Railway Alignment Design
In this page, Railway specific functions in Alignment Design is described. For general use of Alignment Design, see the Novapoint Road pages.
Options
To open the Railway options dialog, select menu Tool; Options... and select the Railway tab.
Accept cant on line elements - If enabled, the Cant column will be accept cant value on lines.
Use sign with cants - If enabled, negative or positive cant will not be set automatically from curve direction.
Use cant offsets - If enabled, two columns opens in the indata panel. Use the first column for moving the cant station into this element with distance from element's start. Use the second column to move element's cant station backwards from end station. Offset value for end should be negative.
Use KM stationing - If this is enabled, KM stationing from KM Calc will be shown in the Result tabs.
Novapoint Railway alignment design uses cant offsets to handle cant transitions between elements. The cant offset can be used with or without Clothoid spirals. If an alignment has no clothoid spirals, the cant transition takes place in the element change.
To be able to start or end a cant transition on a line, you must change two settings in the Options dialog > Railway tab:
Check the Accept cant on line elements box.
Check the Use cant offsets box.
3. Click OK. With these options active, you can add cant to straight lines and also start or end the cant transition on line elements.
Example:
The alignment below has three consecutive curves. The image shows cant transitions starting and ending in adjacent elements:
Element 1 - Line with no cant. But the cant offset at end point =-20 m, meaning that this element’s cant ends 20 m before the endpoint and cant transition to next cant value begins.
Element 2 - Arc with cant=50 mm. There is no cant offset at element’s start point so the full cant of 50 mm starts there. Cant offset -15 m in element’s endpoint. The 50 mm cant ends 15 m before the endpoint and cant transition to next cant begins.
Element 3 - Arc with cant 75 mm. No offset in start or end point. Cant transition starts 15 m before this arc’s start point because of negative offset on element before. Cant transition to next cant value starts in element’s end point.
Element 4 - Arc with cant 50 mm. Cant offset 15 m in start point, meaning the cant 50 mm is obtained 15 m after start point. No cant offset at the end point, the cant transition to next cant value starts in element’s end point.
Element 5 - Line with no cant. Cant offset 20 m from element start point. Cant value 0 mm starts 20 m after the element’s start point. No offset at element endpoint -> Cant=0 the end point.
In summary: Novapoint has no separate cant table. Cant stations are connected to the elements. To adjust the cant stations, you must use the cant offset cells. The cant offset points for an element must be inside the element, meaning that the start offset value must be positive and the end offset value must be negative.