Pulling an oil sample during a routine oil change on a main engine or generator is a practice followed by many engineers on yachts around the world. Oil sample analysis aims to catch irregularities, which can provide an early heads-up for an engineer to investigate further.
Machinery oil sampling is typical at the time of an oil change and involves sending a small quantity to a laboratory for analysis, which will then, in turn, provide a report of sample data and a sample status. Generally, a sample's status can be Okay, Caution, or Severe, although this terminology may vary between laboratories.
Increasingly, sampling is also becoming common across other systems on board as a means of ensuring good working order or acceptable sanitation levels.
A sample is a snapshot in time, how that particular sample was at that moment. Now string together a series of samples over a number of years and you now have insight into how a component operates over time and potentially what its normal acceptable range is.
Hydraulic sampling on systems such as stabilizers, thrusters, deck equipment (davits, capstans, and windlasses), and steering has started to become more common. Sampling on these systems can allow vessels to extend OEM recommended oil change intervals.
In an owner's manual, equipment manufacturers can include that an oil change is required at a certain interval, or an oil sample is recommended to determine if a full oil change is required at that point in time. For the budget-conscious yacht owner, this can be a good course of action.
Potable (drinking) water sampling has become increasingly common in recent years. Whereas once we would see 20 percent of vessels actively testing water quality on board, that figure is closer to 50 percent today. Annual sampling of a vessel's freshwater tank is a great way to do your part as the engineer to ensure those who are exposed to potable water on board are safe. A tip when testing water quality - collect multiple samples, including from holding tank(s), and where filtration takes place. Water may be okay in the tank, but not at the filters.
Those who have been around sampling will know the power of regular sampling rests in the ability to perform trend analysis. Think of it this way — a sample is a snapshot in time, how that particular sample was at that moment. Now string together a series of samples over a number of years and you now have insight into how a component operates over time and potentially what its normal acceptable range is.
Trend analysis provides visibility into whether deterioration is occurring and possibly leading to a major breakdown.
This article was originally published in the January 2023 issue of Dockwalk.