How to Make Tunnels for Model Train Layouts?

If you’re planning on designing for your very own model train layout then knowing how to make tunnels could be important depending on your plan. If you plan to utilize mountain scenery in your layout then tunnels are almost necessary to build.

Another nice feature of building a tunnel for your layout is the ability for tunnels to hide the trains for a few moments in time and then shoot out the other side, causing fun and enjoyment for all observers.

It’s very important to ensure the inside of the tunnel is also well done including the track work and ballast. It’s not uncommon for a beautiful tunnel to look great but then when viewed at eye level, it’s lacking the appropriate detail. 

How to Build a Model Railroad Tunnel Portal?

Model railroad tunnel portals

You can purchase tunnel or can make your own. If you want to buy tunnel, you will find it at any hobby shop as plaster cast forms simulating wood, cut stone, random stone, etc. You can also paint them with brown, tan, gray or whatever you want.

If you have any inclination, you can make your own plaster cast. You can also use strips of basswood to create your own wooden tunnel.

There is an easy way. You can use beaded Styrofoam which comes in boxes of packing material for other items. Take the ½ inch thick sheet of Styrofoam and use a sharp knife to cut it and match the form of a tunnel portal.

Model railroad tunnel portals

You should make sure that you have enough clearance for all your train equipment to get through the portal.

Now you can paint the portal with concrete-color and can add a spray of gray to enhance the crevices. As the train enter or leave the tunnel, you can add a darker stain of gray or black to the top of the portal.

How to Make the Model Train Tunnel Body?

Making the tunnel of model train layouts

There are many ways to make the “body” of the tunnel.

Here’s a description of each of them:

  • You can use a sheet of Styrofoam to cut and build the walls of the tunnel. It can be curved to match the course of the truck. Now cut another piece of Styrofoam and it will cover the tops of the wall. Then use wadded newspaper to create mountain over the Styrofoam tunnel and covered this with plaster cloth.
  • You can cover the track directly with wadded newspaper. And cover the newspaper wads with cellophane. Now your job is to open a can of the great stuff and spray on a mountain over this cellophane-covered newspaper, leaving an opening on each end of the tunnel for the portal. Leave this overnight to dry. Don’t touch it after it’s sprayed out of the can ‘till it’s dry.
    • Then reach in through the portal on each side and pull out the newspaper wads. The plastic wrap ought to keep the newspaper from sticking out to the nice Stuff. You’ll be able to then use a saw or toothed knife to form the highest of the mountain but you want or add plaster material to the highest of the mountain to feature texture and supply a decent painting surface.
Making the tunnel of model train layouts
  • Number three method is to use cardboard web technique. You need to form the sides and top of the tunnel and cover this with wadded newspaper and then plaster cloth to finish the mountain form.

Inside View of Model Train Tunnel

Tunnel in inside of model train layout

You should not neglect the inside part of the tunnel. Be just as concerned about the inside as what is visible from the outside.

Make the inside of a tunnel detailed by using cardstock:

  • Take a piece of black, brown or gray cardstock, or construction paper, cut it to the proper size and insert the rolled cardstock into one end of the tunnel.
  • Allow the cardstock to unfold and position it in order that it creates rounded within walls for the top of the tunnel. That way, after you inspect the top of the tunnel, you simply see black or gray walls rather than plaster or cardboard webbing.
Tunnel in inside of model train layout

You can use rock castings for the inside walls of the ends of the tunnel or use Sculptamold to line the inside walls and then paint it with washes as you would do with regular rocks. It can another nice way to decorate the inside of the tunnel.

Learn More

Here’s How to Build Model Train Hills & Trees Perfectly Every Time


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