Energy efficiency maintenance measures
This chapter concerns issues relating to ships maintenance and their impacts on ship energy efficiency. Examples of the rules and regulations influencing the shipping industry are the International Safety Management Code (ISM), the International Convention on Standards of Training Certification and Watch keeping for seafarers (STCW), the International Ship and Port Facility Security Code (ISPS) and the International Convention for the Prevention of Pollution from ships (MARPOL).
The ISM Code about Maintenance of the ship and is equipment describes in general how ships should be maintained, inspected, non-conformities be reported, and corrective actions be taken. It should also be noted that a ship’s planned maintenance scheme is a statutory requirement of the ISM code. The ISM code requires that the ship’s management provide sufficient resources to maintain the ship safely and the company must supply the necessary resources in the way of parts or shore-side assistance to do this. Poor maintenance can mean that either the ship cannot meet its commercial obligations or can pose a potential safety or environmental hazard. Maintenance instruction according manufacturers and others instruction should always be issued to ensure the uninterrupted and safe operation. Shipping companies must strive for continuous improvement by monitoring safety and conducting internal audits to prevent recurrence of faults. ISM code states that the Company should identify equipment and technical systems that through sudden operational failure might result in hazardous situations.
Maritime Maintenance Management: The ISM Code stipulates that each ship operator is responsible for that safe and pollution free operation of the ship is ensured, and that the ship’s hull, machinery and equipment is maintained and operated in accordance with applicable rules and regulations. The senior management has to be committed to provide required resources, competent crew and a well designed and implemented maintenance management system in order to achieve these objectives on board (MariEMS 2017).
Notable types of maintenance:
- Corrective Maintenance. The traditional way to perform maintenance activities is to repair an object when it has broken down either by accident or as an expected event. Corrective maintenance is defined as activities undertaken to detect, isolate, and rectify a fault so that the failed equipment, machine or system can be restored to its required function.
- Planned/Preventive Maintenance. Maintenance can be defined as systematic inspection, detection, correction and prevention of failures before they become actual or major failures, Planned/preventive maintenance is always time based either by calendar or by the object’s actual runtime.
- Run to destruction. Run to destruction is an alternative method meaning that the object is completely replace when broken down.
- Condition Based maintenance (CBM). CBM is carried out according to the need indicated by Condition Monitoring (CM). CM is defined as continuous or periodic measurement and interpretation of data to indicate the condition determine the need for maintenance. The monitoring is carried out when the object is in operation.
- Opportunistic Maintenance. Opportunistic maintenance is carried out for an object when the opportunity is given, often in connection with unplanned activities for other objects in a system when the system is out of operation.
- Reliability Centred Maintenance (RCM). Reliability Centred Maintenance is a methodology where the maintenance activities are planned according a qualitative risk-based method in order to find the optimal balance between preventive, condition based or periodic and corrective maintenance.
Hull and propeller condition have significant impact on fuel consumption. Main reason for that is marine growth on ships hull and propeller. The most visible forms of these fouling are barnacles and shells which reduce vessels efficiency substantially. These marine growths create a rough surface on the hull which increases resistance of the vessel. Therefore, extra fuel is being consumed to overcome that resistance and maintain vessels speed. Regular maintenance and cleaning of hull and propeller may help to achieve a cost-effective solution for better operational efficiency (MariEMS 2017).