A Bit of Technical News .We have to do periodic inspections of the Propeller Shafts aboard our vessels . The Survey is normally undertaken by SAMSA as part of our annual  hull survey .
We have Water lubricated Stainless shafts which need to be drawn every three years ( This period may be extended to 4 years if the vessel is on a two year dry dock cycle)
Last year we drew the shaft and had the propeller built up so we were surprised this year to find that the Propeller on Spirit of Victoria  showed signs of cavitation after one year .So we removed the propeller and had it built up at AMP ( African Marine Propulsion ) .As there is a lot of heat used in the rebuild process we then need to have conduct a “blueing” again on the shaft .The “Bluing “ of the shaft tapers proves the propeller and coupling fit and is carried  out at Big Bay Marine and witnessed by the SAMSA surveyor . The “Blue” is to taken with the key in the key-way and the coupling or propeller tightened onto the taper . The Photos show the new shaft , rebuilt propeller and the “Blue “ on the tapers ready for the inspection .

Further ready can be taken from Marine Notice 6 of 2002 and Regulations 181-183 .