Chainage Control Tab (Alignment Properties Dialog Box)

Use this tab to establish the Chainage Reference Point and assign chainage equations along the alignment.

Reference Point Chainage

X

Specifies the X coordinate value for the Chainage Reference Point. By default, this value corresponds to the starting point on the alignment. Enter a value or pick a point in the drawing.

Y

Specifies the Y coordinate value for the Chainage Reference Point. By default, this value corresponds to the starting point on the alignment. Enter a value or pick a point in the drawing.

Pick Reference Point

Specifies the XY coordinates for the Chainage Reference Point. Pick points in the drawing to specify the coordinates.

Chainage

Specifies the chainage at the reference point.

Chainage Information

Start

Displays the beginning chainage for the first solved element in the alignment.

End

Displays the ending chainage for the last solved element in the alignment.

Length

Displays the length of the alignment as the summation of the length of solved elements along each alignment.

Measure Curves Along Chords

Specifies that alignment length is measured using curve chord length, and not the true curve geometry. The Unit Chord Length is a read-only value that is taken from the Ambient Settings tab in the Drawing Settings dialog box.

Note: Measure Curves Along Chords is available only in Rail alignments.

Chainage Equations

Add Chainage Equation

Specifies the location for a chainage equation. Click the button and specify the chainage for the new equation by either picking a chainage in the drawing or entering a raw chainage value on the command line.

Delete Chainage Equation

Deletes the selected chainage from the drawing. Select the chainage row that you want to delete and click this button.

Equation

Displays the index number of the equation sorted by raw chainage location on the alignment.

Raw Chainage Back

Displays the chainage value at the location of the Chainage Equation before any Chainage Equation values are assigned. If there is only one Chainage Equation value, then the Raw Chainage Back and Chainage Back values match.

Chainage Back

Displays the chainage value at the location of the Chainage Equation value before any Chainage Equations are assigned. If there is only one Chainage Equation value, then the Raw Chainage Back and Chainage Back values match.

If the alignment contains more than one Chainage Equation value, then the Chainage Back value of all Chainage Equation values, except for the first equation, are relative to the Chainage Ahead value and the Chainage Equation value directly before it.

Chainage Ahead

Specifies the new chainage values immediately after the Chainage Equation value.

Increase/Decrease

Specifies whether the chainages increase or decrease in value following the Chainage Equation location.

Comment

Specifies notes or instructions relevant to the chainage equations. Enter optional comments. These comments can be used in labels for chainage equations.