My N gauge model railway continues with another hill scene diorama nearly completed. Here’s a quick walkthrough of how this was done and other recent progress on it.
As mentioned elsewhere, I’m now working on an OO gauge shed layout but my N gauge model railway is still quietly progressing.
The recent wet weather, however, has been a boon which I alluded to in my email newsletter. With the rain keeping me indoors and specifically, out of the garden and away from the shed, I’ve been spent more time on my loft N gauge layout.
The result: another section is now nearly complete.
Layout Progress
To recap, this layout will eventually be a model railway of Southern England. Obviously, this is a huge undertaking and will require a LONG time and also a lot of space so I’m building it in regions and the first one being Cornwall.
The first baseboard reflected the line around Par and had lines running from a dock area and goods yards, up an incline through some hills, to a mining Tin/Copper area.
But one of these lines no longer stops at the hill-top mines.
No, it now continues bending around and onto a new baseboard.
Here the line splits, with one one track feeding into another yard area while the mainline loops around in an oval that sneaks through and around another hill.
On the top of this hill will be more mines — these sections are set in Cornwall after all — with a tiny mine track way carrying ore down to the railway yards for loading on the trains. (From there the ore is carried back down the original line to the dock area for onward shipping).
It’s part of this oval — where the line emerges from the hill, runs over a gap created by a landfall from the hill above, and into another tunnel — that forms the basis for the diorama.

An early work in progress. Things have come a long way.
The woodwork and electrics for the new board were completed previously but the wet weather has now allowed me to work on the track and scenery for the first diorama of this it and it’s this I’ve now completed with the remainder of the section not far behind.
The result is the picture you see above.
In the diorama, trains will emerge from a tunnel, curve around and over a viaduct and disappear into another tunnel.
A rock face to climbing up the hill can be seen in the background and the viaduct carries the trains over a small gap caused by past rock falls.
Although small in physical size, the scene involves numerous different railway and model making techniques which are covered below.
Tricky Trackwork
The basic shape of the hills was first built using Polystyrene, which I’ll come to shortly, and the track was then laid over this. I did this out of necessity.
The track on the new section is, as mentioned, an extension of the line that runs up to the hilltops on the first baseboard. As such, the track here is higher than that on the first baseboards so I needed a way to raise the track up. I could have built elevated wooden trackbed to hold the track but as the surrounding scenery is made from Polystyrene it made sense to just build up the entire area in Polystyrene and lay the track on this.
As with the rest of the layout, I use standard Peco N gauge track but with the sleepers and rails painted for more authentic colouring.
One slight digression was that the webbing between the sleepers was cut away for the section over the viaduct.
While this webbing is not normally visible thanks to the ballast, on the exposed section of the viaduct the plastic under the rails would have been very obvious and ruined the look.
Cutting this out was tricky as getting between the sleepers with a blade to cut the plastic without damaging the rails on N gauge track needed a steady hand. Luckily, there wasn’t a lot of track to do but I wouldn’t want to do it again!
Hills and terrain

The hills and landscape under construction. The viaduct was yet to be built.
As said, the hills, including the rock face and slope on the downside of the track (at the front in the picture here) were built from Polystyrene. This was glued as covered here and then shaped with a hot knife and using a saw blade for texture.
Once I was happy with the shape, plaster cloth was then placed over the top and painted with an undercoat.
Successive layers of browns, blacks and coal black were then added with dry brushing used to pull out details.
Scatter and vegetation were added using the technique covered here and static grass with my favourite applicator.
I’ll add trees in due course.
Wooden viaduct
Initially, I was going to make the viaduct with a 3D pen but decided against this after a few trial runs.
Then I tried with my go-to material for wooden structures, the match stick.
But even match sticks are too thick for this scale so they had to be sliced down the middle first.
They were then soaked in strong tea and vinegar for a week to bring out the natural wood colouring and grain before washing with a light brown water colour.
This worked but I still wasn’t entirely happy with it.
“Nice try, but no cigar” as the old saying goes.
So along with the matches, I also added some of the faux timber structs from a Faller 222205 “Old coal mine” that I had lying around. The combination did the trick.
After some consideration, I placed the track over the gap first (supporting it with a strip of rail pulled free from another section of track) and then made the viaduct and slid it into place under the track.
This was done to ease construction of the viaduct as it could then be built off-layout rather than constructed within the confines of the small gap under the track.
Another reason for taking the build-and-slide approach is that this won’t be the final viaduct. When time allows I want to create a miniature version of the Trenance Viaduct and use this in the scene.
In real-life, this viaduct is on a curved stretch of track in St. Austell in Cornwall and as such it won’t be out of place on my layout which is set “just up the road” from St. Austell.
Scratch building the original Trenance viaduct in Cornwall for my layout.pic.twitter.com/ZC8C6M8qb9
— ModelRailwayEngineer (@modelrailwayeng) March 13, 2017
Just to make life a bit more challenging, I want to scratch build it in its original Masonry & timber form seen here. This, of course, is going to be a challenge and will take some time so until then the wooden structure fills the gap — literally — safe in the knowledge that when Trenance is ready, I can slide out the current wooden and slot in the new version.
A Tale of Two Tunnels
The tunnels (one behind the train in the top photo and another out-of-shot just ahead of it but seen above) were as part of the hill construction — leaving space for the track.
As per my previous guide on making tunnels, Brick-paper was fixed to inside the tunnel walls and, for now, at least, off-the-shelf tunnel portals have been used for the entrances.
In time, I’ll replace these with scratch built tunnel portals. There’s nothing wrong with the portals, I just want to make my own so it looks like Great Pinnock tunnel in Cornwall, which like the Trenance viaduct is near where this section of the layout is set.
Rolling Stock
Nothing special. The loco is a Dapol N gauge GWR 0-4-0 5764; the wagons are heavily weathered Graham Farish 377-088 7 Plank stock. Likewise, the brake van is a Graham Farish model with the wood slightly discoloured.
I’ve previously fitted knuckle couplers to these but, for now, they’re using the standard ugly pre-fitted variety.
As a finishing touch for the photograph, I took an N scale figure and placed him in the cab of the locomotive.
In the scene photographed, he’s leaning out of the cab to see around the bend on the approach to the tunnel. Placing figures inside cabs in OO gauge is fiddly, on N gauge locomotives getting the figures in the right place is more down to luck than skill but it worked well enough for me.
That’s it. What do you think? I’d welcome any tips on alternative techniques to what I used or how it might be improved. As always, this blog is about sharing ideas and inspiration so please jump in with a comment below.
> A final, personal, note: I spend a huge amount of time testing, photographing, writing and researching techniques for these articles and pay for all the running costs of MRE out of my own pocket. If you found this article useful you can support me by making a donation on my fund-raising page. Thanks and happy modelling, Andy.