Help interpreting legal and mapping curves using Traverse

[Amylewislakecountymn]

I've been stuck on a curve in a legal description I'm trying to map using the traverse tool. My main issue is with the first angle in the curves description. I'm not sure what quadrant to assign to 04-00-00 and I'm also unsure if the direction is tangent, radial, or chord. 

I understand that I'm given the delta angel and what I assume to be chord length. However I don't how to correctly interpret the deflected angles described above. 

[jcarlson]

Since it uses the word "deflect", that usually means it's a tangent curve. Honestly, I don't know what those other degree measurements are. A "4 degree curve" doesn't mean anything to me, especially when the delta angle is given as something else.

I would simply enter the delta angle and the distance, and the tool ought to be able to calculate the rest.

[PrestonDenney]

You can look at this post
https://community.esri.com/t5/arcgis-parcel-fabric-questions/traverse-curve-with-only-angle-and-arc/...

[Rafael_Bombacini_PLS]

Hello

@jcarlson is correct. You can disregard the the degree of curve information and assume it's a tangent curve and simply entering the delta angle and the distance

But................................. Here is what degree of curve means. 🤓

On your first call, your curve length is 100 ft if D (internal angle) is 4 degrees.

Arc definition is the central angle for a 100.00 ft arc; chord is for a 100.00 ft chord. 

Arc Definition Curve

• Definition: An arc definition curve is defined based on the length of the arc itself.

• Measurement: The central angle (often denoted as Δ) and the radius (R) of the curve are key parameters. 

• Usage: This method is typically used in contexts where the actual travel distance along the curve is of primary importance, such as in roadway design.

Chord Definition Curve

• Definition: A chord definition curve is defined based on the straight-line distance (chord) between the endpoints of the curve.

• Measurement: The chord length (C) and the middle ordinate (M), which is the distance from the midpoint of the chord to the curve, are key parameters. The radius (R) and the central angle (Δ) can be derived from these measurements.

• Usage: This method is often used in railway design and other applications where the straight-line distance between endpoints is more relevant than the actual path traveled along the curve.

Key Differences

1. Primary Measurement Focus:

   • Arc Definition: Focuses on the length of the arc.

   • Chord Definition: Focuses on the straight-line distance (chord) between endpoints.

2. Parameters Used:

   • Arc Definition: Central angle (Δ) and radius (R).

   • Chord Definition: Chord length (C) and middle ordinate (M).

3. Applications:

   • Arc Definition: Commonly used in road design where the travel distance along the curve is important.

   • Chord Definition: Commonly used in rail design and other applications where the straight-line distance is more relevant.