Skip to Content

Details for Benchmark: KX1250

N 40° 24.983 W 079° 54.733 (NAD 83)

Altitude: 750.49

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

Location:
In ALLEGHENY county, PA View Original Datasheet
Designation:
3066
Marker Type:
survey disk
Setting:
massive structures
Stability:
Probably hold position/elevation well.

Must Read!

Benchmarks may be on private property or in dangerous locations. Obey local laws. By using the services on Geocaching.com you agree to this disclaimer.

The signal bridge and its base have been removed.

I don't think this one is there anymore. It might be underneath the dirt that is covering some of the mentioned bridge setting, but we dug for awhile and couldnt find it based on the description. The signal bridge has been modified (read: removed) since 1966.

Documented History (by the NGS)

Unknown by PA6600 (MONUMENTED)
01/01/1966 by NGS (GOOD)
DESCRIBED BY NATIONAL GEODETIC SURVEY 1966 2 MI W FROM RANKIN. ABOUT 2.0 MILES WEST ALONG THE BALTIMORE AND OHIO RAILROAD FROM THE STATION AT RANKIN, ABOUT 0.5 MILE NORTHEAST OF HOMESTEAD BRIDGE OVER BOTH THE TRACK AND THE MONONGAHELA RIVER AT MILEPOST NO. 321-12, SET IN THE TOP OF THE NORTHEAST END OF THE CONCRETE BASE AT THE NORTHWEST END OF SIGNAL BRIDGE NO. 321-12, 7 FEET NORTHWEST OF THE NORTHWEST RAIL OF THE NORTHWEST ONE OF 4 TRACKS, 1/2 FOOT SOUTHWEST OF THE NORTHEAST END OF THE BASE AND 1 1/2 FEET BELOW LEVEL OF TRACK.

Control Text

  • 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.

Advertising with Us

Return to the Top of the Page