Question 1

Your examiner asks: "What is the difference between a Breathing Apparatus (BA) set and an Emergency Escape Breathing Device (EEBD), and what are the SOLAS requirements for each on a cargo ship?"

Accepted Answer

BA set (SCBA — Self-Contained Breathing Apparatus): provides compressed air for firefighting and rescue in IDLH (immediately dangerous to life or health) atmospheres. SOLAS II-2/10 requires cargo ships to carry at least 2 BA sets with spare cylinders. Duration: typically 30 minutes working. EEBD (Emergency Escape Breathing Device): a compact device providing 10-15 minutes of breathable air/oxygen for emergency evacuation only — NOT for firefighting or rescue. SOLAS requires EEBDs to be provided for emergency escape from machinery spaces and other areas. Key distinction: BA sets are for entering dangerous atmospheres; EEBDs are for escaping from them. Using an EEBD to fight a fire is unsafe — the duration is insufficient and the device is not designed for active use. SOLAS II-2/13 (Fireman's outfit) and FSS Code Chapter 3: fireman's outfits (including BA set, protective clothing, lifeline, torch, and axe) are required — at least 2 complete sets on cargo ships. SOLAS II-2 Reg 13.4.2: EEBDs shall be provided in each main machinery space. EEBDs typically use compressed air (hood-type) or chemical oxygen generation (KO2) and provide 10-15 minutes — sufficient for emergency escape only. The operational distinction is important in practice: an OOW who equips a crew member with an EEBD to fight a fire, rather than an SCBA, is placing them at serious risk. SCBA cylinder pressure must be checked monthly. During fire drills, the BA sets must be donned and pressure tested — an OOW is expected to be able to don a BA set within 1 minute. SOLAS also specifies that spare BA cylinders must be carried (enough for the number of sets plus spares).

Question 2

Your examiner asks: "Describe the fire triangle and the four internationally recognised classes of fire relevant to shipboard operations. Which extinguishing media are correct for each?"

Accepted Answer

The fire triangle requires three elements simultaneously: heat (ignition source), fuel (combustible material), and oxygen. Remove any one element and the fire goes out. Classes: Class A — solids (wood, rope, bedding) — water, foam, dry powder; Class B — flammable liquids (fuel oil, paint, solvents) — foam, CO2, dry powder; Class C — flammable gases (LPG, acetylene) — dry powder, shut off supply first; Class D — combustible metals (magnesium, titanium, sodium) — specialist dry powder only; Class F (electrical equipment) — CO2, dry powder — NEVER water. Note: electrical fires are sometimes classed separately rather than as a fire class. The fire triangle (heat, fuel, oxygen) underpins all firefighting strategy: cooling removes heat (water); smothering removes oxygen (CO2, foam blanket); starvation removes fuel (shut off supply, remove combustible material). Note the tetrahedron model adds a fourth element — the chain reaction — which halite extinguishing agents (Halon, now banned under MARPOL Annex VI except for existing systems) interrupt. Electrical fires (Class F in some classifications) must never be fought with water or foam — both conduct electricity. CO2 is the correct agent for switchboard and electrical equipment fires. Class D fires (metals) react violently with water — specialist dry powder (not standard ABC powder) is the only safe option. At OOW level, the examiner expects correct extinguishing media for each class and awareness that using the wrong agent can be dangerous.

Question 3

Your examiner asks: "What types of fire detectors are fitted on cargo ships under SOLAS Chapter II-2, and what are the conditions under which each type is most effective?"

Accepted Answer

Smoke detectors (ionisation or photoelectric): detect combustion particles — most effective for smouldering fires producing visible or invisible smoke before open flame. Heat detectors: either fixed-temperature (alarm at a set temperature, e.g. 57-96 degrees) or rate-of-rise (alarm when temperature rises faster than normal, e.g. 5 degrees per minute) — effective for fast-burning fires. Flame detectors: detect infrared or ultraviolet radiation from open flames — effective in machinery spaces with high background heat. Gas/carbon monoxide detectors: detect CO as an early indicator of smouldering fires. SOLAS II-2/7 requires automatic fire detection and alarm systems in crew accommodation, service spaces, control stations, and cargo spaces as appropriate. SOLAS II-2 Chapter 7 and the FSS Code Chapter 9 govern fire detection requirements. Key point for OOW orals: smoke detectors are the most sensitive for early detection of smouldering fires (which produce CO and aerosols before visible flames) — they are required in accommodation spaces. Heat detectors are more appropriate in galleys and machinery spaces where ambient temperatures and aerosols (cooking fumes, diesel exhaust) would cause false alarms from smoke detectors. Rate-of-rise detectors are faster-responding than fixed-temperature but can false-alarm in areas with rapid legitimate temperature changes (boiler rooms, hot work areas). Flame detectors are specifically required in unmanned machinery spaces. CO detectors as an early warning layer are increasingly specified in cargo hold monitoring systems. The FSS Code divides spaces into three categories: A (accommodation), B (service/machinery), and C (cargo) — each has specific detection requirements.