Tunnel with room for 4 or 5 tracks. Has entrance attached to one side of it for connection with my T4 trench assets (use the other side or the 'base' spline to connect to underground assets).
15m wide, maximum clearance 7.5m (so it will fit double stacked containers).
To use just as tunnel (without any trench before or after it), combine this spline with the 'Trench T4 cut end' assets, available at 3 different angles.