Introduction

A fishing vessel is powered with a 9 cylinder diesel engine. Power transfer from the engine to the gearbox is enabled through a flexible coupling arrangement. This coupling is made up of a rubber component attached to a finger coupling, shown in Figure 2 with an array of linkage arms. Failure of the linkage arms in this assembly occurred on repeated occasions. After the initial failure a 2mm vertical misalignment of the rubber component was found and fixed. The coupling and the new linkage arms failed after a further 400 hours.

Introduction

The crankshaft for the compressor that drives the air conditioning unit on board a vessel failed catastrophically. A horizontal crack through the oil hole was observed, and repaired. Following this, the crankshaft (Crankshaft 1) was in service for ~ 174 hrs before experiencing catastrophic failure (Figure 1). A new crankshaft (Crankshaft 2) was inserted, and failure occurred after a further ~ 296 hrs of operation.