From in-house manufacturing to final shaft alignment, MarineShaft delivered a complete repair package with minimal vessel downtime.

MarineShaft has completed a combined rudder trunk and shaft line repair on a vessel at a shipyard in Greece, restoring critical steering and propulsion components to class-approved operating condition.

The project began with an onboard inspection of a misaligned portside rudder trunk. Service engineers measured the damage, defined the repair scope and prepared a class-approved procedure before mobilizing specialist machining equipment from Hirtshals, Denmark. A new rudder trunk lower section was manufactured in-house in 3.2 class-certified S355 steel from the material stock, with chamfer prepared in advance to reduce vessel downtime at the yard.

On-site, the remaining trunk section was machined with chamfer for a precise welded joint, and the replacement lower section was positioned and aligned with the steering gear. After welding and post-weld heat treatment, MarineShaft installed mobile machining equipment directly beneath the trunk and machined the lower bearing seat to final dimensions. The bottom surface was also machined to achieve the correct trunk length, followed by assistance with steering gear alignment and full documentation for owner and class.

In the same attendance, damage to the coupling end of the portside aft intermediate shaft was repaired. MarineShaft mobilized portable machining equipment to Greece, where it was installed and aligned in the engine room, allowing the intermediate shaft coupling end to be machined in place.

Scratches and damage from an angle grinder cut were removed by machining the intermediate shaft coupling end, removing 9 mm of material to achieve a final diameter of 450 mm over a length of 650 mm, followed by polishing.

 To verify the shaft line condition, jack-up tests were afterward carried out afloat in both cold and hot static conditions.

The project demonstrates MarineShaft’s ability to combine in-house manufacturing, mobile machining, alignment, heat treatment coordination and class documentation into one efficient repair solution for both steering and propulsion systems.