U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 8444788 PUBLICATION DATE: 01/06/2004
Name: SHIPYARD POINT, WEYMOUTH FORE RIVER
MA
NOAA Chart: 13270 Latitude: 42° 14.9' N ( 42.24830)
USGS Quad: WEYMOUTH Longitude: 70° 58.0' W ( -70.96670)
To reach the tidal benchmarks from Exit 8 of I-93 North in Quincy, MA, proceed
north on Willard Street for 0.2 km (0.1 mi) and bear right onto Furnace Brook
Parkway, continue for 0.2 km (0.1 mi) and turn right onto Miller Street, then
proceed 0.2 km (0.1 mi) and continue on Copeland Street for 0.6 km (0.4 mi) to
Water Street, then continue on Water Street for 1.6 km (1.0 mi) and bear right
onto Quincy Avenue, proceed for 1.3 km (0.8 mi) then turn left onto Southern
Artery, continue for 1.0 km (0.6 mi) and turn right onto Washington Street, then
proceed 1.3 km (0.8 mi) and follow around circle and exit from the circle to
Bridge Street on the right side of the bridge over the Weymouth Fore River,
proceed to the first left and go less than 0.2 km (0.1 mi) under the bridge and
then turn left onto Bridge Street, then make the next right into the Twin Rivers
Technologies plant. The benchmarks are along the perimeter of the property, on
the West, North, and East sides. The tide gauge was located near the northeast
corner of the Twin Rivers Technologies pier on the Town River.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 4788 A 2003
DESIGNATION: 844 4788 A
MONUMENTATION: Tidal Station disk VM#: 17121
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Sea wall OPUS PID:
LATITUDE: 42° 14.9' N ( 42.24830) LONGITUDE: 70° 58.0' W ( -70.96670)
The primary bench mark is a disk set in the sea wall at the base of the west
side of the eastern-most access to the Twin Rivers Technologies pier along the
Town River, at the north end of the tank field, 42.06 m (138.0 ft) ENE of the
liquid nitrogen tank of the North Tank Field, 34.14 m (112.0 ft) WNW of the fire
hydrant located just outside the eastern wall of the North Tank Field, and 10.97
m (36.0 ft) NNW of Tank S-4 of the North Tank Field. Handheld GPS: 42 14'
52.7" N 70 57' 59.9" W
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 8444788 PUBLICATION DATE: 01/06/2004
Name: SHIPYARD POINT, WEYMOUTH FORE RIVER
MA
NOAA Chart: 13270 Latitude: 42° 14.9' N ( 42.24830)
USGS Quad: WEYMOUTH Longitude: 70° 58.0' W ( -70.96670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4788 B 2003
DESIGNATION: 844 4788 B
MONUMENTATION: Tidal Station disk VM#: 17303
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Silo base OPUS PID:
LATITUDE: 42° 14.9' N ( 42.24830) LONGITUDE: 70° 58.0' W ( -70.96670)
The bench mark is a disk set on the round concrete base of the only silo on the
SE side of the Twin Rivers Technologies plant, between the second and third
piers from the eastern corner of the property, 37.19 m (122.0 ft) ENE of the end
of the concrete at the south corner at the end of the tanks on the SE side of
the property, 32.31 m (106.0 ft) SW of the NE corner of the concrete wall south
of the white hydrogen storage tanks at the eastern corner of the property, 21.34
m (70.0 ft) SW of the base of the second pier from the eastern corner, 0.76 m
(2.5 ft) from the edge of the concrete base on which it lies, and 0.76 m (2.5
ft) above the road surface. Handheld GPS: 42 14' 51.5" N 70 57' 59.8" W
BENCH MARK STAMPING: 4788 C 2003
DESIGNATION: 844 4788 C
MONUMENTATION: Tidal Station disk VM#: 17304
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Retaining wall OPUS PID:
LATITUDE: 42° 14.9' N ( 42.24830) LONGITUDE: 70° 58.0' W ( -70.96670)
The bench mark is a disk set in a concrete retaining wall outside three large
silos across the road from a small blue shack on the NW side of the Twin Rivers
Technologies property, beside Silo 2 (the middle silo), 24.69 m (81.0 ft) NW of
the NW corner of the retaining wall before it turns east and runs along the Town
River, 12.19 m (40.0 ft) SSE of the fire hydrant along the river, 11.89 m (39.0
ft) east of the door of the blue shack ("The Love Shack"), and 1.37 m (4.5 ft)
above the road surface. Handheld GPS: 42 14' 51.8" N 70 58' 02.7" W
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 8444788 PUBLICATION DATE: 01/06/2004
Name: SHIPYARD POINT, WEYMOUTH FORE RIVER
MA
NOAA Chart: 13270 Latitude: 42° 14.9' N ( 42.24830)
USGS Quad: WEYMOUTH Longitude: 70° 58.0' W ( -70.96670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4788 D 2003
DESIGNATION: 844 4788 D
MONUMENTATION: Tidal Station disk VM#: 17305
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete block OPUS PID:
LATITUDE: 42° 14.8' N ( 42.24670) LONGITUDE: 70° 58.1' W ( -70.96830)
The benchmark is a disk set on a concrete block in the south corner of a
concrete fuel tank enclosure at the end of railroad track 3 and inside railroad
tracks 4-7, inside the concrete retaining wall of this enclosure, 29.57 m (97.0
ft) east of the NE corner of the red brick garages marked "oil storage", 22.56 m
(74.0 ft) south of the brick wall at the corner of the building at the end of
track 2, and 3.05 m (10.0 ft) NNE of the end of track 3. Handheld GPS: 42
14' 49.6" N 70 58' 04.9" W
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 8444788 PUBLICATION DATE: 01/06/2004
Name: SHIPYARD POINT, WEYMOUTH FORE RIVER
MA
NOAA Chart: 13270 Latitude: 42° 14.9' N ( 42.24830)
USGS Quad: WEYMOUTH Longitude: 70° 58.0' W ( -70.96670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4788 E 2003
DESIGNATION: 844 4788 E
MONUMENTATION: Tidal Station disk VM#: 17306
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete footing OPUS PID:
LATITUDE: 42° 14.8' N ( 42.24670) LONGITUDE: 70° 58.1' W ( -70.96830)
The bench mark is a disk set in a concrete footing near the front walkway to the
Twin Rivers Park Building, at the main entrance along the road and railroad
tracks on the west side of the property, just inside the brick retaining wall,
36.27 m (119.0 ft) NNE of the soft corner in the building on the brick wall
along the west side of the building where the wall turns to run south, 19.81 m
(65.0 ft) ENE of the northern end of the stone wall along the NW side of the
entrance drive (the stone wall has a fence along the top which encloses a tank
field), 14.02 m (46.0 ft) WNW of the front door of the Twin Rivers Park
Building, and 0.1 m (0.2 ft) above the surface of the road. Handheld GPS: 42
14' 47.3"N 70 58' 06.6" W
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8444788 PUBLICATION DATE: 01/06/2004
Name: SHIPYARD POINT, WEYMOUTH FORE RIVER
MA
NOAA Chart: 13270 Latitude: 42° 14.9' N ( 42.24830)
USGS Quad: WEYMOUTH Longitude: 70° 58.0' W ( -70.96670)
T I D A L D A T U M S
Tidal datums at SHIPYARD POINT, WEYMOUTH FORE RIVER based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: July 2003 - September 2003
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8443970 BOSTON, BOSTON HARBOR
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 3.154
MEAN HIGH WATER MHW = 3.016
MEAN SEA LEVEL MSL = 1.601
MEAN TIDE LEVEL MTL = 1.559
MEAN LOW WATER MLW = 0.101
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
4788 A 2003 4.234 1.218
4788 B 2003 5.372 2.356
4788 C 2003 5.368 2.352
4788 D 2003 5.007 1.991
4788 E 2003 4.775 1.759
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8444788 PUBLICATION DATE: 01/06/2004
Name: SHIPYARD POINT, WEYMOUTH FORE RIVER
MA
NOAA Chart: 13270 Latitude: 42° 14.9' N ( 42.24830)
USGS Quad: WEYMOUTH Longitude: 70° 58.0' W ( -70.96670)
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 NGS's Integrated Data Base (IDB PID)
provides geodetic datum based on traditionally leveled and bluebooked ties to
the National Spatial Reference System(NSRS) https://www.ngs.noaa.gov/datasheets/.
The NGS Online Positioning User Service (OPUS PID) provides geodetic datum based
on GPS position & tie it to the NSRS https://www.ngs.noaa.gov/OPUS/.
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.