Jungfraubahn to celebrate centenary
Top of Europe with new underground visitor attraction
Sika products have been specified for a new underground attraction at the Jungfraujoch, the "Top of Europe", at an altitude of nearly 3,500m.
The Jungfraubahn rack railroad takes visitors from the Kleine Scheidegg pass to the Jungfraujoch, at an elevation of 3,454 m. This groundbreaking feat of engineering was opened on Swiss National Day (August 1) in 1912 after a 15-year construction period (1896-1912), having cost a full CHF 16 million. Open 365 days a year, the Jungfraubahn railroad covers a distance of 9.34 km and overcomes a height difference of 1,393 m. As early as 1913, the Jungfraujoch attracted some 42,880 visitors.
New adventure tunnel: best all-weather attraction
100 years on, the annual tally has risen to 700,000. To guarantee an exciting visit even in poor weather, the Jungfraubahn AG will mark its 100-year anniversary with the opening of a new 255 m long adventure tunnel. This direct underground link between Sphinx Hall and Ice Palace is certain to become the best all-weather attraction anywhere in the Alps.
The new tunnel: circular trail with showcase niches
The adventure tunnel will take the form of a circular trail featuring various attractions in a sequence of caverns (showcase niches). It is designed for wheelchair and fork-lift access. Two travelators, 43 and 70 m long, will be provided along the inclined sections. Part of the installation caverns and muck tunnel will be used for storage purposes.
The new route leads visitors from the Sphinx Hall to the existing Anchorage Tunnel, overcoming a height difference of 8 m. A newly built passageway branches off the Anchorage Tunnel to join up with the access tunnel to the Ice Palace.
An approx. 60 m muck tunnel was built to remove spoil from the excavation face. This runs south-east from the Aletsch Glacier exit to the glacier, where the uncontaminated material is tipped into a crevasse.
The tunnels and caverns were mainly excavated by blasting, with tunneling machines reserved for the sensitive sections. The tunnels and caverns were stabilized with shotcrete, mesh and rock bolts. All works except the muck tunnel were waterproofed by an umbrella membrane covered over by a min. 12cm thick, reinforced shotcrete lining. A conventional drainage solution with perforated pipes and French drains was adopted. The tunnels and caverns incorporate a reinforced-concrete base slab, placed over a cable conduit run.
Logistics/goods shipments
All shipments are made by road as far as Grindelwald-Grund station, from where they are taken by the Wengeneralpbahn rack railroad to the Kleine Scheidegg pass. Here, the materials are reloaded onto the Jungfraubahn railroad and transported to Platform 3 of the Jungfraujoch station.
High-grade concrete, 3,460 m above sea level
The project called for a concreting concept capable of accommodating low temperatures, averaging out at -8.2°C across the year, and ground temperatures potentially as low as ‑15°C.
The adopted solution involves the use of dry-mix materials, delivered to the site in big bags. Here, the dry mix is poured into a wheeled mixer and mixed with water. The 255 m addition to the complex tunnel system at the Jungfraujoch, Europe's highest-altitude railroad station at 3,454 m above sea level, looks certain to boost its pulling power.
| Quantity | Sika Products |
| 2,500 t | 0-8 mm shotcrete |
| 40 t | Sigunit L53 AF |
| 4 t | Sika ViscoCrete 3082 |
| 1,000 t | 0-16 mm in-situ concrete |
| 3,000 m2 | Sikaplan WT |
| 12 t | Sika RockGunit |
| 8 t | SikaShot-3 |
| Additional products | Sika Fuko Swell 1, Sika - 4A, Separol 5 S and Sika Pump – Start 1 |
