Thanks to those who responded to my "P.O.T."
That section of plans did not quite cover my P.Q. by gave me enough information to know that at the southermost frontage of the highway the P.Q. fronts on a curve. I requested the next section and received the plans today.
First thing I see is a different set of ties to my "P.O.T." which generated the last question. The ties are to a gate post and utility pole on the far side of the highway and a tie to the NW corner of my brick P.Q. house. I already have surveyed and tied in the house so now have a head start on ties. 4 stations +/- to the South is another P.O.T. with ties to an iron post and 2 wood fence post on my P.Q. farm's long gone pig pasture. At the NW corner of the pig pasture is a small square area labeled pig sty. I take it they used that terminology for the shelter?
About 50' before the P.Q. frontage ends is the P.C. for a curve. Along the actual tangents of the curve itself are 2 ties points labeled "P.O.S.T.". Along the tangent in the ties are to an apple tree and 2 utility poles. I take it these ties are from the design survey and not the construction plans which called for concrete mons with iron pins. Along the tangent out is the second "P.O.S.T." tie point, 2 of the ties being to a house. I believe the same house is still there and will check it out tomorrow.
What is the specific meaning of "P.O.S.T."? Has anyone ever seen it?
I have a idea of what it could be. This specific curve has 2 P.C.s and 2 P.T.s because the plan shows an "old curve" and a "new curve" with the exact same curve data except for the start/stop stationing. The second point marked "P.O.S.T." is clearly on the new curve location, so I am assuming "P.O.S.T." means "Point On Second Tangent".
Paul in PA
I Believe that means point on spiral tangent. That would make sense with the old curve and new curve radii being the same but having a different of and pt. they added a spiral to the curve to ease the transition to a super elevation.
Pc ant pt.... Stupid autocorrect!!
I have seen it as both Point on spiral tangent and Point on semi tangent. I've never seen it on plans from around here but I've seen it on plans from Eastern states.
P.O.S.T. means "Point on Semi-Tangent"
the semi-tangent being the tangent between the PC and the PI.
The P.O.S.T. station should just be the stationing measured ahead from the PC along the semi-tangent.
It sounds like you are describing a staked centerline and a projected centerline situation. You should also have 2 PI's so that should help you determine which curve you are on (or not)- you may need to scale from each PC along the semi-tangent to check.
Posting an image would help a lot to enable a better explanation.
since you mention PC and PT and nothing about TS, SC CS and ST or spiral angle I'm figuring you are dealing with simple curves.
''P.O.S.T.'' Maybe you have a Sub PI
Point On Semi-Tangent It Is
No spirals.
Somewhere in this house is my "Highway Design" text, but it is not on the bookshelf.
Something just clicked so I took my ACSM definition off the shelf and Golly! there they are. Point On Tangent and Point On Semi-Tangent, if you know the name, they will give you the acronym. Big Duh moment. Simple curves for simple minds.
Thanks to all.
Paul in PA
''P.O.S.T.'' Maybe you have a Sub PI
Well, I think you guys all got it: Point on Semi-Tangent. Attached is an old list of common abbreviations from an old CDOH survey manual. I hope it's legible.
''P.O.S.T.'' Maybe you have a Sub PI
Never encountered that particular definition. Goes to show you that you NEVER get to old to learn something new in surveying.:-)
Point On Semi-Tangent It Is
in Arizona we often see the points located after the P.I. as being xxx.xx' ahead of the P.I., and the points before the P.I. with the P.O.S.T. station and offset.
Point on sub tangent was my experience.
r. ''P.O.S.T.'' Maybe you have a Sub PI
Mr. Locke,
I asked several older surveyors and engineers at the highway department and they didn't know what it meant. I had to go to an old manual to find it out.
Good thing to know, though if you're trying to retrace an old highway right of way.