Woodland Scenics HO C1257 Cut Stone Double Track Tunnel Portal | ModelTrainStuff
REALISTIC PAINTING AND WEATHERING | How to Paint Model Railroad Tunnel Portals - YouTube
Train Tunnel 43 South Portal (Winter) | NEPA Trains
Gareth Dennis on Twitter: "Designing the tunnel portal to dissipate some or all of the energy of the pressure wave so that little or no reflection occurs is the other option. Here