We have two different winch systems one circa 1964 and one circa 2000.
Both systems are broken down and stocked as serviceable assemblies namely drive, gearbox and drum where each can be serviced jointly or independently depending on the available servicing window. Also where the servicing window is very short we stock a complete winch assembly and simply change over the cable. With our 1964 winches this is not possible as they utilize a single drive system which is shifted to the either of the two winch drums, as a result the servicing intervals are much longer.
We have designed a replacement winch system for these older winches that take into account our knowledge and experience of our decoking system operation as well as the recommendations of a detailed Reliability Centered Maintenance Study.
Generally both systems are quite reliable if properly maintained, although we have run into a reliability issue with the Flowserve I-R winches if the band brakes are not properly maintained, in that the drive shaft as it enters the planetary gearbox is prone to fracture if only the motor disk brake is functional.
Because our cokers are on the front end of our operation and supply all of the feed for the operation we tend to stock what seems an excessive amount of spares.