Answer
When a shore analysis report lands on your desk, your first action must be highly systematic to identify any immediate threat to the machinery.
First Check — The Overall Diagnostic Status Flag: Glance directly at the summary flag or evaluation color code (Green/Amber/Red). If it is Red or Amber, immediately jump down to the lab analyst’s handwritten comments for a quick indicator of the primary fault.
Second Check — Water Content: Look for water contamination (measured in % or ppm). Any sudden rise (especially above 0.2% for system oil) is a critical red flag indicating an auxiliary LO cooler leak, jacket water sealing ring failure, or piston cooling line issue. Saltwater contamination is an absolute emergency due to the risk of rapid bearing wiping.
Third Check — Viscosity (at 40°C and 100°C): Check if the viscosity has dropped drastically (indicating fuel dilution from a leaking injector or fuel pump sealing system) or risen significantly (indicating high insolubles, thermal oxidation, or severe soot loading).
Fourth Check — Base Number (BN / TBN): Ensure the oil retains sufficient alkalinity to neutralize acidic combustion products. A sharp drop in BN indicates the oil is losing its protective capability, which will accelerate corrosive wear on components.
Fifth Check — Wear Metals & Contaminants: Look at the elemental ppm levels:
Iron (Fe): Signals cylinder liner, piston ring, or timing gear wear.
Copper (Cu) & Lead (Pb): Signals white metal degradation or main/crankpin bearing wear.
Silicon (Si): Signals dirt/catalytic fines bypassing the air intake filters or fuel system.