4.4.2.1 For membrane tanks,
the effects of all static and dynamic loads should be considered to
determine the suitability of the membrane and of the associated insulation
with respect to plastic deformation and fatigue.
4.4.2.2 Before approval is
given, a model of both the primary and secondary barriers, including
corners and joints, should normally be tested to verify that they
will withstand the expected combined strains due to static, dynamic
and thermal loads. Test conditions should represent the most extreme
service conditions the cargo containment system will see in its life.
Material tests should ensure that ageing is not liable to prevent
the materials from carrying out their intended function.
4.4.2.3 For the purpose of
the test referred to in 4.4.2.2,
a complete analysis of the particular motions, accelerations and response
of ships and cargo containment systems should be performed, unless
these data are available from similar ships.
4.4.2.4 Special attention
should be paid to the possible collapse of the membrane due to an
overpressure in the interbarrier space, to a possible vacuum in the
cargo tank, to the sloshing effects and to hull vibration effects.
4.4.2.5 A structural analysis
of the hull should be to the satisfaction of the Administration, taking
into account the internal pressure as indicated in 4.3.2. Special attention, however, should
be paid to deflections of the hull and their compatibility with the
membrane and associated insulation. Inner hull plating thickness should
meet at least the requirements of Recognized Standards for deep tanks
taking into account the internal pressure as indicated in 4.3.2. The allowable stress for the membrane,
membrane-supporting material and insulation should be determined in
each particular case.