany by population, largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's List of cities in the European Union by population within ci ...

to Hanover. Like all German ''Atlantic '' locomotives, the S 9 quickly proved too underpowered for the increasingly heavy trains it had to haul. Two locomotives (''Hannover 903'' and ''905'') were fitted with superheated boilers in 1913 and 1914 and reclassified as S 8s. After 1919 17 locomotives had to handed over to

Belgium Belgium, ; french: Belgique ; german: Belgien officially the Kingdom of Belgium, is a country in Northwestern Europe. The country is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeast, France to th ...

and 4 to

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...

. Only three of them, the two S 8s and a saturated steam engine, were taken over by the

Deutsche Reichsbahn The ''Deutsche Reichsbahn'', also known as the German National Railway, the German State Railway, German Reich Railway, and the German Imperial Railway, was the German national railway system created after the end of World War I from the regiona ...

as DRG Class 14.0. The two S 8s were given numbers 14 001 and 14 002; the S 9 ("Essen 907") number 14 031. All three were retired by 1926. The locomotives were equipped with Prussian tenders of classes pr 2'2' T 21.5, pr 2'2' T 30 und pr 2'2' T 31.5. Belgian engines managed to outlive German engines by several years since they were only written-off in 1948. They were used on fast trains on the lines around Antwerp.

References

* * {{DEFAULTSORT:Prussian S 09 S 09 4-4-2 locomotives Passenger locomotives Railway locomotives introduced in 1908 Standard gauge locomotives of Germany 2′B1′ n4v locomotives Four-cylinder compound steam locomotives

See also

References