Condition monitoring is a concept which has been proven in land-based industries and is finally beginning to bring benefits to the maritime industry. Machinery failure has been established as one of the major causes of accidents onboard ships. In a recent investigation conducted by the International Maritime Organization, it was found that in a three-year period from 1999 to 2001, 1,454 'serious' and 'very serious' casualties were reported. Of these, 319 (22%) were found to have been directly caused by machinery failure. Collision, grounding, fire onboard and other serious incidents often have their source in machinery failure. Given the high percentage of machinery-failure related incidents, it is clear that adequately addressing this aspect of ship operations will demonstrably help to improve safety at sea. Taking advantage of the benefits of condition monitoring and the condition-based maintenance that it leads to may be one means of doing this. Land-based industries have increasingly switched from traditional forms of routine planned maintenance to conditionbased maintenance practices, and have substantially improved the reliability of their machinery and made savings of 30% to 50% on their annual repair and maintenance bills. The shipping industry may now be in a position to realise similar benefits. What is condition monitoring? Condition monitoring may be described as the technique of assessing the health of a machine by continuously or periodically gathering and analysing data obtained while the machine is operating. When there is sufficient confidence in the interpretation of the data and in the prognosis of detected faults, the operator may switch to a condition-based maintenance regime. Lloyd's Register believes that an effective condition monitoring system must comprise four main elements: • an effective initial set up to ensure the robustness and repeatability of data • training of shipboard staff • on-going analysis of condition data for the purpose of confidently prioritising maintenance based on findings • ensuring quality of technical support to address hardware and software issues. If any of these elements are ignored, the system will not yield the expected benefits. What is ICMS? To bring the benefits of conditionbased maintenance to the shipping industry, Lloyd's Register has teamed up with Rockwell Automation, a provider of automation, control and conditionmonitoring solutions, to provide the Integrated Condition Monitoring Service (ICMS). Lloyd's Register creates a tailored condition monitoring plan to suit each individual ship, and aids onboard implementation by providing the expertise of experienced conditionmonitoring engineers. Lloyd's Register uses a variety of techniques, including vibration measurement, lube oil analysis and thermal imaging to prioritise maintenance procedures. As an integral part of the service, Lloyd's Register provides on-going technical training and support, including expert data analysis and feedback, giving shipowners and operators the confidence to base their maintenance strategies on the technical advice provided by Lloyd's Register and Rockwell. Recommendations and analysis reports are made available to clients through Lloyd's Register's awardwinning classification information web site, ClassDirect Live. "There are several benefits to this holistic approach", says ICMS Product Manager Dr Gopinath Chandroth. "Just as our sensory experiences are made up of diverse inputs, machinery condition monitoring can give us the full story regarding shipboard machinery when we have access to more than one type of data." The benefits of adopting the ICMS approach to condition monitoring and maintenance include: • efficient scheduling and utilisation of maintenance resources • savings in annual repair and maintenance costs • eligibility for Lloyd's Register's MCM [Machinery Condition Monitoring] descriptive note, leading to non-intrusive surveys • global availability of condition monitoring data via ClassDirect Live maritime industry A 'one-off' ICMS is also available for pre- or post-docking health assessments of the machinery space. A complete investigation is carried out into mechanical and electrical systems, in addition to major piping systems and valves. The report produced can then be used to prioritise repair work in drydock, concentrating resources where they are most needed. Proven results The benefits of condition-based maintenance are becoming apparent in the context of ship operations. In a recent case study involving a ro-pax vessel, 77 items of machinery were included in the condition monitoring survey out of a total of 92 items onboard. In all, 20 mechanical defects were identified using vibration, lube oil analysis and thermography. The chief engineer had been concerned because certain centrifugal pumps were breaking down on a regular basis and bearings had to be replaced frequently. The ICMS engineer carried out a vibration frequency analysis onboard and discovered that eight centrifugal pumps located between the two main engines were resonating at the main engine speed. Once this root cause had been identified, the shipowner was able to formulate a solution and plan for its implementation at the ship's next drydocking. Almost all of the electrical switchboards onboard the ship, including those in the accommodation area, the bridge and the engine room were subjected to a thermal imaging survey. Eleven significant electrical defects were noted which the electrician onboard subsequently corrected. On another vessel, the THV Patricia, a buoy tender belonging to Trinity House Lighthouse Services, an unacceptable level of vibration was detected on a capstan motor. Vibration analysis revealed an excessive amplitude at the motor running speed with harmonics and half-time frequencies between the main peaks - classic indications of mechanical looseness. Alubricating oil analysis revealed a large amount of water in the oil charge of the capstan, leading to damage in the capstan bearings and causing possible secondary damage to the motor bearings. "The work carried out by Lloyd's Register on our vessel THV Patricia, was of extreme interest, and the results obtained have proved to be very useful," says Graham Forster of Trinity House Lighthouse Services. "As a direct result, we are planning to design all of our new tonnage specifically with conditionbased maintenance in mind." For further information contact Dr Gopinath Chandroth, ICMS Product Manager Email: gopinath.chandroth@lr.org Tel: +44 (0) 20 7423 1785 Fax: +44 (0) 20 7423 1804 Experienced engineers can help owners and operators to create tailored condition monitoring plans for each individual ship.