Surveyor placed this PK nail/washer is asphalt street over where he got a reading of something below. I removed the nail/washer and found the street control monument.
Date of PK Nail set: June 30, 1997.
Not much left of the nail after only 13 years. The washer fared very well.
You must be in a salt zone.... and, what would or could make it last longer?
Down here, I'd expect that it would last 50 yrs... unless of course it was destroyed by some mechanical action.
And.... what do you SEE with MAG HUBS. (Those new PK's that are magnetized) How well do they fare in the salt?
Thanks for your informative posts.
Keep them coming. I don't always reply to them, I enjoy them.
Nate
That's interesting. Just this morning I found two 1" iron pipes with a wall thickness of about 3/16" which I believe were set in 1949. Their form was good but the slightest touch and they crumbled into a pile of iron oxide. Someone had previously set a spike in the center of one and I took the liberty of setting a standard rod and cap in the center of the other. Very curious since I would have expected these to be in good shape in this arid, sandy loam. I am wondering if the material was inferior or the local soil conditions were bad.
So ... how much did the position of the nail and the position of the monument differ by?
There is one still in place at a section corner not far from here. It was set over 20 years ago in the middle of a county road intersection. It is sort of wedged into a crack between two native limestones. The county can only keep an inch or two of gravel over the bedrock until a heavy rain sweeps it clean.
I did not set it. But, I have used it more than once.
Four hundreths, I'm guessing.
"Hundreths"?
How about hundredths?
J.P. Is there any chance the surveyor who set that actually dug up the street control, filled the hole back in and set the PK above it in an effort to help a fellow surveyor out?
I have followed a surveyor that used to do that, but with buried concrete monuments. I used to curse him in the field when I dug up these little 6inch tall rebar and caps until I saw one of his survey maps that called out he meant to set that above the concrete below to aid future retracements. I still don't like them, since I end up digging for the real monument below, but at least I know his heart was in the right place.
Andy