Question 1

At 0300, a crew member (45-year-old male) wakes with severe chest pain, sweating and nausea. You are 600nm from the nearest port. As Chief Mate, how do you manage this?

Accepted Answer

SUSPECTED MI — CHIEF MATE's MEDICAL MANAGEMENT: SUSPECT ACUTE MYOCARDIAL INFARCTION (Heart Attack): classic presentation: central chest pain, radiation to arm/jaw, sweating, nausea. In a 45-year-old male — must assume cardiac until proven otherwise. INITIAL ASSESSMENT: (1) CALL MASTER: immediately. This is a potential life-threatening emergency; (2) CONSULT SHIP CAPTAIN's MEDICAL GUIDE (MCG) or equivalent: assess symptoms systematically; (3) VITAL SIGNS: pulse (rate, rhythm, strength), blood pressure (if sphygmomanometer available), SpO2 if pulse oximeter available, respiratory rate; (4) CONTACT TMAS: RADIO MEDICAL ADVICE — mandatory on GMDSS-equipped vessels. In UK: TMAS-UK via MRCC (or directly +44 191 293 4422). Give: (a) patient age, sex, symptoms; (b) duration of pain; (c) vital signs; (d) any prior medical history known; (e) medications on board. TMAS physician will provide specific treatment guidance; (5) MCG TREATMENT: while awaiting TMAS — give aspirin 300mg (chew, not swallow) IF not allergic and no obvious contraindication. Aspirin is the first-line treatment for suspected MI. GTN (glyceryl trinitrate) spray if available and blood pressure is adequate (>90mmHg systolic); (6) OXYGEN: if SpO2 below 94% — administer oxygen via mask; (7) REST AND REASSURANCE: keep patient calm. Anxiety worsens cardiac workload; (8) MEDIVAC ASSESSMENT: TMAS will advise whether medical evacuation (medevac) is required. At 600nm — helicopter range may be limited. Consider nearest suitable port for medevac. TMAS (Telemedical Assistance Service): SOLAS Chapter IV GMDSS requires that vessels provide means for radio medical advice. The UK TMAS is operated by the NHS via Tyne and Wear EMS and is available 24/7. It provides physician-to-seafarer medical guidance. TMAS consultation is FREE for vessels using the service — contact via MRCC or direct telephone. Aspirin for suspected MI: aspirin 300mg (chew) is the standard first-aid treatment for suspected MI. This is in the Ship Captain's Medical Guide, the IAMSAR Manual, and multiple national maritime medical guidance documents. The antiplatelet effect of aspirin reduces clot formation in the coronary artery. Every officer on a GMDSS vessel should know to administer aspirin for suspected chest pain/MI presentations. Paracetamol (option B): paracetamol is an analgesic/antipyretic with no cardiac benefit and no appropriate role in suspected MI management. It addresses fever and general pain — not the clotting cascade involved in MI. Prescribing paracetamol for suspected MI would be negligent. Morphine (option D): morphine (from the controlled drug locker) is sometimes used for severe cardiac pain — but its administration at sea requires specific TMAS physician guidance. Administering a "full dose of morphine" without physician guidance, without checking blood pressure, without confirming the diagnosis — is extremely dangerous. Morphine causes vasodilation and can cause BP collapse in patients who may already be hypotensive from cardiac compromise. Never administer morphine without specific TMAS guidance. No doctor exemption: SOLAS does not require all vessels to carry a doctor. The officer responsible for medical care (typically the master or designated officer) is responsible for implementing medical care to the best of their ability with available resources. "Wait for port" is not an option when the patient may be having an MI.

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.