To ensure the safe containment of cargo under all design and operating conditions having
regard to the nature of the cargo carried.
5.1 Definitions
5.1.1 Independent tank means a cargo-containment envelope, which is not
contiguous with, or part of, the hull structure. An independent tank is built and
installed so as to eliminate whenever possible (or in any event to minimize) its
stressing as a result of stressing or motion of the adjacent hull structure. An
independent tank is not essential to the structural completeness of the vessel's hull.
5.1.2 Integral tank means a cargo-containment envelope which forms part of the
vessel's hull and which may be stressed in the same manner and by the same loads which
stress the contiguous hull structure and which is normally essential to the structural
completeness of the vessel's hull.
5.1.3 Gravity tank means a tank having a design pressure not greater than 0.07
MPa gauge at the top of the tank. A gravity tank may be independent or integral. A
gravity tank should be constructed and tested according to recognized standards, taking
account of the temperature of carriage and relative density of the cargo.
5.1.4 Pressure tank means a tank having a design pressure greater than 0.07 MPa
gauge. A pressure tank should be an independent tank and should be of a configuration
permitting the application of pressure-vessel design criteria according to recognized
standards.
5.2 Tank type requirements for individual products
5.2.1 Requirements for both installation and design of tank types for individual
products are shown in column f in the table in chapter 17 of the IBC Code.
5.2.2 Instead of the use of permanently attached cargo deck tanks complying with the
requirements of the IBC Code, portable tanks meeting the construction requirements of
the IMDG Code or other portable tanks specifically approved by the Administration may be
used for cargoes indicated in 1.1.9, provided that the provisions of chapter 17 are
complied with. The applicable tank instruction for the products listed as dangerous
goods in the IMDG Code should apply. Products with pollution hazard only and a
flashpoint above 60°C falling within the scope of the present Code, but for which the
IMDG Code is not applicable, when carried in packaged form, should be shipped under the
tank instruction and special tank requirements as included in the IMDG Code for goods
with UN number 3082.