Question 1

During your oral exam you are asked: what factors should be considered when changing over from one type of fuel to another (e.g. from a heavier fuel to a low-sulphur distillate fuel for ECA compliance)?

Accepted Answer

Factors include the difference in viscosity (affecting fuel pump and injector performance, and potentially requiring adjustment of heating/cooling of the fuel system), lubricity differences (particularly relevant for low-sulphur fuels which can have reduced lubricity affecting fuel pump wear), timing of the changeover relative to entering the ECA (allowing sufficient time for the system to fully transition), and compatibility/mixing issues if fuels of different origins are blended in the system Fuel changeover procedures for ECA compliance require careful management of the transition because a sudden change in viscosity can cause fuel pump and injector issues (either too thin, causing leakage and reduced lubrication, or too thick if changing the other direction), and low-sulphur distillate fuels historically had documented lubricity issues causing accelerated fuel pump wear in some engine types. Timing is critical — the changeover must be completed with sufficient margin before entering the ECA boundary to allow the system to fully purge the previous fuel, and incompatibility between different fuel batches can cause sludge formation or filter blocking if not managed through proper tank and line sequencing — IMO guidance and class notices on this topic followed numerous operational issues after the 2020 sulphur cap changes.

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.