Arlanda Express - line direction swap

[Class73Electro]

Not sure if anyone might know about this, nothing ventured...

Does anyone know why the Arlanda Express trains swap sides in the tunnel under the airport? You enter with the standard left hand side running, but when you get to the station the lines have swapped and you're on the right. I know that the mainline branches off in the tunnel, but shouldn't affect line direction.

 

[edwin_m]

Not sure if anyone might know about this, nothing ventured...

Does anyone know why the Arlanda Express trains swap sides in the tunnel under the airport? You enter with the standard left hand side running, but when you get to the station the lines have swapped and you're on the right. I know that the mainline branches off in the tunnel, but shouldn't affect line direction.

Is the junction in the tunnel grade separated, so one of the diverging tracks goes over or under the main line? If so perhaps they have routed that track to avoid some area of difficult geology, resulting in it landing up on the wrong side of the other track.

 

[Class73Electro]

Is the junction in the tunnel grade separated, so one of the diverging tracks goes over or under the main line? If so perhaps they have routed that track to avoid some area of difficult geology, resulting in it landing up on the wrong side of the other track.

Not sure, would that be possible in a tunnel?

 

[jamesontheroad]

Is the junction in the tunnel grade separated, so one of the diverging tracks goes over or under the main line? If so perhaps they have routed that track to avoid some area of difficult geology, resulting in it landing up on the wrong side of the other track.

Yes, that is effectively what happens. Left-hand running through the main Arlanda tunnel, with two spurs to the Arlanda Express stations at Arlanda South and Arlanda North swapping to right-running because of the configuration of the underground junction.

OpenStreetMap has the most accurate mapping of the railway lines under Arlanda. If you click on this link…

OpenStreetMap

OpenStreetMap is a map of the world, created by people like you and free to use under an open license.

www.openstreetmap.org

… you should see that the northbound line from Stockholm Central towards Arlanda South and Arlanda North diverges from the main line inside the Arlanda tunnel. It diverges to the left (west) then line then passes over (or possibly under… but I think it’s over) the main line.

Once it has crossed to the east side of the main line, it joins a shorter southbound spur which is in between it and the main tunnel. This means they’ve swapped sides.

If that sounds complicated it also hints at the absurd amount of engineering required for these three stations, all of which serve a relatively small international airport. The stations are within about 150 metres of each other, and the terminals are now partially connected airside and completely connected land side. You can technically ride the the Arlanda Express for free between Arlanda North (T5) and Arlanda South (T2) but the time taken to descend to the station, ride the train and ascend to the terminal is about the same as just walking.

 

[Class73Electro]

Yes, that is effectively what happens. Left-hand running through the main Arlanda tunnel, with two spurs to the Arlanda Express stations at Arlanda South and Arlanda North swapping to right-running because of the configuration of the underground junction.

OpenStreetMap has the most accurate mapping of the railway lines under Arlanda. If you click on this link…

OpenStreetMap

OpenStreetMap is a map of the world, created by people like you and free to use under an open license.

www.openstreetmap.org

… you should see that the northbound line from Stockholm Central towards Arlanda South and Arlanda North diverges from the main line inside the Arlanda tunnel. It diverges to the left (west) then line then passes over (or possibly under… but I think it’s over) the main line.

Once it has crossed to the east side of the main line, it joins a shorter southbound spur which is in between it and the main tunnel. This means they’ve swapped sides.

If that sounds complicated it also hints at the absurd amount of engineering required for these three stations, all of which serve a relatively small international airport. The stations are within about 150 metres of each other, and the terminals are now partially connected airside and completely connected land side. You can technically ride the the Arlanda Express for free between Arlanda North (T5) and Arlanda South (T2) but the time taken to descend to the station, ride the train and ascend to the terminal is about the same as just walking.

Oh wow - thanks! I have never appreciated how complicated that little bit of line could be!

 

[jamesontheroad]

You can learn more about the railway line(s) and stations on the website of the company that manages them:

https://arlandabananinfrastructure.se/en/

 

[Class73Electro]

You can learn more about the railway line(s) and stations on the website of the company that manages them:

https://arlandabananinfrastructure.se/en/

Thanks!

 

[JonasB]

In short, it was cheaper to build it that way. I don't know the exact reason why but since it's just a small line with two stations that doesn't continue anywhere it really didn't matter that much.

OpenStreetMap has the most accurate mapping of the railway lines under Arlanda. If you click on this link…

OpenStreetMap

OpenStreetMap is a map of the world, created by people like you and free to use under an open license.

www.openstreetmap.org

… you should see that the northbound line from Stockholm Central towards Arlanda South and Arlanda North diverges from the main line inside the Arlanda tunnel. It diverges to the left (west) then line then passes over (or possibly under… but I think it’s over) the main line.

It's even easier to see on Openrailwaymap. Same data, but a different presentation. https://openrailwaymap.app/#view=13.55/59.64649/17.93033

 

[jamesontheroad]

It's even easier to see on Openrailwaymap. Same data, but a different presentation. https://openrailwaymap.app/#view=13.55/59.64649/17.93033

Much better. This also shows the short dead-end tunnel beyond Arlanda North. In normal operation, trains from Stockholm Central arrive on the right-hand track, then continue forward into the dead-end shunting tunnel before returning right-side running to the departure platform.

I only use the Arlanda Express when someone else is paying - which happens to be happening next week when I need to get downtown rapidly for an event.

In normal times, I just buy a SL 75-minute single ticket and take bus 583 from Arlanda SkyCity or Arlanda T2 to Märsta and then a pendeltåg to Stockholm and stations towards Södertälje. Living in northern Sweden, a couple of times a year I force flight itineraries with a 4-5hr layover in Arlanda so I can take this route into town for lunch, shopping or a museum.