I have been working on an urban survey close to the Ohio river and of course the descriptions and plats go way back, no surveys of record and general urban mayhem. I located all the curb and every building corner within several blocks to try and nail down the lot lines and used many mag nails for traverse points. There was a snow in mid-project and the plows cleaned up all of the debris along the gutters along with the snow. At traverse point #1 yesterday, I noticed not one but four other Mag nails besides mine within a four foot radius. I was not the first surveyor there.
The sad part about this is that there is nothing in two dozen deeds and associated plats that even have a bearing on them, this survey being only one block away from the courthouse where these records are kept. There are obviously several surveys in someone's desk drawer and that is the usual repository for our final work on a retracement survey. The right-of-ways are not actually the width that is stated on the plat, and the plat is a "copied and restored" plat from an older one. I did find a pin and cap from a well respected surveyor, got with the surveyor and he showed me what he had done. Our state society has been the best thing that has happened for getting surveyors together. Our state recording rules is at the other end of the spectrum but we are working on it.
Traverse Point Farm
In an urban area I assume that it has been surveyed before and look for mags. Why put one in when an existing one works OK. That being said sometimes you have a limited window from the front street to rear yard and that other mag or PK may have been OK without that addition, the new or higher vegetation. I do not like to highlight such points in urban areas so they are left bare. That means that I have set up occasionally on the wrong point, but since I always record the setup backsight distances that error gets found early. I make a point of locating such found points as ties and for the possibility on a return trip that "My Point" may already be occupied by a car. Having alternate points has saved time in the past, more than the original location time. On occasion a PK I thought was someone's traverse point turns out to be a property corner, which always helps. When I GPS I almost always use 3 points as a minimum. Those extra mags and PK's come in handy as the GPS can run while I locate features from other points. I have on occasion moved my GPS to a second point 5' away just because I can. The only thing that causes concern is when I find an old rusty PK on my third trip to the site. What else did I miss?
Paul in PA
Traverse Point Farm
I missed the existing Mags when I set up my traverse because of gutter debris. They are nowhere near a corner. On this same survey, I did find and use an existing Mag in a concrete island right out in the middle of the road. Dangerous, busy place but excellent view. I used my S-6 and along with cones, wrapped a safety vest around the tripod for increased visibility.
Traverse Point Farm
I never use mag nails for traversing, particularly when located in an area where it could be confused with a boundary corner or reference point. 60d nails work great in dirt and concrete nails for asphalt.
set an identifiable traverse point you can recognize as your own. (A nail through a marked disk maybe with a point number on it too?) anything you can identify. You set a pk nail or some other generic mark, and what happens if there are several in the same location when you come back; or maybe there is only one pk nail but you can't figure out what is wrong until you realize it isn't the same one you set. (That happened to me once. I was working off old notes and thought I found the pk nail they set back in the day, but distances etc. didn't seem to work.) You might also use someone else's traverse point if you find it instead of setting a different one right next to it, or even use a property pin if it happens to be in a good enough spot to see what you need to see.
Traverse Point Farm
I have known surveyors to use both concrete nails and 60d nails as property corner markers. There are still some fans of PKs, I suppose just because they are cheaper.
> set an identifiable traverse point you can recognize as your own. (A nail through a marked disk maybe with a point number on it too?) anything you can identify.
Yes, that's the system I've used for over twenty years and I find it works great. I place 3/8-inch spikes with stamped 2-inch aluminum or brass washers in drill holes in existing concrete in urban settings and find that the tops of curbs are excellent for durability and ease of recovery.
The actual station mark is the punchmark on the head of the spike in the photo. It was set about twelve years before the photo was taken.
Photo showing vicinity of mark in detail above.
:good:
I see you installed a huge placque next to it (to the left in the picture). That certainly makes it identifiable.....talk about monumentation! 😉
> Our state recording rules is at the other end of the spectrum but we are working on it.
While I have reservations on the mechanics of how it will be accomplished, I am mostly in favor - and have semi-converted a few in the Purchase Chapter.
There has been no update in the BOD meetings on this in a while. Is there still action being taken on it?
