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 11460
15C/rdc
06 MAR 97
From:
Commander, Naval Facilities Engineering Command, NAVFAC Criteria Office (Code 15C)
To:
Distribution
Subj:
INTERIM TECHNICAL GUIDANCE (ITG) - CVN DREDGE DEPTH CRITERIA
Ref: (a) COMNAVSEASYSCOM ltr 11460 Ser 03D3/242 dtd 3 Jan 95
(b) OPNAVINST 11010.20E, Part 5
Encl:
(1) CVN Dredge Depths - Interim Technical Guidance with attachments
1. Purpose: The purpose of this guidance is to define dredge depth criteria for Nimitz Class Aircraft Carriers.
This criteria establishes consistency in application to waterway dredging projects and will be incorporated into
existing military criteria noted in paragraph 4.
2. Background: In San Diego, California, the Navy relied on a more quantitative approach to determine the
required dredge depths for several Military Construction Projects relating to CVN homeporting. This method
saved the Navy over $20 million when compared to the Design Manual 26.1 method. This document is a
summary of the method.
Reference (a) delineated the water depth requirements for Nimitz Class Aircraft Carriers transiting to and
moored at homeports, ports of call, and shipyards. It specified the minimum water depth required while the
ship is in the waterway; however, it did not specify dredge depth requirements. The minimum water depth
required to operate carriers in inner channels and turning basins on the way to and at piers at home ports is
between 49 and 50 feet depending on harbor salinity. These numbers are similar for ports of call. Due to the
reduced displacement when visiting shipyards, the minimum water depth required to operate carriers in inner
channels and turning basins on the way to and at piers at shipyards is between 46 and 47 feet depending on
harbor salinity.
Applying these requirements to determine dredge depths requires additional port specific information.
a. Reference (a) states that "the dredging project depth can be traded off with tides to obtain the
necessary water depth in inner channels and turning basins with the corresponding operational conditions."
Therefore, planners should consider channel accessibility and operational restrictions imposed when selecting
a design water level above the extreme low water.
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