Ceneri Base Tunnel

Background

The Ceneri Base Tunnel is a Swiss railway base tunnel under construction through Monte Ceneri between Camorino in the Magadino Flat and Vezia near Lugano, which shall allow traffic to bypass the conventional high-level railway running through the historic Monte Ceneri Tunnel.^[3] It forms only one element of a wider effort, commonly referred to as the New Rail Link through the Alps (NRLA) programme, which is being developed by AlpTransit Gotthard AG (ATG), a wholly owned subsidiary of the Swiss Federal Railways (SBB). Once completed, the Ceneri Base Tunnel and the larger Gotthard Base Tunnel shall work together to provide significantly shorter journey times between the northern city of Zurich and the Northern Italian city of Milan by providing a flatter route for freight trains than conventional lines have previously allowed for.^[3][4]

In total, the Ceneri Base Tunnel carries a pair of parallel bores, each containing a single-track, set 40 meters apart from one another and connected by cross passages at evenly spaced intervals of 325 meters.^[3] Stretching between the towns of Camorino and Vezia, it possesses a total length of 39.78km; the eastern bore has a length of 15.45km and the west bore is 15.28km long. An operations center controlling ventilation and logistical activities has been constructed at Sigirino.^[3] Operationally, the Ceneri Base Tunnel has been anticipated to be used by in excess of 300 trains each day travelling in both directions. It shall be furnished with ETCS Level 2 signalling, allowing for trains to traverse it at speeds of up to 250 km/h.^[5] For handling emergency situations in the Ceneri Base Tunnel, the Swiss Federal Railways has acquired a fleet of dedicated rescue trains; these are equipped with specialised fire fighting equipment and other useful facilities, such as independent air supplies.^[6]

During July 2001, the proposed Ceneri Base Tunnel was approved by the Swiss Federal Council, clearing the way for detailing planning and eventual construction activity to proceed.^[3] Further Parliamentary approval of the selected route for the tunnel was received in 2003, and the first funding towards construction was released during 2005.^[7] During April 2007, AlpTransit Gotthard AG awarded a Sfr85m ($91.52m) contract for the construction of the first underground element of the tunnel to Consorzio Monte Ceneri (CMC) JV, a consortium of CSC, Lugano, Frutiger, Thun, Rothpletz, Lienhard & Cie, and Aarau.^[3] During June 2009, the Board of Directors of AlpTransit Gotthard AG announced that it had awarded the principal contract for the tunnel's construction to the Consorzio Condotte Cossi consortium. At the time, the tunnel is expected to be operational by December 2020.^[8] This contract was valued at Sfr987 million ($1.6 billion). The estimated total cost for the Ceneri Base Tunnel is Sfr2.4 billion ($2.58 billion).^[3]

Construction

During June 2006, construction work on the tunnel officially commenced.^[3] In November 2008, the excavation of a 2.4km-long (1.5 miles) adit tunnel was completed, it involved the excavation of 160,000m³ of hard rock. A tunnel boring machine (TBM), provided by Robbins Company and equipped with 483mm cutters, was used to bore the adit tunnel over the course of ten months during which it advanced at a rate of 18.5 meters per day.^[9][3] During the spring of 2010, work commenced upon the boring of the Ceneri Base Tunnel itself. During March 2010, it was announced that blasting had begun on the main drives of the twin-bores.^[10] By the end of the year, the rate of tunneling had reportedly attained its full speed. A combination of conventional drilling and blasting techniques were used to bore approximately 37.49km of the tunnel, while the remainder was bored using a tunnel boring machine TBM.^[3]

Breakthrough in the west tube between Sigirino and Vezia occurred on 17 March 2015.^[11][12] Breakthrough in the east tube between Sigirino and Vezia occurred on 30 March 2015. On 21 January 2016, breakthrough was achieved in the west bore between Sigirino and Vigana, while the breakthrough in the east bore between Sigirino and Vigana occurred on 26 January 2016.^[3] That same day, it was announced that the excavation process had been completed, and the installation of railway infrastructure was the next major stage of the work.^[3] During February 2017, the final concrete block was placed in a ceremony marking the tunnel becoming structurally complete.^[13]

During August 2013, the Mons Ceneris Consortium, headed by Mancini & Marti, was awarded a Sfr96 million ($103.36 million) contract to provide railway track and logistics for the tunnel.^[3] That same month, the Cablex-led CPC Consortium won a Sfr129 million ($138.89 million) contract to provide railway systems and overall tunnel co-ordination services. The planning, supply, installation and commissioning of the tunnel control systems, which are to be controlled from a control centre at Pollegio, has been contracted to Tunnel Control Systems.^[3] The awarding of these contracts was not without controversy; a pair of appeals were subsequently upheld by the Federal Supreme Court of Switzerland regarding the awarding process. At one point, it looked as if completion of the Ceneri Base Tunnel may be delayed as a consequence of legal disputes.^[14][15] However, the dispute was settled during September 2014, which unblocked the awarding of contracts as well as allowing for work to proceed.^[16]

During 2017, the installation of this infrastructure, such as the track, catenary, electrical supply cables, telecommunications and radio systems, and various safety and control systems commenced.^[3] During August 2017, the first sections of ballastless track were laid in the northern end of the eastern bore.^[17]

The monthly progress update graphic is available online.^[18]