Street Monuments - Curve

[PLS7393]

A tract map sets monuments at the BC and EC of a curve, and lots are mathematically shown relative to the centerline/monument line per the street monuments. If you get hired to survey one of the lots within the curve, and your field work encompasses setting up and surveying between found monuments that fit per the tract/parcel map, is a Record of Survey required when you show that surveyed chord line as your Basis of Bearings, or even just showing the monuments with a chord line?

This line is not shown on a filed map, rather is a calculated line. It has been brought to my attention by a County Surveyor that I need to reference Section 8762 (b)5 on my submitted map.

If this is the case, again it appears some County Surveyors want to abolish the Corner Record and only have Record of Surveys filed.
If bidding a job, beware when you estimate a CR.

[Warren Smith]

My sense is that PLSA section 8765(d) applies here, provided you are showing the 'lines' of the curve as shown on the underlying map. Using the chord as a basis of bearings shouldn't invalidate the filing of a CR.

[Derek_9672]

8762 (b)4:

(4) The location, relocation, establishment, reestablishment, or retracement of one or more...lines not shown on any subdivision map, official map, or record of survey, the positions of which are not ascertainable from an inspection of the subdivision map, official map, or record of survey.

All data associated with the curve is ascertainable from an inspection of the subdivision map.

[CBarrett]

Your trouble may be that you are using a chord as basis of bearings, which, I am assuming does not have a direct numerical callout/nominal value on the underlying map. Thus, you are not just talking about any chord line, but your basis of bearings. A line that the next surveyor may rely upon for their work. now this chord status went from someone might use it for B of B to someone HAS used it for BofB. It's hierarchy is now elevated.
Chord was previously not drawn and labeled on the underlying map, now it IS and is used as basis of bearings.

Most map manuals that county surveyors have published state that bearings need to based on a line shown on another map, and preferably between two monuments from that same map.

Personally, I think it may be an overkill to say that since one has to actually calc out a chord directing from the map, rather than just reading the nominal value from the face of the map makes a huge difference... but that's where many apparently choose to 'draw the line' so to speak.

What does that have to do with Corner Records?

[mpallamary]

Use a solar or celestial observation. I did it for years.

[PLS7393]

Use a solar or celestial observation. I did it for years.

Don't forget your compass and chain too! Lol

[PLS7393]

Your trouble may be that you are using a chord as basis of bearings, which, I am assuming does not have a direct numerical callout/nominal value on the underlying map. Thus, you are not just talking about any chord line, but your basis of bearings. A line that the next surveyor may rely upon for their work. now this chord status went from someone might use it for B of B to someone HAS used it for BofB. It's hierarchy is now elevated.
Chord was previously not drawn and labeled on the underlying map, now it IS and is used as basis of bearings.

Most map manuals that county surveyors have published state that bearings need to based on a line shown on another map, and preferably between two monuments from that same map.

I guess your replying without reading previous comments, such as from W. Smith?

[hellsangle]

Why can't it be Radius, delta, length as the basis of bearings per the two employed monuments on the subdivision map?
(As long as one called out the radial bearing on the Corner Record.)

I concur with Warren and Keith.

Besides, who is this record for? The surveying community!

If a County map reviewer is making one file a Record of Survey . . . they are making mountains out of moles hills to pad their budget!

We ALL must consider health/safety/welfare of the public - including the County Surveyor. Filing a Record of Survey may not be in the best interest of the publics welfare. (Unless there are other circumstances which should be illuminated upon a Record of Survey.)

[Edward M Reading]

I have to agree with Warren. I would allow this on a CR in SLO County.

[CBarrett]

Your trouble may be that you are using a chord as basis of bearings, which, I am assuming does not have a direct numerical callout/nominal value on the underlying map. Thus, you are not just talking about any chord line, but your basis of bearings. A line that the next surveyor may rely upon for their work. now this chord status went from someone might use it for B of B to someone HAS used it for BofB. It's hierarchy is now elevated.
Chord was previously not drawn and labeled on the underlying map, now it IS and is used as basis of bearings.

Most map manuals that county surveyors have published state that bearings need to based on a line shown on another map, and preferably between two monuments from that same map.

I guess your replying without reading previous comments, such as from W. Smith?

I was just thinking out loud. Seems like an RS would be an overkill in this case. For some reason when I was reading this earlier I had convinced myself that you are already filing an RS rather than a CR.

Keep in mind that LS act spells out that the decision about RS vs. CR is that of the surveyor of record (if I remember right) rather than the county surveyor (as long as it is in conformance with the PLS act).

It's tough to make that determination for people on the forum without seeing the actual situation.

[Mike Mueller]

A line that the next surveyor may rely upon for their work. now this chord status went from someone might use it for B of B to someone HAS used it for BofB. It's hierarchy is now elevated.
Chord was previously not drawn and labeled on the underlying map, now it IS and is used as basis of bearings.

How is its hierarchy elevated? What hierarchy?

The main criteria I use for picking a BofB is to showcase my resolution in the most elegant fashion.
I have always considered the BofB as just some line on a map that I rotate my work to. It has no direct effect (affect?) on any aspect of my boundary resolution, it only changes how measured and record is documented.

For those that think I am crazy, consider this thought experiment: take any map you have ever done and rotate it to a random bearing between any two random monuments, and the relationship of all your set monuments and found monuments will be the same. The interior angles from found monuments to set monuments will be the same.

Mikey Mueller, PLS
Sonoma County

PS Edited to say if there was no discrepancy and it was only using the chord that wasn't literally labeled on the record map, I would submit a CR to the CS and cite their duty to file it no matter what they might think. Unless there is something more going on and they are trying to lead a horse to water?

[DWoolley]

I am struggling to visualize the re-establishment of a tangent curve without establishing and measuring the back tangent and forward tangent as required to determine the measured delta. This is straight out of Wattles.

Why not use one of the tangents rather than the chord for the basis of bearings? If the tangents are not established by field survey there is a much larger issue. I have seen and accepted the chord used for a basis of bearings.

DWoolley

[PLS7393]

I am struggling to visualize the re-establishment of a tangent curve without establishing and measuring the back tangent and forward tangent as required to determine the measured delta. This is straight out of Wattles.

Why not use one of the tangents rather than the chord for the basis of bearings? If the tangents are not established by field survey there is a much larger issue. I have seen and accepted the chord used for a basis of bearings.

DWoolley

Well Duh, if life was so easy, lol.
We up in Northern California live in areas among hills and some subdivisions established streets from multiple curves, both compound and reverse curves, no tangents. Maybe you will traverse the half mile to find your tangent for a good B.O.B. (straight out of Wattles, as you say).
Wattles is a good reference, but now 50+ years old, there are other (newer) boundary books that may become an updated reference, not to date you Dave, just saying, heheheee

[Ian Wilson]

Two purposes here: 1) establish the Basis of Bearings, and, 2) establish the subdivision from the curve.

Basis of Bearings. For me, any two points that can be recovered in the future and used to create a calibration between the record map and my survey is a perfectly good Basis of Bearings. It doesn’t even have to be from a recorded map. It can even be two NEW points that I set on the map.

Test: Are the marks fixed and discrete (tag, tack, etc.)? Can they be found in the future (reasonably expected to remain in place)? Will future surveyors be able to find and accept the points as my BoB points? Can I measure between them with an acceptable degree of accuracy (survey grade)?

Yes? We have a Basis of Bearings.

No? How do we make the answers yes?

Establish the subdivision from the curve points. For this one, you have to consider HOW the curve points were calculated and set. On older roads, the PIs were set and the record radius curves established. Sometime the EC & BC were set by direct set up on the PIs. Sometimes they were “radiated” in from a control point. In the former, they’re usually pretty good. In the latter, depending on geometry, I’ve found them as much a 3 feet out from the points calculated by hold the found “BC” and “EC” points as point on line for the tangents.

Using just a BC & EC monument to re-establish lines and points in the subdivision makes it hard to meet the sufficient monument test or the precision test from PLS Act §8765(d), in my opinion.

As Connie pointed out, “It's tough to make that determination for people on the forum without seeing the actual situation.”

[Peter Ehlert]

Basis of Bearings again? wow

this topic gets rehashed many times through the years:
review the comments here viewtopic.php?t=4901
I still think a Required "Basis of Bearings" statement is outdated and unnecessary, and should be eliminated

not that this helps in this case, but for the Future

[PLS7393]

Basis of Bearings again? wow

this topic gets rehashed many times through the years:
review the comments here viewtopic.php?t=4901
I still think a Required "Basis of Bearings" statement is outdated and unnecessary, and should be eliminated

not that this helps in this case, but for the Future

Peter,
It is not a matter of "What is a B.O.B." as outlined and described in the original post.
Just like the LS Exam, . . . Read the question and answer the question.
Many people may not read the question, and take a "Left turn Clyde".

[Peter Ehlert]

Keith that didn't go over my head.
When the "required" bob was discussed here a burr under my saddle started itching again.
Carry on, my best to you all.

[Mike Mueller]

Wattles is a good reference, but now 50+ years old, there are other (newer) boundary books that may become an updated reference,

Any specific titles you would recommend?

I have personally loved Wattles because he wrote as a person who spent years dealing with the consequences of bad descriptions. His advice was/is grounded in empirical principles based on the outcome of court decisions, or just the simple fact that some ways of describing land seem to end up in court...

Mikey Mueller, PLS
Sonoma County