Five groups have submitted bids for the Pfons-Brenner Lot on the Brenner Baseline project. Developer BBT-SE also reports that all faces are now under excavation at the most recently awarded major contract, Mules 2-3.

Bids received for the Pfons-Brenner Lot are from:

• Pizzarotti, Implenia Osterreich, Metrostav and BeMo Tunnelling JV
• Strabag and Salini-Impregilo JV
• Acciona Construccion and CMC di Ravenna JV
• Astaldi, Ghella, Oberosler Cav. Pietro, PAC JV
• Porr Bau, Hinteregger, Condotte, Itinera JV

With bids received in late April, BBT-SE will first assess their qualitative criteria and then open prices offered for the works. TunnelTalk was told that contract award could be by mid-year, which is ahead of prior indications that had construction starting after award by early 2018. Budget estimate for the major lot is €1.3 billion for a total of approximately 50km of main tunnelling that includes TBM and drill+blast operation, on the Austrian side of the Austria/Italy border.

The last large tunnelling lot on the project is the Pfons-Sillschlucht for almost 14km of main tunnelling work contract. BBT-SE plans to begin procurement within a year and an expected start of construction in 2019.

The most recent contract award was the Mules 2-3 Lot in late 2016 to the Astaldi, Ghella, Oberosler Cav Pietro, PAC JV. Most of the group partners are also bidding for the Pfons-Brenner Lot.

During December to April, the JV began tunnelling on all six excavation fronts to advance a total 65km of access, exploratory and main tunnels by TBM and conventional methods. In total, the lot has almost 40km of main tunnels, nearly 15km of exploratory tunnel and about 10km of logistics and safety tunnels.

Brenner Baseline is 64km long and will be completed between 2007 and 2026. The project calls for approximately 230km of major excavations. The main construction phase started six years ago, in April 2011, and latest progress has seen approximately 61km of principle tunnelling completed, said BBT-SE.

A call for bids is underway for the largest of the two last major tunnelling lots of the Brenner Base railway project being constructed below the Alpine border between Austria and Italy.

Deadline for submissions on the Pfons-Brenner Lot is 18 April. A budget estimate for the major contract is set at €1.3 billion (excluding VAT), which is noted as slightly less than previously indicated.

The lot, located immediately on the Austrian side of the border, includes approximately 50km of tunnelling, the focus being on the 18.6km long parallel reaches of the TBM running tunnels. There will be 8.8km of drill+blast for the exploratory tunnel and future service tunnel that runs between the main tunnels and excavation of the emergency stop and crossover section at St Jodok, plus 55 cross passages to connect the main running tunnels (Fig 1).

Project client, BBT-SE told TunnelTalk that there will be no prequalification or shortlisting of competitors for the contract. Instead, it will be a straight bid competition with contract award anticipated towards the end of 2017. Construction work on site and main excavation of the tunnel headings is then programmed to commence in late 2017/early 2018 at the start of a contract period announced in the tender as 86 months.

In about another year’s time, in early 2018, just as the Pfons-Brenner Lot is due to mobilise, BBT-SE expects to announce the procurement of the project’s last major tunnelling contract, the Pfons-Sillschlucht Lot, also referred to as the Sillschlucht-Ahrental package. Last year the expectation was that bidding for the estimated €600 million construction contract could be underway in 2017 but the client has told TunnelTalk the process is delayed to late 2017 or early 2018, with construction still scheduled to start in 2019. The contract package involves an estimated total of almost 13.8km of main tunnelling works.

Site work on Brenner Base Tunnel started in 2007. The mega-baseline international railway project involves a total of some 230km of principle tunnels (Fig 2). The project is due to be completed in 2026. EU funding is supporting construction of the project together with national funding contributions from Austria and Italy.

With tunnelling well underway in the Austrian-Italian Alps, the Brenner Base Tunnel developer, BBT-SE, is preparing its procurement plans for the final, and largest, tunnel contract packages.

BBT-SE has signalled that a call for bids is planned before the year’s end for the Pfons-Brenner and early in 2017 for the Sillschlucht-Pfons, although it was confirmed to TunnelTalk that a conclusion remains to be reached over the provisional award of the Mules 2-3 Lot of earlier this year.

The Mules 2-3 package is located at the southern Italian section of the project, extending north from Fortezza portal to Brenner and includes 14.7km of the exploratory tunnel; a total 40.3km for the main tunnels (20.15km in each tube), and the St Jodok multifunctional emergency station.

The package has an estimated value of €1.4 billion (excluding taxes) and in March 2016, BBT-SE named an Astaldi-Ghella led JV as being provisionally awarded the contract with a contract bid of €993 million (excluding taxes). The tender assessment was weighted on technical solution, time and bid price. BBT-SE told TunnelTalk that the award has yet to be confirmed and that further details were unable to be disclosed.

Astaldi is the lead JV partner with a 42.51% share, Ghella is the second partner with 42.49%, with each of the three other junior partners – comprising Cogeis, Oberosler Cav Pietro and PAC – holding a 5% share each.

In announcing its provisional selection, BBT-SE said the works were expected to take about seven years, although it had noted previously that the section could take about nine years to complete. Astaldi has said both that open face, drill+blast and TBM excavation is planned for the tunnelling works.

While Mules 2-3 remains to be settled, the developer said it would soon launch procurement for the two remaining northern construction packages on the Austrian side.

The Pfons-Brenner Lot has an estimated construction value also of €1.4 billion and calls for 8.8km of exploratory tunnel and 18.6km in each of the main tunnels. The works will access via the Wolf to advance headings in both directions for the main tunnels and by 3.2km north and 5.6k south in the exploratory tunnel. Additional excavation in the exploratory tunnel was completed as part of the separate Wolf II adit package.

The last of the three major main line packages is the section north from Pfons to Sillschlucht in Austria. The package includes excavation of almost 13.8km of the main twin-tube tunnel excavation and has a BBT-SE estimate of approximately €600 million (excluding taxes). Procurement is expected in 2017 for excavation to begin in 2019.

In total, the Brenner Base Tunnel requires about 230km of tunnels to be excavated and from key adits at Ampass, Ahrental, Wolf, Steinbach and Mules. It will run about 55km between the Innsbruck and Fortezza portals. The twin 8.1m i.d. main tunnels will run 70m apart and will be joined by cross passages at 333m intervals. The 5m i.d. service tunnel runs between the main tubes and about 12m lower in alignment. It is being excavated in advance and in phases, and as an exploratory tunnel. The multifunctional emergency stations will provide access to the surface.

The total length of the Alpine rail project is 64km and it will be the world’s longest tunnel when completed in 2026.

Construction on the project began with initial works in 2007. Progress over the last 10 years has been underway from four active sites Tulfes-Pfons; Isarco River Underpass; Wolf; and Periadriatic Line.

Progress of the works by early August at the sites are:

Tulfes-Pfons

• a relatively short section of main tunnels completed;
• the 9.7km long emergency tunnel (70% done), using the Ampass adit;
• 7km of connecting tunnels (30% done);
• the 1.85km long emergency stop (50%); and,
• a 15km stretch of the exploratory tunnel between Pfons to the Ahrental adit (14% done).

Last year, the Salini Impregilo/ Strabag-led JV launched a 7.93m diameter Herrenknecht TBM on the exploratory tunnel on the Tulfes-Pfons Lot. The contract was awarded in 2014 and requires 38km of tunnelling, including drill+blast work. Tunnelling on the lot is due finishby mid-2019. It is one of two contracts the JV has on Brenner, the other being the Isarco River Underpass at the southern end in Italy near the Fortezza station.

Isarco River Underpass

The JV began construction on the underpass in 2014 and is scheduled to complete the works by late 2022. Ground freezing will take the tunnel under the river and other soft ground works require soil strengthening by jet grouting.

Wolf

Much of the work in the Wolf package has been completed. The 3.2km long access tunnel was completed at the end of 2015 after two years of excavation, and a 1.2km long stretch of exploratory tunnel is almost finished. The contractor is the Swietelsky/ Swietelsky Tunnelbau JV, which was awarded the lot in late 3013 and is due to finish in late 2017.

Periadriatic Line

Finishing works have been underway in the Periadriatic Line from the Mules (Mauls) Adit following excavation between late 2011 and early 2015 through a zone of complex geology on a tectonic plate boundary. The works by the PAC, Cogeis, Oberosler Cav Pietro and Implenia JV excavated 3.7km of the main tunnels and 1.5km of the exploratory tunnel through the fault zone.

Earlier works on the Brenner project included a TBM drive by Seli to advance the exploratory tunnel from the southern end in Italy.