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 bogie ...

Texas Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...

" 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 ...

s with

driving wheel On a steam locomotive, a driving wheel is a powered wheel which is driven by the locomotive's pistons (or turbine, in the case of a steam turbine locomotive). On a conventional, non-articulated locomotive, the driving wheels are all coupled ...

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

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 ...

, plus an additional if the

booster engine A booster engine for steam locomotives is a small two-cylinder steam engine back-gear-connected to the trailing truck axle on the locomotive or the lead truck on the tender. A rocking idler gear permits it to be put into operation by the drive ...

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 e ...

. 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 sq ...

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. With experience the railroad determined that this wasn't necessary and after shopping the middle driver was equipped with flanges. The engine did have

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 facilitates cornering. Purpose Prior to the introduction of the lateral motion device, the coupled ...

s to allow some sideways drive axle travel which did enable it to work on Pennsy curves. Other PRR 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, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

, 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 Class A of the

Norfolk & 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 Railroad 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 P. Huntington, it reached from Virginia's capital city of Richmond ...

. 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. 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 25 were scrapped the next year.

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