The 1000 series was an electric locomotive that the NS ordered based on the Swiss Ae 3/6. This has been adapted to operate under 1,500 volts DC in the flat terrain of the Netherlands. The carrying axles were also combined here with the adjacent driving axle to form a Java bogie. The first three locomotives were manufactured by SLM with electrics from Oerlikon and the other seven only had the electrics from Switzerland. Despite their susceptibility to failure, they were used until 1982, but almost exclusively in front of freight trains. 