U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 14 Station ID: 8635027 PUBLICATION DATE: 05/04/2020 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. Bench marks are located in Dahlgren VA, on the Naval Surface Warfare Center. CAC card is required to access the bench marks. 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 14 Station ID: 8635027 PUBLICATION DATE: 05/04/2020 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#: BBGP62 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 14 Station ID: 8635027 PUBLICATION DATE: 05/04/2020 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 14 Station ID: 8635027 PUBLICATION DATE: 05/04/2020 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: USACE 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 14 Station ID: 8635027 PUBLICATION DATE: 05/04/2020 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 14 Station ID: 8635027 PUBLICATION DATE: 05/04/2020 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 14 Station ID: 8635027 PUBLICATION DATE: 05/04/2020 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 14 Station ID: 8635027 PUBLICATION DATE: 05/04/2020 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#: HV5382 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 14 Station ID: 8635027 PUBLICATION DATE: 05/04/2020 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: Metal Rod VM#: 22306 AGENCY: NGS IDB PID#: HV2956 SETTING CLASSIFICATION: Driven into the gorund OPUS PID#: HV2956 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: NOS 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 14 Station ID: 8635027 PUBLICATION DATE: 05/04/2020 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#: BBGP63 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 14 Station ID: 8635027 PUBLICATION DATE: 05/04/2020 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: AAFR 1990 DESIGNATION: AAFR MONUMENTATION: Metal Rod VM#: 22948 AGENCY: National Geodetic Survey (NGS) IDB PID#: HV8763 SETTING CLASSIFICATION: Stainles steel rod OPUS PID: LATITUDE: 38° 19.4' N ( 38.32317) LONGITUDE: 77° 1.4' W ( -77.02353) The bench mark is a stainless steel rod in a sleeve 26.1 m (85.63 ft) west of a metal sign post, 5.8 m (19.03 ft) SSW from the center of the paved road, and 0.7 m (2.30 ft) NNE from a fiberglass witness post. The datum point is a punch mark on the top center of a stainless steel rod recessed 8 cm below ground, driven to a depth of 11.0 m (36.09 ft) in a sleeve extending to a depth of 1.0 m, and encased in a PBC pipe covered by a standard NGS logo cap flush with the ground.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 12 of 14 Station ID: 8635027 PUBLICATION DATE: 05/04/2020 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: 3 YEARS TIME PERIOD: March 2016 - February 2019 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 (09/10/2018) = 1.530 MEAN HIGHER HIGH WATER MHHW = 0.584 MEAN HIGH WATER MHW = 0.532 North American Vertical Datum NAVD88 = 0.318 MEAN TIDE LEVEL MTL = 0.289 MEAN SEA LEVEL MSL = 0.288 MEAN LOW WATER MLW = 0.045 MEAN LOWER LOW WATER MLLW = 0.000 LOWEST OBSERVED WATER LEVEL (01/05/2018) = -0.976 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW HERO 1987 5.072 4.540 5027 B 2015 3.499 2.967 5027 A 2015 1.661 1.129 STA 42 NO 1 1970 1.756 1.224 STATION DOCK 1974 1.777 1.245 NO 2 1944 4.479 3.947 U 460 1971 4.574 4.042 4 RESET 2015 4.791 4.259 RADAR 3 1974 4.705 4.173 RADAR 2 1974 4.668 4.136 V 460 1971 2.591 2.059 5027 C 2016 3.372 2.840 5027 D 2017 4.622 4.090 AAFR 1990 4.267 3.735
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 13 of 14 Station ID: 8635027 PUBLICATION DATE: 05/04/2020 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 mark AAFR 1990 is based on one differential leveling connection and does not meet the quality control standards of the NOS. Therefore, caution should be used when deriving elevations for this mark.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 14 of 14 Station ID: 8635027 PUBLICATION DATE: 05/04/2020 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.