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Bench Mark Sheet for 8635027, Dahlgren VA

Superseded Epoch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Small blue map location marker Unpublished bench mark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 13

                                                                                
Station ID: 8635027                         PUBLICATION DATE:  07/11/2018
Name:       DAHLGREN NAVAL PROVING GROUND                     
            VA
NOAA Chart: 12287                           Latitude:   38° 19.2' N (  38.31975)
USGS Quad:  DAHLGREN                        Longitude:  77°  2.2' W ( -77.03661)


At 17285 Dahlgren Rd, Dahlgren, VA 22448, the US Post Office, proceed through
the Naval Station gate, and head southeast on Dahlgren Rd towards Hall Rd for
.08 km (0.50 miles), turn right (southwest) onto Caffee Rd for .16km (0.1 miles)
to the intersection of Caffee Rd and Jenkins Rd, turn left (southeast) onto
Jenkins Rd for 0.32km (0.2 miles) to the intersection of Jenkins Rd and Welsh
Rd, turn right (southeast) onto Welsh Rd for .64 km (0.4 miles) to the
intersection of Jenkins Rd and Sampson Rd, turn left (east) and immediately turn
right (south) onto Sampson Rd for 109.72 m (360 ft). The station is an aluminum
elevated platform mounted to a concrete pad located near the west end of the
boat dock.


                         T I D A L   B E N C H   M A R K S
                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of 13

                                                                                
Station ID: 8635027                         PUBLICATION DATE:  07/11/2018
Name:       DAHLGREN NAVAL PROVING GROUND                     
            VA
NOAA Chart: 12287                           Latitude:   38° 19.2' N (  38.31975)
USGS Quad:  DAHLGREN                        Longitude:  77°  2.2' W ( -77.03661)


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


                 PRIMARY BENCH MARK STAMPING:  HERO 1987
                         DESIGNATION:          HERO

MONUMENTATION:           Metal Rod                             VM#:        21795
AGENCY:                  NGS                                   IDB PID#:  HV8122
SETTING CLASSIFICATION:  Stainless steel rod without sleeve    OPUS PID#: HV8122
LATITUDE:   38° 19.9' N (  38.33089)          LONGITUDE:  77°  2.3' W ( -77.03881)


The primary bench mark is located 29.0 m (95.14 ft) east from the east edge of
the an abandoned taxiway, 18.0 m (59.05 ft) WSW from the SW corner of a 1.2
meter (3.93 ft) square concrete foundation for a metal utilities access door,
17.6 m (57.74 ft) NE from the NE corner of a green concrete building, and 0.8 m
(2.62 ft) west from a fiberglass witness post. The bench mark is in the top
center of a stainless steel rod recessed 8 cm below ground in a PVC pipe covered
by a standard NGS logo cap flush with the ground.    



                         BENCH MARK STAMPING:  5027 B 2015
                         DESIGNATION:          863 5027 B

MONUMENTATION:           Bench Mark disk                       VM#:        21793
AGENCY:                  NOS                                   IDB PID#:        
SETTING CLASSIFICATION:  Concrete culvert                      OPUS PID:        
LATITUDE:   38° 19.3' N (  38.32250)          LONGITUDE:  77°  2.2' W ( -77.03670)


The bench mark is set flush in concrete drainage culvert with an aluminum walk
that is on the edge of a drainage basin located on Tisdale Rd, 2.2 m (7.2 ft)
south of the north edge of the concrete culvert, 2.0 m (6.6 ft) north of the
south edge of the concrete culvert, and 0.1 m (0.3 ft) SE of the NW edge of the
concrete culvert.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of 13

                                                                                
Station ID: 8635027                         PUBLICATION DATE:  07/11/2018
Name:       DAHLGREN NAVAL PROVING GROUND                     
            VA
NOAA Chart: 12287                           Latitude:   38° 19.2' N (  38.31975)
USGS Quad:  DAHLGREN                        Longitude:  77°  2.2' W ( -77.03661)


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


                         BENCH MARK STAMPING:  5027 A 2015
                         DESIGNATION:          863 5027 A

MONUMENTATION:           Bench Mark disk                       VM#:        21796
AGENCY:                  NOS                                   IDB PID#:        
SETTING CLASSIFICATION:  Concrete foundation                   OPUS PID:        
LATITUDE:   38° 19.2' N (  38.31975)          LONGITUDE:  77°  2.2' W ( -77.03660)


The bench mark is a brass disc set in concrete, 38.00 m (124.7 ft) east of the
SW corner of concrete bulk head, 2.55 m (8.4 ft) north of the south edge of
concrete bulkhead, 0.41 m (1.3 ft) south of the north edge of concrete pad.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of 13

                                                                                
Station ID: 8635027                         PUBLICATION DATE:  07/11/2018
Name:       DAHLGREN NAVAL PROVING GROUND                     
            VA
NOAA Chart: 12287                           Latitude:   38° 19.2' N (  38.31975)
USGS Quad:  DAHLGREN                        Longitude:  77°  2.2' W ( -77.03661)


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


                         BENCH MARK STAMPING:  STA 42 NO 1 1970
                         DESIGNATION:          STA 42 NO 1 1970

MONUMENTATION:           Survey disk                           VM#:        21797
AGENCY:                  NOS                                   IDB PID#:        
SETTING CLASSIFICATION:  Retaining wall                        OPUS PID#: BBDL64
LATITUDE:   38° 19.2' N (  38.31967)          LONGITUDE:  77°  2.1' W ( -77.03558)


The bench mark is 26.5 m (86.9 ft) SSE of a wire gate, 11.4 m (37.4 ft) south of
building 453, 10.1 m (33.1 ft) west of the west edge of the dilapidated sea
wall, 0.5 ft (15 cm) north of the south face of the sea wall. The mark is
cemented in a drill hole, 1 inch below the paved surface in a concrete headwall.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of 13

                                                                                
Station ID: 8635027                         PUBLICATION DATE:  07/11/2018
Name:       DAHLGREN NAVAL PROVING GROUND                     
            VA
NOAA Chart: 12287                           Latitude:   38° 19.2' N (  38.31975)
USGS Quad:  DAHLGREN                        Longitude:  77°  2.2' W ( -77.03661)


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


                         BENCH MARK STAMPING:  STATION DOCK 1974
                         DESIGNATION:          STATION DOCK

MONUMENTATION:           Triangulation Station disk            VM#:        21798
AGENCY:                  NGS                                   IDB PID#:  HV2958
SETTING CLASSIFICATION:  Headwall of dock                      OPUS PID#: HV2958
LATITUDE:   38° 19.2' N (  38.31969)          LONGITUDE:  77°  2.1' W ( -77.03533)


The bench mark is a standard disk is cemented in a drill hole 1 inch below the
paved surface in a concrete headwall, 96.78 m (29.5 ft) west of the west edge of
the dilapidated sea wall, 26.8 m (87.9 ft) SSE of a wire gate, 11.3 m (37.1 ft)
south of building 453, 0.5 ft (15 cm) north of the south face of the sea wall.



                         BENCH MARK STAMPING:  NO 2 1944
                         DESIGNATION:          863 5027 TIDAL 2

MONUMENTATION:           Tidal Station disk                    VM#:        21799
AGENCY:                  CGS                                   IDB PID#:  HV2955
SETTING CLASSIFICATION:  Concrete porch foundation             OPUS PID:        
LATITUDE:   38° 19.2' N (  38.32031)          LONGITUDE:  77°  2.1' W ( -77.03558)


The bench mark is set in the top of the concrete floor for porch with low roof,
11.28 m (37.0 ft) east of the center line of Welsh Rd, 8.57 m (28.1 ft) NE of
3000-5 anchor monument, 1.83 m (6.0 ft) south of the south wall of amateur radio
building No. 322, 2.29 m (7.5 ft) west of the SE corner of the floor, 0.21 m
(0.7 ft) north of the south edge of the floor. Note--the rod could not be
plumbed due to the low roof of the porch.  

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of 13

                                                                                
Station ID: 8635027                         PUBLICATION DATE:  07/11/2018
Name:       DAHLGREN NAVAL PROVING GROUND                     
            VA
NOAA Chart: 12287                           Latitude:   38° 19.2' N (  38.31975)
USGS Quad:  DAHLGREN                        Longitude:  77°  2.2' W ( -77.03661)


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


                         BENCH MARK STAMPING:  U 460 1971
                         DESIGNATION:          U 460

MONUMENTATION:           Bench Mark disk                       VM#:        21800
AGENCY:                  NGS                                   IDB PID#:  HV2954
SETTING CLASSIFICATION:  Culvert foundation                    OPUS PID:        
LATITUDE:   38° 19.2' N (  38.32028)          LONGITUDE:  77°  2.1' W ( -77.03556)


The bench mark is cemented in a drill hole in a concrete slab, 27.40 m (89.9 ft)
northeast of the center of the intersection of Welsh Rd and Tinsdale Rd, on top
of the SE corner of an 8x8ft concrete culvert for manhole, 12.20 m (40.0 ft)
east of a building, and 0.30 m (1.0 ft) above the level of the ground. Note  the
bench mark is about 14.6 m (47.9 ft) east of 863 5027 TIDAL 2.



                         BENCH MARK STAMPING:  4 RESET 2015
                         DESIGNATION:          4 RESET 2015

MONUMENTATION:           Bench Mark disk                       VM#:        21801
AGENCY:                  NOS                                   IDB PID#:        
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   38° 19.7' N (  38.32806)          LONGITUDE:  77°  2.3' W ( -77.03889)


The bench mark is 21.9 m (71.85 ft) NE of the center of Welsh Rd, 14.0 m (45.93
ft) SW of the center of the road, 14.0 m (45.93 ft) NW of the center of Caffee
Rd, and is on top of a concrete monument that is flush with the ground surface.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  7 of 13

                                                                                
Station ID: 8635027                         PUBLICATION DATE:  07/11/2018
Name:       DAHLGREN NAVAL PROVING GROUND                     
            VA
NOAA Chart: 12287                           Latitude:   38° 19.2' N (  38.31975)
USGS Quad:  DAHLGREN                        Longitude:  77°  2.2' W ( -77.03661)


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


                         BENCH MARK STAMPING:  RADAR 3 1974
                         DESIGNATION:          RADAR 3 1974

MONUMENTATION:           Triangulation Station disk            VM#:        21802
AGENCY:                  NGS                                   IDB PID#:  HV5383
SETTING CLASSIFICATION:  Concrete foundation                   OPUS PID:        
LATITUDE:   38° 19.5' N (  38.32505)          LONGITUDE:  77°  2.7' W ( -77.04444)


The bench mark is cemented in a drill hole in a large concrete slab in front of
building 997 and is flush with the surface of the ground, 12.8 m (42.0 ft) west
of the west rail of the railroad, 10.5 m (34.4 ft) east of the SE corner of
building 997 and 0.30 m (1.0 ft) north of the south edge of the concrete slab.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  8 of 13

                                                                                
Station ID: 8635027                         PUBLICATION DATE:  07/11/2018
Name:       DAHLGREN NAVAL PROVING GROUND                     
            VA
NOAA Chart: 12287                           Latitude:   38° 19.2' N (  38.31975)
USGS Quad:  DAHLGREN                        Longitude:  77°  2.2' W ( -77.03661)


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


                         BENCH MARK STAMPING:  RADAR 2 1974
                         DESIGNATION:          RADAR 2 1974

MONUMENTATION:           Triangulation Station disk            VM#:        21803
AGENCY:                  NGS                                   IDB PID#:        
SETTING CLASSIFICATION:  Concrete foundation                   OPUS PID:        
LATITUDE:   38° 19.5' N (  38.32526)          LONGITUDE:  77°  2.7' W ( -77.04429)


The bench mark is cemented in a drill hole in a large concrete slab in front of
building 997 and is flush with the surface of the ground, 10.1 m (33.1 ft) east
of the NE corner of building 997, 8.8 m (28.9 ft) west of the west rail of the
railroad and 18 cm (7 inches) south of the north edge of the concrete.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  9 of 13

                                                                                
Station ID: 8635027                         PUBLICATION DATE:  07/11/2018
Name:       DAHLGREN NAVAL PROVING GROUND                     
            VA
NOAA Chart: 12287                           Latitude:   38° 19.2' N (  38.31975)
USGS Quad:  DAHLGREN                        Longitude:  77°  2.2' W ( -77.03661)


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


                         BENCH MARK STAMPING:  V 460 1971
                         DESIGNATION:          V 460

MONUMENTATION:           Bench Mark disk                       VM#:        22306
AGENCY:                  NGS                                   IDB PID#:        
SETTING CLASSIFICATION:  Driven into the gorund                OPUS PID:        
LATITUDE:   38° 19.2' N (  38.31992)          LONGITUDE:  77°  2.1' W ( -77.03539)


The bench mark is a disk located 61.3 m (201.1 ft) south of the intersection of
Welsh Road and Tinsdale Road, 6.4m (21 ft) east of the center of a steel gate at
the paved entrance to the dock, 4.11m (13.5 ft) NW of the NW corner of office
building NO 453, 0.48m (1.6 ft) south of a chain link fence, .30 m (1ft) above
the level of the road and is on the top of a copper coated 1.22m (4 ft) length
rod that is attached to a metal base plate.



                         BENCH MARK STAMPING:  5027 C 2016
                         DESIGNATION:          863 5027 C

MONUMENTATION:           Metal Rod                             VM#:        22307
AGENCY:                  CO-OPS                                IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   38° 19.3' N (  38.32242)          LONGITUDE:  77°  2.1' W ( -77.03581)


The bench mark is a stainless steel rod driven 12.2 m (40.0 ft) to refusal
surrounded by a concrete kick block, 65.3 m (214.2 ft) east of the SE corner of
the stair case of building #217 (Center For Excellence Training), 42.4 m (139.1
ft) SSE of the southwest corner of building #216 (Training And Conference
Building), 29.1 m (95.5 ft) west of the centerline of Welsh Road.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page 10 of 13

                                                                                
Station ID: 8635027                         PUBLICATION DATE:  07/11/2018
Name:       DAHLGREN NAVAL PROVING GROUND                     
            VA
NOAA Chart: 12287                           Latitude:   38° 19.2' N (  38.31975)
USGS Quad:  DAHLGREN                        Longitude:  77°  2.2' W ( -77.03661)


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


                         BENCH MARK STAMPING:  5027 D 2017
                         DESIGNATION:          863 5027 D

MONUMENTATION:           Metal Rod                             VM#:        22322
AGENCY:                  NOS                                   IDB PID#:        
SETTING CLASSIFICATION:  Steel rod                             OPUS PID:        
LATITUDE:   38° 19.6' N (  38.32664)          LONGITUDE:  77°  2.3' W ( -77.03836)


The bench mark is a flange-encased stainless steel rod located 34.57 m (113.4
ft) SW of the centerline of Welsh Road, 31.10 m (102.0 ft) west of the
centerline of a tree at the southern most end of a grassy field at the
intersection of Welsh Road and Jenkins Road, and 21.9 m (71.9 ft) NNE corner of
a cannon conrete pad, driven to a depth of 8.2 m (27 ft) and set into concrete
kick block.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page 11 of 13

                                                                                
Station ID: 8635027                         PUBLICATION DATE:  07/11/2018
Name:       DAHLGREN NAVAL PROVING GROUND                     
            VA
NOAA Chart: 12287                           Latitude:   38° 19.2' N (  38.31975)
USGS Quad:  DAHLGREN                        Longitude:  77°  2.2' W ( -77.03661)


                            T I D A L   D A T U M S 


Tidal datums at DAHLGREN NAVAL PROVING GROUND based on:

     LENGTH OF SERIES:      1 YEAR
     TIME PERIOD:           May 2016 - April 2017
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8635750 LEWISETTA, POTOMAC RIVER


Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:

     HIGHEST OBSERVED WATER LEVEL (03/07/2018)         =  1.368
     MEAN HIGHER HIGH WATER                     MHHW   =  0.577
     MEAN HIGH WATER                            MHW    =  0.525
     North American Vertical Datum              NAVD88 =  0.312
     MEAN SEA LEVEL                             MSL    =  0.285
     MEAN TIDE LEVEL                            MTL    =  0.285
     MEAN LOW WATER                             MLW    =  0.044
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (01/05/2018)         = -0.980

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     HERO 1987                                   5.068    4.543
     5027 B 2015                                 3.496    2.971
     5027 A 2015                                 1.659    1.134
     STA 42 NO 1 1970                            1.751    1.226
     STATION DOCK 1974                           1.773    1.248
     NO 2 1944                                   4.474    3.949
     U 460 1971                                  4.568    4.043
     4 RESET 2015                                4.787    4.262
     RADAR 3 1974                                4.702    4.177
     RADAR 2 1974                                4.663    4.138
     V 460 1971                                  2.587    2.062
     5027 C 2016                                 3.368    2.843
     5027 D 2017                                 4.619    4.094


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page 12 of 13

                                                                                
Station ID: 8635027                         PUBLICATION DATE:  07/11/2018
Name:       DAHLGREN NAVAL PROVING GROUND                     
            VA
NOAA Chart: 12287                           Latitude:   38° 19.2' N (  38.31975)
USGS Quad:  DAHLGREN                        Longitude:  77°  2.2' W ( -77.03661)


Foot Notes:

Bench marks 5027 D 2017, RADAR 2 1974 and RADAR 3 1974 are based on one
differential leveling connection and do not meet the quality control standards
of the NOS. Therefore, caution should be used when deriving elevations for these
marks.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page 13 of 13

                                                                                
Station ID: 8635027                         PUBLICATION DATE:  07/11/2018
Name:       DAHLGREN NAVAL PROVING GROUND                     
            VA
NOAA Chart: 12287                           Latitude:   38° 19.2' N (  38.31975)
USGS Quad:  DAHLGREN                        Longitude:  77°  2.2' W ( -77.03661)


                             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 8635027 Dahlgren, VA

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