At sea, smoke is observed from a 40-foot container on deck. The manifest shows it contains UN 2014 Hydrogen Peroxide solution 60% (Class 5.1 oxidising agent). What is your response?

A. CLASS 5.1 FIRE RESPONSE — HYDROGEN PEROXIDE: UN 2014, HYDROGEN PEROXIDE SOLUTION 60%, CLASS 5.1 (OXIDISING AGENT): IMDG Code EmS Guide: F-H (Fire) and S-Q (Spillage). EmS F-H: "Fight fire from a safe distance. Cool containers with water. Do not allow cooling water to enter damaged containers as it may cause steam explosion or spread the fire. Wear self-contained breathing apparatus." HYDROGEN PEROXIDE HAZARD PROFILE: (a) Powerful oxidising agent — dramatically accelerates combustion; (b) Decomposes at elevated temperature releasing oxygen — this FEEDS fire; (c) At 60% concentration — capable of spontaneous ignition of organic materials; (d) Toxic fumes — DO NOT BREATHE decomposition products; (e) Contact with skin/eyes — severe burns. MASTER'S RESPONSE: (1) STOP ENGINE: do not increase ventilation of the area; (2) HEAD TO WIND: position the vessel so wind blows smoke and fumes AWAY from accommodation; (3) NO CREW ON DECK: no approach without full SCBA and chemical protection suit; (4) ASSESS THE SITUATION FROM THE BRIDGE: is the container on fire? Is it simply leaking (note peroxide is clear liquid)?; (5) WATER COOLING: apply fixed deck water spray or fire hoses with full SCBA protection on crew; (6) DO NOT USE CO2 ON A CLASS 5.1 FIRE: CO2 and dry powder are largely ineffective on oxidising fires; (7) CONTACT CHEMTREC or equivalent for real-time chemical expert guidance; (8) MAYDAY: if the fire cannot be controlled; (9) MUSTER CREW at safe upwind station; (10) EMERGENCY CONTACT: IMDG requires a 24/7 emergency contact number on the shipper's DG manifest — use it.

B. Use the CO2 fixed fire suppression system to extinguish the deck container fire immediately. CO2 is effective on all cargo fires.

C. Class 5.1 oxidisers are not flammable. Smoking from a container is likely a chemical reaction, not a fire. Approach the container and open it to inspect.

D. Abandon the vessel immediately. Hydrogen peroxide fires cannot be controlled and the vessel should be evacuated at the first sign of smoke.

A. Three containers overboard is a minor incident. Continue voyage and report at the next port. MAIB notification is only required for vessel damage.

B. Container losses at sea are covered by cargo insurance. Notify the charterer and continue the voyage — the containers are their problem once they fall overboard.

C. Container lashing is the chief officer's responsibility. The master is only accountable for navigational decisions and has no cargo securing liability.

D. CONTAINER LOSS OVERBOARD — MASTER'S OBLIGATIONS AND INVESTIGATION FOCUS: IMMEDIATE ACTIONS: (1) SAFETY: no crew on deck in the current conditions. Head count — is anyone missing?; (2) MANOEUVRE: alter course to reduce vessel motion and prevent further casualties. Inform VTS if in TSS or coastal waters; (3) MAIB NOTIFICATION: lost containers and damage to vessel = significant marine incident. Call MAIB 023 8023 2527; (4) MARPOL: if containers contained goods that are now discharged into the sea — MARPOL reporting obligation (material that could pollute); (5) SOPEP/Emergency Response: if hazardous goods are in the lost containers — what is the UN number? IMDG EmS code? Coastal state environmental alert?; (6) LOG: immediate OLB entry — number of containers lost, position, time, sea state, course/speed; (7) NOTIFY: owner, DPA, P&I Club, charterer; (8) MARK ON CHART: position of lost containers. MAIB will want this. Container stranding is a major navigation hazard — notify MRCC/VTS for NAVTEX broadcast; INVESTIGATION FOCUS: (a) WAS THE CARGO SECURED IN ACCORDANCE WITH THE CSS CODE AND CARGO SECURING MANUAL (CSM)?: the CSS Code (Code of Safe Practice for Cargo Stowage and Securing) and vessel-specific CSM (approved under SOLAS VI/5.6) specify lashing requirements. Did the lashings meet specification? Were they correctly applied?; (b) WAS THE VESSEL'S STABILITY AND LOADING CONDITION APPROPRIATE?; (c) WAS THE WEATHER FORECAST CONSIDERED IN STOWAGE DECISIONS?; (d) WERE LASHINGS CHECKED EN ROUTE?; (e) MASTER'S SIGNATURE ON CARGO PLAN: did the master approve the stowage and securing plan?

A. IRON ORE FINES LOADING — TML AND MOISTURE ASSESSMENT: LIQUEFACTION RISK: iron ore fines are an IMSBC Code Group A cargo (may liquefy). Liquefaction is when cargo behaves like a liquid due to high moisture content exceeding the Transportable Moisture Limit (TML). Several bulk carriers have sunk due to liquefaction (e.g., Bulk Jupiter 2015, Vinalines Queen 2011). TML TESTING: the shipper must provide: (a) TML certificate (maximum 6 months old for iron ore fines); (b) Moisture content (MC) certificate showing actual MC is below TML. The margin: actual MC should be BELOW TML — the IMSBC Code requires actual MC < TML. A "can test" may be used as a pre-load indicator. RECENT RAINFALL — ADDITIONAL DUTY: if rainfall has occurred since the TML/MC certificate was issued, the moisture content of the surface cargo stockpile may have increased. THE MASTER'S DUTY: (1) REQUEST UPDATED MOISTURE CONTENT TEST: ask the shipper for a fresh moisture content test reflecting post-rainfall conditions. IMSBC Clause 4.4.2 allows the master to request additional testing if there is reason to believe moisture content has increased; (2) VISUAL INSPECTION: inspect the stockpile. Wet sheen on surface, water pooling, flowing consistency when disturbed — all indicators of elevated moisture; (3) CAN TEST: IMSBC Appendix 2 — can test procedure. Take a sample of the cargo into a tin can, seal it, shake vigorously. If free moisture appears or the cargo flows — it is too wet to load; (4) REFUSE TO LOAD IF UNCERTAIN: the master has the right (and duty) to refuse to load Group A cargo that may be unsafe. This is backed by ISM Code 5.3.

B. The shipper's TML certificate is valid. Once the certificate is presented, the master has no further obligation to assess moisture content.

C. Iron ore fines do not liquefy in transit — they are a solid mineral cargo. Moisture content testing is only required for agricultural cargoes such as grain.

D. Rainfall affects only the surface layer of stockpiled cargo. Load the cargo at reduced speed and the surface moisture will dissipate once in the hold.