19 June 2001
as core sampling of concrete and wood structures, physical material sampling, or
surface hardness testing. The purpose of this type of inspection is to detect
hidden or interior damage, loss in cross-sectional area, and material
homogeneity. A Level III examination will normally require cleaning. The use of
NDT techniques are usually limited to key structural areas, areas that may be
suspect, or structural members that may be representative of the underwater
structure. Level III inspections require more experience and training than Level I
or Level II inspections, and should be done by qualified engineering or
nondestructive testing personnel. This type of inspection is covered in MO-104.2.
Inspection of waterfront facilities is considered to be a specialized
control inspection within the Navy. The underwater inspection should be done by
a qualified, certified diver supervised by an engineer or a qualified engineering
diver. The structural assessment must be done by an engineer with experience
and skill in inspection procedures and techniques.
Table 5-1 lists the types of damage that are detectable with the three
levels of inspection.
PLANNING FOR INSPECTION. The levels of inspection to be used for
a particular task must be decided early in the planning phase. The inspection
objectives (i.e., baseline, design survey, repair acceptance, research) should be
clearly defined. A site survey of the facilities should be obtained, or conducted if
doing a first-time inspection. A site survey for underwater inspections includes:
bathymetric, oceanographic, and geological data, as well as information on
nearby obstructions or activities. A site survey accelerates the planning process
and will help determine the levels of inspection to be used.
The time and effort required to carry out the three different levels of
inspection are quite different. The time required also depends on whether the
inspection is surface or underwater; on environmental factors, such as visibility,
currents, wave action, water depth, tides, severity of marine growth; and on the
inspector's skill and experience.