Failure Investigation of a Marine Propulsion System

A 39-foot recreational vessel reportedly loss propulsion in one of its four propellers. The propulsion system was removed and a failure investigation was performed on the damaged drive components. The vessel was reported to have impacted a large partially submerged object approximately one year prior to the loss of propulsion. This presentation discusses the methods that were used to non-destructively identify the failure mode as fatigue and the methods used to understand how the vessel service history influenced the failure of the propulsion system.