Solution Space and Optimality Concerns for the Shafting System Alignment of a Typical Bulk Carrier

A study of the shafting system of an 82.000DWT bulk carrier is conducted, comparing the initial alignment of the vessel against the performance corresponding to different bearing offset combinations. The shaft is modelled as a beam and the bearings as single support points. Radial shaft loads, thermal expansion of the engine and propeller thrust eccentricity are taken into account. Simulations are performed for 4 propeller immersion conditions and for various new offset combinations, deviating up to 10mm from the initial offsets. The results are evaluated according to rule requirements and classified as; (i) acceptable, (ii) marginal and (iii) not acceptable.