The GE U30C was developed during the age of the SD40 and SD40-2, one of the most popular locomotive designs ever built, even today. Ironically, part of the U30C's success (as it went on to become GE's best selling Universal model) was due to the fact that EMD was so log jammed with orders that some went elsewhere to fill their power needs, and many turned to GE. By the time the U30C entered production railroads were beginning to understand the advantages of six-axle, high horsepower locomotives (as could be seen in the success of the SD40/-2 series), and while the model was plagued with reliability issues GE strove to resolve these issues and was already regarded for its rugged and reliable traction motor, the model 752. There was also two variants; the U30CG ("G" stood for steam generator), purchased by the Santa Fe and the P30CH for Amtrak.
For General Electric, the U30C finally proved the company could compete against Electro-Motive although it would take nearly 20 more years until it finally surpassed its rival. Interestingly, a number of U30Cs remain in service today years after GE ended production of the model. As several were retired the company instituted a rebuild program which extended service lives of the model with upgraded equipment and components (essentially they became variants of the later "Dash 7" line).
The U30C all but drove the American Locomotive Company out of business as by the mid to late 1960s Alco was on the brink of exiting the manufacturing business altogether. Its comparative models, like the C628, C630, and C636 were simply not even as reliable as GE's models (interestingly, Alco continued to outsource internal components from GE through the end). The GE U30C began production in November, 1966 once again utilizing the company's 4-cycle model FDL16 prime mover which could produce 3,000 horsepower. It featured standard GE angular, boxy carbody designs and the model utilized floating bolster trucks, which were standard on virtually all Universal models.
As for the locomotive's tractive effort, its starting force was about the same as the U28C (91,650 pounds). However, it offered a much better continuous rating of 92,500 pounds. The U30C was much longer than the U28C at 67 feet, 3 inches. While the SD40/-2 series broke the ground on railroads regularly using six-axle, high horsepower locomotives in main line freight service the GE U30C was plagued with reliability issues. Still, because the company produced a very reliable traction motor and roads had difficulty getting orders for the SD40 series many went on to buy the U30C. As General Electric continued to refine the U30C model it became a more reliable locomotive by the early/mid-1970s and was nearly a C30-7 design by the time production had ended.
In all some 18 Class Is would purchase the U30C by the time production had ended in 1976, along with a handful of industrial operations, the US Department of Transportation, and a few for Mexican carrier Ferrocarril del Pacifico. In total, GE would sell 606 U30Cs, including 6 U30CGs built for the Santa Fe (this variant of the U30C featured a steam generator for use in passenger service) who had also purchased a similar design in the U28CG. There was also one other variant of the design known as the P30CH built exclusively for Amtrak. The passenger carrier wound up with 25 examples between August, 1975 and January, 1976 that carried a boxy carbody similar to EMD's F40PH design. However, they were not very successful with numerous reliability issues. They were replaced by EMD's F40PHs and all were retired by 1991.
One additional interesting note is the Reading's five U30Cs, 6300-6304. The railroad received theirs so early, between June/July, 1967 that GE placed the units in U28C carbodies. Today, not only are a handful of U30Cs preserved at museums around the country but some remain in active revenue service, mostly now having been rebuilt with upgraded equipment and components essentially making them a C30-7. Additionally, others were rebuilt into the famed "Super 7s." Lastly, for more information about the GE U30C please refer to the chart above for a complete production roster.