UFC 4-150-08
01 April 2001
conducted as directed by the Berthing Officer or as described in Appendix B, based on
hardware priority level.
4-3
INSPECTION METHODS.
4-3.1
Local Conditions.
4-3.1.1
Mooring Hardware Fittings. Each piece of mooring hardware should be
visually inspected for anomalies. Conditions that are commonly found include cracks,
abrasion (due to wire rope), corrosion and displacement. Cracks are usually the result
of impact loading or overloading the hardware under extreme conditions. Abrasion
normally occurs when mooring lines are pulled around the hardware causing friction and
erosion of the casting under the barrel or horn. If this condition is severe, it will weaken
the casting through loss of cross sectional area. Documentation of the depth of erosion,
location, and area are required to establish loss of strength. The condition of the coating
should be noted. Coatings that have mechanical damage, i.e., cracks, peeling, or
abrasion, should be described. Coating systems that have failed or are worn out should
also be described, as well as any resulting corrosion. Levels of corrosion can be
described as rust stains, light scale, and heavy scale. The surface roughness of the
steel should also be described. Corrosion of the casting should be assessed to
determine the loss of section at critical points on the casting. Heavy corrosion will also
affect the surface roughness of the hardware increasing the chafing and wearing of
mooring lines. Observations of the mooring hardware plumb and level are made to
determine prior overloading and failure of the surrounding soil or fasteners.
4-3.2
Fasteners. Fasteners consisting of steel bolts are used to anchor the
mooring hardware to the supporting structure. In some cases mooring hardware is
embedded directly in the supporting structure. Where fasteners are used, their function
within the mooring system is critical and is almost always the critical structural element.
Fasteners are generally inaccessible as a result of typical mooring hardware details
calling for protection usually in the form of lead fill, bituminous fill or grout being placed
in the bolt pockets. If the fasteners are not visible, then a Level 1 or 2 inspection will
result in minimal fastener data. A Level 3 inspection is required to determine the
condition of the fasteners. For newer structures, the fasteners may pass through
blocking and terminate with nuts and washers bearing on heavy plates. This part of the
structure is accessible and should be inspected for loss of section due to corrosion. If
fasteners are embedded in the structure and the bolt pockets are filled, the only
inspection technique available to the inspector is to remove the casting and observe the
fastener for corrosion and loss of cross sectional area. Load testing of the fasteners can
be conducted without removal of the casting and will result in the determination of an
allowable load. See Appendix B for load testing criteria.
4-3.3
Supporting Structure.
4-3.3.1
Concrete. The majority of heavy load mooring hardware is attached to
concrete decks. Concrete acts well to resist the forces applied by mooring hardware.
The compressive strength of concrete resists the shear forces generated as well as
providing excellent distribution of load through the structure. Factors to consider when
inspecting concrete that supports mooring hardware include cracking, disintegration and
corrosion of reinforcing steel. Cracking occurs in all concrete through many processes
both as a result of natural factors and from outside forces such as impact. The inspector
4-2
Previous Page
