DC machines are becoming obsolete on Norwegian offshore installations. They are no longer used on new rigs, but there are still many DC machines on older rigs. This is starting to become a problem, because there is less knowledge about this type of machine now than there used to be.
In general it will often be cost effective for the customer to repair a DC motor instead of buying a new one. DC machines are difficult to come by and delivery times are long, often close to a year.