These were developed from an experimental modification of the B23-7's 12-cylinder engine in June 1980 to uprate it to 3,000 horsepower.

B30-7A1s, which featured a high short hood, were built only for the Southern Railway.

[1] As of April 2024[update], two B30-7 or B30-7As remain in remote control master unit service on the Union Pacific Railroad (out of the original 55 that were converted).

[3] In early 2017, CSX repainted ex-C&O B30-7 #8272 into its original Chessie System livery and donated it to the Lake Shore Railway Museum in North East, Pennsylvania.

[3][4] Southern Pacific #7863 is preserved by a private owner in South Fork, Colorado.