Model train tunnels are generally a necessity on mountainous layouts, but they can also add greatly to the realism of a scene.
A tunnel is an excellent device for making a model railroad seem to be much bigger than it actually is. A tunnel will hide the train for part of its journey, leaving the viewer to imagine it has departed the area for a distant destination. When the train mysteriously reappears out the other end of the tunnel, it is easy to imagine it’s a completely different train coming from somewhere else. When model trains are constantly in view, realism can suffer.
Here are 4 tips for better tunnels:
1. Blacken the insides of your tunnels. A flat black acrylic paint can be used for the interior roof, walls, and floor. An unpainted “plywood-colored” tunnel interior will look unnatural, and lack the dark and mysterious appearance of a real tunnel. Place ballast on both sides of the track inside your tunnel portal. Continue the ballast for as far as the eye can see.
2. If you are not experienced with making your own tunnel portals, they are reasonably inexpensive to buy. Ready-made tunnel portals sometimes are pre-weathered, but you can add your own weathering effects with gray wash, chalk etc. to add more realism. Smoke and exhaust smudges look good towards the top of the portal. Ready-made portals are certainly more realistic at the entrance to a tunnel than is a roughly cut hole.
3. Allow plenty of clearance inside the tunnel for your longest and tallest trains to navigate safely. There also needs to be adequate clearance for track and trains to the left and right of tunnel entrances. Although this won’t necessarily stop all derailments, it will ensure your trains don’t come to a sudden stop each time they try to enter the tunnel. Also, you’ll want enough space to put your fingers, or a tool (pair of long forceps or tweezers) inside the entrance if a train derails.
4. Allow access to the tunnel interior, because you can almost guarantee your trains will want to derail in the most hard to reach location on your layout, especially inside tunnels! Derailed trains can usually be retrieved easily from inside short tunnels, but longer curved tunnels can be problematic. This is why creating another access point is a good idea, either from underneath the track, or through the side of the mountain. Another option is to make your mountain (or tunnel) as a lift off section.
One quick idea is to build an old photo frame into the scenery. Chuck out the glass and use the frame and backing (face down), in the scenery. When a train derails you simply remove the backing sheet of frame to access the inside of your tunnel. You can hide the frame using bushes, trees, fences, or other scenery props.