Pennsylvania Railroad Class A3

Pennsylvania Railroad Class A3
Technical specifications
Manufacturer(s)	Altoona Works
Build date	1895-1905
Total produced	81
Wheel arrangement	0-4-0
Rail gauge	Standard gauge

Pennsylvania Railroad's class A3 were a class of 81 0-4-0 steam locomotives. They were built by the Pennsylvania Railroad's Altoona Shops from 1895 until 1905.

Designed in 1895, this class had 50" drivers with a slope back tender, the boiler was of the Belpaire type which was first used on the Class R (H3) in 1885. They delivered 18,866lbs. of tractive effort with 160 psi running with 17"x24" pistons as they're performance. During they're service lives they were originally known as the class U but later on reclassified as the A3. A3s were used for switching services to sort out railroad cars at various Pennsylvania Railroad yards. Over time as freight cars got heavier, the engines were too light and not powerful enough when the PRR Introduced the A5s class during 1916. Not only before the A5s were put into service that several A3s were sold to other railroads, but this sealed the fate of them as all the tender versions were retired by the early 1920's. Several during the 1910s were converted to saddle tanks as they were used in lighter rail yard switching and roundhouse shops. They were all eventually scrapped as none of the A3 locomotives survive.

Trivia

• Some A3s were converted to A3as, which were saddle tank engines.
• The A3as also served the Pennsy until as late as 1929 or so, making them the longest lived of the A3 series overall.
• Only a small handful of these locomotives were upgraded with electric lighting as most kept they're as-built oil lamps. 

See also

• List of Pennsylvania Railroad Class A3 locomotives