U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
PUBLICATION DATE: 03/19/1986
Station ID: 8518668 SUPERCEDED DATE: 04/21/2003
Name: HORNS HOOK, EAST 90TH STREET, HELL GATE
NEW YORK
NOAA Chart: 12339 Latitude: 40° 46.6' N
USGS Quad: CENTRAL PARK Longitude: 73° 56.5' W
To reach the tidal bench marks from downtown Manhattan take Franklin D.
Roosevelt Drive north through the underpass at Carl Schurz Park, then after
going through the underpass, turn right into the Fireboat House Environmental
Center. The bench marks are located along York Avenue between East 88th and
East 96th Streets. The tide gage was located on the SE corner of the Pier. The
tide staff has located on the north face of the same pier.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 4 1942
MONUMENTATION: Survey Disk VM#: 2373
AGENCY: PID#: KU1424
SETTING CLASSIFICATION: Concrete Block
The bench mark is set flush in the top and near the center of a large concrete
block on the east side of East River Drive at the foot of East 90th Street. The
mark is at the north end of the east wingwall at the north entrance to a short
tunnel under Carl Shurz Park, 12 feet (4 m) SW of prolonged SW curbline of East
90th Street, 5.5 feet (1.7 m) east of the east curb of East River Drive, set 3.5
feet (1.1 m) above the sidewalk.
BENCH MARK STAMPING: 5 1942
MONUMENTATION: Survey Disk VM#: 2374
AGENCY: PID#: KU1425
SETTING CLASSIFICATION: Concrete Curb
The bench mark is set flush in the top of a concrete curb around the Municipal
Asphalt Plant building, a large concrete structure on East River Drive between
East 90th and East 91st Streets, at the SE truck entrance on the western side at
the center of a rounding corner, 12 feet (4 m) NW of the centerline of a truck
drive through the building, 1.5 feet (0.5 m) SW of the SW face of the building,
and is set 0.5 foot (0.2 m) above the level of the drive.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
PUBLICATION DATE: 03/19/1986
Station ID: 8518668 SUPERCEDED DATE: 04/21/2003
Name: HORNS HOOK, EAST 90TH STREET, HELL GATE
NEW YORK
NOAA Chart: 12339 Latitude: 40° 46.6' N
USGS Quad: CENTRAL PARK Longitude: 73° 56.5' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: EDISON RESET 1953
MONUMENTATION: Survey Disk VM#: 2375
AGENCY: PID#: KU1429
SETTING CLASSIFICATION: Concrete Step
The bench mark is set flush in the west end of the first concrete step leading
to the SW entrance on 96th Street of the Machine and Metal Trades High School,
in the Borough of Manhattan, at the NW corner of the intersection of 96th Street
and First Avenue.
BENCH MARK STAMPING: TORS HOSPITAL 1939
MONUMENTATION: Survey Disk VM#: 2376
AGENCY: PID#: KU1423
SETTING CLASSIFICATION: Granite Doorsill
The bench mark is set flush in top of the east corner of a granite doorsill of
the west employees entrance to Doctors Hospital on the south side of East 88th
Street, near East End Avenue, 96 feet (29 m) NW of the NW curb of East End
Drive, 76 feet (23 m) NW of the east corner of the hospital, 15.5 feet (4.7 m)
SW of the SW curb of East 88th Street, 0.5 feet (0.2 m) south of the building
line, set 0.5 foot (0.2 m) above the sidewalk. (NOTE: Bench mark historically
referred to as Doctors Hospital, however the DOC has been worn off).
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
PUBLICATION DATE: 03/19/1986
Station ID: 8518668 SUPERCEDED DATE: 04/21/2003
Name: HORNS HOOK, EAST 90TH STREET, HELL GATE
NEW YORK
NOAA Chart: 12339 Latitude: 40° 46.6' N
USGS Quad: CENTRAL PARK Longitude: 73° 56.5' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 8668 B 1981
MONUMENTATION: Survey Disk VM#: 2377
AGENCY: PID:
SETTING CLASSIFICATION: Granite Seawall
The bench mark is set flush in the top of a granite seawall in Carl Shurz Park,
200 feet (61 m) SE of the Bench Mark 4 1942, 50 feet (15 m) south of the south
side of Fireboat House Environmental Center, even with the south end of the
second concrete bench from the fireboat station, 25.4 feet (7.7 m) east of a
granite retaining wall between a grassy area and the west side of the park
walkway, and 1 foot (0.3 m) west of the east edge of the seawall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
PUBLICATION DATE: 03/19/1986
Station ID: 8518668 SUPERCEDED DATE: 04/21/2003
Name: HORNS HOOK, EAST 90TH STREET, HELL GATE
NEW YORK
NOAA Chart: 12339 Latitude: 40° 46.6' N
USGS Quad: CENTRAL PARK Longitude: 73° 56.5' W
T I D A L D A T U M S
Tidal datums at HORNS HOOK, EAST 90TH STREET, HELL GATE based on:
LENGTH OF SERIES: 127 HIGHS & 127 LOWS
TIME PERIOD: APRIL 23 - JUNE 27, 1981
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8518750 THE BATTERY
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (05/03/1981) = 7.04
MEAN HIGHER HIGH WATER MHHW = 5.22
MEAN HIGH WATER MHW = 4.89
MEAN TIDE LEVEL MTL = 2.55
* NATIONAL GEODETIC VERTICAL DATUM NGVD29 = 1.75
MEAN LOW WATER MLW = 0.20
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (10/08/1979) = -1.84
* NGVD reference based on adjustment of 1953 and NOS levels of 1981.
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
4 1942 14.36 9.47
5 1942 14.50 9.61
EDISON RESET 1953 12.13 7.24
TORS HOSPITAL 1939 29.05 24.16
8668 B 1981 14.93 10.04
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
PUBLICATION DATE: 03/19/1986
Station ID: 8518668 SUPERCEDED DATE: 04/21/2003
Name: HORNS HOOK, EAST 90TH STREET, HELL GATE
NEW YORK
NOAA Chart: 12339 Latitude: 40° 46.6' N
USGS Quad: CENTRAL PARK Longitude: 73° 56.5' 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.