California Surveyors Forums

Hello.

Generally what was the size of brass disks used for triangulation set by USCGS prior to 1940 ? 3.5"/4"?

Thanks.

I don't have them at my fingertips but there are a lot of publications out there that should provide the details you seek.

Attached photo shows the disc in tenths of a foot (3 1/2") and centimeters.

Measuring and recording the size of disks along with a complete description was inculcated to me very early on as a member of a survey crew.

It is a part of keeping good field notes and documenting the survey so the next surveyor can be sure he is looking at the same evidence you had.

Steve Martin:

I was trained in a similar fashion.

From the "there ought to be law" bin:

Business and Professions Code 8764

"The record of survey shall show the applicable provisions of the following consistent with the purpose of the survey:

(a) All monuments found, set, reset, replaced, or removed, describing their kind, size, and location, and giving other data relating thereto."

Simply stated, anything decribed less than "kind, size, and location..." is negligence.

For example, "Fd. Spk." i.e. found spike is insufficient because there are no less than five types of spikes. Tags? Steel, brass, aluminum. Pipe size? Inside or outside diameter. Again, anything less is negligence.

DWoolley

Steve Martin wrote:Measuring and recording the size of disks along with a complete description was inculcated to me very early on as a member of a survey crew.

It is a part of keeping good field notes and documenting the survey so the next surveyor can be sure he is looking at the same evidence you had.

Me too Steve. It really isn't that hard.

in my wonder years I was taught to make pencil rubbings in the field book.

I'm glad Dawooly isn't a claims officer for an E&O underwriter. Every mistake, omission or error would be an act of negligence for which insurance doesn't cover.

I suppose reporting a survey to the nearest 1" in bearing and hundredth of foot in distance is also negligence even if our rural lot survey wasn't actually performed to 1/1,000,000 relative accuracy.

sheesh.

William Magee:

Technically, a violation of a statute is negligence per se. However, the defenseless will raise the question of damages as a defense. The damages, as they relate to the violations of the Business and Professions Code, are assessed as a violation of public policy.

I recommend avoiding potential allegations of negligence by the misreporting of bearing accuracy to one second (1") and distances to the hundredth of a foot (0.01') by placing an accuracy statement on the work product. How else would the public know the 20 kilometer baseline RTN map is not accurate to 0.01'?

DWoolley

Thanks. Looks like 3.5" I forgot to measure the disk when we were out there. Took a picture of it though.

I always loved the govt notes stating "set standard (insert Govt Agency Name) monument"

The last 3 CL mons I opened were ~2ft down in a well mon, try making a rubbing of that, hard enough to clean it enough to read it.