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Details for Benchmark: AU2759

N 29° 52.267 W 090° 04.167 (NAD 83)

Altitude: 57

Coordinates may not be exact. Altitude is VERTCON and location is ADJUSTED. (more info)

Location:
In JEFFERSON county, LA View Original Datasheet
Designation:
WENN
Marker Type:
survey disk
Setting:
setting not listed - see description
Stability:

Reference Points

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I came across this benchmark while inspecting the Lapalco Bridge today. The disk is in good condition and at the location described.

[last edit: 8/20/2003 5:47:00 AM PST]

[Photos:]
photoLapalco Bridge Benchmark

Documented History (by the NGS)

01/01/1972 by LADH (MONUMENTED)
DESCRIBED BY LA DEPT OF HIGHWAYS 1972 (RT) THE STATION IS LOCATED 5 MILES EAST OF WESTWEGO, 5 MILES SOUTH OF DOWNTOWN NEW ORLEANS AND 3 MILES SOUTHWEST OF GRETNA, IN THE SOUTHEAST QUARTER OF SECTION 44, T14S, R24E, AND ON THE PROPERTY OWNED BY THE LOUISIANA DEPARTMENT OF HIGHWAYS. TO REACH THE STATION FROM THE HARVEY TUNNEL ON THE WEST BANK EXPRESSWAY, DRIVE SOUTHEAST ALONG STATE HIGHWAY 3017 FOR 1.7 MILES TO THE LAPALCO BOULEVARD HARVEY CANAL BRIDGE. THE STATION IS SET ON THE SOUTHEAST SECTION OF THE BRIDGE NEAR THE BRIDGE TENDERS HOUSE. TO REACH THE AZIMUTH MARK FROM THE STATION GO SOUTHEAST ALONG STATE HIGHWAY 3017 FOR 1.10 MILES. THE MARK IS SET ON THE LEFT AND EAST OF THE HIGHWAY NEAR A LOUISIANA POWER AND LIGHT SUB-STATION. THE STATION MARK IS A STANDARD LOUISIANA DEPARTMENT OF HIGHWAYS AND U. S. COAST AND GEODETIC SURVEY DISK SET IN A DRILL HOLE IN THE CONCRETE DECK OF THE LAPALCO BOULEVARD BRIDGE FLUSH WITH THE CONCRETE DECK. IT IS STAMPED WENN 1972. IT IS 45 FEET SOUTH OF THE CENTER OF THE LAPALCO BOULEVARD BRIDGE, 19 FEET SOUTHEAST OF THE NORTHEAST CORNER OF THE BRIDGE TENDERS HOUSE, 18 FEET SOUTH OF THE SOUTHEAST CORNER OF THE BRIDGE TENDERS HOUSE, AND 3 FEET NORTHWEST OF A CONCRETE RAIL ON THE BRIDGE. REFERENCE MARK 1 IS A STANDARD LOUISIANA DEPARTMENT OF HIGHWAYS AND U. S. COAST AND GEODETIC SURVEY DISK SET IN A DRILL HOLE IN THE CONCRETE DECK ON THE LAPALCO BOULEVARD BRIDGE FLUSH WITH THE CONCRETE DECK. IT IS STAMPED WENN R. M. 1 1972. IT IS 33 FEET SOUTH OF THE CENTER OF THE LAPALCO BRIDGE, 18 FEET WEST OF THE WEST END OF A METAL GUARD RAIL, 7 FEET NORTH OF THE NORTHEAST CORNER OF THE BRIDGE TENDERS HOUSE, AND 2 FEET SOUTH OF THE CURB ON THE ROADWAY. THE AZIMUTH MARK IS A STANDARD LOUISIANA DEPARTMENT OF HIGHWAYS AND U. S. COAST AND GEODETIC SURVEY DISK SET IN THE TOP OF A 12 INCH CYLINDRICAL CONCRETE MONUMENT THIS IS FLUSH WITH THE GROUND. IT IS STAMPED WENN AZ. MK. 1972. IT IS 52 FEET EAST OF THE CENTER OF PETERS ROAD, 22 FEET SOUTHWEST OF THE CENTER OF A METAL GATE (ENTRANCE TO LOUISIANA POWER AND LIGHT SUB STATION), 14 FEET SOUTH OF THE CENTER OF A SHELL DRIVE, 8 FEET EAST NORTHEAST OF A METAL WITNESS POST AND SIGN, 7 FEET NORTHEAST OF A POWER POLE. HEIGHT OF LIGHT ABOVE STATION MARK 1 METERS.

Control Text

  • The horizontal coordinates were established by classical geodetic methods and adjusted by the National Geodetic Survey in January 1993.
  • The NAVD 88 height was computed by applying the VERTCON shift value to the NGVD 29 height (displayed under SUPERSEDED SURVEY CONTROL.)
  • The Laplace correction was computed from DEFLEC99 derived deflections.
  • The geoid height was determined by GEOID99.

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