Question 1

Deck foam regulation

Accepted Answer

Deck foam must reach every tank-deck fire fast: monitors at set application rates, controlled clear of the cargo area, flowing within minutes. Monitors discharge about 3 litres per square metre per minute over the deck hazard with controlled expansion ratio. Expansion bands run low at 2–20, medium 20–200 and high above 200 to 1 — matched to fuel and space. Main control sits away from the cargo area so one fire cannot take both monitors and controls. The system must throw foam within 5 minutes of the alarm — prove pumps, proportioning and monitors on schedule. Surveyor follow-up: foam flows but will not blanket — concentrate, expansion or application, and what do you check first?

Question 2

Deck foam system, expansion ratio

Accepted Answer

Deck foam blankets burning oil: low-expansion foam near 3 litres per m² per minute with monitors covering the deck. Low-expansion foam runs 2:1 to 20:1 with monitors throwing 3 litres per m² per minute onto deck and tanks. Medium foam runs 20:1 to 200:1 with high-expansion past 200:1 for enclosed spaces, never open decks. Discharge the full deck cover inside 5 minutes with at least 20 minutes supply on IG-fitted tankers. Main control sits clear of the cargo area with expansion proved by concentrate type and proportioning, not by eye. Surveyor follow-up: foam flowing thin with monitors short of the manifold — concentrate, proportioner or pressure first?

Question 3

Checks and maintenance on foam pfe

Accepted Answer

Foam is proved, not inspected: a density and expansion test, a delivery trial, and a visual check of the whole run. Draw a sample and let the foam build up to depth at about 1 metre per minute to prove it is the right grade. A complete discharge takes at least 30 seconds, and the rate is measured against the required litres per m² per minute. Check the concentrate for separation, contamination and the expiry, with the hydrostatic test on the cylinder at 25 bar. Prove the monitors, valves and piping to the furthest part of the protected area, and record the whole trial. Surveyor follow-up: foam discharging at half rate with the concentrate in date and the pump proved — monitor, pipe or proportioner?

Question 4

Foam system maintenance

Accepted Answer

The foam system is maintained by running it: tank level, concentrate condition, pump, proportioner, monitors and the delivery rate. Keep the foam tank and its day tank at the maker’s levels, with the concentrate clean and unseparated. Prove the proportioner by its calibration figures, and the pump by its delivery trial against the required rate. Exercise every monitor, valve and remote control station, checking the discharge covers the whole protected area. Keep the control station clear of the cargo area, and log the whole test with the rates and pressures found. Surveyor follow-up: system proved twice a year with the level switch on the day tank unproven — which half of the system is untested?

Question 5

High expansion foam low expansion foam

Accepted Answer

Low expansion blankets burning liquid; high expansion fills a room — the choice follows the space and the fuel. Low expansion runs from about 2:1 to 20:1, and is what SOLAS requires for the deck, where throw and knock-down matter. Medium expansion is about 20:1 to 200:1, and high expansion is anything above 200:1. High expansion fills enclosed spaces — holds and engine rooms — with lightweight foam that smothers by volume. It must not exceed about 1000:1, and it is useless where the fire is deep in a tank on an open deck. Surveyor follow-up: high expansion ordered for a spilled deck fire — does the blanket reach the far side, and what blocks it?

Question 6

How much was expansion ratio on your ship?

Accepted Answer

A ship’s foam system is rated on expansion: low expansion is about 12:1 by rule, and high expansion is the 150:1 or 1000:1 range. The expansion ratio is the volume of foam produced divided by the volume of the water and concentrate mixture supplied. For deck systems it shall not generally exceed 12:1; where a low-expansion system runs slightly higher, the solution is still calculated as 12:1. Medium expansion foam is about 15:1 and high expansion goes from 150:1 up to 1000:1, generated through a mesh screen. High expansion foam is mostly air and breaks down in contact with a fire, and the 1000:1 limit is set for exactly that reason. Surveyor follow-up: solution quantity calculated at 20:1 on a system rated 12:1 — is that over-supply or a calculated shortfall?

Question 7

Pfe yearly maintenance. For co2 and foam

Accepted Answer

Every portable extinguisher gets an annual thorough inspection; the intervals then differ by medium, from five years for water to six for dry powder. At longer intervals, at least once a year, a more thorough inspection and maintenance including the chemical charge and the expellant is done by trained personnel. The intervals after that vary by medium — for example foam every three years, CO₂ every five years and dry powder every six years. Cartridge-operated dry chemical and stored-pressure units mounted on vehicles are inspected annually. The service is recorded with its date on the extinguisher itself, so the next due date is visible where the unit stands. Surveyor follow-up: foam extinguisher three years on board with no service tag — is it in date or simply unproven?

Question 8

Procedure of discharging foam

Accepted Answer

Foam goes out from the control station, the monitors are opened one at a time, and the discharge is watched against the rate. The main control station is operated by the chief or the officer of the watch, clear of the cargo area. Open the discharge valve and then the monitors in sequence, aiming the full deck cover with the first jets. The system must cover the deck in not more than 5 minutes and supply foam for at least 20 minutes on an IG tanker. Keep discharging while cooling continues, and never stop the supply while the foam blanket is still building. Surveyor follow-up: all monitors open with foam only reaching half the deck — is it the cover, the rate or the tank level?

Question 9

Types of expansion foam

Accepted Answer

Three grades by expansion ratio: low for knock-down on oil, medium between, and high for filling enclosed spaces. Low expansion is 2:1 to 20:1 and is the deck and tank system required by SOLAS, thrown from monitors at about 3 litres per m² per minute. Medium expansion is 20:1 to 200:1, bridging the two duties where a spread and a fill are both needed. High expansion is above 200:1, giving a light blanket that floods an enclosed space and smothers by volume. Within each grade the agent may be protein, fluoroprotein or a film-forming blend — the choice is fuel and burn rate. Surveyor follow-up: deck system running a film-forming concentrate at low expansion — does that suit fuel oil, and what changes for solvent?

Question 10

Which fire fightng on your ship (foam

Accepted Answer

Your ship’s firefighting is the fire main with hydrants and the emergency pump, plus the fixed systems matched to the cargo. The general system is the fire main, fed by the main fire pump and the emergency fire pump, with hydrants and hoses distributed for each space. Fixed systems are matched to the risk: CO₂ in machinery and accommodation, foam and an inert gas system on tankers, water mist where fitted. Portable extinguishers of the right class are placed for the spaces they cover, and each is on its own muster position. And the fire control plan is what makes the answer ship-specific — it is the arrangement the crew drills, not a generic list. Surveyor follow-up: tanker without foam or inert gas fitted, with only portable extinguishers — what is the deficiency?

Fixed Fire Fighting - Foam — Most Asked Questions

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