Question 1

What is the main purpose of the lubricating oil (LO) system on the main engine?

Accepted Answer

To reduce friction and wear between moving metal parts (e.g. bearings, pistons, gears), and to help carry heat away from those parts and remove small metal particles/contaminants via the filters and purifiers Lubricating oil forms a film between moving surfaces (such as crankshaft bearings and piston rings/liners) that prevents direct metal-to-metal contact — without it, friction would rapidly generate excessive heat and wear, leading to seizure. The oil also absorbs heat from these components and carries it to the LO cooler, and continuously passes through filters/purifiers that remove wear particles and contaminants, which is why monitoring LO pressure, temperature, and cleanliness is a core part of engine room watchkeeping.

Question 2

You're draining a thermal oil system that was running normally a short time ago. Before opening the drain point, what should you confirm?

Accepted Answer

That the system has cooled and depressurised, and you are positioned clear of the drain point's discharge path On the dredger MV Amazone, two crew members draining a thermal oil system after months of contamination were sprayed with hot oil, suffering severe burns. The investigation found company procedures lacked clear instructions for safe drainage — confirming the system has cooled and depressurised, and standing clear of the discharge path, are essential before opening any drain point on a hot oil system.

Question 3

A thermal oil system has been contaminated and needs draining for cleaning. The written procedure tells you to open the drain valve but doesn't specify a cooling-down period or PPE. What should you do?

Accepted Answer

Treat the gap as a hazard in its own right: apply a suitable cooling/depressurising period and full PPE before proceeding, and raise the procedure gap with the Chief Engineer The FEBIMA investigation into the MV Amazone incident found that although the crew followed company procedures, those procedures lacked clear instructions for safely draining a thermal oil system. A procedure that's silent on cooling time and PPE for a hazardous task is a gap to be closed before the job starts — not a green light to skip those precautions.