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Bench Mark Sheet for 8443725, Chelsea MA

Superseded Epoch

Large map location marker Station Location
Small red map location marker Published bench mark
Small blue map location marker Unpublished bench mark

Bench mark positions only appear on the map if their coordinates in the CO-OPS database are at the precision of degrees/minutes/seconds/and tenths of seconds. If the coordinates are less precise, the mark will not appear.

Printable version

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

                                                                                
Station ID: 8443725                         PUBLICATION DATE:  10/07/2003
Name:       CHELSEA ST. BRIDGE, CHELSEA RIVER                 
            MA
NOAA Chart: 13272                           Latitude:   42° 23.2' N (  42.38670)
USGS Quad:  BOSTON NORTH                    Longitude:  71°  1.4' W ( -71.02330)


To reach the tidal bench marks from the intersection of I-93 and Highway 16 in
Boston, proceed east on Highway 16 for 7.1 km (4.4 mi) to Broadway (Highway
107), take the exit for Broadway and continue 0.3 km (0.2 mi) to Eastern Avenue,
bear left and proceed south on Eastern Avenue for 1.6 km (1.0 mi) to Chelsea
Street, then bear left and continue south on Chelsea Street for 0.3 km (0.2 mi)
to the Chelsea Street Bridge. The bench marks are along Chelsea Street south of
the bridge, and the tide gage was located on the bumper pier below the bridge.


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


                 PRIMARY BENCH MARK STAMPING:  3725 A 2002
                         DESIGNATION:          844 3725 A

MONUMENTATION:           Tidal Station disk                    VM#:        16725
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Overhead doorsill                     OPUS PID:        
LATITUDE:   42° 23.2' N (  42.38670)          LONGITUDE:  71°  1.4' W ( -71.02330)


The primary bench mark is a disk set in the south end of a concrete sill for an
overhead door on the west side of the I.N. Caruso Pumping Station at 601 Chelsea
Street, 11.85 m (38.9 ft) south of the flagpole in front of the station, 5.50 m
(18.0 ft) east of the south gate post of a chain link fence along Chelsea
Street, and 2.17 m (7.1 ft) north of the SW corner of the station.

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

                                                                                
Station ID: 8443725                         PUBLICATION DATE:  10/07/2003
Name:       CHELSEA ST. BRIDGE, CHELSEA RIVER                 
            MA
NOAA Chart: 13272                           Latitude:   42° 23.2' N (  42.38670)
USGS Quad:  BOSTON NORTH                    Longitude:  71°  1.4' W ( -71.02330)


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


                         BENCH MARK STAMPING:  3725 B 2002
                         DESIGNATION:          844 3725 B

MONUMENTATION:           Tidal Station disk                    VM#:        16726
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Loading doorsill                      OPUS PID:        
LATITUDE:   42° 23.2' N (  42.38670)          LONGITUDE:  71°  1.4' W ( -71.02330)


The bench mark is a disk set in the NE side of the concrete foundation sill for
the door of the largest of three loading bays at Eagle Global Logistics located
at 160 McClellan Highway, 16.2 m (53 ft) SW of the grey office door, 14.60 m
(47.9 ft) north of the NE corner of a loading ramp, and 0.16 m (0.5 ft) SSW of a
bumper guard.



                         BENCH MARK STAMPING:  NO 1 1945
                         DESIGNATION:          844 3725 TIDAL 1

MONUMENTATION:           Tidal Station disk                    VM#:        16727
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Retaining wall                        OPUS PID:        
LATITUDE:   42° 23.2' N (  42.38670)          LONGITUDE:  71°  1.4' W ( -71.02330)


In Chelsea, near the SW corner of the Chelsea Street Bridge over the Chelsea
River, the bench mark is a disk set in the concrete retaining wall on the west
side of the bridge, 14.70 m (48.2 ft) NW of the traffic light foundation, 14.34
m (47.0 ft) south of the center of the door to the bridge tender office, 6.36 m
(20.9 ft) NW of the bridge gate foundation on the west side of the bridge, and
2.45 m (8.0 ft) west of the steel girder for the bridge.

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

                                                                                
Station ID: 8443725                         PUBLICATION DATE:  10/07/2003
Name:       CHELSEA ST. BRIDGE, CHELSEA RIVER                 
            MA
NOAA Chart: 13272                           Latitude:   42° 23.2' N (  42.38670)
USGS Quad:  BOSTON NORTH                    Longitude:  71°  1.4' W ( -71.02330)


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


                         BENCH MARK STAMPING:   
                         DESIGNATION:          844 3725 MGS 3047

MONUMENTATION:           Rivet                                 VM#:        16728
AGENCY:                  Massachusetts Geodetic Survey (MGS)   IDB PID#:        
SETTING CLASSIFICATION:  Granite step                          OPUS PID:        
LATITUDE:   42° 23.2' N (  42.38670)          LONGITUDE:  71°  1.3' W ( -71.02170)


In Chelsea, near the SE corner of the Chelsea Street Bridge over the Chelsea
River, the bench mark is a monel rivet set in the granite step along the center
of the south side of the Massachusetts Water Resources Authority Sewage Division
building, 52.99 m (173.9 ft) NE of the center of the door painted black of the
I.N. Caruso Pumping Station, 18.83 m (61.8 ft) NW of the fire hydrant protected
by two bollards, and 16.20 m (53.1 ft) NW of power pole number 39-1-3X.



                         BENCH MARK STAMPING:   
                         DESIGNATION:          844 3725  USE

MONUMENTATION:           Survey disk                           VM#:        16729
AGENCY:                  US Army Corps of Engineers (USE)      IDB PID#:        
SETTING CLASSIFICATION:  Doorsill                              OPUS PID:        
LATITUDE:   42° 23.1' N (  42.38500)          LONGITUDE:  71°  1.3' W ( -71.02170)


In Chelsea, near the Chelsea Street Bridge over the Chelsea River, the bench
mark is a disk set in the concrete foundation for the ramp at the entrance to
the double doors located at the NW corner of the Massachusetts Water Resources
Authority Sewage Division building, 31.75 m (104.2 ft) east of the NE corner of
the metal light post with two lights, 13.20 m (43.3 ft) NE of power pole number
1-64-1A, and 12.98 m (42.6 ft) NE of a double door just SW of the ramp.

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

                                                                                
Station ID: 8443725                         PUBLICATION DATE:  10/07/2003
Name:       CHELSEA ST. BRIDGE, CHELSEA RIVER                 
            MA
NOAA Chart: 13272                           Latitude:   42° 23.2' N (  42.38670)
USGS Quad:  BOSTON NORTH                    Longitude:  71°  1.4' W ( -71.02330)


                            T I D A L   D A T U M S 


Tidal datums at CHELSEA ST. BRIDGE, CHELSEA RIVER based on:

     LENGTH OF SERIES:      3 MONTHS
     TIME PERIOD:           July 2002 - September 2002
     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   =  3.155
     MEAN HIGH WATER                            MHW    =  3.019
     MEAN SEA LEVEL                             MSL    =  1.598
     MEAN TIDE LEVEL                            MTL    =  1.562
     MEAN LOW WATER                             MLW    =  0.104
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     3725 A 2002                                 5.819    2.800
     3725 B 2002                                 5.188    2.169
     NO 1 1945                                   4.628    1.609
     844 3725 MGS 3047                           4.784    1.765
     844 3725  USE                               4.915    1.896


Foot Notes:

 

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

                                                                                
Station ID: 8443725                         PUBLICATION DATE:  10/07/2003
Name:       CHELSEA ST. BRIDGE, CHELSEA RIVER                 
            MA
NOAA Chart: 13272                           Latitude:   42° 23.2' N (  42.38670)
USGS Quad:  BOSTON NORTH                    Longitude:  71°  1.4' W ( -71.02330)


                             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.

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Products available at 8443725 Chelsea, MA

Revised: 08/08/2018
NOAA / National Ocean Service
Web site owner: Center for Operational Oceanographic Products and Services