Dig-dig-dig for extra station passageway

Over four long years, we have been hard at work building the roof of the Brittenpassage, the second passenger tunnel at Amsterdam Zuid station. During this last summer, we inserted two huge roof sections made of 7 million kg of concrete underneath the A10 and a railway track. To do this, we had to (temporarily) remove a section of motorway and the track, but replaced it all neatly again after finishing the work. To the naked eye, the amount of work we were doing underground remained invisible for a long time, but this is now changing. With the removal of a total of 50 cubic metres of sand underneath the A10, metro and railway tracks, the initial contours of the future Brittenpassage are finally visible. This marks a real milestone.

The workers from the Nieuw-Zuid (BCNZ) construction consortium are already halfway through the job. They have dug up 25,000 cubic metres of sand – enough to rapidly fill around 1,250 trucks. Underneath the huge roof sections we inserted into position over recent years, a whole new world is gradually taking shape. And it is not only sand that is being removed: one of the underground surprises include the (still intact) remnants of what used to be the Amstelveenboog (‘Amstelveen bend’), the tunnel that the metro and tram route 51 used to use. The walls covered in graffiti all need to be removed – and the same applies to the sheet piling that covers the whole width of the new passenger tunnel. This was installed years ago to enable construction of part of the foundations for the roof sections, but is now no longer needed.  

A lot more sheet piling is still being installed, but now on both sides of the passageway. This is used to prevent the soil collapsing inwards during digging. It also marks the side walls of the passageway. Installing this sheet piling is a major job – it needs to be driven 23 m into the ground, but the height of the passageway is currently just 3 m. For this reason, the sheet piles (and the tubular piles that connect them to each other) are being pressed into the ground in 1.8 m sections using a special machine with jacks. The next section is welded on top of it and also inserted and so it continues. For each sheet pile and tubular pile, around 12 sections need to be attached to each other, which involves a lot of welding.

As soon as the sheet piling is in position on both sides, the digging can continue. The new Brittenpassage will ultimately be 5 m in height, but we are digging even deeper than that – in order to make it possible to build the foundations and install the technical systems in the crawlspace underneath the passageway. In late November, we expect to be installing the first bored piles for the foundations. In February 2024, we will build large footings (very robust concrete structures), on which we will build columns to form the new interim supports for the passageway. As soon as these are in place, the old support pillars can be removed. 

Five of the seven roof sections for the new Brittenpassage are now in position. Underneath these – on the southern side of the passageway – we are currently digging the passenger tunnel. The sixth roof section is ready, but not yet in its final position. It is still being used as a construction road to our work site between the tracks. This month, we will begin construction of the most northerly roof section. In 2024, we will move these last two concrete sheets further north and digging can then start on the northern side. The Brittenpassage is scheduled to open by 2027 at the latest.