Help:Surveyor Topology Section Extend
The section extend tool on the topology tab allows you to add new terrain sections, or 'baseboards' to your Trainz world. This is essential for creating fully fledged Trainz routes and sessions.
To use the tool activate it by clicking on the the section extend icon on the topology tab, then click somewhere of the edge of your current section. A new chunk of terrain will be created (each Trainz section is 720m square when working in 'real scale').
By default ground sections use a 10m grid, where each terrain 'point' is 10m apart. If your route requires finer detail you can create sections which use a 5m grid. These ground sections will use much more memory and should be reserved for when fine detail is a must. To create a section with a 5m grid right-click on the section extend icon and choose "Classic - 5m Grid" from the list. Any newly created sections will now use a 5m grid, don't forget to change the tool back when you're done!