The Albula Tunnel is the centrepiece of the
Albula Railway, which forms part of the
Rhaetian Railway
The Rhaetian Railway (german: Rhätische Bahn; it, Ferrovia retica; rm, Viafier retica), abbreviated RhB, is a Swiss transport company that owns the largest network of all private railway operators in Switzerland. Headquartered in Chur, the RhB ...
network, in the
Canton
Canton may refer to:
Administrative division terminology
* Canton (administrative division), territorial/administrative division in some countries, notably Switzerland
* Township (Canada), known as ''canton'' in Canadian French
Arts and ent ...
of
Graubünden,
Switzerland
). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...
. With its maximum elevation of above sea level, it is amongst the highest tunnels in the
Alps
The Alps () ; german: Alpen ; it, Alpi ; rm, Alps ; sl, Alpe . are the highest and most extensive mountain range system that lies entirely in Europe, stretching approximately across seven Alpine countries (from west to east): France, Sw ...
, and has a mountain overlay of up to . The tunnel has a length of .
It opened for traffic in 1903.
The northern portal of the tunnel is at
Preda
Preda is locality within the municipality of Bergün, district of Albula, Canton Graubünden, Switzerland.
Transportation
Rhaetian Railway operates services to Preda (Rhaetian Railway station)
Preda railway station is a railway station in ...
, in
Bergün, and the southern portal at
Spinas, in the
Bever valley. At a total length of , the tunnel connects the Albula Valley with the
Engadin
The Engadin or Engadine ( rm, ;This is the name in the two Romansh idioms that are spoken in the Engadin, Vallader and Puter, as well as in Sursilvan and Rumantsch Grischun. In Surmiran, the name is ''Nagiadegna'', and in Sutsilvan, it is ' ...
Valley, and, in so doing, passes under the
watershed
Watershed is a hydrological term, which has been adopted in other fields in a more or less figurative sense. It may refer to:
Hydrology
* Drainage divide, the line that separates neighbouring drainage basins
* Drainage basin, called a "watershe ...
between the
Rhine
), Surselva, Graubünden, Switzerland
, source1_coordinates=
, source1_elevation =
, source2 = Rein Posteriur/Hinterrhein
, source2_location = Paradies Glacier, Graubünden, Switzerland
, source2_coordinates=
, so ...
and the
Danube
The Danube ( ; ) is a river that was once a long-standing frontier of the Roman Empire and today connects 10 European countries, running through their territories or being a border. Originating in Germany, the Danube flows southeast for , pa ...
a few kilometres west of the
Albula Pass
The Albula Pass ( Romansh: ''Pass d'Alvra'' or , german: Albulapass) (el. 2312 m) is a Swiss mountain pass in the canton of Graubünden. It lies at the heart of the Albula Alps, on the watershed between the Albula, tributary of the Rhine and the ...
. The tunnel serves both passenger and freight traffic. The ''
Glacier Express
The Glacier Express (GEX) is a direct train connecting railway stations of the two major mountain resorts of Zermatt and St. Moritz via Andermatt in the central Swiss Alps. The train is not an "express" in the sense of being a high-speed train ...
'' passes through it daily. During the winter season, car transporter trains operating between
Thusis
Thusis ( it, Tosana, '' Romansh: Tusàn'') is a municipality in the Viamala Region in the Swiss canton of Graubünden. On 1 January 2018 the former municipality of Mutten merged into the municipality of Thusis.
History
Thusis is first mentioned ...
and
Samedan
Samedan (, ) is a town and municipality in the Maloja Region in the Swiss canton of Grisons. It is served by Samedan railway station on the Rhaetian Railway network and by the Samedan Airport.
History
Samedan is first mentioned in 1139 as ''Sa ...
also used the tunnel until 2011.
Due to the threat of
rockfall
A rockfall or rock-fallWhittow, John (1984). ''Dictionary of Physical Geography''. London: Penguin, 1984. . is a quantity/sheets of rock that has fallen freely from a cliff face. The term is also used for collapse of rock from roof or walls of min ...
s and general deterioration over time, it was planned for the original tunnel to have been renovated during the 2020s. But in 2010, the Rhaetian Railway announced that it had identified the construction of a second tunnel alongside the first as its preferred option, with one of several reasons being a relatively minor difference in cost. Costed at around CHF 244 million, construction commenced during 2014. In comparison to the original Albula Tunnel, the new bore is considerably larger due to newer operational and safety standards. The second tunnel is set to be opened to traffic around 2022, with completion of the project including refurbishment of the original tunnel by 2023. Once completed, around 15,000 trains are predicted to use the tunnel each year; it has been built to allow for a maximum speed of 120 km/h.
History
Construction
The Albula Tunnel is a major feature of the
Rhaetian Railway
The Rhaetian Railway (german: Rhätische Bahn; it, Ferrovia retica; rm, Viafier retica), abbreviated RhB, is a Swiss transport company that owns the largest network of all private railway operators in Switzerland. Headquartered in Chur, the RhB ...
(RhB), an extensive metre-gauge network in the southeast of
Switzerland
). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...
that was launched during 1889.
The railway's management had placed a significant emphasis on the line being attractive to the growing tourism market, thus the line traverses the northern valleys in a deliberately spectacular manner. The highest point of the line, being roughly 1,800 metres above sea level, is where the Albula tunnel was constructed.
The construction effort was impacted by multiple unusual problems. The cold, , water outflows transformed the already fractured rock into a pulpy mass, regularly clogging up the shell of the northern tunnel lead (or
adit). At the same time, a strong water source above the northern tunnel portal dried up. The water streaming in at had to be painstakingly diverted with pipelines. As a result, construction virtually came to a standstill: in the ten weeks from May 1900, only of tunnel were driven. These difficulties could not be overcome by the head construction
contractor
A contractor is a person or company that performs work on a contract basis. The term may refer to:
Business roles
* Defense contractor, arms industry which provides weapons or military goods to a government
* General contractor, an individual o ...
Ronchi & Carlotti, which entered into
bankruptcy
Bankruptcy is a legal process through which people or other entities who cannot repay debts to creditors may seek relief from some or all of their debts. In most jurisdictions, bankruptcy is imposed by a court order, often initiated by the debtor ...
.
From 1 April 1901, the Rhaetian Railway took the construction work into its own hands. With the use of a
bonus system, it was able to regain part of the lost time. At 03:00 hours on 29 May 1902, the breakthrough of the two tunnel leads was achieved, at a point from the north portal, and , from the south portal.
The finished tunnel had a length of 5,864 metres and contained a single track.
It cost 7,828,000
Swiss francs
The Swiss franc is the currency and legal tender of Switzerland and Liechtenstein. It is also legal tender in the Italian exclave of Campione d'Italia which is surrounded by Swiss territory. The Swiss National Bank (SNB) issues banknotes and the f ...
to build. A total of 1,316 people were employed in the tunnel's construction. Overall, there were 16 fatal accidents involving construction workers; a stone memorial to commemorate these victims has been placed at the Preda station.
During 1903, Albula Tunnel was opened to traffic.
Early working of the tunnel was by
steam locomotive
A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material (usually coal, oil or, rarely, wood) to heat water in the locomot ...
s, however both it and the entire route were later electrified using the standardised 15 kV, 16⅔Hz system. Various passenger services use the tunnel on a routine basis, such as the luxurious Glacier Express. According to industry publication Rail Engineer, the danger posed by
rock fall
A rockfall or rock-fallWhittow, John (1984). ''Dictionary of Physical Geography''. London: Penguin, 1984. . is a quantity/sheets of rock that has fallen freely from a cliff face. The term is also used for collapse of rock from roof or walls of min ...
s became ever-present towards the latter half of the twentieth century.
By 2006, inspections of the tunnel determined its condition to have degraded to the point where significant renovations were required. By this time, around 7.4 million passengers, including 2.3 million
commuters, along with a high volume of freight traffic, was using the tunnel every year, thus any closure would have been highly disruptive.
In June 2009, the
Rhaetian Railway
The Rhaetian Railway (german: Rhätische Bahn; it, Ferrovia retica; rm, Viafier retica), abbreviated RhB, is a Swiss transport company that owns the largest network of all private railway operators in Switzerland. Headquartered in Chur, the RhB ...
announced that it was conducting investigations into either fundamental modernisation or reconstruction of the tunnel.
While a second tunnel was constructed during the 2010s, the original Albula Tunnel has been retained.
A total of 12 cross passages are to be excavated between the two tunnels, which shall enable personnel to travel between either bore, useful during emergency situations and routine maintenance activities alike. Following the completion of the second tunnel, the older tunnel has been scheduled to be temporarily closed to rail traffic while extensive repair works are carried out; this activity is to be largely focused on the stabilisation of its walls and roof.
Second tunnel
Due to the declining condition of the original tunnel, the prospects for the construction of a brand new tunnel alongside the old was evaluated alongside other options; Studies determined that the total cost of such a tunnel would be around CHF 244 million.
During 2010, the RHB announced that the building of a new tunnel had been identified as the optimal solution; detailed planning work commenced that same year.
There were several advantages presented by this option. Most obviously, the old tunnel would be able to remain in use throughout the construction of the new tunnel, thus avoiding a lengthy closure of the line for its renovation. The presence of the existing tunnel also enabled it to act as a rescue bore for the new tunnel if ever required to do so. During December 2012, RhB handed over the plans for approval to the Federal Office of Transport. Close cooperation between RhB and authorities is necessary, particularly due to the location being an
UNESCO
The United Nations Educational, Scientific and Cultural Organization is a specialized agency of the United Nations (UN) aimed at promoting world peace and security through international cooperation in education, arts, sciences and culture. It ...
-recognised
World Heritage Site
A World Heritage Site is a landmark or area with legal protection by an international convention administered by the United Nations Educational, Scientific and Cultural Organization (UNESCO). World Heritage Sites are designated by UNESCO for h ...
.
During 2014, construction of the second tunnel formally commenced.
In comparison to the original Albula Tunnel, the new bore is considerably large in terms of both width and height, which is primarily a result of the need to implement various newer operating standards and a greater consideration on its safety.
The larger dimensions of the tunnel enables it to accommodate walkways throughout its length, as well as facilitating ideal clearances for the
OLE fixtures. During its construction, the bore was sufficiently large and flat enough for road vehicles to directly reach the rock face, enabling conventional machinery to be brought in.
Despite its increased width, the new tunnel is actually slightly shorter than the original bore, being roughly 5,860 metres in length.
The tunnelling method was in line with conventional practices of the time.
Construction sites were established at each of the future portals of the tunnel, which accommodated
conveyor systems for moving excavated spoil from the tunnel bore to rail sidings for removal. The boring involved a pattern of drilling, blasting, spoil removal, and ancillary safety inspections.
Fresh air was piped up to the rock face, creating a slightly higher pressure within the tunnel to help blow out both dust and
diesel
Diesel may refer to:
* Diesel engine, an internal combustion engine where ignition is caused by compression
* Diesel fuel, a liquid fuel used in diesel engines
* Diesel locomotive, a railway locomotive in which the prime mover is a diesel engin ...
fumes being emitted by the excavation activities. Channels were also driven to handle water ingress, while both the roof and walls of the bore were stabilised via the application of wet-mix
concrete
Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most wi ...
.
Whilst the
geology
Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Ear ...
surrounding the tunnel is principally
granite
Granite () is a coarse-grained (phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies undergro ...
, a 110-metre section close to the Preda end consists of three different types of rock, known as
cellular dolomite, while a 20-metre section is largely dominated by a soft and
porous
Porosity or void fraction is a measure of the void (i.e. "empty") spaces in a material, and is a fraction of the volume of voids over the total volume, between 0 and 1, or as a percentage between 0% and 100%. Strictly speaking, some tests measure ...
type of dolomite akin to fine sand.
Due to the absence of solid material, the risk of tunnel collapse was notably elevated during this section's construction. It was stabilised by freezing the surrounding ground to a minimum of 2.5 metres outside the excavation zone prior to boring work, which was followed up within the space of a week by the application of a 120 cm-thick lining of reinforced concrete; these measures resulted in slow progress however.
As a result of the heavy snowfall typically present in the Swiss Alps during the winter months, which caused unavoidable accessibility disruptions to the tunnel site, all construction work was suspended between mid-December and the end of February. Outside of this seasonal shutdown, the site was worked 24 hours per day each day via
shift working.
According to Rail Engineer, an average distance of 6.5 metres would be driven during a single day. However, due to geological complications present at one part of the bore, the rate of progress was decreased to only around 0.7 metres per day.
Boring shall involve a total of roughly 244,000 cubic metres of rock being excavated.
The construction phase has been forecast to last 8.5 years; by August 2018, the tunnel's completion was expected sometime in 2022.
On 2 October 2018, breakthrough between the two ends of the new bore occurred, a key milestone in the construction programme.
In addition to the new tunnel itself, both Spinas and Preda stations on either side of the tunnel shall be modified.
Once completed, around 15,000 trains are predicted to traverse the tunnel each year; it has been built to allow for a maximum speed of 120km/h.
Sources and references
Citations
References
* Gian Brüngger, Tibert Keller, Renato Mengotti: ''Abenteuer Albulabahn''. Chur 2003,
* Gion Caprez und Peter Pfeiffer: ''Albulabahn. Harmonie von Landschaft und Technik''. Zürich 2003,
* Hubertus von Salis Soglio: ''Bahnhistorischer Lehrpfad Preda-Bergün''. Herausgegeben vom Verkehrsverein Bergün. Thusis
51997 (sold at RhB outlets or at the Bergün station).
* Henning Wall: ''Albula–Schlagader Graubündens''. Aachen 1984,
* ''Eisenbahn Journal'' Sonderausgabe ''Rhätische Bahn (I)''. Hermann Merker Verlag, Fürstenfeldbruck 1.1988, S. 34–102.
* Friedrich Hennings: ''Projekt und Bau der Albulabahn''. Chur 1908.
* Hennings: ''Die neuen Linien der Rhätischen Bahn.'' In: ''
Schweizerische Bauzeitung.'' Bd. 37/38, 1901, , S. 5–7
PDF; 2,3 MB.
''This article is based upon a translation of the
German language version of November 2009.''
External links
{{World Heritage Sites in Switzerland
Tunnels in Graubünden
Mountain railways
Railway tunnels in Switzerland
Tunnels completed in 1904
World Heritage Sites in Switzerland
Tunnels in the Alps
1904 establishments in Switzerland
Bergün Filisur
Bever, Switzerland
Car shuttle trains