Wanted to walk to Oerlikon at the weekend, but half way I got... uhm... distracted.
Pro side: Got material for a new thread.

So join me exploring the closest #Zurich ever came to a metro: The @vbz_zueri_linie Schwamendingen tram tunnel.
Let's go underground!

We start at Milchbuck station, situated on top of a little pass, which separates the northern neighbourhoods Affoltern, Oerlikon and Schwamendingen from the rest of the city. Since 1986, the tram lines to Schwamendingen branch off here.

Nothing unusual here at first sight, but if we look close at the northern end of the station, we see trams dive down in a tunnel - in fact, into the only tunnel of Zurichs tram network.

The tram tunnel mainly beneath a highway tunnel, is 2.5 kilometers long and up to 25 m below surface. Trams are stopping at three underground stations before they pop up again in Schwamendingen. So let’s have a closer look.

Tierspital is the first stop. You’ll probably immediately see in the picture, why I find this place so fascinating: The stations are lit up in a melancholic, slightly eerie deep blue light.

There are not many passengers here on a weekend. Between two trams, when you’re alone down here, you can here the rumbling of the trams in the adjacent tunnels and a strange howling sound.

And you’ll notice how big the stations actually are. No wonder: The tunnel was originally built for the never completed Zurich metro with 136 m long platforms, equivalent to a six-car metro train. The longest tram consist down here measures 45 m only.

But let’s talk about the extraordinary lighting concept by nachtaktiv lighting designers. The diffuse blue light makes the spaces seem bigger than they actually are. The white wall panels reflect the blue colour.

Brighter and warmer light marks the 45m platform part and the exits. The platform nearly looks like an island in a cold, blue ocean.

Another slightly creepy thing: Because the stations are placed just beneath the highway tunnel, direct access to surface was not possible everywhere. To leave the station, you’ll first have to go deeper down and underpass the tunnels above in winding coridors.

It doesn’t help, that the walls look like a garage with ugly patches on leaking parts. And the howling sound gets really loud, I felt like in a haunted house. But it’s just the air pressed into the tunnel by the trams which is squeezing through small gaps between sliding doors.

At least, there are bidirectional escalators and a nice little twist in the lighting concept. Exits on the (southern) city side are always lighted up in green, those on the (northern) Schwamendingen side in orange.

If you finally make it to the surface, you'll notice that every access is marked by a tram icon in a backlit triangle. And these are probably the only places where you can spot a black VBZ logo in the wild.

And then, there are even more special exits. Let’s go back down and hop on a tram to get to Waldgarten, the next station, to see them. [to be continued...]

Waldgarten. Quick photo of an incoming line 7 service with class Be 4/8 leading, then taking the stairs down (still feels strange) to the surface.

But oh! No stairs or escalators down here. Lifts only! I feel like in a London Underground station. But no semi-public spiral staircase here, no choice but to take the lift.
Kudos to #VBZ for engraving the official tram symbol into the lifts panel!

On the surface, it looks like this. Kind of a oversized garden shed marks the entrance to the tunnel, again with a tram triangle. And you can tell the epoque this has been built by the rounded corners.
If a non-local would recoginse this as an entrance to a tram station?

Oh, and look what we have here! A very unusual but uber cool Tram2000 sign, pointing to the lifts! I think, the three tunnel stops are the only place these gems can be found in Zurich.

Back down on the platform. Since the tunnel opened in 1986, it has been served by the same two lines:
7 Wollishofen–Stettbach and
9 Heuried–Hirzenbach.
Both lines run every 7-8 mins Mon to Sat and every 10 mins on Sundays.

Rolling stock wise, the tunnel is still a #Tram2000 paradise. On the 7, every second tram is a double Be 4/6 set, the other one a Be 4/8 - Be2/4 set. On the 9 you’ll see low floor “Cobras” but also Tram 2000 Be 4/8 solo or Be 4/6 - Be2/4 consists.

Next and last stop is Schörlistrasse, which has a slight curve at the eastern end, where the tunnel leaves the highway trace and curves towards Schwamendingen. Ideal for photos at the moment, as the Schwamedingen side exit is temporarily closed.

Last but not least, lets have a look at symbols and typography here. If you haven’t noticed before: They used triangles not only for the entrance but also for the platform lights.

An important element is the black band. It holds station names at the walls and coloured light plus wayfinding signage in the corridors. You'll even find it at the ceiling on the side of the triangle lamps and on the floor in form of benches and other platform equipment.

What I probably love most is the very neat Helvetica typography in best “Swiss Style” tradition. Station names, wayfinding and even emergency information: All white letters on a black background.

The designers used only a few elements (coloured light, triangles, black band, typography) and applied them very consistently to the quite different types of underground spaces. Most elements are standard industrial parts, which reduced costs.

And into a Tram again, doing the final leg to Schwamendingen. Here, the line resurfaces at the neighbourhood’s central square, reminding us that tunnel portals in built areas are never a really pretty thing.

But what’s this? Shortly before the stop, the tracks cross over. This is due to the fact that Zurichs tram only have doors on the right-hand side, but the tunnel has central platforms which requires changing to left-hand traffic for this partof the line.

In case you wonder: On the Milchbuck side, there is no such thing on the surface. The southbound single-track tunnel crosses under the opposite direction, which is still on the surface there.

Schwamendingerplatz is also the last common station of line 7 and 9 before they separate for the last bit to their respective terminal stations. Nothing more to see here, so I’ll take the tram back through the tunnel.

Bonus: Here’s a video - quite bad, sorry - from the back of the tram showing the (mainly dark) ride from Schwamendingen to Schörlistrasse. Speakers on for the full Tram 2000 sound experience.

To come to an end here: The tunnel wasn’t always so stylish. Todays set-up is the result of a modernisation programme conducted in 2012 by raumgleiter architecture and nachtaktiv lighting design.

How it looked before? Well, judge yourself…
Source: http://wikimedia.com  / CC BY-SA 3.0
(1): Iwouldstay
(2): mn

The tunnel also has a very interesting history. But as this thread already got somehow out of hand, I’ll tell that story another time...