I've been working for a couple of days at the fairly straight-forward task of locating the original common line of a couple of lots in a 1940-vintage subdivision. I would not have thought it was Scientific Rocketry, but the problem has apparently completely defeated a couple of surveyors recently.
The records of the City Engineer indicate that a couple of weeks after the subdivision was laid out by a local engineer/surveyor, the City surveyors went out to stake the newly dedicated street for grading and gravel base. The City surveyor made notes in his field book that indicated he had found markers in place as shown on the plat. The ground had a minor cross slope and the downhill side of the street was plainly filled a bit. That's the way it looks on the ground today.
So now, seventy years later, the task is to find the corner monuments that were established in 1940 as noted on the subdivision plat and found in place prior to street grading.
Do we:
a) Use a laser scanner for any monuments that are sticking up above grade on the downhill side of the street?
b) Use dowsing rods to try to figure out where the corners are, sticking a wire pin flag in the ground when the rods cross and locating the pin flag to study the situation in GIS back at the office?
c) Ask people walking around in the neighborhood where they think the corners might be?
or
d) Use a super-duper high-tech tool called a "shovel" to dig down through about 12" to 24" of fill to the level of what appears to have been natural ground and see whether there is a 1940-looking iron pipe in place?
Tough call, I know.
> d) Use a super-duper high-tech tool called a "shovel" to dig down through about 12" to 24" of fill to the level of what appears to have been natural ground and see whether there is a 1940-looking iron pipe in place?
>
> Tough call, I know.
Did Steve Jobs come up with the "shovel"? I think I saw an ad for that during the Super Bowl. Totally awesome.
I would use an "iShovel."
Please don't operate your iShovel while driving, you could cause an accident that way.
Can we use a Schonstedt also?
> I would use an "iShovel."
>
> Please don't operate your iShovel while driving, you could cause an accident that way.
I think you are onto something Dave. Perhaps the TX boys were using the iShovel with AT&T, and lacked proper coverage.
Can we use a Schonstedt also?
Yes, but not at the same time. One tends to interfere with the other 🙂
> Did Steve Jobs come up with the "shovel"? I think I saw an ad for that during the Super Bowl. Totally awesome.
You're probably thinking of the Shovel app for the iPhone. The bugs haven't entirely been worked out yet, but it's promising.
> Can we use a Schonstedt also?
Well, since the City Engineer's staff also staked the curb and gutter after street grading and the record of that work showed the markers were still in place, why not just split the 1940's-vintage curbs and use those approximate centerlines to calculate the search positions? You might be off by a couple of tenths, though, so don't dig a hole smaller than 0.5 ft. in diameter, just to be safe.
Ok! I say
d) Use a super-duper high-tech tool called a "shovel" to dig down through about 12" to 24" of fill to the level of what appears to have been natural ground and see whether there is a 1940-looking iron pipe in place?
and the use of a metal detector.
Oh! At 24 inches deep can I use a post hole digger as an aid? 😛
> and the use of a metal detector.
Well, to use the metal detector effectively, you will have to pull various ferrous survey markers that surveyors have driven somewhat recently, imagining them to mark the corners originally marked in 1940. We all know that those are very important evidence of where the 1940's-vintage pipe was originally placed, don't we? Okay, some of us don't think that and that's fine.
The first rod and cap marker that my personal pair of vise-grip pliers locked onto was a 12" long #4 bar with a split plastic cap on it. We tied it as we found it and, afterwards, as we left it, to demonstrate that it remained in essentially the same spot. Even with it out of the way, though, I wasn't getting much of a signal from the pipe we found 24 inches down. We had to use the "shovel" to excavate a bit before the magnetic signature really made some noise.
Yes, those entrenching tools, though rightfully frowned upon by the magazines showcasing the "with it, a go-go" type of expensive and sexy tools recommended by advertisers, can actually uncover some curious objects.
I hear that some of these objects actually represent original boundary corners, whatever that means.
Some eccentric geomaticists (formerly called land surveyors) will actually use these objects as evidence of the original locations of boundary lines, whatever that means.
I say give that a try as an academic experiment Kent. Some ancient geomatic engineers used these to re-establish "boundary lines" (read that in an old book) and were actually upheld by courts, even though they disagreed with the county GIS cadastral layer. (Luddites!)
It could be fun as an exercise in "creative anachronism", but of course you should hold to the GIS lines, or else just find two of those iron pipe thingies and set the rest by deed numbers. Always remember, the deed numbers hold over some old-timers faulty measurements.
Good luck with your experiment. Should be fun.
> Good luck with your experiment. Should be fun.
Easily the most fun was showing the landowners where the 1940's-vintage iron pipe was at the bottom of the hole. You don't have to say anything about the 12-inch rebars with plastic caps driven at grade nearby. YOU don't have to, that is. I'm afraid I did.
I explained that it was Adam Smith's invisible hand of the marketplace at work whereby unsuspecting landowners in search of a really great bargain price would unerringly be connected with the least qualified individuals to provide the needed service.
> I explained that it was Adam Smith's invisible hand of the marketplace at work whereby unsuspecting landowners in search of a really great bargain price would unerringly be connected with the least qualified individuals to provide the needed service.
>
I am going to steal this
"YOU don't have to, that is. I'm afraid I did."
Now there you go again, Kent.
It appears you are going to hold those old, inaccurate stobs (deep in a hole, to boot!) over new, modern irons based on the two correct irons that you found first, and not applying the deed numbers to correct those old inaccurate irons.
I should not have to tell you this, but the deed numbers rule over the old surveyor's faulty attempt at setting the corners. I don't care if Grandpa used those old irons to stake his improvements, them old irons were not set akkerut, and are worthless today.
Modern, akkerut surveyor's are not bound by the ignorant musteaks of the past.
> > I explained that it was Adam Smith's invisible hand of the marketplace at work whereby unsuspecting landowners in search of a really great bargain price would unerringly be connected with the least qualified individuals to provide the needed service.
> >
> I am going to steal this
It has a certain ring to it, doesn't it? How else to explain the efficiency by which simple stuff like this gets messed up with such startling regularity?
> It appears you are going to hold those old, inaccurate stobs (deep in a hole, to boot!) over new, modern irons based on the two correct irons that you found first, and not applying the deed numbers to correct those old inaccurate irons.
Actually, one of the surveyors responsible for the recent cadastral misadventure is a magician as nearly as I can tell. His map indicates that he found exactly one rebar stake (of modern origin, it is assumed) that he used as the basis for reconstructing the boundaries of one of the lots. Considering that the entire subdivision has a systematic bias of more than a degree off true, and considering that said recent surveyor doesn't give even the slightest hint how he went about determining the bearing basis of his reconstruction, I have to think that he is an extremely skillful magician. I certainly couldn't tell you how that trick was done.
Speaking of magician
A guy asked me one time, what he should use a a basis of bearing. On this particular job he set his total station up in the middle of a lot and shot everything from one setup. I guess he resected the total station position, but not all his tied corners fit so well.
amazing
Kent,
A common problem in these parts. Surveyors who don't seem to want to take the time to dig.....either in the area records research or in the ground.
Sounds like you did good, Kent.
But to be fair, you make it seem as if the first 12" long #4 rebar you found was pretty close, also. It sounds like you had to remove it and then dig down from that spot to get better sound on the original. How far off was this guy?
Stephen
I guess you could call it a Cat D1 elbow grease powered excavator 😉