Corrective maintenance saves money in the long run

Mar 7, 2016 by Rich Merhige

The old adage “an ounce of prevention is worth a pound of cure” holds a tremendous amount of merit, especially when it comes to the maintenance of vessels. Regardless of how much education is out there, the majority of the time, vessels call on us when they already have a problem.

When approached by a vessel, they are usually reporting a symptom, such as a noise, a leak, or, decreased performance. Right away, they want it addressed, asking for an alignment, service of seals, or another localized service.

Unfortunately, very often, these suggested repairs are only quick fixes that don’t adequately address the root problem, which is causing the problematic symptoms. Even though “quick fixes” may seem like the best course of action due to time and budgetary constraints, this is not always the case, and can often result in larger issues and, a larger repair bill in the long run.

The most common response to fix a failure, outage, or another mechanical issue that’s rearing its ugly head is corrective maintenance.

Corrective maintenance is really a defense mechanism, and the most unreliable approach one can have towards the maintenance of their machinery. Reliability centered maintenance/RCM is a more practical approach of reliability engineering that focuses on root cause of mechanical issues by understanding and monitoring how all mechanical components in a system work and function together.

Reliability Centered Maintenance (RCM) was developed by United Airlines and Boeing in the 1960s and 1970s to improve the reliability of the 747. This program improved maintenance hours from 200 man hours to 3.3 manhours per flight hour. While RCM is gaining more mainstream support in recent times, there is still plenty of hesitation, mostly because it is greatly misunderstood. Despite these successes, misconceptions are that it is too time consuming, goes into too much detail, or zaps too much of a maintenance budget.

One tool of RCM, but certainly not the only part, is to have a list of failure modes and a corresponding list of their mitigating tasks that fall under the umbrella of predictive and preventative maintenance.  

This list alone, could provide a solid maintenance plan. The downside to only relying on a list like this? All components must be installed and used in accordance with manufacturer specifications. This system will not be able to take into account environmental factors, or the different operational contexts of machinery, meaning this alone is completely unrealistic in yachting where virtually no vessel is cookie-cutter. Ideally, you should have three to five tools in place to build a proper maintenance strategy that addresses engineered “knowns” as stated above, but, allows to also monitor equipment based on environment and operational usage.  Above all, these tools should make it easy to identify, plan, and execute predictive and preventative maintenance tasks.

In terms of applying these practices to a vessel’s machinery, condition monitoring systems can go a long way. The most comprehensive of these systems combine diesel engine monitoring, vibration analysis, infrared thermography and oil analysis among other methods of testing to record performance and notate deviations from what is desired and acceptable operationally.  Unfortunately, robust condition monitoring as described is not commonplace in the pleasure craft sector of the marine industry.

Vibration analysis alone can be a very powerful tool to gear attention to red flagged items that need to be addressed before a complete breakdown occurs. For example, when approached by a vessel that is reporting an issue such as noise, or decreased performance, sometimes they’ll right away ask for an alignment. It isn’t always as simple as that. If an alignment is done, but, let’s say the engine mounts are nearing the end of their life, the alignment isn’t going to hold. The alignment was never the issue. The engine mounts were. If the engine mounts aren’t addressed, even the most capable engineer, using the most expensive piece of alignment equipment, will not be able to achieve alignment that will hold.

Utilizing RCM tools such as a failure mode list, along with a condition monitoring tool such as vibration analysis would pinpoint the root causes in the aforementioned scenario that would outline the proper course of action to correct the underlying issues that are causing the symptom of misalignment.

Even though it could sometimes be overwhelming to get to the bottom of mechanical issues, in the long run, it really is the best route to ensure your maintenance dollars are being best used, for the most impactful results.

Rich Merhige is owner of Advanced Mechanical Enterprises and Advanced Maintenance Engineering in Ft. Lauderdale. Contact him through