The British Rail Class 70 was a class of three third rail Co-Co electric locomotives. The initial two were built by the Southern Railway (SR) at Ashford Works in 1940–41 and 1945 and were numbered CC1 and CC2 - the Southern Railway latterly preferring French practice for locomotive numbers which also gave an indication of the wheel arrangement. Electrical equipment was designed by Alfred Raworth and the body and bogies by Oliver Bulleid. CC2 was modified slightly from the original design by C. M. Cock who had succeeded Raworth as electrical engineer. The third was built by British Railways in 1948 and numbered 20003.

Ashford railway works was a major locomotive and wagon construction and repair workshop in Ashford, Kent in England. Constructed by the South Eastern Railway in 1847, it became a major centre for railway works in the 19th and early 20th centuries. After years of decline, it closed in 1982.