How have you made tunnel liners?

[Metro Red Line]

For my tunnel liners, I just get a slab of 1" thick blue foam at each side, and before securing them in, I take an xacto and run shallow random lines through them. Then I chisel them off with the knife and get a rough surface, which I paint an earth color for about 5-8 inches in.

Any deeper than that, doesn't require detail and I paint it burnt sienna.

[ho modern modeler]

I poured a set of rocks from a Woodland Scenics mould (black rubber), then I rolled clay out in a slab about 4"x10" and pressed the rocks into it. I roughed up the clay between the rocks, then poured a mold over the whole thing. Then I glued the sections on the foam tunnel walls with foamboard adhesive and sprayed them with 3 colors of Rustoleum texture paint. It turned out really cool, 1 down 4 to go.

[G Paine]

At Boothbay Railway Village, we have been working on a number of tunnels.

We started casting liners in Hydrocal using the WS tunnel liner form. These make a nice "blasted rock" liner, and can be configured to make single track or double track liners. They work great of straight sections, but have to be cut to fit curves. Also, if you have a narrow space with other structure in the way, they are difficult to fit. The liner mold is a thin blow molded plastic and becomes fragile after a few years. Casting is a slow process, if you need a lot of liner pieces, you probably should get multiple molds. We have 6 of them.
http://www.walthers.com/exec/productinfo/785-1250

Lately, we have been making liners from 1' extruded foam insluation board (blue or pink foam). We make an opening slightly larger than the tunnel portal, and laminate pieces together to make a liner to the appropriate length. Sawing or cutting the opening leaves a rough surface that looks like blasted rock. For curves, foam board can be offset and glued together to fit the curve, the sawtooth apearance inside a can be smothed using a file or Surform tool. We paint the inside with a flat black paint. If a further view block is needed after 6 or 8 inces, we line the edges of the track with 1/4" black foam board leaving the top open. Styrofoam is messy to work with - lots of small pieces that stick everywhere, static cling, but a lot easier to work with than plaster. The foam liner can be easily mofified to fit tight clearances.

[MisterBeasley]

I've also built subways.  One of my lead cars has a video camera in it, so I wanted to line the tunnel walls so that there would be a tunnel wall to see all through the tunnels.

I took a clue from the textured ceiling of my train room, literally.  I made wall sections from styrene, and then mixed up some Hydrocal, quite thin, and rolled it on with a paint roller.  Once it was set, I sprayed with gray primer and misted on a bit of black.

The styrene easily curves around the 18-inch radius walls.  I used the light gray color to "brighten up" the tunnel for the video camera.  You can see a LED on the left (inner curve) wall.  I added lighting, too, but placed it on the inside of the curve where the camera couldn't see it.

Another technique I've seen here is to make a loop of heavy wire, #12 I believe, and connect the ends to the business end of a Weller soldering gun.  This provides a stiff "hot wire cutter" that will hold its shape.  The modeler used this to cut his tunnel through stacked pink foam.

[gandydancer19]

I too only add inside side walls, only on the side that can be seen.  I use cardboard, plastic, or anything that is stiff.  I paint them black for the most part, but may shade them lighter at the front with a dark gray.

I also airbrush the track and ballast flat black starting about three inches inside the tunnel.

[gmpullman]

I kind of followed Garry's example and only concerned myself with the side walls, leaving the top open for access from inside the tunnel. Unless you crane your head around you'd never see the top anyway. I used plaster castings made from a cut stone patterned mold lightly painted with gray primer then washed with india ink.

Have fun!  Ed

[Medina1128]

I made the portal, retaining wall and liner from styrofoam, that were cut to shape and glued together (I used acrylic latex caulk to glue them together). I hand carved the rocks that the portal and retaining wall. I, then glued the portal to the subroadbed. I made sure to check clearance as I shaped the liner. Once, I had the necessary clearance, I covered the inside walls with a layer of plaster, texturing it as I went. I painted the interior using acrylic based paint. Here's where an airbrush comes in handy, so I could make a gradual transition from dark earth based color to black. The liner is only about 8" deep because, The mountain keeps it dark inside. The top of the mountain is removable and there is access from the backside of it; things DO happen inside mountains! 

[Santa Fe all the way!]

This is interesting. I will need a tunnel liner because an approximately 7' section of my shelf layout runs through a closet. The liner will have to keep the trains from getting hung up on my clothes :-). I've been thinking about how I'm going to do this, as the area will need access in case of derailment. I was thinking a couple of 1x4's on hinges. The liner would be attached and made of black construction paper or thin styrene.

[xdford]

I would be using black foam as a liner folded in a U shape over your track. Not only would your locos and rolling stock be protected if they derail but you won't so readily scratch and damage yourself if you have to reach in and rerail your trains.

Hope this Helps 

Regards From Australia

Trevor

[doctorwayne]

Only one short tunnel, about 450' long, on my layout (they weren't very common in southern Ontario) and it's over a mostly-curved section of track on a 2.5% grade

Here's a train exiting the upper portal:

...and, on another occasion, a train emerging from the lower one:

In the second photo, you can see daylight in the tunnel, visible only because the mountain over it hasn't yet been completed. 
Here's a behind-the-scenes look, with the lower portal visible in the distance beneath the unfinished scenery:

The tunnel liner, used only immediately inside both portals, is a piece of black construction paper, formed into an upsidedown "U" and stapled to the edges of the 3/4" plywood subroadbed.  The entire length of the tunnel track has a low "fence" of 1/8" Masonite fastened to both sides of the subroadbed, in case of derailments, and the track is accessible from below.  Once the mountain is closed-in, there should be no light visible inside the tunnel.

Wayne

[mlehman]

I used the Woodland Scenics tunnel lining mold. It forms 1/2 of the liner for a section about 5" long. On most of mine, I added cotton bandage material so that the the first section has a tongue sticking out at the apex embedded in it. When casting the second half, the cloth is embedded in it, linking the two. This is handy a lot of times because you may want to lift a section out for access.

[Capt. Grimek]

A timely thread for me as I'm just now deciding what to use. I'm so far, settling on one wall (only) of black painted tin foil for a hard to reach corner where only that wall can be viewed. It's on a very short (two-three cars) interchange so no flatcar riding cameras will ever go in there.

I'm using Bragdon Geodesic Foam for my mountains so I will make all fully visible tunnel liners with that material. Just take a fresh/uncured casting and drape it over my forearm and voila! a true rock tunnel liner.

The one walled tin foil liner will also be easy to "bat" aside should I ever derail and need to insert a grabber tool in there to retrieve anything. It will also be easy to replace should it get damaged by putting glue on the bottom and placing it inside the tunnel with the same grabber tool.

[BroadwayLion]

How elaborate you get depends on what you are doing.

LION builds subways. Lotsa tunnels, and always needs more tunnel walls. Fortunately subway tunnel walls are mostly concrete. LION models most of these with foam or Homasote, but has recently taken to using just plain old corrugated cardboard. Paint it black, apply some latex caulk to the bottom and drop it in place. They do need covers on them!

But what if you use a "Rail-Fan Camera" Your tunnels will need much more work on them.

But what if you want to access the tunnels to get the 0-5-0 switcher in there? Walls and sides get in the way. LION is considering using removable walls. Install them for a photo shoot, take them down so viewers can see what is going on.

Here are two videos of my layout. Let me know what you think of the tunnels.

ROAR:

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LION has added much since this last video was taken, mostly because him looked at it and liked not what he saw. More tunnels and stations are in place now, but of course it is no where near finished yet. Maybe him will shoot another video tomorrow so that we may display the progress.

ROAR

[Heartland Division CB&Q]

My tunnel liners are intended to look like rock. Only the sides are lined and I made them high enough so you can not see the tops of the liners. They are plaster castings I made. The process was to make a wood frame to hold the mold. The mold is crumpled aluminum foil which is pread into the woord frame. Then I filled the molds with plaster of Paris. To go around the curve, I have a series of straight sections. I used watered down acrylic paints with vaious colors. It was not neccessary to go very deep in the tunnel because of darkness.

[ndbprr]

Concrete or rock? For rock set two one x what height you need and drape plaster soaked paper towells in a U. When dry invert after painting and install.

[chris86]

hi Ron

I made mine from thin foam board and painted with woodland tunnel black. the paints doesn't reflect light and is very convincing.  

pro

cheap and easy to make.

bends around corners

cons

no detail to show cutting, that said with tunnel black most detail would be lost.

chris

[n2mopac]

I am ready to build tunnel liners on my layout. I have looked at several different possible processes for making liners and am weighing the pros and cons of each. Tell me how you have made tunnel liners in the past, what materials you used, and what pros and cons you see. Your input is appreciated.

Thanks,

Ron