RR Curve

Disclaimer: this is the not-awake -waiting for the coffee to finish pre-0600 answer ?????ÿ

17939+61.74

without getting into a significant digits discussion

17939+61.5 (+/-) - (Edited after Coffee)

@rankin_file?ÿ

Hey Rankin, after that coffee kicks in you might find that your solution is based upon a highway curve and not a RR curve ?????ÿ

I second that:?ÿ 17939+61.53

Posted by: @dms330

17939+61.74

That's what I get using RR curve definition of degree to radius, but applying arc length, not RR sum of chords (which will take further calculation).

For sum of chords, we have 40 chords of 100 ft making 80?ø.?ÿ Then 1?ø 34' is another 78.33 ft chord.

So station is 17939+61.53

L = (DELTA/D) * 100 = (81.567/2) * 100 = 4078.33

1789883.2 + 4078.33 = 1793961.53

Val map I have shows PT Sta. as 17939 + 78.55.?ÿ WTF, over?

17939+78.55 - 17898+83.2 = 4095.35

4095.35 / 100 * 2 = 81.9070 = 81?ø 54' 25"

Maybe the delta is wrong on the plans, should be 54' instead of 34'?

Does 81?ø 54' check with the tangent bearings?

?ÿ

Station Equation @ PC, PT, or somewhere in between?

@sergeant-schultz ?ÿwe had a couple of rt curves on some rr plans that were in the neighborhood of 8^C that were also annotated with an ƒ??Rƒ? that we couldnƒ??t match plan stationing by 20ƒ??+/- . The cl of the track physically matched plan ^C

@r-s-mayer This RR doesn't provide tangent directions, just Sta., D, Delta.?ÿ Tracks long gone.?ÿ Ballast scavenged.

@loyal if there is, it's not shown on the map.

@sergeant-schultz?ÿ

Val maps can be interesting documents. I recently was asked to do a survey for a railroad. I was sent a set of val maps. 30 years prior to this request, the railroad had given me copies of their Val maps for the county. The two sets are wildly different.

@mightymoe Interesting wouldn't be my first choice for a descriptor.?ÿ This map, like most (?) lists the vesting deeds, which I have.?ÿ No help there - from Adjoiner A to Adjoiner C, 99' wide, parallel, 49.5' each side of c/l, etc.

Of 24 black squares which (might) designate monumentation, I have found 4.

@sergeant-schultz?ÿ

Val maps are for taxation, they can be an iffy boundary source.

And since they are for taxation there can be multiple versions of them for any area.

Also, I've discovered that deeds can be iffy. One of my ROW projects have deeds to the RR from landowners. Trouble with that is the deeds were granted in the 1920's the RR was there in the 1880's and the patents to the grantor didn't happen till the 1900's.

The val maps seem to be older than the deeds and they don't match up. In fact some of the deeds vary the RR width seasonally. It's wider in the winter, narrower in the summer.?ÿ

@mightymoe?ÿ

I would say iffy at best. I view them as being of somewhat lesser value than Assessor's maps and GIS maps. The Deed, Easement or map of the alignment are what controls the location.

?ÿ

I have never heard that they are for taxation, but rather for inventory purposes.

@jim-in-az?ÿ

As I understand it the maps were made as you say to inventory the railroads property so that a value could be placed on the property and it could be properly taxed.?ÿ