Question 1

What is the purpose of an Oily Water Separator (OWS) fitted in the engine room, and why is its correct operation important?

Accepted Answer

It separates oil from bilge water so that the treated water discharged overboard meets the maximum oil content limit set under MARPOL Annex I (15 parts per million); bypassing or tampering with the OWS (sometimes called a "magic pipe") to discharge untreated oily bilge water is a serious pollution offence with severe legal consequences for both individuals and the company Bilge water in machinery spaces inevitably collects oil from leaks, drips, and maintenance, and discharging this water untreated would breach MARPOL Annex I — the OWS, together with the Oil Record Book entries documenting its use, is the mechanism that allows bilge water to be legally discharged. Any rating who is asked to operate or bypass bilge pumping equipment should understand that any deviation from normal OWS operation must be reported, never carried out informally, as illegal bypass arrangements have led to criminal prosecutions of crew and substantial fines for companies.

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.