Albula tunnel
| Albula tunnel | ||||
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 Preda station with northern portal before the start of construction work on Albula Tunnel II
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| use | Railway tunnel | |||
| traffic connection | Albula Railway | |||
| place | Albula Pass | |||
| length | 5865 m | |||
| Number of tubes | 1 | |||
| Largest coverage | 950 m | |||
| construction | ||||
| building-costs | 7.2 million SFr. | |||
| start of building | October 13, 1899 | |||
| completion | April 15, 1903 | |||
| business | ||||
| operator | Rhaetian Railway | |||
| release | July 1, 1903 | |||
| Longitudinal profile | ||||
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| location | ||||
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| Coordinates | ||||
| Preda | 779297 / 162267 | |||
| Spinas | 784415 / 159401 | |||
Map with all coordinates: The single-lane Albula Tunnel is the heart of the Albula Railway in the canton of Graubünden ( Switzerland ). It connects with its 5,864.5 m tunnel length the station Preda (North Portal) in the Albula valley with the high valley Engadin located Spinas .
The tunnel crosses under the watershed between the Rhine and Inn a few kilometers west of the Albula Pass . With a culmination of 1820 m above sea level. M. it is the second highest alpine tunnel in Switzerland after the Furka summit tunnel . It leads over a length of 4346 m through granite , the rest of the route is mostly in slate , with the exception of a short stretch in cell limestone , of which an 18 m long soaked drifting sand-like zone caused a lot of difficulties during construction. The largest mountain overburden of the structure is 950 m.
history
Driving from the north
Driving at the north portal was difficult at first, as the tunnel builders first had to fight their way through one and a half kilometers of slate and marl . On October 13, 1899, mechanical tunneling began almost four hundred meters behind the north portal, with the straightening tunnel being designed as a bottom tunnel and the Belgian construction method being used. Two water-powered drilling machines were used. The construction progress was initially 100 meters per month, but was slowed down by more and more springs being approached, from which 6 ° C cold water flowed into the tunnel regardless of the season, which hindered the work. In mid-April 1900, the miners encountered a water ingress about a kilometer behind the north portal, which brought with it large masses of the finest dolomite sand and flooded the tracks 70 centimeters high. At the same time, a strong spring dried up above the northern tunnel portal. Work came to a standstill until the water flowing in at 300 liters per second could be drained off with pipes.
Driving from the south
In May 1900 the miners came across cell lime , which was initially easy to mine without machines, until on July 29, 1900 large amounts of water broke in 1,192 meters behind the north portal and covered the bottom of the tunnel with the tracks over a length of 500 meters with sand. From then on it was only possible to work with gear timbering. In the next two and a half months, the miners only managed 6.3 meters. At the end of 1900, the drive had to be completely stopped 1205 meters behind the north portal.
The drive from the south side was also not without problems. The Belgian construction method was also used here. The solid granite is only 260 meters behind the portal, but the route in front of it led through sand that was interspersed with boulders . The individual boulders exerted strong local pressure on the tunnel timbering , so that it gave way in places. On November 19, 1899, the bottom tunnel collapsed 108 meters behind the portal over a length of 12 meters without miners being damaged. The reconstruction of the bottom tunnel lasted until July 1900. The ridge tunnel was continued to be built independently of the bottom tunnel, so that the mechanical tunneling could begin on October 17, 1900, 323 meters behind the portal. Two water-powered drilling machines were also in use on the south side.
Completion by RhB
Due to the difficulties on the north side and the collapse on the south side, the construction company Ronchi & Carlotti withdrew from the contract on February 24, 1901. From April 1, 1901, the Rhaetian Railway took the construction work into its own hands. On the north side, the ridge tunnel was driven further, which on April 15, 1901 struck the Casanna slate 1210 meters behind the north portal. The advance rate was only 25 centimeters per day. The difficult point due to drift sand-like rock was between 1190 meters and 1210 meters behind the north portal. It had to be lined with a 75 centimeter thick vault .
From August 25, 1901, drilling machines were used again from the north side. In order to speed up the work, three drilling machines have now been used on both sides. A drilling machine was used in the straightening tunnel with the aim of driving it as far as possible in order to explore the geological conditions ahead and to have better ventilation of the construction site after the breakthrough. Two more drilling machines on both sides made a slot from the straightening tunnel to the tunnel ceiling, whereupon the full profile was excavated from top to bottom. This so-called old Austrian construction method was used from November 1901 on the north side and from April 1902 on the south side. On May 29, 1902, at 3:30 a.m., the breakthrough of the two alignment tunnels took place, 3030.5 m from the north portal and 2835 m from the south portal. The lining was carried out where necessary by February 1903, on April 15 the superstructure was completed so that the construction trains for the completion of the route from the south portal to Celerina could run through the tunnel. Commercial operation began on July 1, 1903. The cost of the tunnel amounted to 7,228,000 francs .
Change for the Engadine
The completion of the railway system in the Albula Valley was of crucial importance for tourism in the Engadine, as the visitor frequency immediately experienced an enormous increase. Whereas the journey from Thusis to the Engadine previously took 12 hours by stagecoach, the well-known tourist destinations of the Upper Engadine, St. Moritz , Samedan , Celerina , etc., can now be reached in just over 2 hours with the Rhaetian Railway. This can be seen in the doubling of the population of the Upper Engadin district from 4117 in 1888 to 8439 in 1910. In St. Moritz, the population increased from 710 to 3197 and in Samedan from 843 to 1293.
culture shock
The locals had extra income like never before and what they had seen, heard, experienced and experienced in the relatively short construction period far exceeded what modernization had brought them over the past century. It was a shock to popular life, which for the most part was only processed and adapted to the old habits after the construction work was completed. Nevertheless, this sudden connection to the world led to impulses for a more modern society.
Workers' lives
Numerous barracks had to be built to provide accommodation, offices, a hospital, bathroom, church and schools for the engineers and the predominantly Italian working-class families. The building villages in Preda and Spinas had 25 houses. Up to 1,316 workers lived in these in summer and 1,087 in winter, some even with their families. The normal barracks, which were used for sleeping, eating and living for 48 men, were 11.50 m long, 7 m wide and 2.50-4.10 m high. Just imagine what it was like when the southern temperament ran away. One of the engineers at the time wrote about it 50 years later:
“A small church with a pastor and an Italian school with teachers were available. The federal post office was housed in the inn. Of course, the hygienic conditions did not meet the requirements that are placed on a building site today; after all, the management and the good air made sure that no epidemics broke out. The stationed Landjäger had no easy game with the hot-blooded sons of the south. As a precaution, he always left the pub backwards after the police hour. Of course, the technical staff, who were responsible for keeping things in order, had to help the police in every respect. I must emphasize that when the engineers appeared, the greatest turmoil in the economy subsided immediately. The attitude of the Italian workers towards the technical management, then as now, positive, according to the respect for technical achievements that these people always show. All minor disputes and offenses that our Florentine night watchman reported every morning were immediately dealt with in our office, with the assistance of the country hunter: just showing the rubber stick was enough to avoid wasting time. Larger crimes were reported to the district office. The examinations then took place again in our office. The RhB's own cash register was responsible for illness and accidents of the workers, and the technical staff had to deal with these cases and make arrangements for accident compensation and permanent damage themselves. "( Sen Gruber )
A few bitter downsides were mixed in with the joy at the completion of the work: 16 workers died while working on the tunnel. There were 2,128 suspended accidents and 177 workers were permanently disadvantaged. A memorial stone commemorates the victims at the Preda train station. It should be noted that the sick and accident victims were well cared for by having their own hospital with a doctor, a male nurse and several Italian nurses (who worked ten to eleven hours outdoors).
New construction of the Albula Tunnel II
planning
In February 2009 the Rhaetian Railway announced investigations into the fundamental modernization or new construction of the tunnel. The RhB used geological tests to determine whether it would be more economical to renovate the tunnel or to replace it with a new one.
In spring 2010 the RhB favored a new building. At the time, the costs were put at 260 million Swiss francs. The new building is CHF 20 million. more expensive than repairs, but the new building would have advantages in terms of safety, operation, scheduling and construction technology. The greatest advantage here is that train operations can be maintained during the construction work and the old tunnel would be used as a rescue tunnel (second tube), which would increase tunnel safety in the long term. However, the main disadvantage is the significantly higher environmental impact because, for example, the excavated material must be shut down and disposed of. The excavated material from the construction of the Albula Tunnel II is to be used for the production of concrete and gravel; unsuitable material should be deposited in a field chamber at Preda.
Larger geological investigations were carried out in the area of the Palpuogna lake in summer 2012 to check whether problems could be expected with the construction of the new tube, especially with regard to water ingress.
In December 2012, the Rhaetian Railway handed over the extensive planning documents to the Federal Office of Transport . According to the project dossier, construction costs of 350 million Swiss francs are expected, which includes the modernization of the Preda and Spinas stations. A construction period of six and a half years is expected, and commissioning is scheduled for 2020. The new building is compatible with the World Heritage status of the Albula Line , as the old tunnel is preserved and the new building is not visible except for the tunnel portals in the mountain.
From April 12 to May 13, 2013, the public plan was issued as part of the regular railway planning approval process by the municipalities of Bever and Bergün . At the same time, the environmental impact assessment was started, which is necessary because of the clearing associated with the construction project .
The procedure was completed on May 12, 2014 with the approval of the Federal Office of Transport. The excavation of the new tunnel began in August 2015.
Schedule and funding
The goal is to put the new tunnel into operation by the end of 2021. The existing tunnel is then to be converted to its new function as a safety tunnel by the end of 2022. The total investment was stated at CHF 345 million. Up to 2015, the federal government contributed 85% and the canton of Graubünden 15%. From 2016, the tunnel was fully financed from the new rail infrastructure fund.
The tunnel was pierced on October 2nd, 2018 .
Construction work
The new tunnel is being built at a distance of 30 m northeast of the existing tunnel, for the most part using a single-shell shotcrete method . In the portal areas, in the loose rock stretches and in the geologically unfavorable zones with Raibler Rauwacke , a two-shell construction with sealing and inner shell, possibly also with a base vault, is provided. The excavation was carried out by blasting from both portals. The tunnel will have a cross-section of 31.4 m² and will be equipped with a fixed track and overhead conductor rail. There are also two ventilation centers and twelve cross- passages to the existing tunnel at a distance of 425-460 m. Around 244,000 m³ of excavated material is expected by the time it is completed.
After the commissioning of the new tunnel, the old tunnel will serve as a safety tunnel after its renovation.
Work on setting up the construction site began in the summer of 2014 - both in Spinas and in Preda. In Preda the old keeper's house was moved to its new location. In addition, extensive earthworks were carried out. At the end of November 2014, work was interrupted due to the winter break. In spring 2015, they were resumed to complete the construction site equipment. In February 2015 it was announced that the Austrian construction company Porr had been commissioned as general contractor for the tunnel construction, the costs for the main lot amount to around 125 million Swiss francs. The company started tunneling work in April 2015. The construction village at the north portal in Preda was built by the end of August 2015. It consists of over 100 residential, office, sanitary and material containers, so that over 80 miners and workers can live and work there. The notice ceremony took place on August 31st. The actual tunnel work began in September 2015 and was able to continue through part of the rather mild winter.
Web links
- RhB: New construction of the Albula tunnel - information on the project, webcam and history of the tunnel
Individual evidence
- ↑ a b c d e Albula Tunnel . In: Tec21 . No. 18 , 2013, ISSN 1424-800X , p. 13-27 .
- ^ A b Hans Widmer: 50 Years of the Albula Tunnel . In: Neue Zürcher Zeitung . No. 1178 . Zurich May 29, 1952, p. 2 .
- ↑ Gian Gianett Cloetta: population . In: Bergün-Bravuogn. Local lore . 3. Edition. Buch- und Offsetdruckerei Werner Roth AG, Thusis February 1978, p. 124 .
- ^ Sen Gruber: 50 years of the Albula Tunnel . In: Liberal daily newspaper for Graubünden . No. 125 . Chur May 29, 1952, p. 1 .
- ^ RhB: Albula Tunnel on the test stand ( Memento from May 15, 2012 in the Internet Archive ) Press release of the Rhaetian Railway from February 12, 2009
- ↑ a b c Albula Tunnel II . In: Electric Railways . No. 4/2015 . Deutscher Industrieverlag, April 2015, ISSN 0013-5437 , p. 176-177 .
- ^ New construction of the Albula tunnel: RhB sends four tons of paper to Bern. Report from Southeastern Switzerland , December 21, 2012
- ↑ Christian Thumshirn: Albula Tunnel II: Why the construction work is so dangerous In: Neue Zürcher Zeitung of November 12, 2016
- ↑ Green light for Albula Tunnel II report from the NZZ , May 12, 2014
- ^ Albula II - the forgotten new Alpine railway tunnel: The darned Raibler-Rauwacke near Preda in Neue Zürcher Zeitung from June 8, 2016
- ↑ "puncture in the Albula solid". In: SRF. Retrieved October 2, 2018 .
- ^ Renewal of the Albula railway tunnel . In: tunnel . No. 7/2013 . bau-Verlag, July 2013, ISSN 0722-6241 , p. 9 ( online ).
- ↑ Press release by Porr ( Memento from February 27, 2015 in the Internet Archive )
- ↑ a b The RhB invests . ( Memento from June 7, 2015 in the Internet Archive ) Die Südostschweiz, June 5, 2015, accessed on June 11, 2015
- ↑ «Let's tackle it!»: The Albula tunnel begins to be driven. In: Southeastern Switzerland. Retrieved December 28, 2015 .