The PRR J1 was a class of

2-10-4 Under the Whyte notation for the classification of steam locomotives, a locomotive has two leading wheels on one axle, usually in a Bissel truck, ten coupled driving wheels on five axles, and four trailing wheels on two axles, usually in a bog ...

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

" 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, Fuel oil, oil or, rarely, Wood fuel, wood) to heat ...

s built between 1942 and 1944. The J1 had over of

tractive effort In railway engineering, the term tractive effort describes the pulling or pushing capability of a locomotive. The published tractive force value for any vehicle may be theoretical—that is, calculated from known or implied mechanical proper ...

, plus an additional if the

booster engine A locomotive booster for steam locomotives is a small supplementary two-cylinder steam engine back-gear-connected to the trailing truck axle on the locomotive or one of the trucks on the tender. It was invented in 1918 by Howard L. Ingersoll, ...

was used.

Features

As with many of the Pennsylvania Railroad's steam locomotives, the J1 had its headlight above the

smokebox A smokebox is one of the major basic parts of a steam locomotive exhaust system. Smoke and hot gases pass from the firebox through tubes where they pass heat to the surrounding water in the boiler. The smoke then enters the smokebox, and is ...

. Like the M1 the J1 had a keystone numberplate, unlike the round numberplates seen on the rest of the PRR's freight steam locomotives. Wartime restrictions forbid the design of a completely new engine so the PRR basically adopted the C&O design almost without change. As a result, they were equipped with

Baker valve gear After about 1910, the Baker valve gear was the main competitor to Walschaerts valve gear for steam locomotives in the United States. Strictly speaking it was not a valve gear but a variable expansion mechanism adapted to the Walschaerts layout repl ...

instead of

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 ...

which was more common on the PRR. Additionally, they had radial-stay fireboxes instead of the

Belpaire firebox The Belpaire firebox is a type of firebox used on steam locomotives. It was invented by Alfred Belpaire of Belgium in 1864. Today it generally refers to the shape of the outer shell of the firebox which is approximately flat at the top and s ...

es seen on nearly all of the Pennsylvania Railroad's steam locomotives. Mechanically, these locomotives were identical to the C&O's T-1 class 2-10-4s. As initially built, the middle driver was blind to facilitate tracking on curves, which was later determined to be unnecessary, and flanges were added later on. Other changes to the driving wheels included counterbalancing, as it was found in service that the J1s ran roughly like their T-1 counterparts. This was also fixed in later shopping, also increasing the driver diameter to . The engine had

lateral motion device A lateral motion device is a mechanism used in some railroad locomotives which permits the axles to move sideways relative to the frame. The device allows easier cornering. Purpose Before the introduction of the lateral motion device, the coupled ...

s to allow sideways drive axle travel which did enable it to work on PRR curves. Other changes included the curved front side cab windows and the cast pilot with drop coupler.

History

During

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

, the PRR needed heavier locomotives to pull freight and military equipment, but wartime restrictions prohibited the development of a new locomotive design. In response to this the Pennsylvania Railroad borrowed a

2-6-6-4 In the Whyte notation for the classification of steam locomotive wheel arrangement, a 2-6-6-4 is a locomotive with a two-wheel leading truck, two sets of six driving wheels, and a four-wheel trailing truck. All 2-6-6-4s are simple articulated loco ...

Class A of the

Norfolk and Western Railway The Norfolk and Western Railway , commonly called the N&W, was a US class I railroad, formed by more than 200 railroad mergers between 1838 and 1982. It was headquartered in Roanoke, Virginia, for most of its existence. Its motto was "Precisio ...

and a

from the

Chesapeake and Ohio Railway The Chesapeake and Ohio Railway was a Class I railroad formed in 1869 in Virginia from several smaller Virginia railroads begun in the 19th century. Led by industrialist Collis Potter Huntington, it reached from Virginia's capital city of Rich ...

. Both locomotives underwent extensive testing, with the C&O 2-10-4 chosen to be produced. A total of 125 were built at PRR's shops in Juniata, Pennsylvania; the later 60 locomotives were classified as the J1a. They came to be known as the PRR's "War Babies," but the J1's remained in service into the 1950s. When the Pennsylvania Railroad converted from steam power to diesel, 100 were scrapped in 1958 and the remaining 24 were scrapped the next year; however, a former J1 bell is preserved.

References

Bibliography

External links

J1 class diagram
{{PRR locomotives J1 2-10-4 locomotives Railway locomotives introduced in 1942 Steam locomotives of the United States Scrapped locomotives Freight locomotives Standard-gauge locomotives of the United States