From the mid-1960s until the early 1990s the Woodford-Hainault section was largely operated separately from the rest of the Central line, using four-car (later three-car) trains of 1960 Stock. The three-car units had a 1938 tube stock middle carriage. These trains were adapted for Automatic Train Operation (ATO): the Woodford-Hainault section became the testing ground for ATO on the Victoria line. Some Victoria line (1967 Stock) trains were also used to operate this section and named FACT (Fully Automatic Controlled Train). The separate operation has now been abolished, the 1960 Stock has been withdrawn, and through trains to Central London now operate via Hainault and the 1960 Stock (along with the rest of the Central line's 1962 Stock) has been superseded by trains of 1992 Stock.