Four construction sites are currently in operation, three in Austria and one in Italy. If you simply click on a construction lot, it will take you directly to its brief description, the overview plan and the photo gallery.
The excavation progress of the individual tunnel structures in the various construction lots is updated regularly. Work progress is shown on a graph.

Lot H21 Sill Gorge

GENERAL INFORMATION ON THE CONSTRUCTION LOT

The ongoing works on the H21 construction lot "Sill Gorge" - which began in August 2020 and are scheduled to run to the end of 2024 - will provide the link between the northern end of the Brenner Base Tunnel and the central station in Innsbruck. The Sill Gorge is located to the south of Innsbruck. It is a very popular recreation area and is adjacent to the well-known Bergisel ski jump. This construction lot includes the north portal of the Brenner Base Tunnel, a section of approx. 600 m with bridges and a (pre-) tunnel, river engineering measures, road construction measures and, once construction has been completed, re-naturation and landscaping work. The estimated construction costs for this stretch are 60.1 million Euro and Porr Bau GmbH Kematen will carry out the works.

Compared to the other construction sites in the Austrian project area, where works take place mostly underground, this is a construction area where most of the work is carried out above ground. For this reason and due to the proximity to the city of Innsbruck, work is "only" carried out during the day. The "Sill Gorge" section mainly includes the following construction works: a supporting wall (290 metres long), a cut-and-cover tunnel at the foot of the Bergisel (130 metres long), two steel trellis bridges bridges over the Sill river, the northern portal to the Brenner Base Tunnel and a subsequent 130-metre long stretch of tunnel into the adjacent solid rock (Viller Berg tunnel). The tunnel breakthrough will take place here coming from the south, via the neighbouring construction lot H41. In addition, river engineering measures are to be carried out to ensure flood protection and enable fish passage. Renaturalisation and path construction work is planned in order to integrate the Sill gorge recreational area into the existing hiking trail network and make it available to the public once the construction work is completed. In spite of the relatively short stretch, this construction lot thus comprises very complex construction activities.

The stretch leads through the narrow and therefore logistically challenging Sill Gorge. The area is characterized by numerous pieces of infrastructure in the immediate vicinity such as the A12 Inntal highway, the A13 Brenner highway with its well-known arched bridge, the "Untere Sill" power plant belonging to the municipal utilities company "Innsbrucker Kommunalbetriebe", the "Tirol Panorama" museum (Bergisel) as well as the existing ÖBB railway line with the Bergisel tunnel.

The gorge - which is mostly in its natural state - is an important recreational area for the urban population of Innsbruck and can be reached via several hiking trails. In order to maintain public access to the Sill Gorge during the construction period, a special replacement hiking trail was built. In addition, direction signs were installed for better orientation and information boards were built up at access points near the construction site.

At the construction site itself, the construction of the 42-metre road access bridge over the Sill has already been completed. The demolition of the old access bridge and all the river engineering works were completed in spring of 2022. With the dismantling of the AGA weir, fish can once again swim upstream in the Sill. A symbolic start to the excavation of the main tubes southwards took place at the end of October 2021. Shortly afterwards, blasting began at the future north portal of the Brenner Base Tunnel. Since May 2022, excavation has been ongoing on the two approximately 130 m long main tunnel sections of the Viller Berg into the adjacent bedrock. The breakthrough of the "Sillschlucht-Pfons" construction lot H41 from the south is expected in 2024. Concreting and backfill work on the supporting wall on the orographic left side of the river is complete. This is where the tracks will run in the future to provide a low-gradient connection from the Brenner Base Tunnel to the Innsbruck railway station.

The concreting work for the Silltal tunnel was completed at the start of 2024. The tunnel is now being backfilled with previously removed material, and it will be planted with local (indigenous) shrubs in the summer. Furthermore, the final work is currently being carried out on the two railway bridges over the Sill; the steel structures, the fire protection enclosure and the paving slabs for the railway tracks have been completed.

Also, a 55 m long pedestrian bridge in pre-stressed concrete was built over the Sill and this structure will be part of the hiking trail network in the Sill Gorge in the future.

Current construction work

  • A reinforced concrete retaining wall along the Sill, around 200 m long and over 9 m high, with its foundation on bored pilings. This is where the railway line will run above ground between Innsbruck main station and the north portal of the BBT. The supporting wall is currently being backfilled with local excavated material, and follow-up work such as the construction of a service path and railing installations is being carried out.

  • The "Tunnel Silltal" cut-and-cover tunnel through the eastern slope of the Bergisel; it is approximately 130 metres long and built as a cut-and-cover concrete box, including the northern and southern portals. After completion of the concrete works the tunnel will be covered with landfill by the end of this year and re-planted in order to restore the original natural condition of the area.

  • Emergency reservoir and cable collector. Two structures which will guarantee proper rail operations. The cable collector supplies the electrical systems of the tunnel. Any liquids escaping in case of an accident are collected in the emergency reservoir, and from there they can be properly disposed of.

Ecological aspects in H21

An important part of the construction lot is the restoration of upstream fish passage in the Sill. The AGA weir, located at the entrance to the Sill gorge with a drop height of approx. 8 metres, was removed in 2021 and replaced by a roughly 350-m long fish ladder with a low-lying meandering channel in which water runs even during the dry season. In the course of these river engineering works, the riverbed was moved about 8 metres to the east in order to gain sufficient space on the western side for the retaining wall with the new double-track line running on it. Flood-proof and long-lasting, stable embankments were constructed and re-naturalised.

Appropriate renaturalisation and restoration of the original landscape will take place, for example by backfilling the Silltal tunnel at the end of construction, including planting with typical native trees and shrubs, thus restoring the original natural condition of the Sill gorge.

EXCAVATION DATA - All the excavation works in this lot were completed by May 2022

Main tunnel East (completed)
Excavation
120 m
Length
120 m
Cross-section
100 m²

Main tunnel West (completed)
Excavation
130 m
Length
130 m
Cross-section
100 m²
Overview with status of the works
Photo gallery

Lot H41 Sill Gorge-Pfons

GENERAL INFORMATION ON THE CONSTRUCTION LOT

Works on this construction lot began in mid-January 2022 with the set-up of the construction site. Excavation works started in July 2022 towards Innsbruck with the lowering of the cross-chamber slab.

The H41 "Sill Gorge-Pfons" construction lot is located in the northern area of the BBT between the Sill Gorge of Innsbruck in the north and Pfons in the south. The Ahrental access tunnel, which has already been completed in the E41 "Ahrental" prospection lot, is used for the main excavation.

This construction lot represents the continuation of the construction works carried out in the H33 "Tulfes-Pfons" preliminary lot. The tender for the H41 construction lot was awarded on 17/11/2021 to the bidding consortium H41 Sill Gorge-Pfons comprising the companies Implenia Österreich GmbH, Implenia Schweiz AG, Webuild S.p.A, csc costruzioni sa. The total bid amount offered by the bidding consortium is 651 million euro.

In total, approx. 22.5 km of main tunnel tubes and 38 cross passages with a total length of approx. 2.3 km will be excavated by the summer of 2028 in this construction lot. In order to ensure the fastest progress possible in the whole project, the "Sill Gorge-Pfons" project area was extended southwards by three kilometres of main tunnel tubes, where it will connect to the future construction lot H53 "Pfons-Brenner".

The works basically include the following:

  • Remaining excavation of the Innsbruck emergency stop including excavation by blasting of the western mail tunnel tube up to the western assembly chamber for the TBM and to the eastern assembly chamber for the TBM
  • Blasting of main tunnel tubes northwards from Ahrental to the location of the breakthrough in the H21 "Sill Gorge" construction lot (east tube approx. 2,331 m long, west tube approx. 3,415 m long)
  • Mechanical excavation of the main tunnel tubes southwards from Ahrental up to the border of the future construction lot H53 "Pfons-Brenner" (east tube approx. 8,108 m long, west tube approx. 8,396 m long)
  • Inner lining operations in both main tunnel tubes, each approx. 14.4 km long, as well as in the Innsbruck emergency stop, the Ahrental cross-chamber, the cross passages (every 333 m), in the exploratory tunnel, in the Ahrental access tunnel including the Ahrental ventilation chamber and in the Patsch shaft as well as in the Sill Gorge access tunnel
  • Partition wall for the Innsbruck connecting tunnel east and west and tracks in side corridors (safety corridor) for the Innsbruck connecting tunnel east and west
  • Long-distance flushing system in the connecting tunnels Innsbruck east and west
  • Construction of a 69.4 metre long bridge over the A13 Brenner motorway

The following optional work was also tendered:

  • Remaining concrete inner lining in the Tulfes emergency tunnel

Current construction work:

  • Excavation main tunnel west northwards (Innsbruck)
  • Excavation main tunnel east northwards (Innsbruck)
  • Excavation main tunnel east southwards with TBM Lilia
  • Excavation main tunnel west southwards with TBM Ida

Completed construction work:

  • Construction of conveyor belt systems from underground to the Ahrental disposal site
  • Blasting assembly chamber west
  • Blasting assembly chamber east
  • Reinforcement works in the expolatory tunnel
  • Excavation emergency stop
  • Building of a production hall for the manufacture of tubbing rings (pre-cast concrete elements for the inner lining)
  • Construction of conveyor belt systems from underground to the Padastertal disposal site
  • Bridge over the A13 Brenner motorway
  • Erection of partition walls for the Innsbruck connecting tunnel east and west and tracks in side corridors (safety corridor)
  • Installation of the long-distance flushing system in the connecting tunnels Innsbruck east and west

EXCAVATION DATA of June, 25th 2024 (Updated monthly)

Main tunnel tubes SOUTH: TBM excavation
Excavation
6,597 m
Length
16,594 m
Cross-section
85 m²
Mail tunnel tubes SOUTH and assembly rooms TBM: drill and blast (completed)
Excavation
258 m
Length
258 m
Cross-section
82-210 m²
Mail tunnel tubes NORTH: drill and blast
Excavation
4,027 m
Length
5,746 m
Cross-section
70 m²
Crosscuts
Excavation
1,090 m
Length
2,260 m
Cross-section
30-70 m²
Emergency stop Innsbruck, remaining excavation (completed)
Excavation
702 m
Length
702 m
Cross-section
15-100 m²
Overview map
Photo gallery

Lot H33 Tulfes-Pfons

GENERAL INFORMATION ON THE CONSTRUCTION LOT

Since the end of September 2021, all work in this construction lot has been completed.

This construction lot was awarded to the Strabag SE / Webuild S.p.A. (ex Salini-Impregilo) bidding consortium in Summer of 2014.

construction time: 2014 - 2021
section of the tunnel to be driven: 43.3 km
awarded for: € 377 million

It consists of several structures:

  • Tulfes emergency tunnel
  • Innsbruck emergency stop
  • Main tunnel tubes
  • Connecting tunnels
  • Ahrental-Pfons exploratory tunnel

Construction works

Emergency tunnel

The emergency tunnel was being driven parallel to the existing Innsbruck railway bypass. It is 9.7 km long and the excavation cross-section is 35 m². The drill-and-blast excavation work on this tunnel started from three points at the same time: from Tulfes westwards, from the Ampass access tunnel eastwards and again westwards. The emergency tunnel was completed in Summer of 2017.

Main tunnel tubes

The main tubes have been excavated by blasting according to the so-called New Austrian Tunnel Construction Method. The ceremonial first volley was set off on 19/03/2015 in the presence of EU Commissar Violeta Bulc and the Ministers of Transportation of the 7 Alpine countries (Austria, Italy, Germany, Switzerland, France, Liechtenstein and Slovenia. This stretch includes about 6 km of main tunnels with an excavated cross-section of about 70 m2 .

Connecting tunnel between the BBT and the Innsbruck bypass

Construction has been under way since summer of 2015 on the two connecting tunnels between the Brenner Base Tunnel and the existing Innsbruck bypass. The connecting tunnels were also excavated by blasting, with a cross-section of about 115 m². Excavation work was completed in Spring of 2017.

Exploratory Tunnel

The construction lot Tulfes-Pfons included the construction of the stretch of exploratory tunnel between the Ahrental junction point and the town of Steinach am Brenner. The gripper TBM, 200 m long, started work on September 26th, 2015 and excavated about 16.7 km southwards, completing its work on July 6th, 2019. Since the breakthrough, the construction lot has been connected to the Pfons-Brenner lot.

Restoration of the collapse "Iris"

This collapse is a cavity that formed in a fault zone during the excavation of the exploratory tunnel. This had to be backfilled by means of cement mortar injections from an injection tunnel in order to rule out any effects on the overall tunnel system. As part of these repair works, the main tunnel tubes in the fault zone were excavated from July 2020 to May 2021 in advance by blasting using an auxiliary drivage from the exploratory tunnel. This allows to reduce interferences when the next TBM arrives.

Overview with status of the works
Photo gallery

Lot H52 Hochstegen

GENERAL INFORMATION ON THE CONSTRUCTION LOT

All work on this construction lot has been completed since December 2023.

Works on this construction lot began in February 2022 with the set-up of the construction site area at Wolf. On 4 May 2022, the ground-breaking ceremony took place in the costruction lot.
The H52 - Hochstegen construction lot, located within the area of the Steinach am Brenner township, is a part of the previous lot H51 - Pfons-Brenner which has now been restructured. This stretch of the project was divided in several construction lots, in order to guarantee the fastest and most efficient continuation of the works with an aim to driving the entire project forward quickly. The Wolf lateral access tunnel is used as a main access and supply route.

The Hochstegen lot is located in a zone characterized by extremely complex geological conditions. The stretch is about 500 m long, with mainly water-bearing, carbonatic rock layers, meaning that the tunnel excavation in this stretch is particularly challenging. The contract for the works in the H52 - Hochstegen construction lot was awarded to Swietelsky Tunnelbau GmbH & Co KG on December 15th, 2021. The bid was around 102 million Euro and construction time is expected to be 23 months.

The core of the project is the excavation of the exploratory tunnel southwards through the geologically challenging stretch known as "Hochstegen", where excavation will take place with the protection of preliminary sealing and stabilisation injections.

The works basically include:

  • 0.9 km of exploratory tunnel excavated southwards
  • 3.0 km of main tunnel excavated southwards
  • 0.6 km of connecting tunnels
  • 0.3 km of cross-passages

Completed construction work

  • Excavation work in the southern exploratory tunnel and in the main tubes, starting from the auxiliary drivage
  • Installation of an approx. 9 km long conveyor belt to the "H41 Sill Gorge-Pfons" construction lot
  • Construction of an auxiliary drivage from the exploratory tunnel to the main tunnel tubes in the Hochstegen zone
  • Excavation of the northern transition to the Hochstegen marble in the exploratory tunnel and the main tunnel tubes
  • Construction of a cross-over point
  • Injection measures in the area of the exploratory tunnel in the section of the Hochstegen marble

Hydrogeological construction support and monitoring of water resources:

With rock mass improvement measures in the form of injections, both water inflows and a lowering of the water levels in the protected areas "Hinteres Venntal" and "Hinteres Valsertal-Natura 2000" are to be avoided and the inflow quantities significantly reduced.

EXCAVATION DATA - All the excavation works in this lot were completed by November 2023

Main tunnel tubes (completed)
Excavation
3,026 m
Length
3,026 m
Cross-section
60-80 m²
Exploratory tunnel (completed)
Excavation
863 m
Length
863 m
Cross-section
60 m²

Cross-over and connecting side tunnels (completed)
Excavation
970 m
Length
970 m
Cross-section
25-30 m²
Overview with status of the works
Photo gallery

Lot H53 Pfons-Brenner

GENERAL INFORMATION ON THE CONSTRUCTION LOT

On April 4, 2023, the contract for the construction lot "H53 Pfons-Brenner" was awarded to a bidder consortium consisting of Porr Bau GmbH, Marti GmbH Austria and Marti Tunnel AG Switzerland.
With this award, the tunnelling works of the last remaining construction lot of the Brenner Base Tunnel have been commissioned. The contract value for what is now the largest construction lot on Austrian project territory amounts to EUR 959 million. The scheduled construction time for this tunnel section is 70.5 months.

Construction work for this lot started on May 4, 2023, and the order was made for the two tunnel boring machines (TBM) for this lot. The two TBMs will drive a stretch of 7.6 km (a total of approx. 15.2 km) in each main tunnel tube. Due to the ordering, delivery and installation times in the contract, the tunnel boring machines are expected to start driving northwards in the fall of 2024.

Tunnelling work according to the "NATM" (New Austrian Tunnelling Method, cyclical driving) will start much earlier, moving southwards to the national border at Brenner. These works are expected to start in spring of 2024. Until then, the construction site set-up will be ongoing.

The miners will excavate around 5 km per main tunnel tube (10 km in total) in the southern section of construction lot H53 Pfons-Brenner. At the same time, excavation work will continue in the exploratory tunnel, where the miners have to drive approx. 1.3 km.

Parallel to the respective drives in the north and south of the construction lot, 37 cross-passages of approx. 70 m each, i.e. 2,590 m, are being excavated. After completing the tunnelling work in the respective sections, the inner lining work will be carried out in the entire area from the lot boundary with lot H41 Sill Gorge-Pfons to the state border at Brenner, as well as in the access tunnel in Wolf.

The construction lot includes the following excavation works:

  • ca. 15.2 km of main tunnel northwards using a TBM
  • ca. 10.0 km of main tunnel southwards using the NATM method
  • ca. 1.3 km of exploratory tunnel southwards
  • ca. 2.6 km of cross passages (37)

The construction lot includes the following inner lining works:

  • ca. 15.6 km of exploratory tunnel
  • ca. 15.6 km of main east tunnel
  • ca. 15.5 km of main west tunnel
  • ca. 3.1 km of cross passages (45)
  • ca. 5.1 km of auxiliary structures (Wolf access tunnel, spoil tunnel, etc.)

Current construction work

• Blasting excavation main western southbound tunnel
• Blasting excavation main eastern southbound tunnel
• Blasting excavation exploratory tunnel southwards
• Assembly of TBM Olga in the main eastern northbound tunnel
• Assembly of TBM Wilma in the main western northbound tunnel
• Construction site set-up areas

EXCAVATION DATA of June, 26th 2024 (Updated monthly)

Main tunnel tubes NORTH: TBM excavation
Excavation
0 m
Length
15,120 m
Cross-section
85 m²
Mail tunnel tubes SOUTH: drill and blast
Excavation
866 m
Length
9,525 m
Cross-section
80 m²
Crosscuts: drill and blast
Excavation
64 m
Length
2,100 m
Cross-section
30 m²
Exploratory tunnel: drill and blast
Excavation
152 m
Length
1,650 m
Cross-section
60 m²
Overview map and status of the works
Photo gallery

Lot H61 Mules 2-3

GENERAL INFORMATION ON THE CONSTRUCTION LOT

The construction lot "Periadriatic seam", carried out between October 2011 and the summer of 2015, comprised the excavation of 3.7 km of the main tubes and 1.5 km of the exploratory tunnel. The crossing of the Periadriatic fault line, one of the biggest geological fault lines in the Alps, was accomplished without a hitch.

In May 2016 the biggest construction lot of the Brenner Base Tunnel project, known as "Mules 2-3", with a contract volume of 993 mln euro, was awarded to the bidding consortium Webuild S.p.A., Ghella S.p.A., Oberosler Cav Pietro S.r.l. (until June 2018), Cogeis S.p.A. and PAC S.p.A. Works started in September 2016.

This lot reaches from the construction lot "Isarco river underpass" up to the State border with Austria. At the end of the construction period, 39,8 km of the main tubes and 14.8 km of the exploratory tunnel will be excavated, including the emergency stop in Trens and its access tunnel as well as the bypasses which connect the main tubes every 333 m. A total of approximately 65 kilometers of tunnels will be excavated.

Once this construction lot is finished, all excavation activities in the Italian project area will be complete.
On 24/11/2021, the tunnel boring machine in the exploratory tunnel successfully reached its destination at the state border, after 14 kilometres and 3.5 years of excavation northwards. For the first time, the excavation for the tunnel tubes in the BBT project reached the Brenner Pass, which represents a historic milestone.

With the breakthrough on 19/05/2022 the "H61 Mules 2-3" and "H71 Isarco River Underpass" construction lots, which began separately, are now connected. On March 30th, 2023, after four years, the tunnel boring machine "Virginia", working on the main east tunnel northwards, successfully reached its goal. Upon reaching the construction lot border at the Brenner Pass, with "Virginia" the first tunnel boring machine successfully ended its drillings.

CURRENT CONSTRUCTION WORK

Trens emergency stop

Excavation work for the connection of the Mules access tunnel with the future Trens emergency stop began in January 2017 and was completed in June 2020.

The tunnel, with an excavation cross-section of approximately 80 m², extends over a total length of 3.8 km.

The final lining of the Trens central tunnel, of the connection and ventilation tunnels along the emergency stop is currently under construction.

Main tunnels

On 13 March 2017, excavation work began on the main tunnels moving northwards, towards the state border. After approximately 0.8 km, excavation using drilling and blasting was completed and two  double-shielded TBM started excavating.

The TBM named “Flavia” is currently excavating the western main tunnel and is about 2,2 km from the State border.

The ‘Virginia’ TBM completed excavation of the east main tunnel on 30 March 2023, reaching the Brenner Pass.

The southward excavation using drilling and blasting began in April 2017 and was completed for both main tunnels in October 2020.

Final lining is currently being installed in the access tunnel and the Trens emergency stop (Trens central tunnel and connecting/ventilation tunnels). In addition, the base slabs are being laid in the section of the exploratory tunnel excavated using drilling and blasting. The construction of the tunnel-within-a-tunnel in the eastern logistics cavern is currently underway.

EXCAVATION DATA of June 25th, 2024 (Updated monthly)

Access tunnel to the emergency stop (completed)
Excavation
3,805 m
Length
3,805 m
Cross-section
80 m²
Main tunnels
Excavation
37,675 m
Length
39,856 m
Cross-section
85 m²
Exploratory tunnel (completed)
Excavation
14,757 m
Length
14,757 m
Cross-section
35 m²
Crosscuts, safety- and logistics tunnels
Excavation
4,555 m
Length
6,930 m
Cross-section
26-56 m²
Overview with status of the works
Photo gallery

Lot H71 Isarco river underpass

GENERAL INFORMATION ON THE CONSTRUCTION LOT

 

All work on this construction lot has been completed since December 2023.

 

The southernmost lot of the Brenner Base Tunnel, worth 301 million Euro, was awarded to the consortium Isarco s.c.a.r.l., consisting of Webuild Italia S.p.A. (formerly Salini-Impregilo), Strabag AG, Strabag S.p.A., Consorzio Integra and Collini Lavori S.p.A. in October 2014. The works of this construction lot will connect the base tunnel with the existing Brenner railway line and the Fortezza station. Overall, 4.5 km of main tunnels and 1.2 km of interconnecting tunnels to the existing railway line were built.

 

Most of the works in this lot  on the floor of the Isarco valley and included a series of open-air works, including preliminary ground consolidation for the excavation of the tunnels along this stretch, which mainly consists of fluvioglacial non-compact sediments. These ground consolidation works were carried out using the so-called jet-grouting technique.

 

As part of this construction lot, tunnel stretches were excavated crossing right underneath the A22 Brenner motorway, the SS12 state road, the existing railway line and especially the Isarco river. Another special ground consolidation technique was also used to tunnel under the river: freezing.

 

After ground consolidation using the jet grouting technique, four shafts were excavated to a depth of approximately 20-25 metres. From these shafts, underground excavations were started northwards using D&B, drilling and blasting.

CURRENT CONSTRUCTION WORK

By the end of 2016, as part of the so-called preparatory works, the SS12 state road had been rerouted, bridges over the Isarco river and over the Rio Bianco had been built, and an underpass of the Brenner railway line as well as a direct link with the motorway had been completed. These works opened up enough space on the valley floor to set up the construction site and carry out the construction work. In addition, the direct link to the motorway avoided the transit of vehicles through the area.

With the breakthrough with the adjacent lot on 19 May 2022, the excavation of the main tunnels in the Isarco river underpass construction lot was completed. The H61 Mules lot and the H71 Isarco river underpass, once separate construction lots, are now joined, effectively creating a single link from Fortezza almost all the way to the Brenner Pass.

On August 8th 2023, construction work on the future line tunnels in the ‘Isarco Underpass’ construction lot was completed. In eight years of work, more than 6 km of tunnels and their interior lining were constructed.

Once the landscaping work on the outer areas of the construction site is complete, all work on the southernmost lot of the Brenner Base Tunnel will have been concluded.

The objective of the ‘renaturation’ process - a phase following the completion of the works -  is to restore the entire area of the Isarco construction site to its original state, for the benefit of the entire population living in the project area.

EXCAVATION DATA - All the excavation works in this lot were completed by December 2022

Main tunnels (completed)
Excavation
4,478 m
Length
4,478 m
Cross-section
60-150 m²
Connecting tunnels (completed)
Excavation
1,569 m
Length
1,569 m
Cross-section
60-80 m²
Connecting side tunnels, Crosscuts (completed)
Excavation
170 m
Length
170 m
Cross-section
35-45 m²
Shafts and access tunnel (completed)
Excavation
164 m
Length
164 m
Cross-section
65 m²
Overview with status of the works
Photo gallery