RogerBW's Blog

In most Simutrans data files, a station tile has a 5×5 square catchment area. In pak128.Britain, it's 9×9. From such small differences one can generate a truly efficient passenger transport system.

Be warned that this is horrendously expensive, and if you're not in Freeplay mode (or you don't have several million in spare cash) you're likely to ge bankrupt before it starts to pay for itself.

First, pick a big city. No, a really big one. 30,000 people at an absolute minimum, 50,000 is better, several big cities right next to each other best of all.

Now pick your transport mode. There are two good choices here: the Docklands Light Railway B92 set (one tile, found under trams/light rail) and the BR London Overground Class 378 EMU (four cars fit into three tiles). Both of them are selected for lowest cost per passenger-tile; the DLR set is slightly cheaper to run at full capacity, but three tiles' worth of it will carry twice as many passengers as three tiles of Class 378, and that may leave you with trains that don't run often enough. I'm going to use the Class 378 here, meaning I need three-tile-long platforms, which is a useful length for reasons which will become apparent.

The basic idea is to cover the city in a grid of stations that leaves no building outside a station's catchment, but also doesn't overlap catchments. There are two basic approaches to this; I'll cover the more complex but more efficient one first.

The first stage is to pick an accessible corner of the city – insofar as the city is L-shaped, make this the corner of the L – and dig a tunnel down and underneath it (using the deep tunnelling technique I mentioned in the previous Simutrans post). Go to level -2, -3 if you're near the coast and expecting to operate under the sea bed; the point of this is that you won't need to worry about terrain at all.

Each station on the network will consist of 3×3 tiles. Build the tracks for the first one such that its coverage will include all of the corner of the city. (Switching to a station tile tool will highlight the coverage area.) Point the tracks in the direction of the city's long edge. Cross the tracks at the station throat (remember you can only build off an existing tunnel).

The gap between stations must be exactly eight tiles long. The first one is a crossover track feeding what will be all three platforms; then six tiles of parallel tracks; then another crossover track, then the platform tracks for the next station.

Continue if necessary until you've covered the far side of the city.

Now electrify all the tracks. (You can do this later, but with third rail it can be tricky to see whether everything's been hooked up if you've already put station buildings in place.)

At the end of each parallel track section, put in a platform choose signal facing where the station will be.

Put in the actual platforms. (If you have the money, make these big ones with large passenger capacity.)

Now build a tranverse line from one of the stations. Note the more widely-separated track layout; the trains are going to be slowing down round curves anyway, but there's no need to overdo it. Electrify, signal, and add platforms as before.

Now from that spur build a second longitudinal set of tracks parallel to the first, covering as much of the city as you can.

If traffic seems likely to justify it, build as many more longitudinal and transverse lines as you like. It's probably best to start with a single transverse line leaving the network with an "E"-shaped layout, and work towards filling in the grid as traffic demands.

Put in a depot somewhere vaguely central. (Note that you can't put a tram/light rail depot underground, so in that case you should probably put it at the top of the initial dig.)

The simplest approach to line management is to make each longitudinal and each transverse line a separate back-and-forth service, but you can get more cunning: with three platforms per station you can afford to have "express" services that stop only at the busier stations, overlapping loops, etc. Each line should probably have one stop with a 20% minimum load, just so that the trains aren't running constantly, but you'll need to tweak things a bit to work out which stop that should be.

I have found that with three-tile Class 378s it's not worth having a back-and-forth line longer than about four or five stops, as the trains can get clustered waiting for passengers.

Inter-city links (I tend to use maglevs for this) can happen on their own, deeper, level.

An alternative, less efficient but faster-running, approach for the enthusiastic burrower would put all the transverse lines one level down, thus avoiding congestion at stations. In this case you'll need extra linking tunnels and interchanges to allow trains to get from the depot to their service tracks; services should probably be restricted to simple back-and-forth.

If you're using the light rail tools, note that you need to use road tunnels, and there's an extra stage of track-laying: dig road tunnels, lay tracks, electrify tracks, then add signalling (rail signals) and stations. (In current versions you need to use the tram overhead wire to make the system realise the tracks are electrified.)

It is possible to use non-square stations. For example, single-tile platforms in parallel would fit a DLR unit. Just make sure there are eight clear squares between station edges so that the catchment areas don't overlap or leave gaps.