SOLAS 1974 — Safety of Life at Sea
The single most important international treaty for the safety of merchant ships. Interactive deep-dives into Fire Fighting (II-2), Personal Survival (III), GMDSS (IV), Safety of Navigation (V) and SAR — plus a full 14-chapter compliance walkthrough for Flag State and Port State inspections.
Welcome to SOLAS — the Safety of Life at Sea Convention, adopted by IMO in 1974 after the Titanic disaster.
From the Titanic to today
Adopted after the 1912 Titanic disaster and re-enacted in 1974 with the tacit-acceptance amendment procedure, SOLAS is the cornerstone treaty governing the construction, equipment and operation of ships. 14 chapters cover everything from hull subdivision to polar operations.
The five chapters every seafarer must master
Click through each tab to explore the SOLAS chapters that dominate STCW competence assessments, ISM internal audits and PSC inspections worldwide.
1. The Fire Tetrahedron
The modern Fire Tetrahedron adds a fourth face — the uninhibited chemical chain reaction — to the classical triangle. Click any face to remove it and see how that element is suppressed.
Hot-work permits, low-flame surfaces, separated fuel & ignition, oily-rag bins.
Smoke/heat detectors, manual call points, sample-extraction in cargo holds, alarm to bridge.
Fire main, fixed CO₂ / water-mist / foam, portable extinguishers, fireman's outfits, EEBDs.
2. Classes of fire — A, B, C, D, E, F
Each class has a specific fuel chemistry and a matching extinguishing agent. Picking the wrong agent makes the casualty worse — sometimes catastrophically.
Flammable liquids (HFO, diesel, lube oil, paint, solvents)
Hydrocarbon liquids — primary engine-room and tanker risk.
- • Foam (AFFF) — vapour seal
- • CO₂
- • Dry powder (PKP)
- • Water mist
- • Solid water jet (spreads burning oil)
3. Gas fires — LPG / LNG / IGC drill
Step through the IGC / IGF Code response on a gas carrier — the order of actions is what matters most.
🚨 Gas leak ignited on deck (LPG/LNG carrier)
A jet flame is venting from a manifold flange. What is your FIRST action?
4. Class D — Metal fires
Class D — Metal Fires
Magnesium swarf · Aluminium dust · Sodium · Titanium · Lithium-ion batteries
Hot metal + H₂O → metal oxide + H₂ gas → violent explosion. Magnesium burns at 2200 °C and will strip oxygen from the water molecule itself.
Burning metals reduce CO₂ to elemental carbon — the fire grows hotter, not smaller.
- • Class-D powder (graphite-based G-Plus, NaCl-based Met-L-X) — smothers and absorbs heat.
- • Dry sand — emergency smothering when nothing else is available.
- • Isolate combustible metal stowage from the seat of fire; cool surrounding structure with water spray only when no metal is exposed.
- • Lithium-ion (EV cars, battery rooms): copious water for cooling and thermal-runaway control IS now accepted (the cell chemistry is different) — but only with crew at safe distance and isolation of electrics.
5. Breaking the chemical chain reaction
Breaking the chain reaction
Combustion is sustained by free radicals (H•, OH•, O•) that propagate the reaction faster than heat alone can drive it. The 4th extinguishing principle is to chemically interrupt these radicals.
All 14 SOLAS chapters at a glance
Each panel summarises scope, key points, and what Flag State and Port State inspectors will look for. The five chapters explored above are marked 'Deep-dive'.
Flag State vs Port State — who does what?
Understanding the division of responsibilities is essential for any officer preparing for an inspection, audit or oral exam.
| Aspect | Flag State Control (FSC) | Port State Control (PSC) |
|---|---|---|
| Authority | Flag State of registry — primary responsibility under UNCLOS Art. 94 & SOLAS I/6. | Port State where ship calls — verification role under SOLAS I/19 + regional MoUs (Paris, Tokyo, Indian Ocean, etc.). |
| Frequency | Statutory survey cycle: initial → annual → intermediate (2½ yr) → renewal (5 yr). | Random; targeted by risk profile. Re-inspection on detention or 'clear grounds'. |
| Scope | Full construction, equipment, manning, SMS, security — issuance of certificates. | Certificates + condition check + operational drills (fire, abandon ship, steering test). |
| Outcome | Certificate issuance / withdrawal; recognised organisation (RO) acts on Flag's behalf. | Deficiencies, detentions, banning from MoU region. |
- All certificates valid and posted (in date order)
- Crew list, manning certificate, STCW endorsements current
- ISM SMC + DOC originals onboard
- ISPS — SSP, last 10 ports, SSAS test record
- Fire & abandon-ship drills logged within last week
- Lifeboat on-load release test record
- GMDSS radio log + battery capacity test
- ECDIS chart cells up to date
- Garbage Record Book + Oil Record Book entries complete
- Hours of rest / hours of work records compliant (MLC)
Study reminder: SOLAS is amended frequently through MSC resolutions (tacit acceptance). Always cross-check the latest consolidated edition (IMO IB110E) and applicable Unified Interpretations before an inspection or oral exam.