The

Pennsylvania Railroad The Pennsylvania Railroad (reporting mark PRR), legal name The Pennsylvania Railroad Company also known as the "Pennsy", was an American Class I railroad that was established in 1846 and headquartered in Philadelphia, Pennsylvania. It was named ...

's class ''K29s'' comprised a single experimental

4-6-2 Under the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of four leading wheels on two axles, six powered and coupled driving wheels on three axles and two trailing wheels on one axle. The locomotiv ...

"Pacific" type

steam locomotive A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material (usually coal, oil or, rarely, wood) to heat water in the locomot ...

. Constructed by Alco-Schenectady, it was given road number 3395. Although only one demonstrator was constructed, the K29s would become the basis for the highly successful K4s Pacifics and L1s Mikados. The lone example spent most of its life on the PRR's Pittsburgh division main line and was retired around 1929.

History

The sole K29s, PRR 3395, was constructed by the

American Locomotive Company The American Locomotive Company (often shortened to ALCO, ALCo or Alco) was an American manufacturer of locomotives, diesel generators, steel, and tanks that operated from 1901 to 1969. The company was formed by the merger of seven smaller locomo ...

's Schenectady works in 1911 as a demonstrator engine for the

. The success of the single experimental K29s lead to the development of the equally successful K4s class Pacific and L1s class Mikado locomotives. Despite its success, the K29s was one of only a handful of locomotives constructed by Alco Schenectady as the PRR preferred its own

Altoona Works Altoona Works (also known as Altoona Terminal) is a large railroad industrial complex in Altoona, Pennsylvania. It was built between 1850 and 1925 by the Pennsylvania Railroad (PRR), to supply the railroad with locomotives, railroad cars and relat ...

as well the

Baldwin Locomotive Works The Baldwin Locomotive Works (BLW) was an American manufacturer of railroad locomotives from 1825 to 1951. Originally located in Philadelphia, it moved to nearby Eddystone, Pennsylvania, in the early 20th century. The company was for decades t ...

Philadelphia Philadelphia, often called Philly, is the largest city in the Commonwealth of Pennsylvania, the sixth-largest city in the U.S., the second-largest city in both the Northeast megalopolis and Mid-Atlantic regions after New York City. Sinc ...

for large scale locomotive production. The sole K29s spent its entire operating life on the PRR's Pittsburg Division main line pulling limited passenger trains and being used as a helper engine. Rumors circulated stating the K29s was able to haul 13 full sized passenger cars unassisted on an uphill grade between

Gallitzin, Pennsylvania Gallitzin is a borough in Cambria County, Pennsylvania, in the United States. It is bordered by Gallitzin Township and Tunnelhill, all of which sit astride the Eastern continental divide. Tunnel Hill and Gallitzin both are pierced by railroad t ...

and

Altoona, Pennsylvania Altoona is a city in Blair County, Pennsylvania. It is the principal city of the Altoona Metropolitan Statistical Area (MSA). The population was 43,963 at the time of the 2020 Census, making it the eighteenth most populous city in Pennsylvania. ...

. By 1929 however, the K29s was stricken from the PRR's locomotive roster.

Specifications

The K29s had six driving wheels measuring in diameter each and a total wheelbase. The total weight including engine and tender was , while the engine alone weighed . The K29s used the

Walschaerts valve gear The Walschaerts valve gear is a type of valve gear used to regulate the flow of steam to the pistons in steam locomotives, invented by Belgium, Belgian railway mechanical engineering, engineer Egide Walschaerts in 1844. The gear is sometimes name ...

, with cylinders. The

tractive effort As used in mechanical engineering, the term tractive force can either refer to the total traction a vehicle exerts on a surface, or the amount of the total traction that is parallel to the direction of motion. In railway engineering, the term tr ...

was . It also had a total firebox heating surface of and a fire grate of . It was paired with a Class 80-P-83 tender that could carry of water and 14 tons of soft coal. The K29s had an unusually massive boiler for its time, measuring between and in diameter and in length from firebox to smokebox door. Most of the basic specifications can also be found on the succeeding K4s Pacifics, which was directly developed from the K29s.

History

Specifications

References

Further reading