Construction of the new RBS railway station in Bern
Construction of the new RBS railway station in Bern

Construction of the new RBS railway station in Bern

Bern has the second largest railway station in Switzerland. The existing RBS railway station was opened in 1965 and is capable of handling around 16,000 pas­sen­gers. Today, some 60,000 people use the RBS railway station every day. Com­pared to 2016, the capac­ity utilisation of Bern station as a whole is expected to increase by a further 39% by 2030. The old RBS station cannot be expanded, so a new RBS station will be built under tracks two to seven. This will consist of two large under­ground halls, each with two tracks and a 12-metre-wide central plat­form. Ultimately, this will provide significantly more space and com­fort, and will also allow for trains to run more frequently and longer trains.

How is Marti involved in the construction of the new facility?

Marti will be working on phase 1.3. Thomas Heid, site manager for phase 1.3, explains: "You could say that phase 1.3 is the key ele­ment of the entire project." Phase 1.3 con­sists of two caverns: the north cavern and the south cavern. The cav­erns are 199 and 209 metres long respec­tively. They are both 17 metres high and 23.8 metres wide. Words alone cannot convey the scale of these dimen­sions. When you visit the site for the first time, you are over­whelmed by the sheer size of the cav­erns. By way of com­par­ison, a seven-storey building would fit into the cav­erns in terms of height. Now that’s impres­sive. Students will have the oppor­tu­nity to visit the caverns in October 2024 as part of the Concrete Colloquia 2024. The open day will be held on 7 September 2024. Anyone who is inter­ested can register for this day.

That's already quite impres­sive, but there's more to it than just that.

Art in construction and in the tunnel

Concreting the inner vault with ribs is a tech­ni­cally very demand­ing task. The rein­force­ment was pre-assembled in the cavern during the assembly of the vault form­work car­riage. The vault blocks are now being concreted in several phases using the impres­sive formwork carriage, which was developed and built by Marti Technik AG in close col­lab­ora­tion with Marti Tunnel AG. Each section of the vault is five metres long. The fluc­tu­ations in the raw materials, the blocking of the fibres between the rein­force­ment and the logistics chain (multiple handling, free fall of approx. 25 m) as well as the weather conditions, which varied greatly over the course of the project, have pro­longed the devel­op­ment and new paths had to be taken. A stable mixture for the vault con­crete was developed and suc­ces­sfully tested with the newly developed additive "Quantum Compound" from Bau­stoff­park Walliswil. Marti is confident that they can sat­isfy the high aes­thetic expec­ta­tions and is looking forward to the challenges ahead with this unique ribbed vault.

The formwork carriage is truly a 260 tonne masterpiece. It took around nine months to plan and produce the parts. Some 20 trucks were needed to transport the indi­vid­ual parts to the con­struc­tion site. The parts were then low­ered into the cavern via the shaft, where ten employ­ees assem­bled the formwork carriage over a period of several months.

Con­struc­tion of the form­work carriage began in December 2023 and the first block was con­creted in March 2024. One block contains around 80 cubic metres of the self-com­pact­ing fibre concrete specially developed for this pur­pose by Marti and is five metres long, 20 metres wide and 16 metres high.

The spec­ifi­ca­tions in terms of geometry, the required tol­er­ances and the desired exposed concrete properties call for the highest levels of expertise, experience and com­mit­ment from everyone involved – from planning, con­struc­tion and concreting to the very tricky stripping process and curing.

The form­work carriage is 100% electrically powered. It sits on four hydrauli­cally driven bogies. The lifting supports that are used to position the height and posi­tion of the carriage and thus the formwork to within mil­lime­tres stand on these. All of the functions and move­ments are hydrauli­cally controlled by the employ­ees from the central control station.

The team is confident that it will be able to satisfy the high aesthetic expec­ta­tions and is looking forward to the chal­lenges ahead with this unique ribbed vault.

Conclusion

The con­struc­tion site in the heart of Bern allows Marti to capitalise on the broad knowl­edge and skills of all its employ­ees. Everyone involved puts in a remark­able per­for­mance every single day. Federal Councillor Albert Rösti summed it up perfectly at the break­through on 23 June 2023:

"I can barely imagine the amount of work that everyone involved has done here. They are the ones who have achieved this, the credit is all theirs. You all deserve a big round of applause."

I can barely imagine the amount of work that everyone involved has done here. They are the ones who have achieved this, the credit is all theirs. You all deserve a big round of applause.
Albert Rösti,
Federal Councillor

Facts & figures

Dimensions of the caverns (Lot 1.3):

  • Length: 199 m (north) and 209 m (south)
  • Height: 17 m
  • Width: 23.8 m

Formwork carriage :

  • Weight: 260 tonnes
  • Dimensions of the vault blocks: 5 m long, 20 m wide, 16 m high
  • Concrete per block: 80 m³
  • Drive: 100 % electric

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