Machinery Matters: by Larry D. Rumbol
“Condition monitoring” is one of those phrases one hears in conferences and learned corners of the dock. Those really familiar with it call it “ConMon,” never a term I was happy with. The fact is that we all practice condition monitoring without knowing it, every day. Casting an eye over the heel or sole of our shoes and considering the chafe on a warp or sail is condition monitoring.
Is what I am about to use, operate, rely on for safety, etc., fit for that purpose, or is it going to break itself, injure me or someone else, or just plain fail and stop other things working, too?
Classification societies such as Lloyds and the American Bureau of Shipping and insurance companies call condition monitoring “best practice” and have done so for years, yet many engineers (and humans) run equipment (and shoes) to failure. They suffer the consequences of machinery failure, expense, collateral damage, lost time and, of course, wet feet. It’s a human condition to prevaricate. It’s a built-in mechanism that we have to fight. How often do we say things like “It’ll be alright”, “it’s only warm”, “let’s wait until the next trip”, “it always squeaks,” and so on.
Classification societies and insurance companies have the benefit of huge amounts of empirical data that show unequivocally that early intervention always pays dividends and that a “run to failure” operational mode is exponentially costly indeed.
As an engineer, one can and should rise above these outdated methods. No screwdriver handle should ever come close to an ear to identify a strange noise, nor any bare hand touch a motor to see if it is hot. We have the technology and we have had it for many years.
Think of machinery as a human; if you want a health check, you have a blood test. For blood, think oil. Blood touches everything in a human as does oil in machinery, or at least, all the parts that have an interface and could potentially wear or fail. Blood rarely gets sick; it’s a carrier, as is hydraulic and lube oil, and through this wonderful dynamic of touching everything, it will pick up telltale signs of what is going on with the machinery it touches and protects.
Forget physically touching and listening to machinery; that is imprecise, potentially dangerous and open to random interpretation. Spectrographic oil analysis is the technology to use and will identify the start of a mechanical issue long before it manifests as an irreversible problem. Through analysis of the oil’s chemical elements and physical properties and analysis of their precise values against well-known norms, machinery condition can be precisely monitored and/or anomalies investigated. Oil and hydraulic samples are regularly taken (100ml is typical and undertaken via the dipstick hole with a special hand pump) and sent via a courier system to the lab. Here it is logged, decanted and processed. Elemental analysis is looking for wear metals, oil additive depletions and contaminants.
Physical properties such as viscosity at specific temperatures and other parameters such as wear debris will be scrutinized, allowing a picture to be built up that is supported by a comprehensive lab report with a plain English explanation. The lab report is not a diagnosis or a cure; it is vital information that allows an engineer to go straight to the heart of a potential problem — note, potential problem. This is advance information that allows simple intervention in slow time to prevent an anomaly becoming a costly mechanical breakdown with all that involves in cost, time and often reputation (personal and vessel).
Aircraft rarely break down catastrophically as the consequences are always dire. As such, sophisticated condition monitoring systems were developed to identify every anomaly early and provide ground crew with vital information to act accordingly before there is the slightest risk to the machinery integrity.
Marine engines and machinery are now becoming equally sophisticated, with ever smaller tolerances and a reduced ability to shrug off a mechanical incident like older, more solid (less efficient), perhaps over-engineered equipment of the past.
Accelerated wear is no longer something we have to endure, nor is breakdown inevitable. It is something we endeavour to prevent by timely intervention and regular oil sampling and trend analysis. Trending is the graphic representation of results identifying anything out of the norm and monitoring its rise or fall with the added benefit of a visual representation. Trending is key to understanding the normal operational parameters of an engine or machinery and is a precise indication that these parameters are a) changing, or b) post change or intervention, are returning to normal.
So there we have it – condition monitoring, simple and effective, yet not everyone does it. Insurance companies call the consequence of running to failure “catastrophic damage,” an unfixable, huge expense in time and money that was 99% predictable and preventable.
The cost of oil analysis is less than the price of a gasket set for the smallest engine, and has been proven to be one of the most cost-effective maintenance spends ever. However, choose the lab wisely. Rather like cheap parachutes, the risk and irreversible consequences far outweigh the meager savings made. Use the best, most experienced and highest quality laboratory available.
Larry D. Rumbol has 40 years of expertise in marine condition monitoring and is marine business development manager with Spectro | Jet-Care in the United Kingdom, United States and Switzerland. Comments are welcome below.