How do you make ballast look real?

To some extent, making the ballast look real on your model railway is one of the hardest tasks that you will encounter when detailing your layout.

Your rolling stock already looks pretty good, the manufacturers have seen to that. A hill is a hill and no two are the same, so even if yours didn't turn out exactly as planned, by the time you have added your grass and scatter all is forgiven, and as long as your station kits are not put together with a glue gun (yes we've all been there) then your stations should be looking pretty good too.

But now its time to weather your track. It's time to get the paint out, possibly for the first time since your layouts construction began, and if it goes wrong, then that's all your hard work laying the track and ballasting down the drain.

Before we get into the nitty-gritty (excuse the pun) it would be useful to explain how ballast is used, and the journey it goes on in real life and therefore you will develop an understanding of why ballast looks the way it does.

Ballast is the stones that you see at the side of and between the sleepers on railway tracks. Its function is to stop the tracks from moving around on the ground by displacing the force exerted when a train passes by. Ballast also facilitates drainage and helps prevent weeds growing around the tracks.

How deep the layer of ballast is depends on many factors including how frequently trains run on the line, how heavy the trains are and what speed they are likely to be travelling at. Typically high-speed lines will require a much deeper layer of ballast than a branch line and have much wider shoulders (the ballast at the side of the track) too.

In fact the ballast itself sits on top of a layer of smaller stones known as the sub-ballast which helps support the railway and keep it level.

The stones that ballast is made up of must be irregular shapes with very angular edges so they interlock together (this is a bit like gluing the ballast on your own layout). As time goes by though, the angular corners of the stones can become smooth and worn. This is one of the reasons why ballast has to be replaced sometimes and you often see fresh stretches of ballast along railway lines.

The colour of ballast varies depending on era and location. Nowadays the railways tend to import most of its ballast either domestically or internationally, so freshly laid ballast usually has a fairly uniform look and colour about it, but this practice has only really been commonplace in the last forty years. Before that the sourcing of ballast would have meant a trip to the local quarry, so different regions ballast would have a different appearance in colour and type.

Other factors that influence the colour of ballast include the type of trains which run on them. Steam trains, for example, would deposit ash onto the track giving a blackish appearance especially in engine sheds. Diesels deposit oil and until recently passenger coach toilets would deposit... Well, you get the idea. Whereas modern electric trains with waste collection tanks and retarders or engine braking do not deposit much at all, even brake dust deposits are not as prevalent as they once were.

So there you have it, the further back in history you go, the dirtier the tracks, and with different colours of staining from different types of pollutants, the faster the line the deeper the ballast and the more likely it is to have fresh ballast laid. So before deciding on how to make your ballast look real you must first consider the era of your railway and which scene you have depicted.

There are many products out there to help you weather your track, the colour you choose is at your discretion. A good generic place to start would be to use a  Railmatch "Sleeper Grime" colour for the ballast in and immediately to the side of the track followed by a light coat of "Roof Dirt Grey" down the centre of the track, these can be applied with either an airbrush or normal brush. 

Don't forget though: take it slowly and lightly, you can always add more paint, removing it however  is a little more tricky.