The new grinding technology for shipboard diesel engines crankshaft bearings has been developed. This novel technology allows improving technological processes performance and considerably saves the repairing time of the ships diesel engines. However, impact of this novel grinding technology to the surface roughness parameters is not yet clear and requires addition scientific analysis. Furthermore, it is important to note that crankshaft bearing surfaces must be seen as three-dimensional object with definition of microtopographical surface roughness parameters which reflect to real surface. During the PhD research the three-dimensional parameters of the crankshaft bearings surfaces were defined. The mathematical model of those microtopographical roughness parameters was determinate. Also, based on real metrological and technological surface parameters of the crankshaft bearings, the calculations of these surface roughness parameters were done. It was stated that the optimal three-dimensional surface roughness parameters for crankshafts are following: mean arithmetical deviation of surface RaT, and two perpendicular surface spacing parameters between the peaks Sm1 and Sm2. To obtain microtopographical values of above mentioned parameters the discrete method were applied by breakdown of observing surface to several separate profiles. Thus shipboard diesel engines crankshafts three-dimensional surface roughness parameters were identified and practically applicable calculation formulas of these parameters were determinated.