3 October 2005
Planning. NAVFAC Field Components, and Activities should assist
Claimants, Regional Commanders, and Shipyards to determine the number, location,
and critical ship class requirement for moorings used locally during Mooring Service
Type III. Mooring Service Type should be identified during the planning phase of
waterfront structures. Recommendations are provided in TR-6012-OCN Rev B U.S.
Navy Heavy Weather Mooring Safety Requirements.
Analysis and Design. Engineers at NAVFAC Field Components should
analyze moorings according to climatological criteria stated in TR-6012-OCN Rev B
U.S. Navy Heavy Weather Mooring Safety Requirements. Commercial enterprises
providing mooring for US Navy ships should likewise conform to the criteria contained
herein. Lines should provide a factor of safety against breaking of 2.5. Design pier and
wharf fittings for a working load equal to the break strength of the largest lines expected
to use the fitting. Moorings used for Type III service are subjected to significant
dynamic wind loads and should be analyzed accordingly. NFESC has capability of
providing this type of analysis on a reimbursable basis. Aramid and nylon lines also
respond differently to dynamic loads and should be properly modeled in the analysis.
Engineers should also verify the capacity of ship fittings for Type III Moorings. Dynamic
analysis indicated that in order to moor a CVN in heavy weather a ship alt is required as
well as facility upgrades at NNSY and NAVSTA Mayport. Ship alts, if required, should
be coordinated with NAVSEA.
Maintenance. Maintenance personnel should inspect moorings to ensure
acceptable performance during heavy weather. UFC 4-150-07 Maintenance of
Waterfront Facilities and UFC 4-150-08 Inspection of Mooring Hardware, provide
Operations. Activities should provide additional mooring lines to
supplement ship mooring lines for use during Mooring Service Type III.
ENVIRONMENTAL DESIGN CRITERIA FOR SELECTED SITES. A risk-
based approach is used in Heavy Weather mooring design to help ensure that ships are
safe no matter where they are moored. Site-specific design criteria (i.e. winds, water
levels, waves, etc.) associated each berth are used to help ensure that all ships are
safely moored. These criteria are contained in TR-6012-OCN Rev B U.S. Navy Heavy
Weather Mooring Safety Requirements.