PA/PB Diesel Locomotive

Prototype Information

The ALCO PA hit the rails in 1946 as a powerful passenger diesel built to compete with EMD’s E-units. Its 16-cylinder 244 engine produced 2,000 horsepower, and the streamlined carbody rode on A1A-A1A trucks for a smooth, fast ride. Railroads loved the PA for its power, reliability, and distinctive styling.

ALCO built nearly 150 A units and a handful of B-unit boosters between 1946 and 1953. The Delaware & Hudson, New York Central, and Baltimore & Ohio put them on flagship trains across the Northeast and Midwest.

As passenger service declined, many PAs moved to freight or short-line work. A few survive today in museums or on tourist railroads, standing as ALCO’s most famous passenger locomotive.