Question 1

TMAS has advised that the crew member with suspected MI requires immediate hospital treatment. The vessel is 300nm from Aberdeen. Describe the medevac coordination process.

Accepted Answer

MEDEVAC COORDINATION — CHIEF MATE's PROCESS: AUTHORITY AND DECISION: the MASTER decides whether to request medevac — but the decision is usually based on TMAS advice. TMAS physician recommends medevac based on clinical assessment. MEDEVAC INITIATION: (1) VHF/HF to MRCC Aberdeen (or JRCC in Scotland — operated by HM Coastguard): initial contact on VHF 16 or MF 2182 kHz. Switch to working channel as directed; (2) MESSAGE FORMAT: (a) Vessel name, call sign, IMO number, flag; (b) Position (lat/lon) — current and updated ETA position in 4 hours; (c) Speed and course; (d) Wind, sea state, visibility; (e) Nature of medical emergency (brief: "suspected MI in 45M, 300nm from Aberdeen, TMAS advises immediate hospital treatment"); (f) Number of persons on board; (g) Landing area for helicopter (if applicable — clear deck, fire hose/extinguisher standby); (3) VESSEL COURSE ALTERATION: alter course toward Aberdeen to reduce helicopter range if requested. Confirm with MRCC; (4) HELICOPTER PREPARATION (if helicopter coming): (a) Mark the helicopter deck — if the vessel has an HDA (Helicopter Designated Area), clear it; (b) Wind sock or smoke marker upwind; (c) Brief the patient on the helicopter lift procedure; (d) Prepare patient documentation — patient notes, TMAS consultation record, medication given, vital signs record; (e) Remove loose items on deck; (f) Post fire watch — fire extinguisher standby during helicopter operations; (5) PATIENT PREPARATION: prepare patient on stretcher if possible, in warm clothing, with documentation. Continue monitoring vital signs. UK MRCC / JRCC coordination: in UK waters and the UK search and rescue region, HM Coastguard operates Joint Rescue Coordination Centres (JRCCs) with Maritime Rescue Coordination Centres (MRCCs). The primary contact for SAR and medevac in UK waters is Aberdeen Coastguard (JRCC Aberdeen). Aberdeen SAR helicopter range: RAF and coastguard helicopters based at RAF Lossiemouth (Sikorsky S-92/AW189) have a range of approximately 300nm from the base. A vessel 300nm from Aberdeen may be at the limit of helicopter range for a one-way transit, but the helicopter can refuel at sea from the vessel or the patient can be winched and the vessel directed toward the coast to reduce transit distance. 300nm is NOT automatically beyond range — MRCC will assess. Patient documentation: this is a critical element that is often overlooked in the urgency of a medevac. Hospital doctors receiving a patient from a vessel medevac need: (a) patient's name, age, nationality; (b) description of symptoms and onset time; (c) vital signs trend (recorded over time); (d) medications administered on board; (e) TMAS consultation record. Without this information, hospital treatment is delayed while the patient is re-assessed from scratch. Flag state authorisation (option C): medevac does not require flag state authorisation. The master requests medevac through the MRCC of the relevant SAR region. The MRCC coordinates the response. The flag state is notified but does not need to authorise the response — this is a life-safety action.

Question 2

As Chief Mate on a chemical tanker, you are planning to load benzene (UN 1114, Class 3, PG I) after carrying methanol. What segregation, tank preparation, and safety measures apply?

Accepted Answer

BENZENE LOADING AFTER METHANOL — CHIEF MATE's PLANNING: CARGO COMPATIBILITY CHECK: (1) Are methanol and benzene compatible for sequence loading? Methanol (Class 3/6.1) and benzene (Class 3) are both flammable — BUT they are not compatible in the sense that residual methanol in a benzene cargo = CONTAMINATION. Check the IBC Code compatibility matrix and the charterer's cargo compatibility requirements; (2) TANK WASHING: tanks previously carrying methanol must be thoroughly washed before benzene loading. Methanol is water-soluble and miscible — water washing followed by recirculation is appropriate. Complete drying is required as water in benzene cargo = haze/contamination; (3) BENZENE PROPERTIES (UN 1114): (a) Class 3, Packing Group I (very high flammability); (b) Boiling point 80°C, flashpoint -11°C (extremely flammable); (c) TOXIC: a human carcinogen (Group 1 IARC). Vapour exposure risk — PPE: SCBA and full chemical protection suit for all operations; (d) Vapour density 2.7 (heavier than air — accumulates in low areas); (4) MARPOL ANNEX II: benzene is Annex II Category X substance (most hazardous). Pre-washing before any discharge — MANDATORY; (5) IBC CODE SPECIAL REQUIREMENTS: benzene requires closed loading, vapour return line (vapour recovery or destruction), enclosed gauging (no open ullaging), and restricted access during loading; (6) SAFETY ZONE: 3-metre exclusion zone around manifold during loading operations. No ignition sources within 30m. IGS may not be required (benzene is non-reactive to inert gas atmospheres) but nitrogen blanket may be required; (7) EMERGENCY: EmS F-E (flammable liquids fire) and S-E (spillage). Benzene as a carcinogen: benzene is classified as a Group 1 carcinogen by IARC (International Agency for Research on Cancer). The IMDG Code and IBC Code impose additional health protection requirements beyond standard Class 3 liquid handling. Exposure limits: the UK COSHH regulations specify a Workplace Exposure Limit (WEL) for benzene of 1 ppm (8-hour TWA). This is extremely low — the vapour pressure of benzene at ambient temperature means significant benzene vapour can be present at open ullage points, manifold areas, and any open sampling. ALL operations involving benzene cargo must use SCBA and appropriate chemical protection. IBC Code Chapter 15 special requirements: Chapter 15 of the IBC Code specifies additional cargo-specific requirements for each chemical. For benzene — these include: (a) vapour emission control; (b) closed operations; (c) emergency shutdown system; (d) health monitoring for crew. MARPOL Annex II Category X: benzene is among the most strictly regulated liquid cargoes under MARPOL Annex II. Discharge into the sea of any benzene-contaminated washwater is absolutely prohibited unless processed through a compliant retention/disposal system. Pre-wash is mandatory before ANY discharge of residues in any sea area. Cross-contamination (option B): loading benzene into a tank with methanol residue creates a contaminated benzene cargo. Methanol is infinitely miscible with benzene — even small traces will reduce benzene purity below specification. Additionally, water from tank washing that is not completely dried creates a benzene/water haze that similarly renders the cargo off-specification.

Question 3

In port, a cargo hold is opened and a strong smell of chlorine is detected. The manifest shows UN 1017 (Chlorine, Class 2.3 Toxic Gas) in the lower hold. Crew members are near the hold. As Chief Mate, what do you do?

Accepted Answer

CHLORINE GAS RELEASE — EMERGENCY RESPONSE: UN 1017, CHLORINE, CLASS 2.3: (a) Extremely toxic gas — IDLH (Immediately Dangerous to Life and Health) 10 ppm; (b) Heavier than air (vapour density 2.5) — accumulates at low levels in holds; (c) Bleach-like odour detectable at 0.5 ppm — if crew can smell it, concentrations may already be dangerous. IMMEDIATE ACTIONS — FIRST 60 SECONDS: (1) SHOUT AND CLEAR: warn all crew in the vicinity to MOVE AWAY UPWIND. Do not send crew into the hold without SCBA; (2) WIND AWARENESS: position crew UPWIND of the hold opening. Chlorine disperses downwind; (3) NO IGNITION SOURCES: chlorine in combination with hydrogen (from bilge gas) could explode — no smoking, no naked flames. However, chlorine itself is not flammable; (4) CALL THE MASTER: immediate notification; (5) SOUND GENERAL ALARM: if the release is significant or risk of spread to accommodation; (6) CLOSE THE HOLD: if it can be done safely from outside without entering — secure the hold to contain the release; (7) EMERGENCY SERVICES: contact port authority and emergency services (shore fire brigade with HazMat team); (8) IMDG EmS: EmS code for UN 1017 is F-C (non-flammable gas fire) and S-U (toxic gas spillage). S-U: keep people away from damaged area. Contact 24-hour emergency advice centre; (9) EMERGENCY CONTACT: the DG manifest must show a 24/7 emergency contact. Call them immediately; (10) DO NOT VENTILATE BY BLOWING AIR INTO HOLD: this could disperse chlorine gas to adjacent areas. Chlorine toxicology: chlorine is one of the most dangerous gases that can be encountered on a cargo vessel. WWI chlorine gas attacks used concentrations above 1,000 ppm — but even at 30 ppm, severe chest pain, vomiting and pulmonary oedema occur. At 430 ppm — death within 30 minutes. Critically: chlorine is HEAVIER than air — it accumulates at the lowest point (bottom of the hold). Crew near the open hatch may not immediately appreciate the concentration at lower levels in the hold. IMDG EmS S-U: the Spillage Schedule for toxic gases (S-U) specifies: "ELIMINATE all ignition sources. STOP leakage only if safe to do so. Move people from danger area upwind. Advise competent authority of potential hazard. Contact chemical experts." "Rag over the face" approach (option C): chlorine at dangerous concentrations is immediately incapacitating. A crew member who enters a hold with chlorine vapour above IDLH using a rag as protection will quickly become incapacitated. This would turn a dangerous goods incident into a rescue situation requiring entry into a toxic atmosphere — putting additional lives at risk. The USCG and MAIB have investigated several cargo incidents where rescue attempts without SCBA resulted in rescuers also becoming casualties. Ventilation with fans (option B): ventilating by blowing air INTO the hold could spread chlorine gas to adjacent spaces, including engine room intakes and accommodation. The correct approach is to CLOSE the hold and control the release, allowing emergency services with HazMat equipment to handle decontamination. Detection threshold vs danger threshold: the detection odour threshold for chlorine is 0.5 ppm. This is BELOW occupational exposure limits (1 ppm ceiling under COSHH). Detection does not mean safe — it means dangerous concentrations may be nearby.