Analysis of the naval register classification for a marine diesel engines and review of the engine testing, inspection and certification process.

The thesis project was developed as part of an internship held at the FPT Industrial research and development center located in Turin, Italy. The objective was to follow the activities related to the certification process of a new developed marine diesel engine. The commercialization of marine engines must be accompanied by a certification procedure according to a classification society that in this particular case was assessed by the RINA (Registro Italiano Navale) corporation. The certification procedure must be followed to guarantee the correct engine design and construction for marine applications to attain a sound fabrication and the safety of life at sea. The studied engine is based on an off-road application and thus, a marinization process was followed to apply modifications and develop specific components in order to adapt the base engine for its use in marine applications considering the harsh conditions of a marine environment, the new operating conditions, and the more stringent safety and environmental regulations. A theoretical analysis of the propulsion and engine matching for marine applications was followed. The parameters that have an effect on the engine performance, such as the vessel resistance, type of hull and engine – propeller matching were studied. Also, a review of the main systems present in the engine test cell for the tests development and for the data acquisition, including the software for the test bench and engine control was done. As part of the certification process, different homologation tests should be followed on the evaluated engine. These tests subject the engine to demanding and to fast load variation working conditions, evaluating the engine durability, fatigue and correct operation during intermittent loads. During all the tests, the monitoring of different engine parameters such as, temperatures, pressures and speeds, was done through the use of alarms and indications established according to the threshold values for attaining a safe and sound engine operating conditions and as required in the RINA regulations. Additional tests for verifying the lowest propulsion engine speed and the compliance of the engine speed governor were performed. Before the official certification tests, different experiments simulating the same engine homologating working conditions were performed in order to verify the correct functioning of the engine, the sensors and all the systems present in the test cell. During this step and as part of the followed engine tuning, the injection characteristic curve was modified, the ECU dataset was updated and the impact of these changes on the engine operation was studied. Finally, after the homologation tests, the engine was disassembled and tightening torque checks followed by a visual inspection on the main components was held in order to check for possible overload working conditions, fatigue issues or premature wear not allowed by the RINA regulations.