4.1.1 Particular
attention should be paid to the forward and aft bottom areas, for
evidence of ‘setting-up’ of the shell plating due to pounding
or slamming. In some naval ships a slight permanent set is tolerated
in the plating in the forward and aft areas to reduce the weight of
plating, the appropriate Plan Approval office will be able to advise
if required. The amount of deformation often termed the ‘starved
horse effect’ should be of the order of the construction tolerances, see
Ch 3 Construction Procedures, and limited to these regions.
Where large deformations occur, that are significantly greater than
the construction tolerances or deformation in surrounding plating,
internal areas will need to be inspected to see if there is any damage.
4.1.2 Damage to internal
structural members will normally be in the form of buckling of web
plating adjacent to the shell, buckling of primary members, such as
floors, frames, girders or bulkheads and fractures to connections
between bottom plating, secondary stiffening and primary supporting
members. Internal damage of this nature should be repaired.
4.1.3 Areas with
large flare above the waterline, such as sponsons and the bow region,
should be examined for bow flare impact damage. Where there is significant
deformation of the shell plating the internal structure should be
examined and dealt with as defined in Ch 7, 4.1 General 4.1.2.
4.1.4 Ships such
as landing craft, where the operational requirements demand that they
manoeuvre close inshore, are likely to suffer bottom shell damage
and excessive wear from chafing while laying aground. The efficiency
of the bottom shell plating in the area where grounding occurs is
to be determined. When cement is fitted internally over the bottom
shell or where the ship has a large plating thickness and it is not
practicable to ascertain the true condition of the plating by hammer
testing, the thickness of the plating should be determined by non-destructive
means.
4.1.5 Special attention
should be paid to areas of shell plating directly below ship side
discharges as these may be areas of heavy corrosion of the external
surface of the plating.
4.1.6 Indentations
to the plating may occur in way of the berthing girder which is located
approximately 1,0 m above the waterline and directly below the anchoring
equipment. Where the indentation is deep or extends over more than
one frame space the internal structure should be examined and dealt
with as defined in Ch 7, 4.1 General 4.1.2.
4.1.7 The approximate
extent and amount of all deformation of the shell plating that is
not repaired should be reported, so that comparisons can be made with
previous information.