Review of Locomotive 2021 Part 1 - "Diesel dynasty"
Yesterday, Trains Magazine just released the new Locomotive 2021 annual issue as a digital copy via Zinio. In case you’re curious, I chose only the digital version instead of the printed copy. Regardless of your choice, Locomotive 2021 has pretty much everything you can expect from previous issues, including “Motive Power Review”, new locomotive construction and rebuilds/modernizations (2020), and “the big six fleets by the numbers”. One of the biggest highlights in this edition is the history of General Electric’s longest lasting diesel engine line: the 7FDL series.
This locomotive you’re looking at is sort of the granddaddy of all GE mainline diesels. It was originally built and painted in 1954 as a four-unit Erie Railroad A-B-B-A set, numbered 750A, 750B, 750C, and 750D. The first A-B half (A and B) was powered by two of the 12-cylinder engines (1,800 horsepower each) while the second half (C and D) used a pair of 8-cylinder engines (1,200 hp each). Altogether, the entire demonstrator set was rated at 6,000 hp! That’s the same output produced by a single 16-cylinder 7HDL prime mover, which was used solely for the GE AC6000CW locomotive in the 1990’s! All of the four engines for No. 750 were built by Cooper-Bessemer (C-B), who eventually sold the 7FDL design rights to GE by the early 1960’s.
After five years of their demonstration, the two pairs of A and B units were all upgraded to 2,000 hp provided by the improved 12-cylinder C-B engines. Union Pacific purchased all four of these unique locomotives and repainted them in its classic Armour Yellow scheme while renumbering them to 620A, 620B, 621A, and 621B. They were also given a new model name: the UM20B. Appearance-wise, the GE demonstrator set had an extremely rare carbody design. Although the A units somewhat resemble the ALCO FA diesels (interestingly codesigned by GE), they have a fairly different nose design as well as the ribbed sides. The UM20 was believed to be the only set of “first-generation” streamlined cab units ever built by GE during the early dieselization years. However, in 1993, the builder introduced the GENESIS series, which very likely represented the reintroduction of a cab unit design, albeit with the high-tech monocoque body.
In between, GE built a few types of semi-streamlined cowl units such as the Canadian-designed DASH 8-40CM. In fact, Locomotive 2021 features an article about these distinctive diesels, most of which will probably be sent to scrap. More about the C40-8M on the next blog post. Sadly, the UM20B demonstrator set might have faded away, but there is the lone survivor of its Cooper-Bessemer engines. Previously installed in the 750C booster unit, the 8-cylinder diesel was last used by a gas compressor company in Mount Vernon, Ohio. It is now owned by the Lake Shore Railway Historical Society of North East, Pennsylvania and became an important piece of engineering history in 2020, thanks to the American Society of Mechanical Engineers.
The Cooper-Bessemer design allowed the successful 7FDL diesel engine to make General Electric Transportation the No. 1 North American locomotive builder by the 1980’s, and the company (now under Wabtec) has continued to stay at the top. Despite its obsolescence caused by the lower-emissioned Evolution Series GEVO engine, the FDL is still being offered for not only export production but even for domestic modernizations of existing locomotives. That’s why the magazine article is titled “Diesel dynasty”. This is a fantastic story! Highly recommended for GE locomotive fans!
Photo credit: Mike Sosalla
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