The break-downs were not fortuitous and our investigation pointed to that it was attributable to mis-matching of propeller, engine and hull (hydrodynamics). The smaller ships of same shipping lines were satisfactory. After exhaustive analysis, it was found maintaining similar propeller and similar engine, the principal dimension (length) was increased. This led to mismatch. Present-day engines are governor programmed, highly supercharged and speed limited as per scavenge air. Due to increased ship resistance, engine speed was reduced, thereby affecting Turbo Charger speed, scavenge air pressure and combustion.