Code No: 950
Video Running Time: 26 minutes
This training package explains the importance as well as the
complexity of effective tank cleaning on chemical tankers. It shows
that efficient tank cleaning is important to ensure that the cargo
to be loaded will remain within specification during the voyage and
the discharge. Tank cleaning also is important to ensure that the
cargo is carried without danger to the ship, its personnel and
other cargo on board.
The video considers the many factors that must be taken into
account during the planning stages of tank washing - among them
are:
- the construction of the tank walls
- the nature of the last cargo
- the washing medium
- the cleaning processes to be applied
- the appropriate techniques to be employed the time available
for cleaning and the nature of the next cargo to be loaded
All these need to be considered in the light of the current
regulations including MARPOL.
The planning process is further complicated by the possible
combinations of last cargo and next cargo, ranging from easy
chemicals to high-grade chemicals, to CPP, vegoils, molasses and
caustics. The task for the officers in charge is to select and
employ the correct tank washing and testing procedures every time,
without fail, as the price of errors can be high in terms of human
life and commercial losses.
Having discussed the complexity of the planning process, the
video describes the relative simplicity of the actual washing
process. By gathering the relevant facts and strictly following the
rules and procedures laid down in the controlling literature
available on board ship, the washing itself should be
straightforward.
The most important sources of information are listed. These
include:- the Company's Tank Cleaning Manual, The Cargo Data
Sheets, MARPOL Annex l & ll, US Coast Guard Chemical Data Guide
for Bulk Shipment of Chemicals, Dr Verwey's Guide, the Cargo
and Oil Record Books and the ship's Tank Cleaning Record
Book.
How these documents are used in the planning and execution of
tank washing is the key component of the content of the video. A
typical procedure for getting from a dirty tank used for carrying
vegetable oil to a safe clean one, ready to transport methanol, is
illustrated in the video. Finally, reference is made to a number of
special last cargo/next cargo situations where the tank washing
processes differ considerably from the sample case shown.
