Top Three Most Powerful ALCO Passenger Diesels
The American Locomotive Company (ALCO) is perhaps best known for some of the most beautiful diesels ever designed, especially for passenger service. As a similar case to Electro-Motive, ALCO produced passenger cab units that rode primarily on three-axle, two-motored A1A trucks, a common practice during the early diesel era. Examples include the DL series and the popular PA series. However, it also manufactured some cab units (e.g. FA series) equipped with two-axle B trucks and optional steam generators, but these are otherwise considered to be freight units. Even a few RS-series road switchers were no strangers to passenger duty. As a side note, ALCO and its Canadian subsidiary, the Montreal Locomotive Works (MLW), built several fleets of FPA diesels, all of which were delivered with steam heaters. As in the previous passenger locomotive rankings, any diesels fitted with optional steam generators or head-end power (HEP) but not classified as separate variants are omitted in the top three ALCO/MLW models to be mentioned.
First up, the Bronze Medal of Passenger Power is going to the gorgeous PA-1 and its cabless PB-1. Launched in September 1946, the 2,000-horsepower PA was the first locomotive to use the 16-cylinder ALCO 244 diesel engine; it was initially designed as a 12-cylinder prime mover for the freight-only FA-1 model a few months earlier. Interestingly, the older DL locomotives were powered by a pair of turbocharged, six-cylinder 539T engines, each producing 1,000 hp. That gives a total of 2,000 hp in 12 cylinders, compared to 16 in a single 244 model. Yet the PA didn’t require a double engine to produce the same rating as in the pre-World War II DL series.
Earning the Silver Medal of Passenger Power is the PA-2, along with the PB-2. While nearly identical to its direct predecessor, the PA-2 had the same 244 engine but with 2,250 horsepower, a difference of just 250 horses. Appearance-wise, one minor detail that makes the PA-2 different from the PA-1 is the absence of two curved grille pieces immediately behind the cab portion. Still, these two PA models had the most attractive nose design ever created.
Finally, the Gold Medal of Passenger Power is going to Bombardier’s high-speed “Light, Rapid, Comfortable” LRC diesel locomotives. In 1973, MLW assembled the first LRC unit as a 2,900-hp demonstrator with the 12-cylinder ALCO 251F engine. The head-end power supply required about 900 horses, so the traction output for the LRC would almost be the same as the aforementioned PA-1. It wasn’t too long before MLW was effectively absorbed by Bombardier. Production LRC locomotives were first built in 1980 and used the bigger 16-cylinder 251 engines to produce 3,725 hp. These units could provide 1,025 hp for HEP. If you calculate the difference for the traction motors, the LRC’s would certainly be more powerful than the previous two ALCO passenger diesels in this ranking, even with the HEP deducted from the total output.
Please stay tuned for the next blog post.
