USCGC MACKINAW to get new AC Drive System

On 11 June 2021, The GBS Group was awarded a contract by the U.S. Coast Guard to replace the AC Drive System for the USCGC MACKINAW (WLBB 30) Bow Thruster and Motor Generator Sets.  This work consists of the design, procurement, installation and testing of the new system to replace the existing obsolete system.  The work follows from recommendations made by The GBS Group under an overarching five-year contract that supports the maintenance of the Integrated Power Plant System for USCGC MACKINAW.

The ship currently employs obsolete ADDvanatge 32 Avtron AC drives that were provided to Marinette Marine as part of the new build process in 2003.  The control boards were originally developed in 1992 and went obsolete in 2010.  The drive OEM (Nidec) which is subcontracted to The GBS Group has developed a clean tech refresh path with the current Nidec Unidrive 700M AC drive. It is a form and fit replacement which will retain the existing cabinetry and reuse the existing field wiring.  The existing interface to the ship control system will remain the same.

The GBS Group provided the programmatic and integration support for this effort as well as the installation work in the ship’s homeport of Cheboygan, MI.  From the GBS Director of Engineering, Mike Cotton, “this is another great example of the GBS Group’s engineering, installation, and design capabilities throughout the maritime industry.  We completed the factory acceptance test at the Nidec facility in Cleveland, OH on 01/24/2022 and immediately shipped the drives to Cheboygan, MI to start the installation on 02/07/2022.  The ships availability was limited to 20 days to complete the removals and installation for both the motor generator and bow thruster drives.  This included removals of the old drives, installation of the new drives, pier side testing, and sea trials to confirm the drives performed as expected.  Due to the dedication and long hours onboard, the GBS engineering and installation team was able to meet the deadline and the ship left on time.”