An S-Bahn is a type of suburban rail network with a bigger footprint than a traditional metro, which links a city to its outer suburbs and inner commuter towns.

The name is an abbreviation of the German: in various cities across the German-speaking world, you'll find Schnellbahns (“fast trains”), Stadtbahns (“city trains”) or Stadtschnellbahn (“fast city trains”).

The Berlin S-Bahn and U-Bahn map. This will become relevant soon enough. Click to expand.

But you'll also find S-tog systems in the Denmark and Esko systems in the Czech Republic. And while no one tends to call it an S-Bahn, the Parisian RER (“Réseau Express Regionale”) is really another version of the same sort of thing: a regional metro system, with largely segregated tracks, on which a number of suburban branch-lines combine to provide frequent services through the city proper.

London doesn't really have anything quite comparable to this, for reasons I delved into a couple of weeks back. (Short version: north of the river, at least, the Tube tends to play the same role.) But it does have the London Overground, and it's soon to have Crossrail, which are sort of the same thing if you squint.

So on Christmas Eve, a German train fan posting on the RailForums website as U-Bahnfreund (“subway friend”) decided to treat those networks and Thameslink as if they were London's S-Bahn network and draw a map, which he then put it on Wikimedia Commons:

Ooooh. Click to expand. Image: U-Bahnfreund/Wikimedia Commons.

Let’s get the inevitable nerd whinges out of the way first. These services are not all really much like S-Bahns, are they? Crossrail and that first phase of the Overground you can make a case for. But the Overground lines from Liverpool Street, where services are lower and stopping patterns more confusing? That silly branchline between Romford and Upminster?

And then there’s Thameslink, shown here with the vast number of branches it'll have once its apparently endless rebuilding project – once known, hilariously, as Thameslink 2000 – is finally completed. Even if the powers that be resist the urge to change the proposed service pattern for the 179th time, most of those outer branches will see relatively tiny numbers of trains, and several of them serve destinations a quite ludicrously long way form central London (hi, Peterborough). It’s not obvious to me why these services should qualify for S-Bahn status when the more frequent inner suburban routes run by, say, South West Trains shouldn't.

But let's leave the mean-spirited nitpicking aside and look at the actual map because it’s bloody gorgeous. Inspired by the Berlin S-Bahn map (above), it treats the inner ring of orbital Overground services as a box, from which other lines radiate. It places Farringdon, where Thameslink and Crossrail will cross, at its centre (a position roughly occupied by the Hauptbahnhof – main station – on the Berlin map).

Click to expand. Image: U-Bahnfreund/Wikimedia Commons.

It also gives each individual route its own line identity, consisting of a letter (which shows which network it's part of – T, C or O) and a number (which narrows it down further). Similar routes have similar colours, and shortened versions of services end in a five, a sort of digital version of “and a half”. Here's the complete index:

Click to expand. Image: U-Bahnfreund/Wikimedia Commons.

Dotted lines mean “peak hours only”, incidentally.

It's so well-done, in fact, that I find myself wishing London’s rail network really did work a bit like this. I’m forced to conclude the problem is less the choices that have been made about how to represent the system, than the incoherence of the system itself – that the problem is not the design, but in the actual, real London.

At any rate: this map does at least offer insight into how much tidier London's rail network could look, given a little German rationality and efficiency. U-Bahnfreund, if you're reading, we salute you.

UPDATE, 1700hrs:

Our mystery map-maker has come forward. He’s called Simon, and he tweets as @SimonSchre.

I created a map of the London Overground, Crossrail (Elizabeth Line) and Thameslink services as of 2019 in the style of Berlin’s S-Bahn and U-Bahn map (@BVG_Kampagne). Check out this forum thread about it: https://t.co/BQ2CXWHFGt // cc @geofftech @TubeMapCentral @transitmap pic.twitter.com/mLVedDTMKG — Simon S. (@simonschre) December 26, 2017

He messaged me to explain some of the thinking beind the map:

To answer some of your questions: this was really just a holiday project so I did not put *too* much thought into it. I chose these three systems (Thameslink, Overground and Crossrail) as together, they kind of resemble Berlin’s S-Bahn system (S1/2/25/26 north-south, S3/5/7/75/9 east-west and S41/42/45/46/47/8/85 circular), also, it was already hard enough to figure out all the service patterns planned only for Crossrail and Thameslink in 2019, let alone for the entire London rail system (see below though).

Once I picked these three systems, I drew all lines that (will) belong to them, including the Romford-Upminster shuttle, the Overground lines from Liverpool Street, and the outermost branches of Thameslink.

But just like you pointed out, many S-Bahn-like railway lines, especially in South London, are left out, and some of the lines shown do not really qualify for the label (although here in Germany, the S-Bahn brand also becomes increasingly “misused”, with some S-Bahn lines that are diesel, only run every one or two hours etc).

This is why I spent the first days of 2018 unravelling the London suburban railways, as of the 2018 timetable, and came up with a new version of the “S-Bahn” system with 94 individual lines (some are express services though, and there are still some weird stopping patterns or frequencies), with most lines running twice per hour. For example, the Southeastern service from Victoria to Orpington via Beckenham is the S50, or the Northern City line to Moorgate is covered by lines N3 and N4 to Welwyn, Hertford and Letchworth.

I also started drawing a new map for this new version (with a new style) and by February I had all of North London finished – but because I also had a lot to do for school and the South London system is really complicated, I did not continue the map.

Although I appreciate that you like my map, I must say that there are loads of other people who can draw maps much better than me; I even struggle creating a map of the buses in my home city in Germany.

It is perhaps understandable that his full London rail map seems unlikely to see the light of day. Pity, though: I’d like to see someone come up with 94 different colours.

Jonn Elledge is the editor of CityMetric. He is on Twitter as @jonnelledge and on Facebook as JonnElledgeWrites .