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 TB 55-1900-201-45/1
SECTION IV. Replacement of the Shell and Deck Plating
2-4. Shell and Deck Plating Replacement.
a. The sheer strake, insofar as is practicable, should be kept clear of welded fittings. Where there is no alterna-
tive but to make attachments in this area, the attachment should be suitable flared with curved brackets, as applicable.
The upper edge of the sheer strake should be fair and smooth, free of notches, nicks, cuts, weld craters and any irregular
edge burning. Because of the change in ship steel requirements, the foregoing requirements are particularly applicable to
vessels constructed prior to 1947.
b. Insofar as practicable, the stringer plate should be kept free of welded attachments.
c. Where heavy deck fittings, such as chocks, bitts, and cleats are to be replaced, the fittings are to be installed in
accordance with the vessel's drawings. Any variance from this must be accomplished through a modification work order
(MWO). If an MWO is applicable, precautions must be taken not to position fitting in a direct line athwartships or on
plating between existing fittings.
d. Repairs involving less than a full plate should generally be made by means of an insert plate. Inserts should
ordinarily cover at least one frame space and the corners cut on the radius.
e. In certain cases, a welded lapped patch plate may be used in lieu of an insert plate for the permanent repair of
small damaged areas which lie wholly within an individual panel of plate. However, except for temporary repairs, their
use should not be permitted in the strength deck, bottom, shell plating or areas of high corrosion.
f. A welded doubler plate is not, in general, considered suit- able as a permanent repair measure for the main
hull girder. Doublers may properly be used to provide local reinforcement at hatch corners, overboard discharges,
seachests, mast or kingpost foundations, etc. Doublers may be accepted in nonstrength areas where their purpose is
essentially to restore watertight integrity and local strength. Such areas include:
(1)
Deck plating well inboard between cargo hatches.
(2)
Forecastle decks and poop decks limited to approximately the forward or after one-tenth length of the
vessel.
g. In the case of structural members such as frames, beams, stiffeners, etc., it is a practical repair measure to
crop out the distorted or wasted section of the member, the outer flange for example, and replace with new material.
Where this method is used, the following conditions should prevail:
(1) There should be sufficient material in the remaining portion of the member to permit sound attachment of
the new material.
2-8
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