U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 8665567 PUBLICATION DATE: 05/23/2003 Name: BEN SAWYER BRIDGE, IWW SOUTH CAROLINA NOAA Chart: 11524 Latitude: 32° 46.4' N USGS Quad: FORT MOULTRIE Longitude: 79° 50.5' W To reach the tidal bench marks from the intersection of U.S. Highway 17 and State Highway 703, proceed SE on State Highway 703 for 2.98 km (1.85 mi) to Ben Sawyer Memorial Bridge; just before the bridge turn left onto a paved road leading to the East Cooper Outboard Club property, follow the road for about 0.3 km (0.2 mi) to the Intracoastal Waterway and a dock. The bench marks are along State Highway 703 and along the access road. The tide gage and staff were on the dock about 183 m (600 ft) NE of the bridge. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 5567 A 1976 DESIGNATION: 866 5567 A TIDAL MONUMENTATION: Tidal Station disk VM#: 4197 AGENCY: National Ocean Survey (NOS) PID#: CJ0591 SETTING CLASSIFICATION: Copper-clad steel rod The primary bench mark is a disk set on the East Cooper Outboard Club property, 62 m (203 ft) NE of the NE corner of the clubhouse, 4.02 m (13.2 ft) WSW of a 1 m (3 ft) diameter pine tree, and 1.46 m (4.8 ft) SE of power pole #91562 with two guy wires. The bench mark is level with the ground, crimped to a copper-clad steel rod driven 12.2 m (40 ft) to refusal, and encased in a PVC pipe and concrete kickblock. BENCH MARK STAMPING: PLEASANT 1942 DESIGNATION: PLEASANT MONUMENTATION: Triangulation Station disk VM#: 4194 AGENCY: US Coast and Geodetic Survey (USC&GC) PID#: CJ0167 SETTING CLASSIFICATION: Concrete monument The bench mark is a disk set in the top of a concrete monument between the highway and the marsh, 20.97 m (68.8 ft) NNW of power pole #21418 with two guy wires and a street light, 20 m (66 ft) SSE of bench mark PLEASANT NO 1 1942, 10.03 m (32.9 ft) ENE of the centerline of the highway, 0.91 m (3.0 ft) WSW of a wooden post, and 0.12 m (0.4 ft) above the ground.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 8665567 PUBLICATION DATE: 05/23/2003 Name: BEN SAWYER BRIDGE, IWW SOUTH CAROLINA NOAA Chart: 11524 Latitude: 32° 46.4' N USGS Quad: FORT MOULTRIE Longitude: 79° 50.5' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: PLEASANT NO 1 1942 DESIGNATION: PLEASANT RM 1 MONUMENTATION: Reference Mark disk VM#: 4195 AGENCY: US Coast and Geodetic Survey (USC&GS) PID#: CJ0168 SETTING CLASSIFICATION: Concrete monument The bench mark is a disk set in the top of a concrete monument between the highway and the marsh, 32.46 m (106.5 ft) SSW of the south anchor for a large TV mast, 20.42 m (67.0 ft) SSE of power pole #116233 with three guy wires, 10 m (33 ft) ENE of the centerline of the highway, 0.49 m (1.6 ft) SSW of a witness post, and 0.06 m (0.2 ft) above the ground. BENCH MARK STAMPING: X 70 1952 DESIGNATION: X 70 MONUMENTATION: Bench Mark disk VM#: 4196 AGENCY: US Coast and Geodetic Survey (USC&GS) PID#: CJ0165 SETTING CLASSIFICATION: Bridge abutment The bench mark is a disk set in the NW abutment of Ben Sawyer Memorial Bridge, 5 m (18 ft) SW of the centerline of the highway, 1 m (2 ft) west of a concrete and steel banister, and 0.15 m (0.5 ft) above the highway.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 8665567 PUBLICATION DATE: 05/23/2003 Name: BEN SAWYER BRIDGE, IWW SOUTH CAROLINA NOAA Chart: 11524 Latitude: 32° 46.4' N USGS Quad: FORT MOULTRIE Longitude: 79° 50.5' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: 5567 B 1976 DESIGNATION: 866 5567 B TIDAL MONUMENTATION: Tidal Station disk VM#: 4198 AGENCY: National Ocean Survey (NOS) PID#: CJ0590 SETTING CLASSIFICATION: Copper-clad steel rod The bench mark is a disk set at the entrance gate to the East Cooper Outboard Club property, 51.51 m (169.0 ft) NE of the centerline of the highway, 4 m (13 ft) SE of the centerline of the driveway, 0.55 m (1.8 ft) NW of a witness post, and 0.37 m (1.2 ft) ESE of the north corner of a concrete block pillar. The bench mark is level with the ground, crimped to a copper-clad steel rod driven 12.2 m (40 ft) to refusal, and encased in a PVC pipe and concrete kickblock. BENCH MARK STAMPING: 5567 C 1976 DESIGNATION: 866 5567 C TIDAL MONUMENTATION: Tidal Station disk VM#: 4199 AGENCY: National Ocean Survey (NOS) PID#: CJ0589 SETTING CLASSIFICATION: Copper-clad steel rod The bench mark is a disk set on the east side of State Highway 703, 0.72 km (0.45 mi) NW of the NW end of Ben Sawyer Memorial Bridge, 8.44 m (27.7 ft) ENE of the centerline of the highway, 5.91 m (19.4 ft) west of power pole #21429, 2.19 m (7.2 ft) NW of the SW anchor of a guy wire, and 0.49 m (1.6 ft) ENE of a witness post. The bench mark is level with the ground, crimped to a copper-clad steel rod driven 12.2 m (40 ft) to refusal, and encased in a PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 8665567 PUBLICATION DATE: 05/23/2003 Name: BEN SAWYER BRIDGE, IWW SOUTH CAROLINA NOAA Chart: 11524 Latitude: 32° 46.4' N USGS Quad: FORT MOULTRIE Longitude: 79° 50.5' W T I D A L D A T U M S Tidal datums at BEN SAWYER BRIDGE, IWW based on: LENGTH OF SERIES: 3 MONTHS TIME PERIOD: July 1976 - September 1976 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8665530 CHARLESTON, COOPER RIVER ENTRANCE Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER (MHHW) = 1.710 MEAN HIGH WATER (MHW) = 1.596 NORTH AMERICAN VERTICAL DATUM-1988 (NAVD) = 0.963 MEAN SEA LEVEL (MSL) = 0.853 MEAN TIDE LEVEL (MTL) = 0.826 MEAN LOW WATER (MLW) = 0.057 MEAN LOWER LOW WATER (MLLW) = 0.000 National Geodetic Vertical Datum (NGVD 29) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 5567 A 1976 2.434 0.838 PLEASANT 1942 2.573 0.977 PLEASANT NO 1 1942 2.613 1.017 X 70 1952 9.018 7.422 5567 B 1976 2.359 0.763 5567 C 1976 2.814 1.218
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 8665567 PUBLICATION DATE: 05/23/2003 Name: BEN SAWYER BRIDGE, IWW SOUTH CAROLINA NOAA Chart: 11524 Latitude: 32° 46.4' N USGS Quad: FORT MOULTRIE Longitude: 79° 50.5' 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 (NAVD 88). NGVD 29 is a fixed datum adopted as a national standard geodetic reference for heights but is now considered superseded. NGVD 29 is sometimes referred to as Sea Level Datum of 1929 or as Mean Sea Level on some early issues of Geological Survey Topographic Quads. NGVD 29 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 NGVD 29 are available from the National Geodetic Survey (NGS) data base via the World Wide Web at National Geodetic Survey. NAVD 88 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. NAVD 88 replaces NGVD 29 as the national standard geodetic reference for heights. Bench mark elevations relative to NAVD 88 are available from NGS through the World Wide Web at National Geodetic Survey. NGVD 29 and NAVD 88 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 NAVD 88 elevation is shown on the Elevations of Tidal Datums Table Referred to MLLW only when two or more of the bench marks listed have NAVD 88 elevations. The NAVD 88 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, NAVD 88 bench mark elevations computed indirectly from the tidal datums elevation table may differ slightly from NAVD 88 elevations listed for each bench mark in the NGS database.