Wear Characteristics of Stern Tube and Strut Bearing and Journal Materials.

This is the first report on the progress of an investigation to determine the wear characteristics of stern tube and strut bearing and journal materials. An Amsler wear testing machine was adapted to produce the desired conditions of sand contaminated water lubrication. Nine journal materials, including brasses, bronzes, monel, and stainless steel were run against four bearing materials, each combination being tested for one hour. The bearing materials were Buna-N synthetic rubber, Lignum Vitae wood, and two phenolicimpregnated, laminated plastics. The results indicate that there is no best journal material for all stern tube and strut bearing applications. The choice of a journal material must be based on both journal and bearing wear for a journal having good resistance to wear may cause heavy bearing wear. The importance of the relative amount of wear that can be accepted by each component can only be determined by a cost analysis of bearing and shaft replacements for each class of vessels.