3.21 HEATED CARGO AND HEATING COILS

Adjustment of the cargo heating system is normally the duty of the pumpman. The Cargo officer should however alert the engine room just before loading of heated cargo begins. When cargo has been loaded into a tank to sufficient depth to cover the heating coils, the steam can be turned on that tank.
The cargo watch officer should notify the pumpman at the time a tank is ready for heating.
Steam should not be put on the heating coils until they are fully immersed in oil and full steam flow should not be started before the heating coil return line is fully covered in the cargo tank.
When opening the heating system, open the return line valve first, then open the steam supply valve. Also open the return line deck vent and check for the presence of oil in the first flow of water leaving the steam return line. This can be done by sight by day, or at night by the feel and scent of the water for the presence of oil. If any indication of oil is detected in the return line water, the steam supply and return valves should be immediately closed and the engine room informed.
The temperature of the cargo should be noted when the cargo loading begins and hourly thereafter. Cargo suppliers are usually responsible for supplying cargo at or near the required discharge temperature. It is the ship's responsibility to maintain the required temperature during the voyage. If cargo is delivered to the ship significantly below the required temperature, the chief officer and master should be advised immediately. The master may lodge a note of protest against the terminal for insufficient cargo temperature. He must notify owners or charterers immediately as extra bunkers may be needed to raise the cargo temperature to the required carriage temperature. Bunkers used to raise the cargo temperature will be for a different account.
There are numerous crude oils, many of which require heating. Some of the more demanding high pour-point cargoes are included in the list below: (temperatures in degrees Celsius)

High pour crudes should only be allowed to fall below their discharge temperatures in transit if the season, anticipated sea temperature and heating capacity of the ship will permit the cargo temperature to be raised to the required level by arrival at the discharge port.