N gauge trains


How to Build Model Bridges and
Tunnels on a Small N Scale Layout

Guest Contributor: Mike Williams

Adding bridges or tunnels to your small n scale layout can add life to your model train. It might sound difficult, but by paying attention to the details and following simple steps, you can add bridges and tunnels in your layout and enjoy the feat of designing a complex layout.

Building Bridges

Follow the given steps to design a lifelike bridge in your small N scale layout:

1. Design the bridge that you want to model.

2. Assemble all the parts that you require to build the bridge. Real life bridges are usually made of steel, but using tiny steel beams is not practical for the model train layout.

3. You can use parts made of wood, plastic, or brass for your railroad bridge.

4. Use a good miter box to cut the beams squarely and accurately.

5. Make more than one assembly jig because majority of the truss bridges are made of multiple truss panels and repeated floors.

6. You can use pushpins to hold things down on your layout.

7. Use sand paper to clear the edges and remnants.

8. Paint the bridge and add weathering effects to make it look old.

9. You can make your bridge look more real by adding a flowing river under it.

Constructing Tunnels

Adding tunnels in your small N scale layout will add drama to your model train. It creates an amazing affect of model trains disappearing and reappearing through the tunnel. This will keep the viewers interested in your setup and will make your layout more fun. Following are the simple steps that you can follow to add tunnels in your model layout.

1. To measure the width and height, place the tallest rail car or engine on a section of your train track and measure the height in millimeters (or inches).

2. Once you have taken the measurements add 20% to these measurements to allow the train to pass easily through the tunnel.

3. Secure the road bed with white glue and rail nails.

4. Make reference point along the sides of the track according to the minimum clearance width.

5. Mark the exit and entry point of the tunnel on the base of the layout.

6. Use a newspaper to mark the location of the track between both portals.

7. To make the interior walls of the tunnel, cut the newspaper along the lines that you have drawn.

8. Cut and mark the outer side of the tunnel to define the shape of the model mountain.

9. Match the template with the reference line and trim if necessary.

10. Take a foam sheet and place the template over it. Mark the edges of the template to make it easier for you to cut.

11. Cut several layers of foam using a hobby knife.

12. Stack the layer one over another and apply glue between the layers to form a tunnel and mountain around the track. Secure the foam with the help of nails

13. Add the top sheet of foam once you have achieved the desired height of the tunnel.

14. Add portals at entry and exit and secure them at the base of the layout.

These are some simple steps that you can follow to add life to your layout by adding realistic tunnels and bridges in your small N scale layout.

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Narrow Gauge and Nn3 Variants


Many hobbyists (particularly those new to this great hobby) get confused with narrow gauge, N scale and that Nn3 variant. Well, in some locations in the USA, special purpose railroads operated on rails that were less than standard gauge because the equipment could be made to work in tight spaces or places where creating a standard gauge right of way was extremely difficult and/or expensive.  


These “narrow gauge” railroads were used to haul timber and mined ores, among other things, and several examples live on as tourist attractions featuring historic locomotives and rolling stock. A very common narrow gauge rail separation was three feet, so when you see an “n3” appended to a model railroad gauge, it represents a model whose scale rail separation is three feet. Again, using our math skills, we can see that the actual Nn3 rail separation is going to be around 6 mm. This is very close to the Z-scale separation of 6.5 mm, so Z-scale trackage is sometimes used to model N scale narrow gauge railroads. 


However, when it comes to model railroading the majority of N scalers stick with N scale without any variants. N scale is the most popular of scales after HO scale (in the USA) and the popular OO gauge (in Europe). The popularity of N scale trains is due to the fact that many people are downsizing their housing and moving from large houses with big yards to low maintenance apartments. This is particularly so with the Baby Boomers as they age. Even with an average sized home, model railroading can take up quite a lot of space use up most of one bedroom or a garage, so N scale the smaller sizing of N gauge becomes a practical necessity for many. 


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N-scale bridges