My dad was a surveyor. As such, i grew up surveying. There were times of boredom, while others worked. I played, while on the job. I prospected, looked for gold, caught bugs, made roasted caterpillars etc.
One day, on a job way down in some river bottoms, sw of Murfreesboro, dad was gone with the client, for a long time. I had hacked out and set the traverse points. One fell in a creek bottom. I wound up digging a hole some 5" deep, setting a nail, and, having extra time, piled small stones all around it.
About 20 yrs later, someone had destroyed the section corner, near this traverse pnt. I was able to reset the sec cor, from this traverse pt.
Since then, I have learned to pack the ground, in a circle, 6" around, making a depression. This packs the soil. Makes it harder to disturb the ctrl point.
Also, leaving the nail top 1" subsurface, makes it less prone to being destroyed.
If possible place an handful of gravel over the top. It hides it. Protects the flagging from sunlight. If you set them well, they become useful, later, in ways that are often not readily apparent today.
If someone moves your monument, you can readily solve the problem.
Pack em hard, set em deep. Ya never know....
N
In order for that to work you need both stable points and a recoverable database of ties. A great many surveyors have neither. Good for you.
I like to set control points much more substantial than nails. 1/2" x 24" iron rods with a red plastic cap is what I use. If you set just a couple of those on each of your jobs (the base station and a check point, perhaps) Big Help will be restoring corners from them one day.
Yep. Been doing just what Mark said for 25 years and still find and use them.
Back when I was just starting out, the company that I worked for did much the same. All traverse points were 60d nails that were punched through shiners and tied with a streamer of flagging. When we wet them, we dug a hole a couple of tenths deep and packed the bottom with the handle of our machete. After the nail was set, two references were set with 20d nails in trees. Distances and bearings were pulled and recorded in the field book. Once while working in a creek bottom we came back and tied into a traverse that was run over ten years prior and closed out. To my surprise we were well over 1:10,000 which for the area we were in was way tighter than needed. Of course, like Mark stated, we had a really good system of recording what jobs were in which book and what area of the state each book was used. We also had a top notch IT guy who was in the process of building a database of every job we had done since Cad drafting had become the norm.
Since then I have tried a few times to institute similar programs but a lot of field crews these days don't carry a compass. All they know is how to push the buttons on the magic box and get the satellites to tell them what to do. I feel very fortunate to have started out working under such capable surveyors. I learned much from them and their equally capable crew chiefs. It is a shame that more in our profession don't take the time to mentor and instill good work practices.
For most of my gps base points, i set a log home spike. It's about 10-12" long. Generally, it's buried, and packed 1-2 inches deep, and painted on top.
Another thing i usually do, is set up extra control stations, at random locations, that have good sky view, and are suitable as such. Since all my work is now tied in with spc, via DPOS (Javad's OPUS), i can return to any job, and stake autonamously, This typically gets me within 3'. Close enough to find control, via Mr Shonstedt.
But, back to the topic at hand, and especially in pre-Javad era, i would often set offset points, to d/d int ties into the woods. I got in the habit of dropping a concrete nail down the hole, made by the prism pole, or gps pole. This tended to secure locations, for my benefit, later.
Also, I conscript alum cans, smash them, drive a big spike through them, paint them, and set my control 1-2" deep.
The idea is to get beyond the 3g syndrome.
Get job
Get done
Get on to the next.
I'm building my own personal private cadastre. Not my personal private catastrophe!
I like what others have said above... 1/2" rebar, with caps, that say CONTROL point, or such like.
Time is like gold. Take a little time now, save alot of time later.
Nate
One thing I've noticed over the years with the switch to more GNSS and less conventional is I generally leave far fewer traverse spikes and Mag nails behind so I've been trying to make a conscious effort to keep my eyes open for good safe places to leave more of these behind. A quick compass and tape measurement in the field notes to a utility pole or pedestal with an address makes finding these little gems years later a piece of cake. Having just a couple of control points in an area seems to me to be leaving to much to chance that they'll be wiped out sooner or later.
About fifteen years ago I was doing a survey that involved a land swap to move an Alcohol Rehab facility and the neighbors were less than thrilled. I noticed while out doing the GPS control work I was being shadowed by a fella who refused to approach and was watching from a distance trying to be inconspicuous. Struck me as odd at the time as this was a rural area. When I went out to set all the boundary monuments with a total station occupying that control, my back sight checks were all out 5-10'. I was pulling my hair out trying to figure out how things got so gobbed up. Then I looked closely at the point I was set up on. They were flush with the ground. I always sink them down a tenth or two. That SOB that had been shadowing me went in after I left and moved all my control points 5-15' and reset them hoping to trip me up.
Another big advantage of sinking them down a couple of inches, is that if the wind blows debris, that it will get trapped in the little bowl, and obscure the ctrl point. If you place a handful of dirt, it will jump start the process.
As time moves along, our methods change. No more long traverses. Just short ties, or none. So, add a few control points as you work. Also, bridges often have an aluminum survey station added to one corner. Great place to shoot, for control.
N
I'm very curious about the ultimate fate of the roasted caterpillars.........................
I'm with Mark, I like to set several substantial control points on site. I just followed behind another surveyor on a road project. His control was 16p nails set in soft ground. Hard to find and even harder to get back onto the control within the tolerance I like to see for road and rail design projects.
somewhat off topic but just occupied a pk I set in 87 two days ago, while not real old it still was cool knowing I had set it.
Jim
I set skinny rebar for anything that I think is worth keeping. They're pretty easy to find. Just look for the hammer that got left behind with it.
Nate The Surveyor, post: 418582, member: 291 wrote: Pack em hard, set em deep. Ya never know....
BTW - in my area there is generally a pretty deep organic layer at surface and that stuff just doesn't stay packed. Hence the need for a longer rod.
