To Add Floating Curves With Spirals to Alignments

Add floating curves with spirals in situations where you need a transition spiral and the curve geometry must pass through a specified point.

To add a floating curve with spiral (from entity, through point) off a curve

Add a floating spiral-curve group, with a specified radius, spiral length, and pass-through point, to an existing line or curve entity.

When the attachment entity (1) is edited, the spiral length (3), solution angle (4), and curve radius (2) and pass-through point (5) do not change. The attachment point and curve length adjust to accommodate edits to the attachment curve.

1. Click the alignment. Click Alignment tabModify panelGeometry Editor.
2. On the Alignment Layout Tools toolbar, click Floating Curve With Spiral (From Entity, Radius, Through Point) to add a floating curve with a spiral off a curve.

   The current spiral definition is displayed on the command line.

3. Specify the curve entity to add to.
4. Specify the radius, or enter D to specify the degree of curvature.

   Specify a new value, or press Enter to accept the value that is displayed on the command line.

   • If the alignment has design criteria applied to it, the minimum value for the current design speed is displayed.
   • If the alignment does not have design criteria applied to it, the default value specified in the curve and spiral settings is displayed.
   Note: To calculate the radius or degree of curvature using other known curve parameters, enter 'CCALC to open the Curve Calculator.
5. Specify either the spiral length or the A value.
6. Specify whether the curve solution angle is either greater than or less than 180 degrees.
7. Specify whether the curve is compound or reverse to the curve it is being added to.
8. Specify the pass through point.

To add a floating curve with a spiral (from entity, radius, length) off a line

Add a floating spiral-curve group, with a specified radius and length, to an existing entity.

When the attachment entity (1) is edited, the spiral length (3) and curve radius (2) and length (4) do not change. You can adjust or move the attachment curve and the entire curve and spiral entity moves with it.

1. Click the alignment. Click Alignment tabModify panelGeometry Editor.
2. On the Alignment Layout Tools toolbar, click Floating Curve With Spiral (From Entity End, Radius, Length) to add a floating curve with a spiral off a line.

   The current spiral definition is displayed at the command line.

3. Specify the line entity to add to.
4. Specify the radius, or enter D to specify the degree of curvature.

   Specify a new value, or press Enter to accept the value that is displayed on the command line.

   • If the alignment has design criteria applied to it, the minimum value for the current design speed is displayed.
   • If the alignment does not have design criteria applied to it, the default value specified in the curve and spiral settings is displayed.
   Note: To calculate the radius or degree of curvature using other known curve parameters, enter 'CCALC to open the Curve Calculator.
5. Specify either the spiral length or the A value.
6. Specify whether the curve solution angle is either greater than or less than 180 degrees.
7. Specify an end point.