Sumida Crossing, the model railroad layout


Tōkyō is a big city, and trying to replicate even a small part of it in a model railroad would be a vast undertaking. But within the city are many different railroad stations, both large and small. Sumida Crossing is based around two typical ones: an elevated multi-modal station, and a smaller neighborhood station. The city is also interesting due to the way urban and suburban residential, commercial and light-industrial areas mingle together; many Tokyoites live within walking distance of their workplace, and detached houses can be found in the shadow of multi-storey towers. Greenery and waterways mix (sometimes vertically!) with urban features such as highways, and the ancient can be found side-by-side with the ultra-modern. I’ve tried to capture the “flavor” of that complex mixture in a small space, with trains.

The following video provides an overview of trains running on the layout:




Design


The railroad layout design was constrained by available space, and a focus on running full-length passenger trains of up to 16 cars, which even in N scale are quite large. Within those constraints, I wanted to create something with multiple lines, so that I could run bullet trains (“Shinkansen”) and ordinary narrow-gauge trains side by side. The multiple lines can also be used to replicate two different narrow-gauge lines run in parallel, which is quite common. Of course that means that the track has to be ordinary 9mm N-scale track, but as all commercial standard-gauge Shinkansen and narrow-gauge Japanese trains are built for 9mm track, just to slightly different scales, that’s the easy solution anyway.

Sumida Crossing is an oval, with a center view block dividing it into three main scenic areas: the Riverside Station, loosely based on Ochanomizu Station in Tōkyō, the River Crossing, loosely based on the Sumida River, and the elevated Urban Station (pretty much free-lanced, but similar to many urban stations). At the right end, view blocks were planned to hide the return curves and the helix down to staging tracks. The planned staging tracks would have been located about 16 inches below the urban station, and a second set could be located under the riverside station by extending the two entrance tracks through, with a simple curve below the river scene. But the helix and staging were never built, and trains are placed on the layout to run, and removed and stored when not in use.

Construction


These three scenes are built on a standardized 2-foot by 4-foot table structure, made from a box of 1x3 pine with a single cross-piece for support, and a 1/2-inch birch plywood top, held together with screws. The upper surface of the plywood is painted to represent water, and has insulation foam applied for landforms. Some structures (like the expressway and the platforms of the urban station) attach directly to the plywood top. The underside of the top is used to attach wiring, with removable jumpers between individual tables. A backdrop of painted hardboard with a photograph laminated to it is attached to each table. All of the tables rest loosely atop a pine framework, and everything is held together with bolts, washers and nuts. This makes for fairly rigid and heavy sections, but they’re still small and light enough to be moved individually by a single person, and can be transported in a car (although the backdrops may have ended up a bit large to transport inside the car). This allows the layout to be broken down and relocated when I move.

As the layout has been built, the ongoing work has been summarized in a sequence of pages. The Construction Index lists these, and related pages of interest.

Track


The track consists of three double-track loops:
- Commuter Line
- Express Line (a.k.a., the Shinkansen Line)
- Subway Line

and there is also a short light-rail (“tram”) line within the Urban Station scene.

The Commuter Line replicates a typical narrow-gauge double-track commuter line, which can serve an area entirely within the city (using “Commuter” trains) or extend outward to surrounding areas (“Suburban” trains); most do both, and also serve a variety of “Express” trains providing regional intercity transport. The difference between Commuter and most Suburban trains is minor, and more due to interior details like seating and the presence or absence of tables and toilet facilities, due to the duration of the commute. Some express commuter trains are substantially different, utilizing “limited express” trains that otherwise serve resort areas and similar functions, and which are thus both more luxurious than the rather utilitarian commuter trains, and more distinctive in appearance. A small amount of freight service remains on Japanese lines, and can be found on the ordinary narrow-gauge tracks as well, even in many urban areas.

The Shinkansen system is completely separate from the narrow-gauge system in the real world, as they use different gauge tracks and higher-voltage AC power supplies (narrow gauge trains typically use low-voltage DC, or sometimes AC but not usually at the same voltage as Shinkansen). Shinkansen also do not share their tracks with freight or slower trains (although there are different grades of Shinkansen on the same line, they’re mostly differentiated by how many stops they make). And Shinkansen lines are always grade-separated, typically on viaducts within cities, and on fills and cuts, and sometimes viaducts, further away. On the layout, the outer loop is grade-separated, and can serve the role of a Shinkansen line, although it can also be used as a second commuter line if desired. As long as I don’t run both Shinkansen and other trains on it at the same time, there’s no real conflict.

The Subway line exists partly to capture a bit more of the “layered” nature of the city, and partly because some commuter trains run through into subway lines, so having both adds some operational complexity. Trains used in subway tunnels are specialized, typically being narrower and shorter than normal commuter stock, and with emergency exits on the ends (not normally found on above-ground stock) for exiting in tunnels.

And finally, the Tram line is a light-rail line entirely within the Urban Station scene. There are two of these remaining in Tōkyō. Both are largely on private right-of-way rather than using in-street track, and both use high-level platforms rather than ground level entry. But they share the low speed and frequent stops of older streetcar systems. This line exists to help add to the “multi-modal” nature of the urban station (which also has a bus park, in addition to the commuter and shinkansen line platforms). But it’s also to give me an excuse to buy a few modern articulated light-rail cars.

Scale


Japanese train models come in two different scales, 1:150 for narrow-gauge trains and trams, and 1:160 scale for standard-gauge Shinkansen models. The former isn’t quite correct (the 9mm track is still too wide), and the differences between the two scales are subtle, and many “N-scale” buildings aren’t strictly built to any specific scale, so there can be worse errors when putting a train beside a structure than you’d get from two different-scale trains next to each other. In any case, since I want to model both on one layout, I’m going to be mixing scales. What I’ve decided is to aim to do most things in 1:150 scale (and anything I scratchbuild will be to that scale). However, I’ll mix cars, buildings and figures in both scales (with some attention paid to not mixing them in a way that’s obviously conflicting).