General Electric’s U23B
General Electric broke into the domestic road-switcher locomotive market over six decades ago with its U25B model in 1961. The U-series line would continue to evolve and grow, laying the foundation for the company’s ascent to becoming the No. 1 locomotive builder in North America in later decades.
The U23B was essentially a lower-horsepower, shortened version of the U30B that produced 3,000 hp from a 16-cylinder prime mover. The 2,250-hp, 12-cylinder U23B would be built over a nine-year span from the late 1960s to the late 1970s, resulting in 481 units for 17 customers. This made it the second best-selling U-series model. While competing EMD models of the same era were made in larger numbers and have survived in greater quantities, a handful of these versatile units are still in service across the country, pulling tonnage for short line railroads today.
In addition to the handful of U23Bs in service with their as-built design, there were a few programs to extend the life of the model; some of these are also still operating. General Electric began remanufacturing U-series locomotives in the 1980s as part of their Super 7 program. This included 16 U23Bs rebuilt into Super 7-B23s. Unfortunately, the U23B shape was completely replaced with a carbody resembling the Dash 8 locomotives being built new at the time by General Electric. Mainly the frame and internal components were reused from their U23B cores.
Also in the late 1980s, a second program was undertaken by Santa Fe which planned to remanufacture its U23Bs into a 3,000-hp SF30B model. Only the prototype was produced before the program was canceled. Although external modifications were made, it retains much of the U23B look. Fortunately, it still survives today on a short line in Minnesota.
These U23Bs and their rebuilt cousins are known to be in revenue service today:
U23B
Ashtabula, Carson & Jefferson (Ohio, Pennsylvania)
Finger Lakes Railway (New York)
Huntsville & Madison County (Alabama)
Lehigh Line (Pennsylvania)
Naugatuck Railroad (Connecticut)
Super 7-B23
SF30B
Check out previous article from this series, “Canadian National cowls: Where are they now?
The U23B is my favorite GE locomotive. I’m glad to see a few are still chugging along.