2006-12-08

GU1670 - An Important Mark, in a different way than most

Until recently, I was employed by a Civil & Survey engineering firm that was the contract engineer for the City of Coalinga, California. As the 'field guy' for the acting Engineer, I was fairly familiar with the local benchmark network. A few years ago, I was given the task to map a portion of State Highways 33/198, about 1.4 miles long, through the town of Coalinga. It was an infrastructure project for curb, gutter, sidewalk (etc.) improvements. During the project, I tied into multiple city benchmarks and other various benchmarks within the project area. Four of the 'others' are in the NGS database - AH5203, GU1673, GU1670, & GU4200. AH5203 - COALINGA RESET, at the north end of the project, was destroyed by the DOT while building a new bridge. (According the one of their surveyors, it is to be reset, again, by them.) For obvious reasons, it was not tied into. GU1673 - J156, is the main benchmark for all the vertical control in town, and was adjacent to the roadway and well within the project area. GU4200 - INTERSECTION, is a street centerline monument in a well, also well within the project area. GU1670 - G944, at the south end of the project was not located, and consequently, not tied into.

GU1670 was a standard brass disk set in a round concrete post. It was set on the side of the road, across from the old fire station behind a curb. It was reported as 'found' in 1984 and then 'not found' in 1985, and for all intents and purposes, it should have been there as no improvements have been done in the area in some time. I couldn't find it as part of the project, but the benchmark hunter in me kept looking. I went back multiple times over the next few years, kicking dirt and looking in the logical and not so logical places, with no luck. This site probably had the most visits by me for any mark I've looked for without finding anything.

As I mentioned at the beginning of this thread, my employment has recently changed. My present employer has a collection of surveying equipment and artifacts on display throughout the office. Last week I was speaking with one of the other employees (relatively new to the survey industry) about the purpose of benchmarks and their markings. I was using one of my employer's display benchmarks to show him what I was talking about. During our discussion, the designation of the mark caught my attention; 'G944 1958'. The '944' was familiar - there was a '944' series of marks around the Coalinga area, set in the late 50's. I routinely used 'Y944', north of Coalinga, as a calibration point for my survey-grade GPS. I searched the NGS database for G944 in the State of California and only got one hit - it was GU1670. After nearly four years of searching, I found the brass disk I'd been looking for, more than 75 miles away.

Now, for the rest of the story....

Flash back to 1987. I was studying Architecture at a local college and got hired by a Civil & Survey engineering firm as a draftsman. This was before computers and CAD; all the plans and maps were drawn by hand with pen & ink. I was hired because of my drawing ability and penmanship, not because I knew anything about surveying or engineering. I honestly didn't know what either a surveyor or civil engineer was, let alone what they did. As I drafted the maps and plans, I would ask about things I saw or drew onto the plans. Over time I found that I was more interested in the surveying portion of my job over the civil engineering portion, and the architecture I was studying for that matter. (That interest in surveying is still there, nearly 20 years later. The architecture is all but forgotten.) I routinely asked the chief surveyor and the lead crew chief questions. I remember posing the question 'what is a benchmark?' to the lead crew chief. He explained it to me using an old brass disk he had on his desk that he used as a paperweight.

Now, flash forward to last week. My new employers are the same chief surveyor and the lead crew chief I worked with back in the 80's. About seven years ago, they cleaned out their desks and went out on their own. Now I'm back with them. GU1670 was in their small collection. When I told them that I'd been recently looking for that mark, one of them, the old lead crew chief said 'Really? I used that thing as a paperweight for years!'

GU1670 "G944" 1958


GU1670 sitting in a collection of old survey equipment and artifacts.


GU1670 sitting in a collection of old survey equipment and artifacts.


GU1670 sitting on a plane table with an alidade.


The stem of GU1670.

2006-08-16

Today's Efforts

I benchmark often. Many of my finds are logged on GC.com and occasionally reported to the NGS. I don't log any finds on Waymarking.com. Waymarking.com is often mentioned in the benchmarking forums on GC.com, as the 'survey mark/other benchmark' group owner(s) frequent the benchmark forum.

Today's stats:
- One triangulation station occupied. Reported as found on GC.com. Reported in good condition to NGS.
- One triangulation station found. To be reported as found on GC.com. To be reported as found to NGS.
- One triangulation station (tank) revisited. Reported as found on GC.com. Reported in good condition to NGS.
- One triangulation station (tank) verified as destroyed per prior NGS reports. To be reported as destroyed on GC.com. To be reported as destroyed to NGS.
- One triangulation station with reference mark (each with PID) was searched for. Neither mark found but may still exist. Additional site visit required prior to making a report to either GC.com or NGS.
- One azimuth mark placed on airport runway approach ramp was not searched for.
- One benchmark disk verified destroyed. To be reported as destroyed on GC.com. To be reported as destroyed to NGS.
- One benchmark disk not found and believed destroyed. To be reported as destroyed on GC.com. To be reported as not found to NGS.
- One benchmark disk search was cut short by CalTrans utility workers literally working on the mark location.

No marks logged on Waymarking.com.


Benchmark Hunting Forum
Benchmarks on Waymarking.com
Recovered US Benchmarks on Waymarking.com

2006-07-05

CX1725

County: Dona Ana
State: New Mexico

Mapped Location

PUBLISHED DATA
Lat: N 32° 16.914
Long: W 106° 51.959
Alt: 4191
Designation: 3210635018
Marker Type: survey disk
Setting: setting not listed - see description
Stability: Mark of questionable or unknown stability.

FOUND DATA
Lat: N 32°16.913
Long: W 106°51.959
Alt: 4200


Benchmark detail and the GPSr


View North


View East


View South


View South

2006-06-01

GU1690 - X 237

This mark was ORIGINALLY VISITED on February 14, 2003.

County: FRESNO
State: CALIFORNIA

PUBLISHED DATA
Lat: 36° 11.950
Long: 120° 19.600
Alt: 792.1
Designation: X 237
Marker Type: bench mark disk
Setting: set into the top of a round concrete monument
Stability: May hold, but of type commonly subject to surface motion.

Documented History (by the NGS)
1/1/1935 by CGS (MONUMENTED)

1/1/1958 by NGS (GOOD)
DESCRIBED BY NATIONAL GEODETIC SURVEY 1958 3.8 MI S FROM OILFIELDS. 3.75 MILES SOUTH ALONG STATE HIGHWAYS 33 AND 198 FROM THE Y JUNCTION OF STATE HIGHWAYS 33 AND 198 AT OILFIELDS, IN R15E T20S S10, 0.1 MILE NORTHEAST AND ACROSS THE HIGHWAY FROM A FENCE CORNER AND A BOARD GATE, 45 FEET NORTHWEST OF THE CENTER LINE OF THE HIGHWAY, 2 FEET SOUTHWEST OF A WITNESS POST, ABOUT 1 1/2 FEET HIGHER THAN THE HIGHWAY, AND SET IN THE TOP OF A CONCRETE POST PROJECTING 1/2 FOOT ABOVE THE GROUND.

1/1/1972 by NGS (GOOD)
RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1972 RECOVERED IN GOOD CONDITION.

1/1/1983 by NGS (GOOD)
RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1983 THE MARK IS 0.3 M ABOVE THE HIGHWAY. RECOVERED IN GOOD CONDITION. NEW DESCRIPTION FOLLOWS. 8.2 KM (5.1 MI) NORTH ALONG STATE HIGHWAY 33 FROM THE CITY HALL IN COALINGA, 1.05 KM (0.6 MI) NORTHEAST OF THE Y JUNCTION OF TORNADO AVENUE, 13.7 METERS (45 FT) NORTHWEST OF THE HIGHWAY CENTERLINE, 121.4 METERS (398 FT) NORTHEAST OF THE NORTHEAST GATE POST FOR A PIPE GATE, 27.1 METERS (89 FT) NORTHEAST OF THE NORTHEAST END OF A WOODEN RIGHT OF WAY FENCE BRACE, 0.3 METER (1 FT) NORTHWEST OF THE RIGHT OF WAY FENCE. THE MARK IS 0.3 METERS SW FROM A WITNESS POST.

1/1/1984 by USGS (GOOD)
RECOVERY NOTE BY US GEOLOGICAL SURVEY 1984 RECOVERED IN GOOD CONDITION.

1/1/1985 by NGS (GOOD)
RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1985 RECOVERED IN GOOD CONDITION.

1/1/1987 by NGS (GOOD)
RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1987 RECOVERED IN GOOD CONDITION.

8/28/1991 by NGS (GOOD)
RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1991 7.9 KM (4.90 MI) NORTHERLY ALONG STATE HIGHWAY 33 FROM THE CITY HALL IN COALINGA, 27.1 M (88.9 FT) NORTHEAST OF A BRACED FENCE POST, 13.7 M (44.9 FT) NORTHWEST OF THE CENTERLINE OF THE HIGHWAY, 0.6 M (2.0 FT) ABOVE THE LEVEL OF THE HIGHWAY, 0.4 M (1.3 FT) NORTHWEST OF A FENCE, 0.3 M (1.0 FT) SOUTHWEST OF A WITNESS POST, AND THE MONUMENT PROJECTS 0.2 M (0.7 FT) ABOVE THE GROUND SURFACE.


FOUND DATA
Lat: 36° 11.971
Long: 120° 19.617
Alt: NA

Found it at 17:40, 14 February 2003. Found it as described and in good condition.

WGS84 coordinates found by 2.5 minute occupation with 9 strong satellites and 1 WAAS satellite.

Benchmark detail.


The concrete post setting.


View to the north showing the benchmark, concrete post, and witness post.


Benchmark detail.


View to the northeast showing the benchmark, concrete post, and witness post relative to the highway (SR33/SR198).


View to the north showing the benchmark, concrete post, and witness post.


View to the southwest showing the benchmark, concrete post, and witness post relative to the highway (SR33/SR198).

2006-03-02

GU0169

GU0169
36°45.138'N
120°39.459'W
Elev: 318'

Found USC&GS mark stamped '102.64 L1' at 11:15, 02 March 2006 as described and in good condition. Go to description is adequate.

Published NAD83 coordinates are located about 136 feet south-southeasterly of the found WGS84 coordinates. WGS84 coordinates for the mark found by 4 minute occupation with 10 strong satellites and 2 WAAS satellites.






GU0167

GU0167
36°45.126'N
120°39.443'W
Elev: 321'

Found USC&GS mark stamped '102.64 L' at 11:10, 02 March 2006 as described and in good condition. Go to description is adequate.

Published NAD83 coordinates are located about 65 feet south-southwest of the found WGS84 coordinates. WGS84 coordinates for the mark found by 4 minute occupation with 10 strong satellites and 2 WAAS satellites.











GU0168

GU0168
36°45.088'N
120°39.455'W
Elev: 328'

Found USC&GS mark stamped '102.64 R' at 11:00, 02 March 2006 as described and in good condition. Go to description is adequate.

Published NAD83 coordinates are located about 35 feet southeast of the found WGS84 coordinates. WGS84 coordinates for the mark found by 4.5 minute occupation with 10 strong satellites and 2 WAAS satellites.











GU0146

GU0146
36°44.507'N
120°39.447'W
Elev: 341'

Found USC&GS mark stamped 'H804 RESET' at 10:50, 02 March 2006 as described and in good condition. Go to description is adequate.

Published NAD83 coordinates are located about 525 feet west-northwesterly of the found WGS84 coordinates. WGS84 coordinates for the mark found by 5 minute occupation with 7 strong satellites and 2 WAAS satellites.