Chemical Tankers / Day 4 / Day 4 Topic 4 Cargo Care
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Chemical Training
Cargo care and special operational tasks
Cargo care and special operational tasks
Cargoes transported on a Chemical Tanker differ widely in characteristics and mode of handling, this fact that requires attention and, in some cases, records are to be maintained during transit.
Voyage Order notes from Ship Operator included in the voyage order mail.
Reference is made to Chemical Tanker Manual (Section 7) and for Special
cargo ( Section 16).
Cargo care and special operational tasks
It is essential that cargo care instructions received from the Ship Operator are fully understood and followed – if in doubt clarify with your SMO / Charterer’s immediately.
There will be cases when the shipper’s instructions received at the loading port will differ from those given by the Ship Operator . This discrepancy must be advised immediately but the instructions in the loading port must be followed until the instructions are verified.
Sources of Cargo Care instructions
Our responsibility to care for the customers cargo does not cease after loading, it continues throughout the voyage to the discharge port and during the discharge.
Ongoing cargo care is a most important aspect of the chemical tanker trade, even though the Chief Officer has the primary responsibility for conducting and recording these tasks, it is important that personnel at all levels are aware of the basic cargo care functions.
Cargo care and special operational tasks
Maintaining watertight integrity of cargo tanks - checking securing on departure and before and after heavy weather.
Some cargoes require a nitrogen blanket to prevent oxygen or moisture entering into the vapour space of the tank. Otherwise the cargo could react with the oxygen, moisture or salts dissolved in the air and become off-specification.
Maintenance of nitrogen blankets and positive tank pressures – this is to
be recorded within (Nitrogen Log) form CHEM 04 .
Cargo care and special operational tasks
Heating and cooling of cargo (temperature log).
Cargoes that require heating must be monitored at least once daily and a temperature log be maintained. Ensure that correct heating medium is
used, and that heating coils in tanks that do not require heating are
blown dry and blanked/ isolated. Prior to loading heated cargo, heating coils should be pressure tested and results recorded in the log book
Cargo care and special operational tasks
Category Y, high viscosity and solidifying cargoes may require prewash, if not heated.
The Master has to obtain the shipping document with information from shipper when transporting such cargoes so that the products will be heated accordingly to avoid the prewash obligation if possible.
Cargo care and special operational tasks
Cooling, in specialized cases, is required to prevent products from givingoff toxic and flammable vapours.
Special care requirements are generally documented in the condition of carriage details contained in the ships Certificate of Fitness and also in the IBC/BCH Codes. The Company and Charterers are to be consulted if additional information is required.
Cargo care and special operational tasks
Monitoring temperatures in unheated tank for signs of abnormal activity (polymerization? – expansion?).
The temperature of inhibited cargoes must be checked and recorded daily
(TNK 08) in order to be able to note any abnormal rise that may indicate either inhibitor failure and/or polymerisation.
Any rapid rise or excessive temperatures should be notified immediately to the Management Office with a request for corrective action to be taken.