The Optimum Alignment of Marine Shafting

Abstract

Alignment of marine shafting generally implies a judicious misalignment of the supporting bearings in order to achieve acceptable values of bearing reactions and shaft stresses. To achieve a true optimum it is necessary to describe quantitatively the desirable features of an alignment, and a combined technical/economic basis for this description is presented. The result is a well-defined problem that is solved by mathematical optimization methods. Results of the procedure are illustrated by alignment plans derived for, and adopted by, ships recently built in the United States and abroad. The practical realization of an alignment plan is discussed and means of speeding up the implementation process are proposed. Improvements in the elastic representation of the shaft system are described and the question of hydrodynamic support in journal bearings is considered. Discussers: Technical Staff, ABSP. F. Nuclo C. L. Stahly