Pennsylvania Railroad B6

The Pennsylvania Railroad class B6 was the railroad's most successful class of switcher locomotive, which the company called a shifter. It used the 0-6-0 wheel arrangement that the railroad preferred for larger switchers, with the Belpaire firebox and 56-inch drivers typical of the system. The prototype was built at the Altoona Works in 1902, and later subclasses, the B6sa and B6sb, added radial-stay fireboxes, Walschaerts valve gear and power reverse. Many hundreds were built between 1902 and 1920. The last PRR locomotive in active service was a B6, number 5244, leased out until July 1959, and two survive.