Data Sheet for the Canton Viaduct
Bench Mark
DATABASE: Sybase
PROGRAM: Datasheet
VERSION: 6.55
RETRIEVAL DATE: 11/5/2001
DESIGNATION: F 31
PID (Permanent Identifier): MY0489
STATE/COUNTY: MA/NORFOLK
USGS QUADRANGLE: 116 (NORWOOD)
*CURRENT SURVEY CONTROL
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* NAD 83 (1986) 42 09 28 (N) 071 09 14 (W) SCALED
* NAVD 88 22.820 (meters) 74.87 (feet) ADJUSTED
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GEOID HEIGHT: -28.35 (meters) GEOID99
DYNAMIC HT: 22.814 (meters) 74.85 (feet) COMP
MODELED GRAV:980,341.9 (mgal) NAVD 88
(North American Vertical Datum of 1988)
VERT ORDER: FIRST CLASS II
The horizontal coordinates were scaled from a topographic map and have an estimated accuracy of
+/- 6 seconds.
The orthometric height was determined by differential leveling and adjusted by the National Geodetic Survey
in June 1991.
The geoid height was determined by GEOID99.
The dynamic height is computed by dividing the NAVD 88 geopotential number by the normal gravity value
computed on the Geodetic Reference System of 1980 (GRS 80) ellipsoid at 45 degrees latitude
(g = 980.6199 gals.).
The modeled gravity was interpolated from observed gravity values.
North East Units Estimated Accuracy
SPC MA M 878,650 228,600 MT (+/- 180 meters Scaled)
SUPERSEDED SURVEY CONTROL
NGVD29 (National Geodetic Vertical Datum of 1929) 23.060 (m) 75.66 (f) ADJ UNCH 1 2
Superseded values are not recommended for survey control. NGS no longer adjusts projects to the
NAD 27 or NGVD 29 datums. See file dsdata.txt to determine how the superseded data were derived.
MARKER: DB: BENCH MARK DISK
SETTING: 36 = PIER
STAMPING: F 31 1965
STABILITY: B = PROBABLY HOLD POSITION/ELEVATION WELL
HISTORY Date Condition Report By
1965 MONUMENTED CGS
STATION DESCRIPTION
Described by COAST AND GEODETIC SURVEY 1965 at Canton
At Canton, along Neponset Street at the Viaduct where the street crosses under the New York, New Haven and Hartford Railroad about 0.3 mile South of the Canton Junction Station, set vertically in the West face of the concrete portion of the center pier of the stone Viaduct, 10 1/2 feet South of the center line of the North lane of Neponset Street, 17 1/2 feet North of the center line of the South lane and about 1 ½ feet above the level of the North lane of Neponset Street.
For more information about the terms used above, visit the Digital Survey Data sheet or read Geodesy For The Layman.