This project involved the urgent repair of a 1750 kVA, 4-pole marine shaft generator, which had suffered extensive damage affecting both its magnetic core and electrical winding.

Shaft generators operate as an integral part of a vessel’s propulsion system, driven directly by the main engine. Their location and installation conditions often make inspection and maintenance more demanding than in conventional land-based applications, placing particular importance on reliability and careful repair work when failures occur.

Scope of Repair

Inspection revealed significant damage to the generator, including deterioration of the magnetic core and winding system.

The repair required the removal of the damaged laminations, followed by the manufacture of new laser-cut laminations matching the original core geometry. Once the magnetic core had been restored, a completely new formed winding was manufactured and installed.

The completed winding then underwent Vacuum Pressure Impregnation (VPI) treatment, providing mechanical stability, improved insulation, and long-term protection against the demanding operating conditions encountered in marine service.

Restoring the Magnetic Circuit

Repairing a damaged laminated core requires more than replacing steel components.

The magnetic circuit of the machine depends on the geometry and condition of the laminations, making dimensional accuracy and careful assembly essential. Any deviation may influence magnetic losses, temperature rise, vibration, and the long-term performance of the generator.

For this reason, the reconstruction of the core and the manufacture of the new winding were treated as a single engineering process rather than as separate repair operations.

Urgent Delivery

Because the generator formed part of an operating vessel, the repair was carried out under a demanding delivery schedule.

Following completion of the core reconstruction, rewinding, VPI treatment, assembly, and testing, the machine was prepared for return to service and delivered within the required timeframe.

Projects such as this combine reverse engineering, core reconstruction, winding manufacture, and generator repair, illustrating the range of work involved in restoring critical rotating electrical machines for marine applications.