Benchmarks...

February 1, 2008

(5) 1.18 In. Copper Survey Mark

(10) 2 In. Dome-Top Aluminum Benchmarks W/ Custom Stamping

(NOTE: These didn't have the "triangle with center dot" that I requested, so they are being exchanged)

6 Pc. Chisel & Punch Set

36 Pc. 1/4 In. Stamping Set

Copper Marks: $11.50

Aluminum Marks: $21.90

Chisel & Punch Set: $10.00

Stamping Set: $6.90

--------------------------------

TOTAL = $50.30

February 1, 2008

I still need to get out and buy a quart of Drylok Fast Plug (benchmark cement) and some sort of drill bits(?) to make holes for monumentation in rock outcrops.

February 1, 2008

Does this mean you will be making personalized Benchmarks for your Geocaching/Benchmarking friends??

:drama:

February 1, 2008

Does this mean you will be making personalized Benchmarks for your Geocaching/Benchmarking friends??

:drama: Well, has anyone placed a 1K memorial cache for you yet? Or planning for a 2K cache? I'm thinking FTF gift..

February 1, 2008

Does this mean you will be making personalized Benchmarks for your Geocaching/Benchmarking friends??

Well, has anyone placed a 1K memorial cache for you yet? Or planning for a 2K cache? I'm thinking FTF gift..

I am not exactly dead.... :drama:

but, to answer your question NO. :drama:

I am going to hit 2k tomorrow sometime....North Raleigh area, if you want to join us let me know and I will send you the details, leaving my place about (9:15 am plan for the entire day, I'm driving). you know how to reach me, but I would not recommend the cell. I have about 29 on the list including a couple of puzzle caches that have been solved and one that we would love to put you to work on....(think Mother in Peril, but far easier).

February 1, 2008

my grandfather was a surveyor i have about 100 of the dome top ones plus oem copper ones also lol

February 1, 2008

my grandfather was a surveyor i have about 100 of the dome top ones plus oem copper ones also lol

:drama: ..100 benchmarks?! And I'm stuck here with only 15 :drama: Kidding, of course. I don't know if I'd be able to find a good place to monument 100 marks. What kind are they - do you happen to have a picture of them? If they were your grandfather's I'd imagine they would be of better quality than mine.

1.2k · February 2, 2008

These are very interesting. Let me know when you place one. I want to see how it turns out. (Are you gonna practice stamping on scrap metal, first?)

-Paul-

February 2, 2008

These are very interesting. Let me know when you place one. I want to see how it turns out. (Are you gonna practice stamping on scrap metal, first?)

-Paul-

I'll post here, as well as on my website (see sig line), once I get one of them set. I tried the metal stamps on a penny.. didn't work too well. I'm going to find something alluminum that I could practice on more. I have a spot in mind for one mark, but I first need to decide on a way to make a decent hole in a rock outcrop - drill, chisel, ext.

February 2, 2008

...but I first need to decide on a way to make a decent hole in a rock outcrop - drill, chisel, ext.

..here's the thread from a few years ago when Spoo tried it: see link

February 3, 2008

...but I first need to decide on a way to make a decent hole in a rock outcrop - drill, chisel, ext.

..here's the thread from a few years ago when Spoo tried it: see link

I've seen that thread, but the stems on my disks are significantly smaller than his. Do you know where could I find a hole chisel like that, but smaller diameter?

1.2k · February 3, 2008

Just curious, what is the "Chisel & Punch Set" used for?

February 3, 2008

... Do you know where could I find a hole chisel like that, but smaller diameter?

..I've seen a drill bit @ Home Depot that is made for drilling thru concrete, etc. - I wonder if 1 (or 2) might work?

February 3, 2008

Just curious, what is the "Chisel & Punch Set" used for?

Well I don't really need all of those, just one chisel. I plan to use them to make a slight depression around the hole in an outcrop, like Spoo did here.

February 3, 2008

... Do you know where could I find a hole chisel like that, but smaller diameter?

..I've seen a drill bit @ Home Depot that is made for drilling thru concrete, etc. - I wonder if 1 (or 2) might work?

I actually picked up a Star Drill today for $6.00 It will be perfect for the alluminum disks:

1.2k · February 3, 2008

Just curious, what is the "Chisel & Punch Set" used for?

Well I don't really need all of those, just one chisel. I plan to use them to make a slight depression around the hole in an outcrop, like Spoo did here.

Aah! Cool, okay.

Nice job. Looks like fun tools. :blink:

February 4, 2008

A star drill like shown above is the old standby for drilling a hole in bedrock or a large concrete structure, see 1936 photo at: http://www.flickr.com/photos/12262796@N06/2242780234/. Hint, rotate the drill slightly after each strike. More recently NGS has used powered (gas, then electric) rock hammers.

For a cross-sectional view of a survey disk in bedrock see: http://www.flickr.com/photos/12262796@N06/2242760608/

GeorgeL

NGS

P.S. Its always better to stamp the disk before setting it in the drill hole.

February 4, 2008

I've always assumed that a wedge was placed in the drill hole so that it would spread the notched bottom of the stem for a snug fit. Is that true, or is the notch on the stem just there to keep the disk from rotating once it has been cemented in?

2.7k · February 4, 2008

A star drill will take you about 3 hours of pounding to get a hole deep enough, depending of course on the material you're drilling. :blink: I have used them.

I'd suggest the masonry power drill bit route if you can find one of a large enough diameter and you have a battery powered drill. You might even want to get a couple sizes of drill bits, and drill with the smaller one first.

February 4, 2008

A star drill like shown above is the old standby for drilling a hole in bedrock or a large concrete structure, see 1936 photo at: http://www.flickr.com/photos/12262796@N06/2242780234/. Hint, rotate the drill slightly after each strike. More recently NGS has used powered (gas, then electric) rock hammers.

For a cross-sectional view of a survey disk in bedrock see: http://www.flickr.com/photos/12262796@N06/2242760608/

GeorgeL

NGS

P.S. Its always better to stamp the disk before setting it in the drill hole.

Thanks for your help! Will a regular hammer work with the star drill, or should a bigger and heavier mallet be used? I'll be sure to rotate the drill and pre-stamp the disk like you explained.

February 4, 2008

A star drill will take you about 3 hours of pounding to get a hole deep enough, depending of course on the material you're drilling. I have used them.

I'd suggest the masonry power drill bit route if you can find one of a large enough diameter and you have a battery powered drill. You might even want to get a couple sizes of drill bits, and drill with the smaller one first.

That's what I was going to do, but I'd have to purchase a battery-powered drill and concrete bits. I didn't want to spend that kind of money, so decided to go with a star drill and do the extra work.

1.6k · February 4, 2008

Looking at the cross section picture I was wondering if anyone knows the radius of curvature of the standard domed disks.

I noticed an interesting thing when I was looking at error sources in leveling. If you precisely center a rod on a domed disk, and then rock it to some small error in plumbing the rod, a sight at the height on the rod equal to the disk radius of curvature will have error cancellation. Did they pick the radius with some typical height of sight in mind?

February 5, 2008

For a cross-sectional view of a survey disk in bedrock see: http://www.flickr.com/photos/12262796@N06/2242760608/

GeorgeL

NGS

..slightly off-topic, but one of the other pics in the collection shows a "tri-station W/ air hole" - what is the purpose of the air hole? I notice they don't really show up until the 60's & the thinner disk style..

1.4k · February 5, 2008

For a cross-sectional view of a survey disk in bedrock see: http://www.flickr.com/photos/12262796@N06/2242760608/

Cool photos. I especially like the ones of the survey camps from the 1930s.

Patty

February 5, 2008

Thanks for your help! Will a regular hammer work with the star drill, or should a bigger and heavier mallet be used? I'll be sure to rotate the drill and pre-stamp the disk like you explained.

I use a 2 lb. sledge and can drill a 1/2" x 3" hole in Vermont granite in under an hour.

February 5, 2008

Thanks for your help! Will a regular hammer work with the star drill, or should a bigger and heavier mallet be used? I'll be sure to rotate the drill and pre-stamp the disk like you explained.

I use a 2 lb. sledge and can drill a 1/2" x 3" hole in Vermont granite in under an hour.

Ok, thanks. Looks like I'll have to get out and find a bigger hammer!

February 5, 2008

You'll want something like this to hit the star bit:

http://www.harborfreight.com/cpi/ctaf/disp...temnumber=46821

I like a 3 pounder but I haven't used a star bit since we got a good hammer drill.

1.6k · February 5, 2008

Wear safety glasses! An old friend of mine lost vision in one eye from a chip.

February 5, 2008

You'll want something like this to hit the star bit:

http://www.harborfreight.com/cpi/ctaf/disp...temnumber=46821

I like a 3 pounder but I haven't used a star bit since we got a good hammer drill.

Took your advice, I just got back from buying one of these:

$8.50

And some of this:

$6.00

Wear safety glasses! An old friend of mine lost vision in one eye from a chip.

I'll be sure to do that!

Edited February 5, 2008 by wwflover13

February 6, 2008

You need to work quickly with that fast plug. I mixed some in a bucket once and it hardened before I could get to the top of a ladder. The stirring stick was still in it and it look like a big concrete popsicle

February 6, 2008

You need to work quickly with that fast plug. I mixed some in a bucket once and it hardened before I could get to the top of a ladder. The stirring stick was still in it and it look like a big concrete popsicle

Ok, I'll keep that in mind when I'm ready to set one.

What procedure do you think I use with it? I was thinking I'd drill the hole, pour in some cement, and then push the disk into it.. but is there a better way? If that's how it should be done, how much cement should I put in the hole?

February 6, 2008

Here is a photo of a disk stem with a wedge: http://www.flickr.com/photos/12262796@N06/2242978434/ . This is a scan from a 1913 USC&GS publication and was one of our oldest styles of disks, note the flat top. The wedges were not used in later versions. For a photo of 5 stem types used by the USC&GS over the years see: http://www.flickr.com/photos/12262796@N06/2242186427/.

According to an old disk specification diagram that I have, the spherical radius of curvature of the top of the disk is about 5 inches. The curved top soon replaced the flat top so that a point near the center of the disk would always be the highest point and not some point along the edge (if the disk was not set perfectly level). In third-order leveling, rocking a level rod is a method to help ensure that the rod is straight up. The rod-person stands behind the rod, facing the level instrument in the distance and gently rocks the rod fore and aft a small amount. The instrument observer observes the slightly changing readings and always takes the minimum (lowest) reading, because that’s when the rod is straight up (in line with local gravity). In higher accuracy leveling, a level bubble is placed alongside the rod to ensure that it is straight up. If anyone has a photo of one of these old USC&GS disks with the flat top I’d love to see it (I don’t have one in my collection and I’ve never seen one!).

For instructions on how to set a disk in bedrock see: http://www.ngs.noaa.gov/ContractingOpportu...xt_V13B_new.pdf

Pages 389 – 393.

For a short period of time, USC&GS brass disks were manufactured with air holes slightly offset from the center. The theory was that this would allow air to escape from behind the disk as the disk was being pushed into the wet concrete, helping ensure a strong fit. It was soon realized that this was a bad idea. Surveyors, thinking that the hole was the mark, often centered their survey equipment over the air hole instead of the center mark on the disk. Use of disks with air holes started about 1952 and at least one of these disks was set as late as 1969. For a photo, see: http://www.flickr.com/photos/12262796@N06/2181230234/ . Note, the solution to the air gap is to place some wet concrete on the back of the disk before it is pushed into the wet concrete in the hole, see Step 5 in the instructions referenced above.

GeorgeL

NGS

February 6, 2008

Thanks!

February 6, 2008

If anyone has a photo of one of these old USC&GS disks with the flat top I’d love to see it (I don’t have one in my collection and I’ve never seen one!).
GeorgeL

NGS

Hi George

Here's one: LW1577

It's on the front step of the old Marine Biological Laboratory building in Woods Hole, Mass.

Feel free to snarf the photo.

Edited February 6, 2008 by Papa-Bear-NYC

February 7, 2008

Another one in Oregon. QE0867 Datasheet Geocac page. If you can use the photo feel free to do so.

February 7, 2008

Another one in Oregon. QE0867 Datasheet Geocac page. If you can use the photo feel free to do so.

I believe George was looking for a USC&GS flat style disk. Although the one you show is older (1903) it's a USGS disk and it looks rounded.

BTW: that has to be close to when the USGS started using disks. Pretty nice find.

Edited February 7, 2008 by Papa-Bear-NYC

2.7k · February 7, 2008

and it looks to be an aluminum one.

February 7, 2008

Papa Bear, Thanks for the great photo, that is exactly what I was looking for! My spreadsheet (from much research of old USC&GS documents) indicates that this style of BM was first used about 1908. USC&GS started using disks with the curved top about 1921.

GeorgeL

NGS

February 7, 2008

I received the corrected benchmarks today:

They actually made me 11 instead of the 10 I had originally ordered, for the inconvenience.

February 7, 2008

Another one in Oregon. QE0867 Datasheet Geocac page. If you can use the photo feel free to do so.

I believe George was looking for a USC&GS flat style disk. Although the one you show is older (1903) it's a USGS disk and it looks rounded.

BTW: that has to be close to when the USGS started using disks. Pretty nice find.

HMM. You may be right... but I thought it was perfectly flat. You can see by the date in the photo that I found it in 2004 so my memory may be flat instead of the mark. Then I also overlooked the fact that he was interested in a USC&GS and not a USGS disk.

Either way I will now I will have to go out and check the silly thing. :unsure:

Good thing it is only about a 1/2 mile from my office. :unsure:

Edit to add that I have found a different & flat US&GS & State Survey Marker in Idaho. RZ0823

Back on topic: wwflover13, the benchmarks that you have are great. Do you recall if there was a minimum on the amount you could order or could you order just one or two at a time?

Edited February 7, 2008 by TheBeanTeam

February 7, 2008

...My spreadsheet (from much research of old USC&GS documents) indicates that this style of BM was first used about 1908. USC&GS started using disks with the curved top about 1921.

GeorgeL

NGS

...sorry to hijack the thread again, but I've also been curious as to the manufacturers of some of the old disks 20's - 70's - have you collected that info as well?

PS - thanks for the info on the air holes

wwflover13 - how many are you going to set around the house? I have a corner lot - If I did this, I would love to monument at ground level at edges of the property (neighbors willing) & of course beside the mailbox :unsure: ..maybe one on the front porch. ...and the back porch ....OK - yeah, I could set all 11!

February 7, 2008

...

Back on topic: wwflover13, the benchmarks that you have are great. Do you recall if there was a minimum on the amount you could order or could you order just one or two at a time?

For the copper ones there was a minimum purchase of 5, and for the alluminum ones it was a minimum of 10. Stamping was free.

...

wwflover13 - how many are you going to set around the house? I have a corner lot - If I did this, I would love to monument at ground level at edges of the property (neighbors willing) & of course beside the mailbox ..maybe one on the front porch. ...and the back porch ....OK - yeah, I could set all 11!

I may set a copper one in our driveway while the cement is still wet. We're having a new garage built, and concrete for the driveway should be poured any day now - they were actually supposed to come today and do that...

February 8, 2008

As a surveyor by avocation, I have to admit that having people setting a lot of their own monuments around makes me a little nervous. Particularly the ones marked 'Survey Point'. Of if someone were to mark an elevation on one of the benchmark discs.

Please exercise some caution. Surveyor's as well as land owners sometimes mistake things that look like a survey monument as a corner of some property, and that can lead to a lot of unforseen mischief in future years.

- jerry wahl

February 8, 2008

As a surveyor by avocation, I have to admit that having people setting a lot of their own monuments around makes me a little nervous. Particularly the ones marked 'Survey Point'. Of if someone were to mark an elevation on one of the benchmark discs.

Please exercise some caution. Surveyor's as well as land owners sometimes mistake things that look like a survey monument as a corner of some property, and that can lead to a lot of unforseen mischief in future years.

- jerry wahl

..my thought was to have them set by a surveyor (I need to have this done as my local gov't has torn out the only remaining corner points which were RR spikes in the middle of the road) instead of an iron pin & marked "boundary" or similar. I see those 1 1/2" flat disks (plugs) w/ a cross pre embedded in a small concrete 'monument' used as R.O.W. / boundaries around here.. (still want a full sized disk for the rock in my yard, tho!)

February 8, 2008

RE FLAT DISKS - The USC&GS AND STATE SURVEY disks were used during the 1930’s and I believe that all of them had convex (curved) tops. There are two sizes of these disks, standard and a little smaller at 3.0”. To the best of my knowledge, the USC&GS flat topped disks were only used from about 1908 to about 1921.

RE DISK MANUFACTURERS - The only information I have is a copy of an order from 1985. It was to the D. Ballauf Manufacturing Co., Inc. of Washington D.C. and was to make NATIONAL OCEAN SERVICE disks (These NOS disks are used for NOAA tidal and hydrographic surveys still today).

GeorgeL

NGS

1.5k · February 8, 2008

RE: USC & GS and STATE SURVEY

I put together a little info on these WPA set marks.

HISTORY OF THE LOCAL CONTROL SURVEYS PROJECT

1.6k · February 8, 2008

Regarding disc manufacturers:

One that I know of (and has been around a long time), and I think has done discs for NGS and other survey related US Gov't agencies is Berntsen.

For those of you who may not know, the Lady in Charge at Bertsen (Rhonda) is also "one of us" and enjoys benchmark hunting and geocaching. She also started a nice web magazine Caching Now, where you can read interesting articles about both pusuits. They are always looking for new articles, and could really use one from a knowledgable Surveyor on CORS and OPUS (NGS Surveyor??). A "Contact Us" link is on the website if you are interested.

[Full disclosure: OK, I do write for them a little, and have done some Disney Benchmarking with Rhonda, so I'm not really a disinterested party!]

February 8, 2008

Regarding disc manufacturers:

One that I know of (and has been around a long time), and I think has done discs for NGS and other survey related US Gov't agencies is Berntsen.

Berntsen (a great company!) was founded in the early 70's I believe - I believe they do (did) the modern (NGS) ones - I'm most curious about the older USC&GS ones.. .I'm sure some of the companies may not be in busines any longer..

February 8, 2008

RE: Going back and checking the disk mentioned in this post.

Well my memory wasn't flat at all. The disk is flat without a bit of curvature to it.

It is a nice disk and my oldest & favorite recovery to date.

RE FLAT DISKS - The USC&GS AND STATE SURVEY disks were used during the 1930’s and I believe that all of them had convex (curved) tops. There are two sizes of these disks, standard and a little smaller at 3.0”. To the best of my knowledge, the USC&GS flat topped disks were only used from about 1908 to about 1921.

GeorgeL

NGS

Rats, now I need to go out and check that one again too.....Only this one isn't 1/2 mile it more like a 1,000 miles round trip. :rolleyes: It will have to wait until the holidays. I am relatively certain this disc was as flat as the first one but that small percentage of "maybe not" will make me check it again if I have the chance.

As a surveyor by avocation, I have to admit that having people setting a lot of their own monuments around makes me a little nervous. Particularly the ones marked 'Survey Point'.

- jerry wahl

Good point. While vanity marks probably will not cause confusion in most cases, it is good to consider the possibility.

RE: USC & GS and STATE SURVEY

I put together a little info on these WPA set marks.

HISTORY OF THE LOCAL CONTROL SURVEYS PROJECT

Great history. Thanks for the link.

wwflover13,

Did you get the chance to place a mark in you drive? Photos? Thanks for the wonderful topic.

Edited February 8, 2008 by TheBeanTeam

February 9, 2008

RE DISK MANUFACTURERS - The only information I have is a copy of an order from 1985. It was to the D. Ballauf Manufacturing Co., Inc. of Washington D.C. and was to make NATIONAL OCEAN SERVICE disks (These NOS disks are used for NOAA tidal and hydrographic surveys still today).

GeorgeL

NGS

A quick check of the Historical Washington Post Archives shows the D. Ballauf Manufacturing

Company being headquartered at 619 H. Street and 621 H. Street N.W., Washington, D.C.

"The company manufactures currency counting machine and precision machinery for

oceanography and missiles" - Washington Post, Sept 6, 1960.

Ballauf Manufacturing opened their doors for business about 1928 or 1930, as near as I can tell.

~ Mitch ~

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