Overhaul and replacement of DC propulsion thrusters

Customer: Sea Launch
Date: Winter 2011/2012
Location: Malaysia

The field servicedepartment of Karsten Moholt has been hired by Sea Launch to perform maintenance on some of the equipment onboard their rig. Sea launch is a sea based launch system for satellites. The rig was formerly used in the North Sea and is named LP Odyssey.
LP Odyssey is maneuvered by DC thrusters. Two of these were to be replaced, and two of them overhauled. The ones that were going to be overhauled had their end shields disassembled to get access. The brush rockers were fixed, and all the brushes were replaced and adjusted to fit. The motors were cleaned with compressed air and partially with chemicals. The belts on all of the fan motors were replaced.
The motors that were being replaced had to be completely dismantled onboard. The pieces were transported out and off the rig. Likewise, the new motors were transported onboard the rig in pieces, and assembled on site.
The air gap between the commutators and brush rockers are adjusted to be between 2.3 mm and 4.6 mm. All of the fans and fan motors had to be replaced after the test run because of overheating and vibration problems. New shunt cables were fitted and all heating elements were replaced on both motors.