Propeller Shaft Repair for a Large Ferry with the Aid of Laser Cladding Technique
The process of reconditioning a propeller shaft from a large ferry boat with the aid of a robotic "Laser Cladding" system is described. The shaft was damaged following a failure of the aft sealing system and the loss of lubrication. This resulted in an accumulation of considerable wear and cold cracking to significant depths. The propeller shaft, which measured 11.5 metres in length and weighed 26.2 tons, was transported to the workshop. The whole process, which was supervised by the classification society, was preceded by the conduction of a series of experiments such as tensile bar breaking test, Charpy impact testing, as well as metallographic imaging. Based on these results suitable filler materials were selected. The damaged section of the shaft was rebuilt utilising a Laser Cladding system to weld 100 hours continuously and deposit 300 kg of material.