Newbie Question

[troutlvr]

I'm new at geocaching and at Benchmark hunting. Tonight I went out to find benchmark AA5147. I have to think I found it, since it was marked with a witness post on an orange stick, with the words "SURVEY MARKER" on it. Also, my GPS read a distance that varied between 7-2 feet. However, the description of its location also included, "The disk is located 77.59 ft N04W of the center of a fire hydrant ..." and some more references to light poles, power poles and a catch basin. What does the direction N04W mean? From the marker in the ground, the hydrant was nearly due north.

Second, the marker is supposed to be an aluminum survey disk, set in top of a poured-in-place concrete monument. The monument was there, with a metal post in the center of it, cut off flush with the top, but no aluminum survey disk.

Can I assume I found it? I took pictures, which I'd be glad to post.

Thanks for your help.

Dan

[+Kewaneh & Shark]

quote:

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Originally posted by troutlvr:

"The disk is located 77.59 ft N04W of the center of a fire hydrant ..." ...What does the direction N04W mean? From the marker in the ground, the hydrant was nearly due north.

Second, the marker is supposed to be an aluminum survey disk, set in top of a poured-in-place concrete monument. The monument was there, with a metal post in the center of it, cut off flush with the top, but no aluminum survey disk.

Can I assume I found it? I took pictures, which I'd be glad to post.

Thanks for your help.

Dan

---

 

To answer the first question, I'd have to guess that N04W would mean North 04d 00' 00" West, since you say that the hydrant in nearly due north of the cap. I would ask though, is the hydrant about 77-78 feet away?

 

As far as the second question: if the concrete monument is there, and the historical calls all point to the monument, I would assume you found it. The aluminum cap has probably been knocked off or removed.

 

I would go ahead and post it as a find, and then watch it to see if anyone else finds it. If they find the same, (or something different) you'll know.

 

Keep on Caching!

- Kewaneh

[+raouljan]

"For the quad system, the important thing to keep in mind is that no angle can ever have a number larger than 90 degrees. Going more than 90 degrees around the circle puts you into another quadrant, where the angle will be less than 90 degrees.

 

For example, if you wanted to describe the idea of "NE" using any compass, you would say "think of the direction North, then rotate 45 degrees to the East" If you were using a degree compass, the shorthand notation for the idea of "NE" would be written "45d", since you always start at North, and think of turning in the direction of East. Using a quad compass, the shorthand would contain a little more information: "N 45d E".

 

Now think of describing the idea of "SE". Using a degree compass, you would say "135d", meaning "think of North, then rotate 135 degrees in the direction going East". This won't work for a quad compass, since there aren't any numbers larger than 90. So, on a quad compass SE would be "S 45d E", meaning "think of South, then go back 45 degrees to the East."

 

Simply put, a degree compass always has N in mind for a starting point, and all bearings are in increments of degrees turning in the direction from N to E. But with a quad compass, measurements can start with either a N or S designation, and the direction can increment either toward the E or the W.

 

For examples, quad notation for SW would be "S 45d W", while NW would be "N 45d W". A bearing of "172d" on a degree compass would be "S 8d E" on a quad compass. A bearing of "327d" on a degree compass would be "N 33d W" on a quad compass. Got it?"

 

From

http://www.kooters.com/sezbrntn.html

 

It's amazing where this stuff takes you, no?

[survey tech]

N04W is a direction, in the form known as a bearing. It means 4 degrees west of north. Similarly, N04E would mean 4 degrees east of north, S04E = 4 degrees east of south, and S04W = 4 degrees west of south. A bearing can be any number of degrees up to 90. It appears AA5147 has been decapitated and what you have found is the remaining part of the base.

[survey tech]

Oops, Y'all beat me to it, great minds think alike.

[+raouljan]

survey tech

 

At least we kept away from "strike and dip"

[troutlvr]

Many thanks for all of you who helped answer my question. To answer Kewaneh's question, yes, the hydrant was approximately 77-78 feet away (actually about 27 paces). But I would have described the hydrant as being located 77' N04W of the disk, rather than the description of the benchmark which says the disk is 77' N04W of the hydrant. I did use my compass, and the hydrant was just a bit west of due north of the monument.

Having struggled for years through many legal descriptions on deeds that never fully made sense to me, thanks again for the help on the quadrant system!

 

Dan

[ArtMan]

quote:

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Second, the marker is supposed to be an aluminum survey disk, set in top of a poured-in-place concrete monument. The monument was there, with a metal post in the center of it, cut off flush with the top, but no aluminum survey disk. Can I assume I found it?

---

 

I had a similar instance with HV2224 , where I found just a metal stalk in concrete, with the actual disk missing.

 

Taking a conservative, literalist approach, I logged it as 'not found' since, it seemed to me, the disk was no longer there, so how could I find it. I also reported it to NGS as 'not found.' Black Dog Trackers logged his visit just as a note.

 

But since we operate on the honor system here, and there is no Benchmarking Police Force, you must be guided by your own sense of what is right.

[+Kewaneh & Shark]

In taking a conservative, literalist approach as ArtMan describes, if the benchmark is only described as a brass cap and you cant find it, you can't log it as a find. But what if you find an aluminum cap with the same markings that match all the calls in the location where the brass cap is to be? Taking that conservative, literalist approach, you can't log it as you found aluminum, not brass. Also, keep in mind that a benchmark is not always a disk. They can be a concrete or stone monument, or even a pile of rocks.

 

In the instance of the cap (or lack of cap) you were seeking, the benchmark was more than just the cap. A concrete post was also described, and the "metal post in the center of it, cut off flush with the top" (the cap stem) indicates that the cap was there. If the historical ties fit the concrete post, you found it.

 

As a surveyor, if I was searching this monument for a particular job, I would declare it as found, but damaged. If the cap was used only for vertical measurements - and not all are - it's pretty useless now. If it was a monument for horizontal & vertical purposes, the metal post may still be able to be used for horizontal measurements, but not used to define an elevation.

 

Much of a surveyor's responsibility is to make a judgement on the evidence found, whether the evidence is data found on recorded maps, measurements (which don't always match), and whether the historical evidence of a monument shows that the monument (or a portion of it) still exists, and can be used. You found a portion of the monument - the concrete base and cap stem (metal post) - and the history points to it. Remember, many times, there is more to a benchmark than a cap or disk. All of the evidence needs to be looked at and evaluated. A competent surveyor who is guided by his or her own sense of what is right would probably call it a find.

 

However, in taking ArtMan's literalist approach, if you are looking strictly for a cap, I would agree, you didn't find it.

 

Keep on Caching!

- Kewaneh

[+Black Dog Trackers]

Actually, for the hobby of benchmark hunting, I think that finding the shank of a sheared off benchmark in the proper (near) lat-lon location and especially physical situation could be counted as a find. In the case of HV2224, my using a note rather than logging it as a find is random - I could have done it eiither way. There's approximately a zero chance that it is something other than the benchmark's location, given the situation.

 

Since we're just hobbyists and not professional surveyors, it is of no significant problem if a find is logged in error. On the other hand, I'd be very reluctant to report a disk as missing to NGS without both finding the missing shank in place and seeing the circular evidence of a benchmark disk at the listed location. In the case of HV2224, this was the case so ArtMan's note to NGS is proper.

 

I have been to a location where within 25 feet of each other, there were 3 benchmark disks placed by 3 different agencies, two of which don't have any data on the geocaching site's database (one is state and the other is county). So, there's always the chance that a broken shank is from someone else's benchmark! Reporting such as a find would be an error.