The JNR EF66 is an electric locomotive built by Kawasaki and Kisha Seizo. It has a max speed of 110km/h and designed to haul 1000 ton trains at that speed. These locomotives use 1500V DC catenary and use 1067mm gauge track. The full production type was built at 1968-1975, while the later types were built from 1989 at the request of JR Freight. The prototype locomotive, EF66-901, was built in 1966. As of April 1 2016, only 39 of the 89 locomotives remain in service. After the privatization of JNR, JR Freight decided to try out an experimental livery of EF66-20, giving it a unique look from the other locomotives, and was repainted to the usual two-tone livery, similar to the paint of the EF66-100s in 1993. From 1988, several EF66s were refitted with coolers, and from 1993, several EF66s including EF66-20 were refurbished, removing the JNR decorations on the front and giving it the usual two-tone livery, and in 2004, more locomotives were refurbished, giving them a blue livery similar to the JNR one.