Display of Long Sections

Within a long section window, it is possible to display any number of long sections simultaneously. How these long sections are represented depends upon the relationship they have with each other.

If all the long sections come from the one family, i.e. they have been generated from a parent primary alignment and secondary alignments to that primary, they will all share the common chainage of the primary alignment. If chainages are being displayed in the table, there will only be one chainage row displayed, which will contain the chainages of all the long sections. The actual lengths of these control alignments will, in all probability, be of differing length. To be able to match up the chainages only one long section will be able to be displayed without being distorted along its length. The other long sections will have to be compressed where the length of the control alignment is longer and stretched to fit where the control alignment is shorter. By default the base alignment for distance, (the undistorted control alignment), will be the primary alignment, but this can be changed to any of the secondary alignments.

Also when displaying long sections, that all relate to the one family of primary and secondary alignments, the chainage along the primary alignment is always the common denominator. This means that long sections along secondary alignments can only be displayed along the region controlled by the primary alignment. When chainages are displayed as a common row this can sometimes have strange effects on the distance rows and the display of the long section, especially if a secondary alignment has a tendency to turn back on itself. In this case the long section of the secondary alignment will double back on itself and the distances will decrease, or will appear jumbled if the distances progressing up the alignment become mixed with the distances coming back down the alignment.

If long sections have been generated from different control lines, or unrelated alignments, they can still be viewed in the same window, but they will all be displayed by their distance. This is due to the fact that there is no relationship between them, so they are all drawn from left to right, starting at distance zero, without any distortion of their length. This can also be applied to primary and secondary alignments that do relate to each other, by choosing not to select a base alignment for distance. This will show the long section for its complete length without any distortions.

When displaying independent long sections, or selecting not to use a base alignment for distance, distance becomes the common denominator between the long sections. This means that only one distance row will be displayed in the table, which will contain the distances relating to all long sections.