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 TB 55-1900-201-45/1
cargo, etc. Such conditions, if they are scattered and not serious to the extent that the members are torn or broken loose
from their fastenings, may be permitted to remain until there is other work required in the area. However, this principle
would not apply to structural columns.
SECTION IV. Notes on Repairs
E-23. Fractures.
a. Fractures in hull plates, etc, usually start in localized, highly stressed areas. In the preliminary inspection, the
first thing to be determined is whether or not the fracture started in a notch or sharp angle (stress raiser), and if it did, to
eliminate this feature.
b. Major fractures. When major fractures occur and where considerable material is to be removed and new plates,
frames, etc., are to be inserted, the repair may involve appreciably more restraint and less favorable welding conditions
than for new construction. The type of repair to be made and welding procedure to be used should be carefully evalu-
ated.
c. Cracks. Cracks in the deck or in the bottom within about the admidships half length and which originate in
structural discontinuities will frequently require the fitting of a suitable repair insert in order to minimize weld restraint in
the local area of stress concentration. Cracks which have opened too far or are too irregular to permit satisfactory weld
preparation, or which are located so that access is insufficient for producing sound, full penetration welds, also call for the
fitting of inserts. Evidence of deterioration or poor quality of the fractured plate are additional reasons for plate replace-
ment.
d. As previously noted, localized bands of accelerated corrosion should ordinarily be taken as evidence of such
deterioration and the affected portion of plating replaced. Where none of the foregoing conditions exist, the crack may
be repaired by welding without replacement of plating.
e. In repairing cracks which do not involve steel replacement, the following procedure should be followed:
(1) Locate the ends of the crack, and approximately two plate thicknesses beyond the end, drill a hole to prevent
its ex-tension. The use of dye penetrant or other NDT method is desirable to locate the ends of the crack or to insure the
crack does not ex-tend beyond the holes. The diameter thickness. Then, V out the crack by chipping or gouging to an
accepted edge preparation for welding plates of the particular thickness involved.
(2) Gas free, remove ceiling, etc., as necessary to provide full access to both sides of the crack. Thorough in-
spection of both sides of the crack should always be carried out.
E-14
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