With 600 units sold, the U30C proved to be a viable alternative for customers who were unable to purchase SD40s from Electro-Motive Diesel (EMD) due to production backlog.

However, most railroads were assured of the reliability of the GE Model 752 DC traction motor and began to place orders for U30Cs starting in 1966.

The U30C served customers of all kinds, from mining to general freights, coal trains, and even as a power source unit for the Department of Transportation's subway-car test tracks in Pueblo, Colorado before a connection from the commercial electric power grid could be established (Cudahy 1979).

[4] • VLIX #1497 (ex-L&N 1497) is preserved at the Southern Appalachia Railroad Museum in Oak Ridge, Tennessee, awaiting restoration.

[5] • VLIX #9009 (ex-DEEX #009) is preserved at the Southern Appalachia Railroad Museum in Oak Ridge, Tennessee, awaiting restoration.