- Discharge Req:
- At Least 50% discharge @ 1 min.
- At Least 85% discharge @ 2 min.
- Capacity Req:
- 30% of gross vol @ THE LARGEST PROTECTED cargo space
- 40% gross vol @ machinery space EXCLUDING CASINGS
- 35% gross vol for vessels GT < 20000 (WHEN CASINGS ARE INCLUDED)
- Total no of CO2 cylinders depend upon the highest gross vol out of points 1,2,3 in a particular ship
- Safety procedures against unauthorised use of the system
- Machinery Space valve to be fitted with alarm (audio+visual) and blower trip
- Alarm must trigger well before operation
- Permanent piping arrangements
- Distribution Manifold+ piping, pressure test @ 122 bar
- Pipe D > 19mm
- Cu and flex pipes allowed between cylinder outlet and Manifold
- Pipes to Cargo Spaces, not to pass through E/R
- Hydraulic Pressure Testing for bottles after 20 years from date of installation and thereafter every 5 years
- Quantity of CO2 to check every 4 years which can be distributed as 25% of bottles annually, this must ensure checking of each bottle every 4 years
- All Stop valves to check monthly to ensure their position and working
- The installation must be checked monthly for leakages
- All connection to cable operating system to inspect for tightness every 3 month
- All control valves to inspect annually
- Air blow through annually
- Quantity of CO2 shall be calculated at Density = 0.56 m3/kg
- Mixing Ratio of CO2,
- Gross vol of E/R including casing = 35%
- Gross vol of E/r excluding casing = 40%
- Gross vol of cargo holds = 30%
- Quantity of CO2 = (gross vol x mixing ratio)/0.56
- Required No of Cyl = (quantity of co2/45) [in case of 45kg cyl]
- Refer to the example for CO2 calculation for better understanding
|co2 calculation: sorry about poor picture quality|
- It is recommended that in the event of any fire breaking out onboard, including one that requires the fixed CO2 system to be activated, the nearest Coastguard to your position is informed as soon as practicable.
- Carbon dioxide (CO2), a compound of carbon and oxygen, is a colourless gas with a slightly astringent smell causing coughing to occur when inhaled; at high concentrations it is acutely toxic. As it is about 50% heavier than air, it will form a blanket over a fire and smother it.
- To obtain “total flooding” of an engine room, a CO2 concentration of about 35% by volume or more is required to be obtained within 2 minutes. This will reduce the oxygen content of the air in the space to less than 15% to extinguish the fire. At this CO2 concentration human life cannot be supported.
- It is therefore essential that personnel leave the space as soon as the CO2 warning alarm sounds. CO2 should not be discharged into a space until all those within have left and a full head count has been taken.
- Before a space is filled with CO2 it is essential that the compartment ventilation flaps are properly closed and sealed, ventilation fan emergency stops and all fuel and hydraulic oil remote quick closing valves are operated.
- Masters, skippers and crew should be fully competent with the remote and local operation of the fixed CO2 fire extinguishing system for the isolation of fuel oil, hydraulic oil and ventilation systems from the space.
- Typically, it takes about 15–20 seconds after release of CO2 before the concentration within the space reaches a dangerous level.
- Inform Bridge which inturn inform nearest Coast Guard
- All personell evacuated and head count done
- Ventilators & Fans Auto Stop upon opening the CO2 release cabinet
- Dampers, Skylight & All Entry Doors Closed
- M/E and other machinery stopped
- All QCVs operated
- All pumps stopped
- Emergency Generator Run for using Emergency Fire Pump for boundry cooling (if required)
- Fire mains Isolating Valve to be closed so that pressure is not lost by supplying water to deck line
- It is strongly recommended that expert advice should be obtained from ashore before ventilation of the space or any attempt at re-entry is made. The nearest Coastguard to your position may be contacted who will assist in trying to obtain this advice. Unless specifically requested, this will not be interpreted by the Coastguard as a request for on-scene fire-fighting assistance.
- Immediately after activation of the CO2 system checks should be carried out to ensure that the gas has been correctly released from the cylinders. This can be achieved by feeling the CO2 cylinders which should be cold to the touch and visually checking the individual cylinder release valves to ensure they are in the open position.
- Crew should keep well clear of the ventilation flaps to prevent the inhalation of noxious gases.
- Ventilation of the space should not be resumed until it has been definitely established that the fire has been extinguished. This is likely to take several hours.
- Entry into a space that has contained CO2 should only be attempted by trained personnel wearing breathing apparatus with safety lines attached and sufficient back-up immediately available should difficulties arise.
- An attendant should be detailed to remain at the entrance to the space whilst it is occupied.
- An agreed and tested system of communication should be established between any person entering the space and the attendant at the entrance.
- Should an emergency occur to the personnel within the space, under no circumstances should the attendant enter the space before help has arrived and the situation has been evaluated to ensure the safety of those entering the space to undertake the rescue.
- In the event that the ventilation system fails any personnel in the space should leave immediately.
CO2 Fixed Installation Explanation+Procedure
[Unitor Example Used: All Rights Reserved to Unitor]
Unitor CO2 System is designed as total flooding system
|co2 ffs high pressure system|
From main distribution valves, a piping system is used to distribute the gas to the discharge nozzles which are places uniformlythroughout the protected spaces.
When releasing the system, the main distribution valve opens. The pilot gas to the pressure operated CO2 cylinder top valves is delayed for a specified time.