A reefer ship is a refrigerated cargo ship, typically used to transport perishable commodities which require temperature-controlled transportation, such as fruit, meat, fish, vegetables, dairy products, and other foods.
TYPES OF CARGOES
Refrigerated cargoes -can be divided into three class
frozen class – example meat, butter, poultry, and fish these cargos are carried in hard frozen state as the temperature around – 8 degree to – 12degree centigrade to prevent the growth of bacteria.
Chilled cargo– example cheese, fresh vegetables, eggs .
temperature maintained in the compartment for these cargos are around -2 degree Celsius to 6 degree Celsius.
maintaining the right temperature is more critical with chilled cargo then frozen cargoes as condensation of moisture due to variation of temperature encourages bacterial growth.
Air cooled cargo – Example fruits , here temperature of around 2 degree to 12 degree Celsius is maintained by air circulation.
The temperature at which the individual cargoes are carried may vary beyond the above-mentioned limit depending on many factors, some of the factors and mentioned below
1)The ambient temperature at the loading port
2)The duration of the voyage
3) The state in which the cargo is delivered like frozen, ready for consumption or any other form whatever is adequate for the situation.
PRECAUTIONS WHEN CARRYING REFRIGERATED CARGO
- Preparation of the compartment –
- Compartment must be Dry, Clean, free from any odour or taint.
- If necessary it must be deodorizer using ozone, sodium bicarbonate or patent deodorizers.
- Bilges to be cleaned, Suction to be checked.
- Insulation to be checked and repaired if required.
- Permanent dunnage to be checked.
- Brine trap to be checked .
- Precooling the compartment before loading–
- Compartment should be cooled down prior loading to a temperature slightly below the transit temperature.
- Once the compartment is ready for loading a survey is carried out by the cargo surveyor who inspect the compartment for cleanliness, Fitness for loading of cargo.
- A loading certificate, showing the temperature of each compartment is issued before any cargo is stowed in the space.
- Loading of cargo–
- Local regulations regarding opening and closing of compartments and accepted working temperature for stevedores.
- The stowage should be aimed so as to allow a free circulation of cold air around the cargo.
- Clean cargo should not be in contact with dirty cargo.
- Inspect the incoming cargo for any inherent damage.
- During cargo operation when compartment is open frost may form onto the brine pipes this must be brushed away.
- During Transit –
- Temperature control is most essential and must be strictly maintained.
- Daily record should be manitained
- CO2 is monitored. (As its presence is important for some cargoes but excess of CO2 can be harmful for the cargo.)
- During Discharge-
- If concentration of CO2 is higher than 7% the compartment must be vented with fresh air prior to man entry for discharge.