Roles and application of hull monitoring systems

Abstract

This paper describes results of investigation on examples of hull damage relating to hull monitoring and examination of stress and acceleration of a large bulk carrier corresponding to condition of shipping seas and apparent slip ratio of propeller at rough seas using data through onboard tests.Typical hull damage relating to cargo and ballast operation and hull damage relating to ship handling at rough seas were extracted and studied from a view point of hull monitoring.Condition of shipping seas based on log book was used in the examination and the results show that deck longitudinal stress at midship well correspond to condition of shipping seas. It is also found that vertical acceleration at bow well correspond to condition of shipping seas as same as longitudinal stress.Apparent slip ratio of propeller was obtained using mean value of ship speed and propeller revolution. The results show that deck longitudinal stress at midship well correspond to apparent slip ratio of propeller in head and bow wave. It is also found that vertical acceleration at bow fairly correspond to apparent slip ratio in head and bow waves.