ONDECK
Academy
OOW Oral Prep
Module 08 — OOW 3000 GT Oral Preparation
LSA & Fire
Fire classes & extinguishing agents · LSA equipment · EPIRB · SART · Immersion suits · Drills · Abandon ship
Fire — The Triangle and Classes
Fire requires three elements: Fuel (combustible material) + Heat (ignition source) + Oxygen. Remove any one element and the fire is extinguished. Every firefighting method works by removing one of these.
| Class | Fire type | Correct agent | Never use |
|---|---|---|---|
| Class A | Solid materials — wood, fabric, paper, plastics | Water, foam, dry powder, CO₂ | — |
| Class B | Flammable liquids — fuel, oil, paint, solvents | Foam, dry powder, CO₂, BCF | Water — spreads the fire |
| Class C | Flammable gases — LPG, acetylene | Dry powder — isolate the source first | Water, foam |
| Class D | Flammable metals — magnesium, lithium | Dry sand or specialist dry powder only | Water (violent reaction) |
| Class F / K | Cooking oils and fats | Wet chemical extinguisher | Water — violent steam explosion |
| Electrical | Energised electrical equipment | CO₂ or dry powder — non-conductive | Water or foam — conductor |
Portable Extinguishers — Quick Reference
| Type | Colour | How it works | Best for |
|---|---|---|---|
| Water | Red | Cooling — removes heat | Class A only |
| Foam (AFFF) | Red / cream panel | Smothers — removes oxygen; cools | Class A and B |
| CO₂ | Red / black panel | Smothers — displaces oxygen | Electrical, Class B — engine rooms, galleys |
| Dry Powder (ABC) | Red / blue panel | Chemical chain reaction interruption | Class A, B, C — versatile but messy, impairs visibility |
| Wet Chemical | Red / yellow panel | Saponification — reacts with cooking oils to form a soap layer | Class F — galley cooking fires only |
Fixed Fire Suppression Systems
CO₂ System (Engine Room / Paint Store)
- Floods the space with CO₂ — displaces oxygen
- All personnel must be evacuated before activation
- Ventilation must be stopped — close dampers and fans
- Space must not be re-entered until CO₂ has cleared and O₂ level confirmed safe
- Two-stage release prevents accidental activation
Water Mist / Sprinkler
- Cools and smothers — fine water droplets absorb heat and reduce oxygen
- Lower water volume than conventional sprinkler
- Effective on Class A and B fires
- Does not damage equipment as severely as flood systems
- Common in accommodation and machinery spaces on superyachts
Drills — Requirements SOLAS III
| Drill type | Frequency | Notes |
|---|---|---|
| Abandon Ship / Lifeboat drill | Monthly — all crew to muster stations. Lifeboat drill at least every 3 months | Within 24 hours of departure if more than 25% of crew have not participated in a drill on that vessel in the previous month |
| Fire drill | Monthly — alternated with abandon ship drill where practical | Fire party to demonstrate use of equipment — breathing apparatus, hose, extinguisher |
| GMDSS communications test | Daily / Weekly / Monthly tests as per schedule | DSC test call, EPIRB registration check, SART test |
| Emergency steering drill | At least every 3 months | Transfer to emergency steering — all OOWs must demonstrate competence |
NEW CREW: A fire and lifeboat muster must be held within 24 hours of any new crew member joining the vessel. This is not optional — it is a SOLAS requirement.
Life-Saving Appliances — Key Equipment
| Equipment | Function | Key facts |
|---|---|---|
| EPIRB Emergency Position Indicating Radio Beacon | Transmits a distress signal on 406 MHz to the COSPAS-SARSAT satellite system — identifies vessel and position | Registered to the vessel — registration must be kept current. Float-free bracket — auto-activates when submerged to 1–4m. Manual activation available. Hydrostatic release unit (HRU) must be serviced every 2 years. SOLAS requires annual battery and hydrostatic release check |
| SART Search and Rescue Transponder | When activated, responds to 9 GHz (3cm) radar — creates a line of 12 dots on the rescuing vessel's radar display pointing to the survivor | Range approximately 10nm for an aircraft radar, 5nm for a ship's radar. Battery life minimum 96 hours on standby / 8 hours activated. Hold vertically — optimal signal. AIS-SARTs now also used — transmit GPS position via AIS |
| Immersion Suit | Thermal protection in cold water — reduces heat loss, extends survival time | Must be donned within 2 minutes — practice is essential. Must fit over clothing. Covers the entire body except the face. Positive buoyancy with integrated lifejacket for most types. Tested — must be tried on at abandon ship drills |
| Lifejacket | Keeps the wearer face-up with the airway clear of water | 150N minimum buoyancy for adult. Self-righting — turns an unconscious person face-up. Light and whistle mandatory. Serviced annually. Worn — not carried |
| Liferaft | Inflatable survival platform for crew and passengers | Hydrostatic release — float-free activation at 1.5–4m depth. Painter line — secure to vessel before deploying. Equipped with SOLAS pack: water, rations, flares, bailer, knife, pump. Serviced every 12 months at approved station |
| Rescue Boat | Fast craft for recovering persons from the water and conducting SAR operations | Ready for launch within 5 minutes at all times. Crew must be able to launch and recover at sea. Must have: engine, compass, first aid, tow line, fire extinguisher, searchlight |
| Pyrotechnics | Visual distress signals | Parachute rocket flares — red, burn 40 seconds, visible 28nm+. Handheld flares — red, burn 60 seconds. Orange smoke — day use, calm conditions. Expiry date — must be in date or disposed of correctly |
Abandon Ship Sequence
Do not abandon ship until the Master orders it — the vessel is the best liferaft until it is no longer safe to remain on board.
| Action |
|---|
| 1. Master orders abandon ship — seven short blasts + one prolonged blast |
| 2. Send Mayday with position if not already done — activate EPIRB |
| 3. All persons don lifejackets and immersion suits |
| 4. Muster at assigned stations — account for all persons |
| 5. Launch survival craft — liferafts to leeward if possible |
| 6. Take SART, portable VHF, flares, water, medication into survival craft |
| 7. Cut painter line only when all have boarded and are clear of the vessel |
| 8. Move well clear of the vessel — suction risk as vessel sinks |
| 9. Activate SART and maintain VHF watch on Ch 16 |
Agent Selection — The Triangle Applied, Not Recited
| Fire | Attack | Never | Why |
|---|---|---|---|
| Class A (solids — bedding, linings) | Water — cooling wins | — | Heat is the leg to remove |
| Class B (fuels, oils) | Foam blanket, CO2, powder | Water jet | The jet spreads burning fuel; foam smothers |
| Live electrical | Isolate FIRST, then CO2 | Water while live | Isolation converts it into an ordinary fire |
| Class F (galley oils) | Fire blanket, wet chemical | Water — ever | A cup of water flash-boils into ~1,700 volumes of steam and throws burning oil |
| Lithium battery runaway | Sustained WATER cooling, isolation to open deck | Relying on smothering | The cell makes its own heat and oxygen — only heat removal stops the chain; expect re-ignition for hours |
The examiner marks the reasoning, not the list: water is a HEAT weapon, CO2 and foam are OXYGEN weapons, isolation removes the ENERGY. Answer from the triangle and every agent question answers itself — including the ones you haven't been asked yet.
The Fixed CO2 Flood — Sequence and the Sealed-Space Discipline
Engine-room fire beyond first response: muster and head-count — absolute, because the end of this sequence is flooding a space with gas that kills; fuel quick-closing valves shut; ventilation stopped, flaps and dampers sealed; head-count confirmed AGAIN; the master releases. Then the part that saves the ship: the space stays shut for hours — read the fire through boundary temperatures from outside, boundary-cool the adjacent bulkheads and the deck above, and re-enter only cooled, ventilated, risk-assessed, with BA teams and charged hoses. Cracking the door "for a look" at thirty minutes vents your only agent onto hot fuel that relights — and there is no second charge.
BA Control — The Board That Keeps Rescuers Alive
Nobody enters a smoke-filled space without the system around them: the entry control board — names, cylinder pressures, time in, whistle time calculated — run by a dedicated controller; a dressed back-up team before the first team enters; door discipline (read it, crack it against your weight, cool the gas layer with short pulses before advancing); and comms on a schedule so silence itself is an alarm. The arithmetic is unforgiving: a 300-bar set at heavy work gives twenty-something minutes, and the whistle margin is the exit, not the reserve. On a yacht with one BA team, the honest consequence: no relief team may mean the attack waits for the fixed system — a decision, not a failure.
LSA Numbers That Get Asked Cold
| Item | The figure |
|---|---|
| Liferaft HRU | Fires at ~1.5–4 m depth; serviced/replaced per its expiry (typically 2 years); the painter's weak link parts AFTER inflation |
| Liferaft service | Annual, at an approved station (extensions per flag rules) |
| Immersion suit donning | 2 minutes, drilled, unaided |
| Lifejacket lights | ≥8 hours' operation; whistle attached |
| EPIRB | 406 MHz to Cospas-Sarsat; ≥48 h transmission; battery and HRU dates in the planned maintenance; registration current — the RCC acts on what the database says |
| SART | 96 h standby / 8 h active; X-band only; mount ≥1 m above sea level in the craft |
| Pyrotechnics | Rocket parachute flares, hand flares, buoyant smoke — in date, stowage known, disposal via proper channels |
| General emergency alarm | Seven or more short blasts + one long — the MUSTER signal; abandon ship is the master's VERBAL order, never an alarm alone |
Cold Water — The 1-10-1 Clock Behind Every Drill
One minute of cold shock — the involuntary gasp that drowns unprotected airways before hypothermia is even relevant; ten minutes of meaningful movement before cold incapacitation strips grip and swimming; roughly one hour to unconsciousness — which means you PERSIST: he's cold, not dead. Recovery doctrine follows the physiology: flotation to him while his hands still work, horizontal-ish recovery where practicable (circum-rescue collapse is real — cold hearts arrest on rough vertical handling), gentle movement, insulate, monitor, treat as a casualty even if he's talking. This clock is why MOB drills are timed in minutes, why lifejackets that right an unconscious wearer matter, and why the suit-versus-jacket answer is "both — one buys the airway, the other buys time."
Additional Question
Walk me around your vessel's fire plan — what is it, where is it, and who is it actually for?
The fire and safety plan shows every fire boundary, detection zone, extinguishing system, extinguisher, BA set, escape route and remote shut-off aboard — posted where the crew work, and a copy in a prominently marked weathertight enclosure OUTSIDE the deckhouse. That external copy answers the 'who for': it's for the SHORE fire brigade who board a burning vessel knowing nothing — their first act is pulling that plan. Aboard, it's the attack team's map and the induction tool for new crew. And the follow-up I'd expect: I should be able to stand at my muster station and point to the nearest hydrant, extinguisher, BA set and two escape routes without looking at the plan — that's what familiarisation signed off.
Oral Exam Practice Questions
Question 1
What class of fire is a fuel oil fire and what do you use to extinguish it?
Class B — flammable liquid. Extinguish with foam (AFFF), CO₂, or dry powder. Never use water on a Class B fire — it will spread the burning liquid and intensify the fire. In the engine room I would use the fixed CO₂ system — but only after confirming all personnel are evacuated and ventilation is shut down.
Question 2
What is an EPIRB and how does it work?
An Emergency Position Indicating Radio Beacon. When activated it transmits a distress signal on 406 MHz to the COSPAS-SARSAT satellite system. The signal identifies the vessel by its MMSI registration and provides a GPS position. The EPIRB must be registered to the vessel and the registration kept current — an unregistered EPIRB is useless. It has a float-free bracket with a hydrostatic release unit that automatically activates when submerged to 1–4 metres. Manual activation is also available. The EPIRB is tested and inspected annually (self-test plus shore-based maintenance per flag requirements); the battery is replaced at the manufacturer's interval — typically around five years — and the HRU is replaced by its expiry date, typically every two years.
Question 3
What are the drill requirements under SOLAS?
Abandon ship and lifeboat muster — monthly. Lifeboat drill — at least every three months. Fire drill — monthly, alternated with abandon ship drill where practical. A muster must be held within 24 hours of any crew member joining the vessel. Emergency steering drill — at least every three months. All drills must be recorded in the log.
Question 4
What is a SART and how is it used by the rescue vessel?
A Search and Rescue Transponder. When activated it responds to 9 GHz radar transmissions from search vessels or aircraft. On the rescuing vessel's radar screen it creates a line of 12 equally spaced dots — the first dot is at the SART position and the line extends away from the rescue vessel. Hold the SART vertically for the best signal. Range is approximately 5nm from a ship's radar and 10nm from an aircraft. Battery life is 96 hours on standby and 8 hours when activated.
Question 5
Engine room fire — what are your immediate actions?
Sound the general alarm — seven short blasts, one prolonged. Call the Master. Stop ventilation to the engine room — close all fans and dampers. Close the fire door. Account for all engine room personnel — confirm everyone is out. If the fire cannot be fought with portable extinguishers, prepare to release the fixed CO₂ system — but only after confirming all personnel are clear. Alter course to put the fire downwind. Send Mayday if vessel safety is threatened. Prepare for abandon ship if the fire cannot be controlled.