The Pennsylvania Railroad's class H6, H6a, and H6b steam locomotives were of the 2-8-0

2-8-0

Under the Whyte notation for the classification of steam locomotives, 2-8-0 represents the wheel arrangement of two leading wheels on one axle , eight powered and coupled driving wheels on four axles, and no trailing wheels...

 "Consolidation" freight type, the most numerous class on the railroad with 2032 units. The three sub-classes differed as follows:

Class	Firebox	Gate	Tractive Force	Driver Size	#Built	Years Built
H6	narrow	33.3	42717	56”	189	1899-01
H6a	Wide	49	42168	56"	1242	1901-05
H6b	Wide	49	42168	56"	603	1905-13

In the 1920s, 699 H6a and H6b had superheaters added and cylinder size increased from 22” to 23” and reclassified to H6sa and H6sb.

Class H6 were used throughout the system as mainline freight haulers, on local freights, and as switchers in yards. They were frequently seen double and triple heading long freight trains up the steep grades on the Pennsy.

Survivors

PRR #2846, an H6sb built in 1905 by the Baldwin Locomotive Works

Baldwin Locomotive Works

The Baldwin Locomotive Works was an American builder of railroad locomotives. It was located in Philadelphia, Pennsylvania, originally, and later in nearby Eddystone, Pennsylvania. Although the company was very successful as a producer of steam locomotives, its transition to the production of...

, has been preserved by the Railroad Museum of Pennsylvania

Railroad Museum of Pennsylvania

The Railroad Museum of Pennsylvania is a railroad museum in Strasburg, Lancaster County, Pennsylvania.The museum is located on the east side of Strasburg along Pennsylvania Route 741...

 with two other examples of the H class. #2846 was added to the National Register of Historic Places

National Register of Historic Places

The National Register of Historic Places is the United States government's official list of districts, sites, buildings, structures, and objects deemed worthy of preservation...

in 1979 as Consolidation Freight Locomotive No. 2846.