HowTo/Build a Tunnel
Tunnels work in the same way as bridges. Repeat the steps above but firstly select a tunnel rather than a bridge. For your first tunnel, lay it on a flat section of ground so that the hills don’t interfere with the operation. You can always add the hill afterwards
Once you have 3 spline points in a tunnel, select Move Track (M) and Click and drag the middle spline point to create a bend in the tunnel.
Notice that in TANE, the tunnel exits “snap” to the terrain at 45-degree increments. You may need to re-Route your track to align it correctly to the tunnel entrance and exit.
Ensure that you hide the tunnel exit properly by using the terrain Height Adjust tools and the track Smooth Spline tool to tidy up the entrance.
To join track to bridges or tunnels you should always use single track, even for a double track, bridge or tunnel.
Lay the spline point away from the bridge first and then move the track towards the end spline. The track will snap to the bridge object.
Use Smooth Spline to tidy up the terrain.