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Predictive is the new Preventive


In COVID-19 times, Condition Monitoring (CM) and preventive maintenance is key to significant cost savings compared to Run-To-Fail practices

The science of predictive maintenance

Conferences today are done virtually, including telemedicine – allowing patients to connect remotely with their doctors for consultation. Applying this concept into maritime, ship operators are now able to decide efficiently and make effective maintenance decisions. Named Condition Monitoring (CM), it is supervising the health and functionality of critical assets. Mechanical faults can be picked up during nascent stage, minimising risks of critical failure while out at sea. Such works reduce maintenance costs considerably in the long term.

For ship operators, it is crucial to keep the vessel in its best operational modes. CM neither enhances machine capabilities nor prolongs failure. The key is obtaining crucial information about the ship’s overall condition, symptoms of failure and their severities. The data can be transferred to a mobile device or online system which is accessible anytime.

A stationary online CM system can also connect to permanently mounted accelerometers affixed to the desired machinery. The system is subsequently configured with a database to reflect status, identify failure modes and automate diagnostics.

Temperature, pressure, and vibration data are collected across all channels simultaneously and transferred to the integrated ship management system via ethernet or to onshore servers via mobile cellular router. These systems detect machine failures such as misalignment, excessive gear mesh, unbalance, groundings, bent shafts, propeller issues and bearing failures. The online CM system can also be configured to send email notifications of machinery status updates to phones or computers. Ship operators enjoy overall real-time updates of machinery conditions and cost savings. Unplanned breakdowns and accompanied hidden costs are virtually ridded. Data can also be transmitted to shore – skipping the analyst’s round trip to the vessel.

Preventive maintenance remains popular

The often practiced Run-To-Failure (RTF) maintenance strategy’s high costs and frequent contribution to nearby equipment malfunction was no deterrent to ship operators. Despite the nature of faults amplifying over time instead of happening suddenly, CM reception rate remains low. Its power to identify symptoms of failure, assess overall condition, enable heightened productivity, operational reliability and safety while saving costs did not warrant much attention. A common reason is the preconceived notions of costs and complexity. Low adoption rate breeds technological inertia due to lack of data. However, preventive maintenance’s efficacy scores only 23 per cent. The United States Navy 1982 MSP (Managed Service Provider) Study revealed 77 percent of failures occur randomly.

A substantial shift has yet to take place. Lloyd’s Register’s Technical Investigation Department only recorded 17 per cent of classed ships operating with an approved preventive maintenance system. Within this population, only 12 per cent adopt CM. This results in incomplete maintenance records, as ships would need to be disassembled for assessment to remain enroled in the system. CM in this instance closes the gap by providing the same data to surveyors without touching the machine. Classed vessels without CM systems would need to reapply annually to stay enroled.

About the author

Rich Merhige is Founder & President of Fort Lauderdale-based Advanced Mechanical Enterprises (AME). He was the subject of an “Executive Achievement” feature in the May/June 2014 edition of the magazine. The opinions expressed herein are the author’s and not necessarily those of The Maritime Executive.


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