I’ve been posting a lot of reviews this past few weeks and thought it was time to get back into posting some how-to guides! So today the topic drawn out of the hat is How To Build Model Railway Bridges.
As with all aspects of Railway Modelling, or Model Railroading as our American friends affectionately call it, is there’s always more than one way to do it. Especially if you’re working on a tight budget. You can use a whole plethora of different materials including:
All these materials can be used in some way shape or form to produce some very realistic bridges. There are also many many types of bridges that we could create for our model railway including:
- Girder bridges
- Suspension Bridges
- Canal Bridges
- Brick Built Bridges
- Suspension Bridges, the list goes on…
So in part 1 of this tutorial, we’re going to look at making a Model Railway Viaduct using polystyrene, one of the cheapest and easiest products to work with. It’s readily available from most DIY stores or you can even use chunks of it use as packing material to piece together your bridge. The choice is yours. This method is suitable for OO gauge, HO scale and N gauge.
Part 1: Designing & Creating the Basic Bridge
Planning Your Bridge
Firstly, work out exactly where your bridge is going to go on your layout.Is it spanning a valley, will it be between two inclines and span a river or other section of track? How wide to the arches need to be to fit over the other features on your layout?
Create A Template
Draw up a template on paper or thin card (I prefer card). To do this, first measure the length of the area your bridge will span and mark it on your template. Then mark the centre of the bridge. Now begin to draw the outline of the bridges side profile, making sure it’s symmetrical about the centre point. Use a compass or anything round that’s off a suitable size to create the arches of your viaduct. For N Gauge, the lid from a spice jar may be ideal. For OO gauge, maybe a coffee mug will be perfect.
Once you have your template, cut it out using a pair of scissors.
Mark Out Your Cut Lines On The Polystyrene
Now transfer your template onto the polystyrene by drawing round it using a fine tipped permanent marker. Pin your template down to the polystyrene using dressmakers pins to stop it moving as you work.
Cut Out Your Viaduct
This is the fun bit! If you’re lucky enough to have access to a hot wire cutter specially designed for cutting foam and polystyrene, an you have a steady hand, feel free to use that to cut out your bridge. If not you can use a sharp craft knife and a lot of patience. The preferred method as shown in the video is first to use a suitable sized hole saw to cut out the arches. Depending on the thickness of polystyrene, it may be necessary to drill down from either side to remove the unwanted sections from the tops of the arches. Or you may find it easier to drill from one side to get a nice smooth curve, then cut the rest of the way through with a coping or fret saw.
Finally using a band saw, razor saw, coping saw or Scroll saw, make the remaining straight cuts up the walls of the arches to remove the unwanted sections of polystyrene.
If you need a wider bridge than the polystyrene that you’re working with, just cut out multiple versions of your first shape and glue them side by side to achieve the desired width.
When you’re done, you should have a rather splendid looking viaduct! All that’s needed now is to make it look like it’s made of brick or stone & add some weathering.
Part 2: Adding Realism To Your Model Railway Viaduct
This stage can be done either now, if you’re eager, or leave it right until the end, but this important stage is to give our bridge a realistic finish. Now there world really is your oyster here. Depending on the type of countryside you’re modelling on the rest of your layout, choose a material that’s in-keeping with the bridges surroundings. Would it me made from plain old red brick? Would it be stone blocks or large boulders? Choose a finish that you think will work best for your layout. Use a brick or stone paper from Model Railway Scenery which you can download and print to cover your viaduct, cover it with small pebbles from a garden centre… You can get really creative here! For a finer rendered finish, use glue regular sand to the surfaces of the bridge to represent concrete etc. Use a mix of materials to add detail & interest.
If you’re using pebbles and sand for example you may want to apply these now, then leave painting until after completing the remaining tasks.
Create Channels for Track & Cabling
Next, using a heated iron (any bent piece of metal of suitable width, heated with a candle etc will do the job). Press the iron into the polystyrene to effectively melt a bed for your track and any cables that will be running over the bridge. This allows you to hide them below the surface, under ballast etc.
Painting & Weathering Your Bridge
The best paints for adding colour to your bridge are low cost artists acrylics which can be sourced from your local art shop, in fact many discount stores and pound shops sell artists acrylics, so try those first for some real bargains. Choose natural, earthy colours, and be subtle. Less is more when it comes to weathering and detailing bridges. Use darker blends at the base of the bridge pillars to simulate algae & dirt. If your bridge is to span another railway track, don’t forget to add smoke and diesel exhaust discolouration. Artists charcoals are good for this, but failing that a lump of barbeque charcoal will do. Once you’ve created the desired effect, hold it fast with a light coat of hairspray to stop it smudging if you happen to touch it.
Install Your Bridge!
Now that all the hard work is done and your bridge is looking as realistic as possible, it’s time to install your bridge, which should be just a simple case of sliding it into place and securing your track to it using long track pins. Whether you use underlay under the track on your bridge is entirely up to you. You’ll probably be able to get away with just ballast and save a few pennies to be honest.
If you need to fix your bridge in place, just use a dollop of PVA glue under a couple of the bridge pillars to hold it in place.
Now sit back, relax, and admire your handy work!