While high adhesion was clearly an important requirement, the locos had to be designed with a low axle load (16 t, compared to 18 t for the EF63s) allowing them to be used on other sections of the Shinetsu Main Line with stricter axle-load restrictions.
The need to reduce unnecessary weight led to the EF62s being the first DC electric locomotives in Japan to include an electric generator (320 kW) for train heating rather than using a steam generator.