Operational experience has shown that occasionally the surfaces of main crank bearings deteriorate in service. The cause of a bearing failure can usually be identified, but occasionally the reason is not clear.
If failed bearings are showing signs of high bearing edge loading, it may be beneficial, in consultation with the Original Equipment Manufacturer, to fit blended edge (BE) bearings, for which there is now considerable service experience. MAN Diesel & Turbo produce a range of BE bearings for their MC engine series as detailed in the information sheet here
Note: BE bearings do not replace the requirement for consistent and rigorous dimensional checks during build or for following approved maintenance practices in service. They are, however, a less invasive solution to bearing edge wear than, for example, journal refurbishing or engine re-alignment.