U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 8518643 PUBLICATION DATE: 12/12/2014
Name: RANDALLS ISLAND, HARLEM RIVER
NY
NOAA Chart: 12339 Latitude: 40° 48.0' N ( 40.80000)
USGS Quad: CENTRAL PARK Longitude: 73° 55.7' W ( -73.92830)
To reach the station from the E end of the i-278 robert f. Kennedy bridge
(triborough bridge) in queens at the E bank of the east river, proceed 1.8 km
(1.1 mi) W and then N on the i-278Robert F. Kennedy Bridge, stay right at the
fork for Manhattan and continue 1.0 km (0.6 mi) N and then west to the toll,
exit i-278 on the right immediately after the toll and follow the exit ramp
around 0.5 km (0.3 mi) E onto Bronx shore road to the first allowed U-turn, make
a U-turn and proceed W 0.2 km (0.1 mi) to the first available right turn and the
gated entrance to the NYPD launch repair shop and the tide station on the dock
in the Harlem river. Bench marks are in the vicinity of the tide station and
along the Robert F. Kennedy Bridge.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 8643 E 1981
DESIGNATION: 851 8643 E 1981
MONUMENTATION: Bench Mark disk VM#: 2372
AGENCY: National Ocean Survey IDB PID#:
SETTING CLASSIFICATION: Concrete guardrail OPUS PID:
LATITUDE: 40° 47.9' N ( 40.79911) LONGITUDE: 73° 55.6' W ( -73.92608)
The primary bench mark is a disk set in the concrete guardrail on the N side of
the on ramp, 43.75 m (143.5 ft) S of a concrete pier for the bridge, 11.15 m
(36.6 ft) W of a light pole on the inner highway ramp, 8.25 m (27.1 ft) NNW of
the center of a manhole, 0.33 m (1.1 ft) above the road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 8518643 PUBLICATION DATE: 12/12/2014
Name: RANDALLS ISLAND, HARLEM RIVER
NY
NOAA Chart: 12339 Latitude: 40° 48.0' N ( 40.80000)
USGS Quad: CENTRAL PARK Longitude: 73° 55.7' W ( -73.92830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 8643 C 1981
DESIGNATION: 851 8643 C 1981
MONUMENTATION: Bench Mark disk VM#: 2370
AGENCY: National Ocean Service IDB PID#:
SETTING CLASSIFICATION: Concrete bridge support OPUS PID:
LATITUDE: 40° 48.0' N ( 40.79989) LONGITUDE: 73° 55.6' W ( -73.92628)
The bench mark is a disk set in the N concrete bridge support on the E Harlem
river bank, 52.50 m (172.2 ft) WNW of the centerline of the park pathway
underneath the bridge, 19.21 m (63.0 ft) NNE of the S support of this pair,
17.23 m (56.5 ft) N of the center of an electric utility manhole, 2.46 m (8.1
ft) NNE of the SW corner of the concrete bridge support and 0.38 m (1.2 ft) SSW
of the chain link fence around the NYPD launch repair shop.
BENCH MARK STAMPING: 8643 F 2014
DESIGNATION: 851 8643 F
MONUMENTATION: Bench Mark disk VM#: 21105
AGENCY: National Ocean Service IDB PID#:
SETTING CLASSIFICATION: Concrete crane base OPUS PID:
LATITUDE: 40° 48.0' N ( 40.80058) LONGITUDE: 73° 55.6' W ( -73.92653)
The bench mark is a disk set in the N side of the concrete base for the crane
near the NE corner of the boat basin, 37.73 m (123.8 ft) WNW of the NW corner of
the launch repair shop, 7.15 m (23.5 ft) S of the center of the base of the
concrete dock arm that extends WNW into the Harlem river, 5.43 m (17.8 ft) S of
a light pole, 2.70 m (8.9 ft) NNE of the base of the crane and 1.98 m (6.5 ft)
ENE of a metal cleat.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 8518643 PUBLICATION DATE: 12/12/2014
Name: RANDALLS ISLAND, HARLEM RIVER
NY
NOAA Chart: 12339 Latitude: 40° 48.0' N ( 40.80000)
USGS Quad: CENTRAL PARK Longitude: 73° 55.7' W ( -73.92830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: P 339 1952
DESIGNATION: P 339
MONUMENTATION: Bench Mark disk VM#: 21106
AGENCY: US Coast and Geodetic Survey IDB PID#: KU1407
SETTING CLASSIFICATION: Concrete bridge abutment OPUS PID:
LATITUDE: 40° 47.8' N ( 40.79586) LONGITUDE: 73° 55.3' W ( -73.92089)
The bench mark is a disk set in the bridge abutment on the N side of the ramp,
12.32 m (40.4 ft) SW of the center of the maintenance garage door, 6.15 m (20.2
ft) NNW of the back side of the curb, 3.36 m (11.0 ft) N of a concrete bridge
support, 1.90 m (6.2 ft) NE of the corner of the abutment and 0.64 m (2.1 ft)
above the sidewalk.
BENCH MARK STAMPING: 8643 G 2014
DESIGNATION: 851 8643 G
MONUMENTATION: Bench Mark disk VM#: 21107
AGENCY: National Ocean Service IDB PID#:
SETTING CLASSIFICATION: Small bridge abutment OPUS PID#: BBDM52
LATITUDE: 40° 47.5' N ( 40.79108) LONGITUDE: 73° 55.7' W ( -73.92775)
The bench mark is a disk set in the NW bridge abutment of the pedestrian bridge,
47.90 m (157.2 ft) NE of the bollard in the center of the boardwalk on the S
side of the bridge, 16.50 m (54.1 ft) SW of the center of the gate in the metal
railing on the E side of the wooden boardwalk, 5.23 m (17.2 ft) SE of the inland
edge of the rock riprap along the edge of the water, 0.30 m (1.0 ft) NW of the
side of the boardwalk, 0.26 m (0.9 ft) NE of the end of the steel bridge span,
and 1.23 m (4.0 ft) above the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 8518643 PUBLICATION DATE: 12/12/2014
Name: RANDALLS ISLAND, HARLEM RIVER
NY
NOAA Chart: 12339 Latitude: 40° 48.0' N ( 40.80000)
USGS Quad: CENTRAL PARK Longitude: 73° 55.7' W ( -73.92830)
T I D A L D A T U M S
Tidal datums at RANDALLS ISLAND, HARLEM RIVER based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: May 2014 - July 2014
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8518750 THE BATTERY, NEW YORK HARBOR
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 1.537
MEAN HIGH WATER MHW = 1.444
MEAN SEA LEVEL MSL = 0.759
MEAN TIDE LEVEL MTL = 0.749
MEAN LOW WATER MLW = 0.055
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
8643 E 1981 7.344 5.900
8643 C 1981 4.632 3.188
8643 F 2014 3.126 1.682
P 339 1952 11.202 9.758
8643 G 2014 3.807 2.363
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8518643 PUBLICATION DATE: 12/12/2014
Name: RANDALLS ISLAND, HARLEM RIVER
NY
NOAA Chart: 12339 Latitude: 40° 48.0' N ( 40.80000)
USGS Quad: CENTRAL PARK Longitude: 73° 55.7' W ( -73.92830)
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.