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.


Popular Posts