NP2025.4 - Changes in railway computations

With the NP2025.4 and newer versions the railway model have some changed behaviours and possibilities when working with the model.

When bringing an existing railway model created in older versions than Novapoint 2025.4, into Novapoint 2025.4 and newer, you are asked to convert your models to be able to continue. This is a requirement to continue working with railway models in Novapoint 2025.4.

This conversion is a compatibility break. Building in older versions will not be directly possible, but can be done by reading back the description (or doing manual changes to the surface description and subsequent pavement descriptions).

What happens when you open you railway model built in older versions, in Novapoint 2025.4 or newer?

In addition to the backup PARAM file, the conversion will do the following things:

• Create railwaysurfaces -2.19 and 2.19 as the ballast slope surface

  • the content on surface immediately on the inside of 3.01 (typically ±1.03 and ±2.05) will be moved to this surface

  • any descriptions using 2.19 surfaces will be moved accordingly

• Railwaysurfaces -3.01 and 3.01 will be analysed with respect to the defined formation width in the railway wizard.

  • based on this analysis the 3.01 surfaces will be split in sections for where the width is equal to the defined formation width, and sections where the formation width is different than that (user-defined width)

• Alignment as surface edge used on railwaysurfaces -3.01 and 3.01 will be moved to the 3.02 surfaces.

Working with railwaysurface 2.19 and 3.01

After the conversion of the railway model the 2.19 and 3.01 surfaces will have a changed appearance in the description.

• Surfaces 2.19 and 3.01 has a column for 'Width (calc.)' that shows an automatically calculated width of the ballast slope

• Surface 3.01 in addition has two new columns for formation width definition

  • • 'Form.width source' can be set to 'To formation width' or 'User-defined width'

      • • 'To formation width' will input the width in 'Width form center of track' as it is defined in the cross-section wizard

        • 'User-defined width' will allow the user to define the formation width as different values along the track

• Surface 3.01 no longer allows for using alignment as surface edge to define it. You will need to use the 3.02 surface for this.

The column 'Width (calc.)' will update and show the computed values based on changes done in the railway surface and pavement description once a rebuild of the model is done.

Working with other railway surfaces

Between the railwaysurfaces used for railway sleepers and those used for the ballast slope you can now more freely use these surfaces for making your design. We recommend using surfaces between 2.04 and 2.18 for this, avoiding using surfaces that are closer to the tracks than these.

Working with the ballast layers

The ballast layers now allows for a more flexible definition if it is needed. The formation level is represented as the bottom of all ballast layers and will cap all ballast layers that protrudes below it. The ballast and formation levels are defined to be flat, except of the Ballast 1 which follows the top surface. This is not different from before, but should one need to define this differently, this can now be done more easily.

Previously, when ballast layers deviated from the definition found in the cross-section wizard there could be issues the ballast slope, cut (5.11 and 6.11) and fill (7.11) slopes of the railway model. With these changes, this is now resolved.