Anyone visit the Westchester County (aka Robert Kenngott and Valhalla) CBL lately?
I've never been there and would appreciate some info on the line.
It looks from Google Earth like the zero point may be obstructed by new construction.
I usually use the "unsafe" Morris County, NJ baseline but it has been getting progressively overgrown by hedges.
If anyone has been to Morris lately I'd appreciate info on that line as well.
Thanks.
Scott - here is the official data:
Us Department of Commerce – NOAA Calibration Base Line Data Quad: N410733
NOS - National Geodetic Survey Base Line Designation: Robert Kenngott CBL New York
Silver Spring MD 20910 Project Accession Number: 15483 Westchester County
Nearest Town: Valhalla
List Of Adjusted Distances ( 7/ 5/2005)
ADJ. DIST.(M) ADJ. DIST.(M) STD.
FROM STA.TION ELEV.(M) TO STA.TION ELEV.(M) HORIZONTAL MARK - MARK ERROR(MM)
STA. 00 146.860 STA. 710 132.430 710.0039 710.1505 .1
STA. 00 146.860 STA. 860 131.388 860.0161 860.1552 .1
STA. 00 146.860 STA. 1190 129.255 1190.0175 1190.1477 .1
STA. 710 132.430 STA. 860 131.388 150.0121 150.0157 .1
STA. 710 132.430 STA. 1190 129.255 480.0133 480.0238 .1
STA. 860 131.388 STA. 1190 129.255 330.0012 330.0081 .1
A tape calibration monument was set at 100 foot point of the baseline. The reduced mark to mark
distance is 100.00 ft. (not measured this survey)
Description Of Robert Kenngott Base Line ***NOTE: Formerly "Valhalla CBL"
Year Measured: 1979
Year Re-measured: 2003
Chief Of Party: LPB
The Base Line is located 2.6 km (1.6 mi) northeast of Elmsford, 1.9 km (1.2 mi) southwest of Valhalla, and 1.9 km (1.2 mi) west of North White Plains, along the western edge of the Westchester Community College Campus.
The Base Line is a north-south line with the 0 meter point at the north end. The CBL consists of the 0, 710, 860, and 1190 meter points with a 100-foot tape calibration section located between the 0 and 710 meter points, and 30.48 meters north of the 710 meter point. The reduced mark to mark distance is 100.00 ft.
All marks are Westchester-Putnam Association of Professional Land Surveyors disks set in the top of 25 cm (10 in) diameter concrete posts. Each point has two reference marks, one of which is set on line and the other at 90 degrees to the line. All of the disks are Stamped with their base line designation and the year 1978.
To reach the base line from the intersection of State Highways 100, 100a, and 100C, north of Elmsford, go east on Highway 100 for 0.6 km (0.4 mi) to the Westchester Community College Campus entrance on the right. Turn right and go south on the paved road for 0.6 km (0.4 mi) to a paved road left. Turn left and go east for 0.2 km (0.1 mi), uphill, and through two parking areas to a road right. Turn right and bear left around the circle for 30 meters to a paved drive right, marked "Service Vehicles Only". Turn right and proceed downhill on this drive for 80 meters to a paved drive right, just before reaching the Science Building. Turn right and go uphill on the paved drive for 30 meters to a clearing on the right, at the crest of the hill. Park here and proceed on foot, bearing left and downhill on a path which passes a greenhouse and goes into the woods to the 0 meter point.
To reach the other CBL points, go back to the main entrance drive. Turn left and go south, then east for 1.4 km (0.9 mi) to an intersection. Turn right and go south for 0.2 km (0.1 mi) to a jogging track and the 710 meter point on the right. Continue ahead for 0.3 km (0.2 mi) to a clearing and the 860 meter point on the right, at the south end of the jogging track. Turn left and go south (through a locked gate) on the track road for 0.3 km (0.2 mi) to the 1190 meter point at the end of the road.
The 0 meter point is Stamped "00 Sta. 1978" and projects 10 cm (4 in) above the surface of the ground. It is 26.0 m (85.3 ft) southwest of the southwest corner of a greenhouse, and 5.1 m (16.7 ft) northwest of a 61 cm (24 in) beech tree.
The 710 meter point is Stamped "710 Sta. 1978" and is located just south of the inside of the northeast corner of the jogging track, flush with the ground. It is 44.3 m (145.5 ft) southeast of a concrete water fountain, and 14.9 m (48.9 ft) west of a narrow gateway in a chain link fence.
The 860 meter point is Stamped "860 Sta. 1978" and is located 13.7 m (44.9 ft) north of the north edge of the road, 5.0 m (16.4 ft) east of RM 2 860, 3.7 m (12.1 ft) south of a narrow gateway in a chain link fence, 2.9 m (9.5 ft) north of the north edge of a boulder, and flush with the ground. The 1190 meter point is flush with the ground, Stamped "1190 Sta. 1978", and is located at the end of a track road, 5.0 m (16.4ft) south of rm 1 1190 1978, and on the north side of a four-trunk tree.
The 100 foot taping Station is Stamped "RM 1 710 1978" and is located 30.48 m (100 ft) north of the 710 meter point, 5.1 m (16.7 ft) southwest of a chain link fence, 4.0 m (13.1 ft) northeast of the northeast edge of the jogging track, and is flush with the ground.
USER NOTES: CBL users should take care in plumbing over all points. Elevations are for CBL use only. Use extreme caution on the road near the 860 elevations are for CBL use only. Use extreme caution on the road near the 860 meter point. Traffic has limited sight due to the road curvature!!! Also, take care not to confuse the 1190 meter point with the RM 1 which has three, steel witness posts.
This base line was established in conjunction with the Westchester-Putnam Association of Professional Land Surveyors and the Westchester Community College. For further information contact Mr. Alan Gassman, 225 Orchard Street, White Plains, New York 10604, telephone 914-288-9063.
Revised 6/21/05
As of our November Westchester-Putnam meeting, the new construction is close to the line, but it should still be OK, by dumb luck; the surveyor doing the site survey to plan for the new work apparently did not know the baseline was there....
I have contacted Al, our "CBL guy" to verify that is still the case and will let you know when I hear from him.
Ken
Scott - Al's reply:
Regarding the Kenngott CBL, I know for certain that the sight is open between station 710 to station 860. I presume that it is actually open all the way from station 710 to station 1190.
Do not attempt to drive a vehicle down to station 1190 as that area is muddy and you will get stuck, even with 4 wheel drive. Do not confuse station 1190 with the reference marker northerly of station 1190.
The construction mentioned is northerly of station 710 and should not interfere with any sight to station 0, as this construction is predominantly westerly of the sight line.
It has been a year or two since I checked station 0. There was a tree down near the station but it could still be set upon. That station is behind the college science building. I do not know if any tree limbs have grown out to block the sight line from station 0 to the other stations. There would not be any construction in the vicinity of station 0 as it is on a wooded hillside.
I am the surveyor for the Westchester County Department of Public Works and can assist any surveyors in finding the stations if needed.
Al
Contact:
Acg2@westchestergov.com
The following is the link to the NY CBL webpage
