Question 1

During the fire event, the fixed gas detection system on deck shows naphtha vapour rising in cargo tank 3 ullage space to 22% LEL. This is likely due to the loss of inert gas pressure — the IG blower runs off the main engine. The cargo system operator is asking what to do.

What is the priority action?

Accepted Answer

Immediately check that all cargo tank valves, manifold valves, and ullage plugs are closed and secured. Initiate manual monitoring at the tank tops. Stop all non-essential electrical loads that are non-intrinsically safe near the cargo area. Notify all crew not to use mobile phones, radios, or produce ignition sources on deck. The LEL reading means a flammable atmosphere is developing — ignition sources must be eliminated immediately Opening tanks to ventilate naphtha vapour is catastrophically wrong — it replaces an inerted atmosphere with fresh air/vapour mix, potentially creating an ignitable atmosphere throughout the tank. Compressed air is not an inert gas and would create the same problem. 22% LEL means the concentration is well within measurable explosive range — any ignition source on deck (radio, non-ATEX equipment, static) can trigger a tank explosion. Ignition source elimination is the immediate priority while the team assesses IG restoration options. This scenario has killed crews.

Question 2

MV SOLWAY STAR, 1435. The engine room fixed fire detection alarm activates on the bridge panel — zone indicated is bilge area, below the main engine. The ER is manned — the chief engineer and two ratings are on watch below.

What is the OOW's FIRST action?

Accepted Answer

Sound the general alarm immediately. Inform the Master. Do NOT ring the engine room to ask them to investigate — they are in the fire zone. The general alarm brings the emergency team to their stations and ensures the CO₂ room and fire parties are ready before any further assessment Ringing the engine room is the most common and most dangerous instinct when a fire alarm sounds — it asks people in the fire zone to investigate and reassure you. The correct response is immediate general alarm: it activates the emergency team, gets the CO₂ room manned with the correct personnel, and starts the accountability process. A false alarm muster costs 15 minutes. A delayed alarm in a real bilge fire on a naphtha carrier costs lives. The decision to discharge CO₂ will be made by the Master with full accountability — not by an OOW who has run to the CO₂ room alone.

Question 3

Thirty seconds after the general alarm, the chief engineer radios the bridge: "I can see smoke near the bilge pump. I'm going to check if it's a small oil fire — I'll call you back in two minutes." The fire party is mustering on deck.

What is the Master's response?

Accepted Answer

Order the chief engineer and ALL engine room personnel to evacuate immediately and close the ER fire dampers and watertight doors. Do not allow investigation without full BA team and hose in place. Smoke in an ER bilge area of a naphtha carrier is a serious fire risk — vapour ignition can occur in seconds The bilge area of a chemical tanker carrying naphtha (flash point −40°C) means flammable vapour is present at ambient temperature. A small visible fire can flash over in seconds if the fuel supply (oil in bilge) is not interrupted. Allowing a solo investigation without BA, without a charged hose, and without the fire team in position violates every principle of fire fighting practice. The chief engineer's instinct to deal with it quickly is understandable — and potentially fatal. Close the space, get personnel out, assess from outside.