The GE U25C was the builder's first entry into the six-axle locomotive
market, first built during the early 1960s a few years after the company
had released its first production locomotive in the United States, the
U25B. This initial model, and the following U28C, sold rather poorly
for General Electric (although several Class Is did experiment
with and purchase a few units). Much of this can likely be attributed
to two things; first, while GE had collaborated with other companies in
the industry for decades (such as the American Locomotive Company) it
had never built its own locomotives; and second was the fact that many simply were not yet interested in six-axle designs.
However, future models like the U30C and U33C sold quite well for the
company as railroads began to embrace and see the benefits of powerful
six-axle locomotives. After the mid-1970s nearly all domestic-built GE
diesel locomotives were of the C-C variety.
New NP U25C #2509 sits between two freight cars at Burlington's Daytons Bluff Yard as it heads towards its new home during late June of 1964.
The GE U25C first began production in September, 1963, four years
following the production of the U25B, its four-axle cousin. At the time
of its production many were still reluctant to use six-axle,
high-horsepower diesel locomotives in main line freight service
so GE had a tough time making a case for the U25C even though it
featured reliability and straightforward design features which the
company became well known for. Utilizing GE's 4-cycle model FDL16 the
U25C could produce 2,500 horsepower. Since the unit featured a C-C
design it not only provided more traction but also could be operated on
light or secondary lines as its weight could be more evenly distributed
over the rails.
The classification for the GE's six-axle designs are quite similar to its four-axles. For instance, in the case of the U25C; "U" regarded its Universal line, "25" was the first two digits of its horsepower rating, and "C" described its powered axle rating (C-C). At 60 feet, 2 inches in length the U25C was actually the same length as the four axle U25B. However, beginning with the U28C GE began increasing the length of its C-C road switchers (and they continued to grow with the U30C through U36C). All of the locomotive's internal equipment including main/auxiliary generators and traction motors were all constructed by GE itself while air equipment was supplied from Westinghouse Electric.
Another new NP U25C, #2508, has just been delivered at St. Paul during June of 1964. Just below the cab is stenciled "Radio Equipped," a relatively new concept in locomotives at the time.
The most noticeable benefits of the U25C was, as mentioned above, its
starting tractive effort rating of 90,000 pounds nearly 17% higher than
with the U25B. This allowed the locomotive to get trains started much
faster. While railroads were still reluctant to purchase
high-horsepower six-axle locomotives at the time within a few years they
began to come around as GE would sell more and more such models
following the U28C, U30C, U33C, and U36C (combined, these models would
sell well over 1,000 examples).
By the time production on the GE U25C had ended in December, 1965 some
113 units had been sold six different Class Is including the
Atlantic Coast Line (21); Burlington (12), Lake
Superior & Ishpeming (2), Louisville & Nashville (18), Northern Pacific (30), Pennsylvania (20), and ten that were purchased for the Oro Dam in California (these units later went to the L&N). Today, at least one GE U25C is known to be preserved, LS&I #2501, still owned by the railroad since it was
bought new in 1964 and on display in Marquette, Michigan.
Seaboard Coast Line U25C #2100 sits next to lots of other power at the Byran Park Shops in Richmond, Virginia during May of 1972.
For more reading about GE's U-boat line the bookU-Boats: General Electric's Diesel Locomotive by author Greg McDonnell provides a complete history of the company's first production diesel models. Also, noted historian Brian Solomon has authored a number of books covering the history and background of GE's locomotives. Two, which provide a general but thorough coverage include GE Locomotives and GE And EMD Locomotives: The Illustrated History. As with virtually all of Mr. Solomon's you can expect a well-written title with large, crisp, and sharp photographs.