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Superseded Bench Mark Sheet for 8670424, Port Wentworth GA

Present Epoch

Printable version

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  5

                                                   PUBLICATION DATE:  11/20/2002
Station ID: 8670424                                SUPERCEDED DATE:   04/21/2003
Name:       PORT WENTWORTH                                    
            GEORGIA
NOAA Chart: 11512                                  Latitude:         32°  8.6' N
USGS Quad:  PORT WENTWORTH                         Longitude:        81°  8.5' W


To reach the tidal bench marks from the end of interstate 516 and Route 21 in
Savannah, GA. Proceed north on State Highway 21 for 6.6 km (4.1 mi), turn right
on Crossgate Drive, proceed east on Crossgate Drive for 1.4 km (0.9 mi), turn
right on State Highway 17/25, proceed south on State Highway 17/25 for 0.8 km
(0.5 mi), turn left on to Oxnard Drive also into Dixie Crystals Sugar Refinery,
proceed east on Oxnard Drive for 0.72 km (0.45 mi) to the front gate of the
Dixie Crystals Sugar Refinery.  The tidal bench marks are on the Dixie Crystals
Sugar Refinery property.  The tide gage was located on the south side of the
plant pier on the Savannah River.    Note: Contact plant security at main gate
or Engineering Department at 912-964-1361 for access to the bench marks.


                         T I D A L   B E N C H   M A R K S


                 PRIMARY BENCH MARK STAMPING:  A 3 1943
                         DESIGNATION:          A 3

MONUMENTATION:           Bolt                                      VM#:    16682
AGENCY:                  US Army Corps of Engineers (USE)          PID#:  CK0429
SETTING CLASSIFICATION:  Building foundation


The primary bench mark is the top of a 1-inch hexagonal brass bolt in the top of
the projection of the concrete foundation of a 4-story brick building at the
refinery, at a slight inset of the brick wall, about 0.05 mi. (0.08 km) east of
the main entrance gate, 1.58 m (5.2 ft) west of NE corner of the building, 1.50
m (4.9 ft) east of east side of a door, 0.06 m (0.20 ft) north of north face of
building, and about level with ground.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  5

                                                   PUBLICATION DATE:  11/20/2002
Station ID: 8670424                                SUPERCEDED DATE:   04/21/2003
Name:       PORT WENTWORTH                                    
            GEORGIA
NOAA Chart: 11512                                  Latitude:         32°  8.6' N
USGS Quad:  PORT WENTWORTH                         Longitude:        81°  8.5' W


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  A 3 A 1943
                         DESIGNATION:          A 3 A

MONUMENTATION:           Survey disk                               VM#:    16683
AGENCY:                  US Army Corps of Engineers (USE)          PID#:  CK0428
SETTING CLASSIFICATION:  Building wall


The bench mark is a disk set vertically in the east face of the concrete
foundation of a 6 m (20 ft) high tin building housing the bag station, about
0.15 mi. (0.24 km) east and south along streets through the refinery near the SE
corner of the plant, about 73 m (240 ft) west of a loading dock on the Savannah
River, 0.18 m (0.6 ft) norht of the SE corner of the foundation, and about level
with a concrete ramp which parallels the south side of building and leads to the
loading dock.



                         BENCH MARK STAMPING:  NO 1 1934
                         DESIGNATION:          867 0424 TIDAL 1

MONUMENTATION:           Tidal Station disk                        VM#:    16684
AGENCY:                  US Coast and Geodetic Survey (USC&GS)     PID#:  CK0427
SETTING CLASSIFICATION:  Ramp


The bench mark is a disk set in the top of a concrete ramp on the south side of
warehouse No. 1, about 0.15 mile (0.24 km) east and south along streets through
the refinery, at the south side of the refinery. Note - a spur railroad track
parallels this building and leads to loading dock on Savannah River.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  5

                                                   PUBLICATION DATE:  11/20/2002
Station ID: 8670424                                SUPERCEDED DATE:   04/21/2003
Name:       PORT WENTWORTH                                    
            GEORGIA
NOAA Chart: 11512                                  Latitude:         32°  8.6' N
USGS Quad:  PORT WENTWORTH                         Longitude:        81°  8.5' W


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  X 212 1955
                         DESIGNATION:          X 212

MONUMENTATION:           Bench Mark disk                           VM#:    16685
AGENCY:                  US Coast and Geodetic Survey (USC&GS)     PID#:  CK0430
SETTING CLASSIFICATION:  Building wall


The bench mark is a disk set vertically in the north face of the concrete
foundation of a 8 m (25 ft) high concrete, brick, and tin building (boiler and
power building), inside a metal addition to the original building in the area of
an emergency generator, about 18 m (60 ft) SE of the main entrance gate, 0.48 m
(1.6 ft) east of the NW corner of the building, and 0.39 m (1.3 ft) above
ground.



                         BENCH MARK STAMPING:  X 212 RESET 1984
                         DESIGNATION:          X 212 RESET

MONUMENTATION:           Vertical Control disk                     VM#:    16686
AGENCY:                  National Geodetic Survey (NGS)            PID#:  CK6223
SETTING CLASSIFICATION:  Sidewalk


The bench mark is a disk set in the sidewalk to the left of the refinery
entrance gate, at the SW corner of a first aid station, 1.90 m (6.23 ft) SW of a
brick column, and 0.24 m (0.79 ft) east of the end of the sidewalk.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  5

                                                   PUBLICATION DATE:  11/20/2002
Station ID: 8670424                                SUPERCEDED DATE:   04/21/2003
Name:       PORT WENTWORTH                                    
            GEORGIA
NOAA Chart: 11512                                  Latitude:         32°  8.6' N
USGS Quad:  PORT WENTWORTH                         Longitude:        81°  8.5' W


                            T I D A L   D A T U M S 


Tidal datums at PORT WENTWORTH based on:

     LENGTH OF SERIES:      3 MONTHS
     TIME PERIOD:           May 2002 - July 2002
     TIDAL EPOCH:           1960-1978
     CONTROL TIDE STATION:  8670870 FORT PULASKI, SAVANNAH RIVER


Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:

     MEAN HIGHER HIGH WATER                     MHHW   =  2.623
     MEAN HIGH WATER                            MHW    =  2.531
     North American Vertical Datum              NAVD88 =  1.471
     MEAN SEA LEVEL                             MSL    =  1.416
     MEAN TIDE LEVEL                            MTL    =  1.298
     MEAN LOW WATER                             MLW    =  0.065
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     A 3 1943                                    5.721    3.190
     A 3 A 1943                                  4.989    2.458
     NO 1 1934                                   5.769    3.238
     X 212 1955                                  6.028    3.497
     X 212 RESET 1984                            6.143    3.612


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  5

                                                   PUBLICATION DATE:  11/20/2002
Station ID: 8670424                                SUPERCEDED DATE:   04/21/2003
Name:       PORT WENTWORTH                                    
            GEORGIA
NOAA Chart: 11512                                  Latitude:         32°  8.6' N
USGS Quad:  PORT WENTWORTH                         Longitude:        81°  8.5' W


                             D E F I N I T I O N S


Mean Sea Level (MSL) is a tidal datum determined over a 19-year National Tidal
Datum Epoch.  It pertains to local mean sea level and should not be confused
with the fixed datums of North American Vertical Datum of 1988 (NAVD88).

NAVD88 is a fixed datum derived from a simultaneous, least squares, minimum
constraint adjustment of Canadian/Mexican/United States leveling observations.
Local mean sea level observed at Father Point/Rimouski, Canada was held fixed as
the single initial constraint.  NAVD88 replaces NGVD29 as the national
standard geodetic reference for heights.  Bench mark elevations relative to
NAVD88 are available from NGS through the World Wide Web at 
National Geodetic Survey.

NGVD29 is a fixed datum adopted as a national standard geodetic reference for
heights but is now considered superseded.  NGVD29 is sometimes referred to as
Sea Level Datum of 1929 or as Mean Sea Level on some early issues of Geological
Survey Topographic Quads.  NGVD29 was originally derived from a general
adjustment of the first-order leveling networks of the U.S. and Canada after
holding mean sea level observed at 26 long term tide stations as fixed.
Numerous local and wide-spread adjustments have been made since establishment in
1929.  Bench mark elevations relative to NGVD29 are available from the National
Geodetic Survey (NGS) data base via the World Wide Web at 
National Geodetic Survey.

NAVD88 and NGVD29 are fixed geodetic datums whose elevation relationships to
local MSL and other tidal datums may not be consistent from one location to
another.

The Vertical Mark Number (VM#) and PID# shown on the bench mark sheet are unique
identifiers for bench marks in the tidal and geodetic databases, respectively.
Each bench mark in either database has a single, unique VM# and/or PID# assigned.
Where both VM# and PID# are indicated, both tidal and geodetic elevations are
available for the bench mark listed.

The NAVD88 elevation is shown on the Elevations of Tidal Datums Table Referred
to MLLW only when two or more of the bench marks listed have NAVD88 elevations.
The NAVD88 elevation relationship shown in the table is derived from an average
of several bench mark elevations relative to tide station datum.  As a result of
this averaging, NAVD88 bench mark elevations computed indirectly from the tidal
datums elevation table may differ slightly from NAVD88 elevations listed for
each bench mark in the NGS database.

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Products available at 8670424 Port Wentworth, GA

Revised: 08/08/2018
NOAA / National Ocean Service
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