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Maximizing fluid life can minimize cost

OO Charlson Caterpillar2

Although perhaps not as exciting as a new delivery or christening, there are few events more satisfying to owners, captains, and crews than an uneventful return to their vessel’s home port; as the boat approaches its mooring, the illuminated wheelhouse, gyrating radar array, and low, gentle undulating hum from the engine room are all testaments to an attentive crew who’ve ensured the proper maintenance and operation of the vessel’s systems.  Whether the boat is a four-year-old megayacht or a forty-year-old tug, operators invariably seek to maximize their vessel’s uptime and keep the obligatory maintenance periods as short as possible.  At Caterpillar, we know that our products are the lifeblood of our marine customers’ operations, and as such, our aim is to provide customers with not only extremely reliable products, but also unwavering support that keeps that product in peak condition to help our customers succeed.  

Truly useful and meaningful support from a diesel engine manufacturer entails a variety of requirements, ranging from establishing a broad dealership network, developing quality products to deliver through those dealerships, and creating components to service those products through their lifecycle.  After all, even machinery of the soundest design will surely be rendered useless if it’s denied its requisite maintenance. By the same token, even the most frequent and comprehensive maintenance routines will be for naught if inferior or unsuitable parts are used.  As a very basic example, consider an engine that’s built with an oil sump capable of 250 hour oil change intervals. Changing the oil every 50 hours would cause no harm to the engine, but it would incur an unduly high lube oil expense in the ship’s ledger while adding absolutely no benefit.  On the other hand, changing the oil on the same engine at 1,000 hours after an incredibly short-sighted cost-benefit analysis would invite accelerated wear of vital engine components and ultimately shorten the engine’s lifespan by several orders of magnitude.  The key to minimizing engine downtime is, of course, to adhere to the maintenance intervals and procedures outlined in the Operations and Maintenance Manual (OMM) shipped with each engine. However, there are several useful and straightforward procedures that owners, captains, or engineers can take advantage of to maximize engine life and minimize the cost of maintenance.  

In decades past, boat owners that sought to maximize their engines’ lives adhered to recommended service intervals and procedures religiously.  While maintaining engines with such zeal today would undoubtedly ensure an exceptionally long service life, advances in spectroscopy and fluid analytics have enabled Cat® dealers to adjust their customers’ equipment fluid change intervals to levels that can differ from what is initially recommended in service literature.  Finding the optimal change intervals can be accomplished by analyzing the engine’s oil at several stages of the oil’s lifecycle.  The analysis, called S•O•SSMservices, includes measuring levels of various elements such as (but not limited to):

  • Copper (oil cooler core, piston wrist pin bushings, governor bushings, timing gear bearings, etc.)
  • Chromium (Piston rings)
  • Aluminum (Pistons, main bearings, connecting rod bearings)
  • Iron (crankshaft, camshaft, valves, cylinder walls, timing gears, oil pump)
  • Lead (camshaft bearings, overlay on main and rod bearings)

Cat Photo 1First, a sample of the new oil directly from the bottle (or drum) must be collected to use as control.  Of course, it’s imperative that this is the exact type and batch of oil that will be introduced into the engine, or else the initial analysis will be completely irrelevant.  Secondly, a baseline sample is taken; this occurs after the oil and filter change is complete and the engine is brought up to operating temperatures.  Any residual wear materials left in the oil pan or contaminants introduced during the oil change will appear during this time.  Once the engine is back in regular operation, two or three oil samples must be taken in order to determine the rate of oil degradation (including detergent depletion) as well as monitor engine component wear.  Finally, when it’s time to change the oil, a final sample should be taken to establish the end result of the oil and evaluate the results.  After a thorough analysis by Caterpillar, it’s possible that the engine’s oil change interval can be carefully extended by fifty hour increments.  

Regardless of the oil change intervals, it’s still imperative that operators use the best diesel engine oil available; cheap oil that barely meets minimum requirements can be expected to only barely allow components to reach their minimum component life.  Conversely, using the highest quality oil is one relatively inexpensive step that operators can take to ensure a long engine life.  Caterpillar offers the highest quality fluids needed for routine operation of their marine engines, including Cat diesel engine oil (DEO) and extended-life coolant (ELC). In the same way that high quality oil adds to the life of powerplants, so too does quality coolant.  In order to prevent corrosion and cavitation of the engine block, liners, and other components, Caterpillar recommends the use of Cat ELC (Extended Life Coolant) and Cat SCA (Supplemental Coolant Additive).  An S•O•S analysis of coolant will reveal the engine’s level of protection against boiling and freezing (glycol concentration), erosion, and incorrect pH.  Furthermore, the analysis offers operators the identification of impurities that cause corrosion and scaling and also identifies the possibility of potential devastating electrolysis.  By monitoring these elements and following dealer recommendations, it’s possible to achieve a 12,000-hour coolant service life with the use of Cat ELC Extender; for a towboat working round the clock on the Mississippi, that’s nearly a year and a half between coolant changes! 

No matter the manufacturer or age, marine diesels require a watchful eye and thorough proactive maintenance to stay in service reliably.  Although oil and coolant are only two components of engine operation and maintenance, their upkeep is of paramount importance to the safety of the crew and passengers and the ultimate profitability of the operator.  For those operating Cat engines, utilizing S•O•S services can extend the life of the powerplants and save money, but as always, engines of any brand will benefit from thorough and methodical upkeep and maintenance.  


Growing up in the Gulf Coast town of Pass Christian, Mississippi, Charlson Smith has been a mariner all of his life.  While on summer break from the University of Mississippi, he would spend his time operating a 65’ Donzi sportfisher out of New Orleans, Lousiana, the coast of Mississippi, and Port Everglades, Florida. Upon earning his MBA from Ole Miss, Charlson joined Caterpillar Marine Power Systems as a marketing representative.  His office is at the Marine Center of Excellence in Greenville, South Carolina.  He can be reached at or (864) 370-6505.

For more than 85 years, Caterpillar Inc. has been making progress possible and driving positive and sustainable change on every continent. With 2011 sales and revenues of $60.138 billion, Caterpillar is the world’s leading manufacturer of construction and mining equipment, diesel and natural gas engines, industrial gas turbines and diesel-electric locomotives. The company also is a leading services provider through Caterpillar Financial Services, Caterpillar Remanufacturing Services, Caterpillar Logistics Services and Progress Rail Services.

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