By combining class-approved straightening techniques with laser cladding, MarineShaft delivered a fast and permanent propeller shaft repair with full RINA class approval.

During docking at a German shipyard, the shipyard faced a familiar challenge with damaged shafts and worn bearing journals, in this case, two damaged propeller shafts.

MarineShaft specializes in repair and reconditioning of propeller and rudder equipment, and received the shafts, including propellers and couplings, for inspection and repair.

Following a thorough technical inspection, including crack detection tests, the company prepared a detailed repair plan, which was approved by the classification society, RINA, involved.

Besides worn bearing journals, the runout measurements revealed a deflection on one of the propeller shafts.

The repair process

MarineShaft performed cold straightening of the bent shaft, followed by an additional NDT inspection.

The shaft bearing journals were then machined and rebuilt to the original dimension by applying two layers of laser cladding. The material Inconel 625 was applied – a material known for its excellent wear, corrosion, and heat resistance.

The laser cladding technique ensures perfect bonding of the applied material to the base material, with a heat input that is only 1/10 that of regular welding, resulting in minimal heat input into the shaft.

After laser cladding, the shafts were machined to their final dimension of Ø140.0 mm, and the coupling flange face was re-machined to ensure perfect alignment. The repair also included welding, grinding, and polishing of the STB and PS propeller.

The entire repair process was completed in just 9 working days, providing a cost-efficient, durable, and sustainable solution that restores full operational reliability — quickly and with class approval.

MarineShaft’s wide range of class-approved repair solutions – including cold straightening, advanced welding techniques, and a stock of raw materials for replacement parts such as liners and other components – all support fast and full-scope repair solutions for critical maneuvering equipment.