DNV launches new tailshaft condition notation

DNV is offering a new notation, TMON(Oil lubricated, +), that is designed to minimise tailshaft and propeller risks by enhanced condition monitoring and early detection of potential failures. The classification society’s existing class notations TMON(Oil lubricated) and Shaft align are prerequisites for assignment of the latest notation.

DNV Maritime Senior Principal Engineer, Arun Sethumadhavan, explained: “The aim of the new notation is to raise the level of monitoring even higher to ensure optimal performance of the stern tube bearing. More influencing factors can be monitored in a proactive approach towards failure detection warning. Picking up early signs of, for example, increasing bearing temperature and undesired operational conditions such as incomplete immersion of the propeller, are crucial.”

Marit Laumann, head of section, Machinery & Marpol, at DNV Maritime, commented: “It is an important development, as an aft bearing damage carries the risk of diminished or total loss of propulsion, expensive repairs and off-hire time, reputational damage and increased insurance premiums.”