Greetings All,
Locomotive Spotlight #3-2026 / Penn Central U25Bs
Welcome to another edition of the long running Locomotive Spotlight Series. Today the spotlight will shine on the General Electric ground breaking U25B. We'll also take a look at two Bowser HO scale Penn Central U25Bs that recently joined the fleet thanks to 1:1 Sir Neal.
The GE U25B was General Electric's first independent entry into the United States domestic road switcher diesel-electric locomotive railroad market for heavy production road locomotives since 1936.
From 1940 through 1953, GE participated in a design, production, and marketing consortium (Alco-GE) for diesel-electric locomotives with the American Locomotive Company.
In 1956 the GE Universal Series of diesel locomotives was founded for the export market. The U25B was the first attempt at the domestic market since its termination of the consortium agreement with Alco.
The U25B (nicknamed U-Boat) is the first commercially successful domestic diesel electric road locomotive designed, built, and sold by General Electric after its split with the American Locomotive Company (Alco).
"9/30/76, CR U25B 2548" by OHFalcon72 is licensed under CC BY-NC-ND 2.0.The U25B was announced by General Electric as a domestic model on April 26, 1960. It was the first locomotive powered by GE's highly successful FDL-16 engine.
The U-Boat put GE on the road to becoming the top locomotive producer in the U.S., much to the chagrin of EMD. It introduced many innovations to the U.S. diesel locomotive market, including a pressurized car body and a centralized air processing system that provided filtered air to the engine and electrical cabinet, thus reducing maintenance.
The U25B was also the highest-horsepower four-axle diesel road locomotive in the U.S. at the time of its introduction, its contemporaries being the EMD GP20 (2,000 hp) and the Alco RS27 (2,400 hp).
Though many were produced and sold, the only remaining U25B locomotives are in museums, as many were retired or scrapped at the end of their service life by the end of the 1980s.
The Models
A pair of new Bowser Executive Line U25Bs were purchased via TrainWorld after being advised by 1:1 Sir Neal that they were on sale for a good price in early 2026 when I was seeking an intervention for a large rolling stock purchase. The models are of Penn Central Phase IV #2568 and a Phase III #2647 with a red P.
What are these Phases?
As described by Allen Hazen
at Railroad.Net
Phases" are a railfan category, and usually are defined by superficial (but visible) design changes the locomotive builder's don't think merit a change in model designation. "Railroad Model Craftsman" published a very good two-part article on the U25B (by Bob Kenderdine and "Win Cuisinier", with HO-scale drawings by George Losse.
They defined five "phases":
Phase I: very early units with ladders instead of corner steps (most of these are high-short-hood, but they included GE's first low-nose demonstrator in Phase I)
Phase IIa: ("Classic"): units built between 4/62 and about 4/64, with one-piece windshield, handrail stanchions mounted on top of walkway
Phase IIb: ("Late classic"): built from about 4/64 to the end of 1964, differing from IIa in details of the arrangement of hood doors-- New Haven's first order (2500-2509) were built in October 1964 and were of this phase.
Phase III: ("Transitional"): built in first four months of 1965, with two-piece windshield and handrail stanchions bolted to the sides of the frames (the latter a feature of later GE locomotives up to the present!), but keeping the level nose of the earlier U25B.
Phase IV: built 5/65 to 2/66, differing from phase III in having the sloped nose (and externally like the early U28B of, e.g., the P&LE). New Haven's second order (2510-2525), built in October-November 1965, were of this phase.
Back to the Models
The 2568, a phase IV U25B, was built for the New York Central between July and September 1965. This was the second highest number in the NYC U25B fleet (2500-2569). The NYC began rostering the U25Bs in early 1964 with an order of thirty locomotives. Happy with the locomotives they returned to GE for an additional forty units.
After running thru the yard tracks and turnouts the U-Boats are in the engine terminal for more fuel and sand drawing a crowd of local railfans. Engine hostler Wet Willie, the 1:87 scale railfans best friend, has placed the new engines in the closest track near the street for photos.
Two boats are caught in this photo. U-Boat 2568 and 1:87 Scale Sir Neal's 1955 Cadillac convertible which is a land yacht!
The Bowser U25Bs feature some nice details like signal lines, an air hose, the walkway chain, window wipers and the signal box in front of the engineers window.
Initial Testing
The U-Boats make their first revenue run. They ran well until both derailed twice in typical Penn Central fashion! Back to the workbench they went.
Troubleshooting the Problems and Causes
The U-25Bs had both rear trucks derail on the same two turnouts. With a fleet in excess of 100 locomotives and hundreds of pieces of rolling stock these are the only two to derail at these turnouts so I took a close look at the rear trucks.
The four axles in question were within the NMRA wheel spacing gauge however when I opened the trucks for closer inspection I observed that the metal axles, while in gauge, were not evenly inserted into the plastic gear with more axle showing on one side than the other.
I was able to adjust this by slowly twisting the axles to evenly seat them evenly within the NMRA gauge. After all four were done and the trucks reassembled the U25Bs were sent out on another test run around the layout where they ran just fine on all of the tracks and turnouts in both directions.
The U25Bs Earn Revenue
After they began to run reliably the U-Boats were lightly weathered with Testor's Dullcote to tone down their shiny appearance and give them a more Penn Central appearance.
Now entrusted with high priority freight the 2647 and 2568 lead a symbol train past North Side Yard in Empire City.
See the U25Bs in Action!!
A Special Thank You
A special thank you to 1:1 Scale Sir Neal for telling me about the sale which resulted in these two purchases. And further drained my wallet!!😉
Final Thoughts and Comments
The Bowser U25Bs run silky smooth and very quiet singly or when running in multiple. With the early derailment issues which were kind of a weird anomaly now cured the U-Boats will be enjoying a lot of layout time.
Additional Links
General Electric U25B Handbook.
Photo of PC U25B #2569
Photos of PC U25B #2647
Photo of PC U25B #2647 at Syracuse, NY 07-28-74.
Photo of Conrail U25B #2657 at Ridgefield Park, NJ 10-10-76.
Thanks for reading and watching!!!
See you soon!!!
