Lay out a horizontal alignment

An alignment in CivilCraft is a chain of tangents through points of intersection (PIs), with a circular curve at any interior PI that has a radius. It is stationed from a start station you choose. A project can hold many alignments.

Draw the alignment

1. Press AA, or click Alignment in the Design group. The hint says "Alignment: click the PIs in order. Enter or double-click finishes, Backspace drops the last, Esc cancels."
2. Click the first PI (the start of the alignment).
3. Click each following PI in order. A red line follows the pointer and shows the length and bearing of the tangent you are drawing, for example "212.40 ft N 63°12'05" E".
4. Click the last PI (the end of the alignment).
5. Press ReturnEnter. The alignment is drawn with stationing and is selected. The status bar says, for example, "Alignment 1: 386.36 ft, curves of 100 ft radius where they fit. Edit radii in Properties; Profile (R) to design its grade."

While drawing: DeleteBackspace removes the last PI, EscEsc cancels, and dragging on empty space pans without adding a PI.

Every interior PI gets a curve of 100 ft (30 m in a metre project), or the largest whole radius that fits in half of each tangent if 100 ft does not fit. Very sharp or straight-through PIs get no curve.

Set radii and coordinates

With the alignment selected, the right panel shows Alignment:

1. Name and Start station. Type a station as 10+00 (feet) or 0+500 (metres), or as a plain number. See Units, stations and number formats.
2. Length and End station are worked out for you.
3. The PIs table lists each PI's Easting and Northing, and a Radius for each interior PI. Type a new value and press ReturnEnter.
   • A radius of 0 makes an angle point with no curve.
   • The first and last PI never have a radius.
   • The small x at the end of a row removes that PI (an alignment keeps at least two).
4. Read the Curves list: for each curve, its PC and PT stations, radius R, deflection Δ and direction (left or right), length L, tangent T, external E and chord.
5. The line under the curves gives the bearing of the first tangent.

If two curves need more tangent than there is between their PIs, a red box says so: "The curves at PI 2 and PI 3 overlap: they need 240.00 of tangent, the PIs are 180.00 apart. Use smaller radii." The alignment is not drawn correctly until you fix it, and it is left out of LandXML exports.

Move PIs on the plan

1. With Select active, click the alignment to select it. Square grips appear at its PIs.
2. Drag a grip. The alignment, its stationing, profile and corridor follow.
3. Release. The move is one undo step.

Adding a PI between two existing ones is not available yet: remove the alignment and draw it again, or type new coordinates for the PIs you have.

Read station and offset

Move the pointer over the plan. The status bar shows the nearest alignment (or the selected one) with the station and the offset, L or R looking up-station, for example "Alignment 1: Sta 2+15.30, offset 18.42 R". Beyond either end it adds "(beyond the end)".

What is drawn

On the plan, in DXF and in PDF: the centerline (tangents as lines, curves as true arcs), a tick every 50 ft (20 m) with a longer tick and a station label every 100 units, and PC and PT ticks labeled with their stations.

Delete an alignment

Select it and press fn DeleteDelete, or click Delete in the toolbar or at the bottom of the right panel. Its profile and corridor go with it. ⌘ZCtrl+Z brings it back.

Next

• Design a vertical profile.
• Spirals are not available yet; see Not built yet.