Oil – liquid form, volatile
Chemical – toxic, hazardous, highly reactive, corrosive
Gas – poisonous, toxic, explosive, highly flammable
Loading and discharging procedure
- The vessel is safely secured alongside
- The ship has performed all the various precautionary measures
- The choice of tank has been made
Loading and discharging requirements:
- Firefighting equipments
- Safety equipments
- Protective clothing
- Anti-pollution equipment
- Scuffer plugs
- Safety signs and notices
Toxicity – is the ability of the substance to cause damage to living tissue.
Explosimeter - it is an instrument used for measuring the composition of hydrocarbon gas and air mixture usually giving the result as a percentage of lower flammable limit.
IGS – inert gas system
Inert gas system is an inert gas plant and inert gas distribution system together with the means to prevent back flow of cargo gases to the machinery spaces. It also consists of fixed and portable measuring instrument and control devices.
Inert gas system is used in cargo tanks to protect the cargo from polymerization, oxidation and humidity, and to replace air thereby prevent fire and explosion.
Inert gas is produce by passing hot flu gases from the boiler through a scrubber, the gases are cooled and cleaned of corrosive products, and the cooled and cleaned inert gases are delivered by means of fan to the tank.
Risk of spillage prevention:
- ship’s movement alongside must be restricted by adjusting mooring
- pipelines, joints and valves must be kept under observations while cargo handling
- drip trays and drip pans must be fitted or placed @ vulnerable points, hose connections
- all scuffers must be closed to prevent the discharge of oil from deck to overboard
How an OOW (officer on watch) can prevent oil spills?
- Activate (ESD) Emergency Shut Down
- Immediately report to the master and terminal
To control marine pollution:
- Know and familiarize Marpol 73/78 and annexes
- Observed discharge restriction
- Recycle as much as possible
- Use drip pans and drip trays
- Use anti-pollution equipment
To prevent oil spill on board:
- Do not use hoses with leaks
- Avoid bending flexible hose excessively
- Hoses should be suspended from suitable equipment
Sources of ignition:
- Mechanical energy
- Electrical energy
- Chemical energy
- Static electricity
- Auto ignition
- Direct heat