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Coordinates: 45°08′27″N 6°41′20″E / 45.14083°N 6.68889°E / 45.14083; 6.68889
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{{short description|Railway tunnel through the Alps}}
The '''Fréjus Rail Tunnel''' (also called '''Mont Cenis Tunnel''') is a rail tunnel of {{convert|13.7|km|mi|abbr=on}} length in the [[Europe]]an [[Alps]], carrying the [[Turin–Modane railway]] through [[Mount Cenis]] to an end on connection with the [[Culoz–Modane railway]] and linking [[Modane]], [[France]] and [[Bardonecchia]], [[Italy]]. It passes beneath the ''[[Pointe du Fréjus]]'' (2932 m) and the ''[[Col de Fréjus]]'' (2542 m).


{{use dmy dates|date=January 2018}}{{use British English|date=January 2018}}
[[Image:TrafFerrFrejus.JPG|350px|thumb|The Tunnel entrance from the Italian side (Bardonecchia)]]


{{redirect-distinguish|Mont Cenis Tunnel|Mont d'Ambin Base Tunnel}}
The initial gallery was 12.8 kilometres long, twice as much as the previously longest tunnel. Drilling started in August [[1857]] from [[Bardonecchia]] and in December 1857 from [[Modane]]. On 26 December 1870, French and Italian workers shook hands as both teams met halfway: the galleries were aligned to about 40 cm horizontally and 60 cm vertically. The tunnel opened for traffic on 17 September 1871, thus making it the oldest of the large tunnels through the Alps. The gallery was extended to its present length in [[1881]] with a new reinforced entrance on the French side.


{{infobox tunnel
The construction, directed by [[Germain Sommeiller]], was scheduled to take 25 years, but was completed in only 14 years thanks to technical innovations such as [[Jackhammer|pneumatic drilling]] machines and electrical ignition of explosive charges. In the final construction years, the use of recently-invented [[dynamite]] further accelerated the tunnel's completion. The next two Alpine tunnels were built with similar techniques: the [[Gotthard Rail Tunnel]] opened in [[1882]] and the [[Simplon Tunnel]] in 1906.
| caption = The Italian Portal of the Fréjus Rail Tunnel
| character = Passenger and freight
| coordinates = {{coord|45|08|27|N|6|41|20|E|display=title|region:FR_type:landmark_source:dewiki}}
| el = [[3 kV DC]]
| end = [[Modane]], France
| gauge = {{Track gauge|Standard gauge}}
| image = Bardonecchia (TO) - portale sud del traforo ferroviario del Frejus.jpg
| linelength = {{convert|13.7|km|mi|abbr=on}}
| location = [[Mont Cenis]]
| name = Fréjus Rail Tunnel
| notrack = Two
| opened = 17 September 1871
| start = [[Bardonecchia]], Italy
| traffic = Railway
}}


The '''Fréjus Rail Tunnel''' (also called '''Mont Cenis Tunnel''') is a rail tunnel of {{convert|13.7|km|mi|abbr=on}} length in the [[Europe]]an [[Alps]], carrying the [[Turin–Modane railway]] through [[Mont Cenis]] to an end-on connection with the [[Culoz–Modane railway]] and linking [[Bardonecchia]] in [[Italy]] to [[Modane]] in [[France]]. Its mean altitude is {{convert|1,123|m}} and it passes beneath the ''[[Pointe du Fréjus]]'' ({{convert|2,932|m}}) and the ''[[Col du Fréjus]]'' ({{convert|2,542|m}}).
The Fréjus tunnel remains today as an important link in the connection between [[Rome]] and [[Paris]], via [[Turin]] and [[Chambéry]]. Following the development of car and truck transportation, the [[Fréjus Road Tunnel]] was built along the same path from [[1974]] to [[1980]]. A future high-speed rail tunnel to improve transit capacity between [[France]] and [[Italy]] is being planned as part of the [[Lyon Turin Ferroviaire]] initiative.


Headed by the Savoyard civil engineer [[Germain Sommeiller]], construction of the tunnel commenced during August 1857, at a time when both ends of the future tunnel were in the [[Kingdom of Sardinia]]. From the onset, the tunnel was an ambitious engineering challenge, its gallery being twice the length of any tunnel previously constructed. Some figures believed that it would take as many as 40 years to complete; the total construction time was 13 years, the work having been greatly accelerated by the introduction of new technologies such as [[Jackhammer|pneumatic drilling]] machines and [[dynamite]]. On 17 September 1871, the Fréjus Tunnel was opened to traffic for the first time, facilitating a new era of interaction between France and Italy.
==Mont Cenis Pass Railway==
{{main|Mont Cenis Pass Railway}}
From [[1868]] to [[1871]] the Mont Cenis Pass Railway, a temporary mountain railway line over the Mont Cenis Pass, was used primarily to transport [[England|English]] [[mail]] to [[India]] as part of the [[All Red Route]]. The temporary line was built by Brogdens, [[Thomas Brassey]] and others (see [[John Brogden and Sons#Other work|John Brogden and Sons]]), and employed English engine-drivers.


The Fréjus tunnel remains an important link in the connection between [[Rome]] and [[Paris]], via [[Turin]] and [[Chambéry]]. Following the development of car and truck transportation, the [[Fréjus Road Tunnel]] was built along the same path from 1974 to 1980. During the 2000s, the Fréjus Rail Tunnel underwent a series of works to modernise and improve it, including the increase of its bore to accommodate wider rail vehicles, such as container trucks on piggy-back wagons, as part of the [[Alpine rolling highway|Autoroute Ferroviaire Alpine]]. A future high-speed rail tunnel to improve transit capacity between France and Italy, called the [[Mont d'Ambin Base Tunnel]], is being planned as part of the [[Turin–Lyon high-speed railway]] project.
The line used the [[John Barraclough Fell|Fell]] design of [[Fell mountain railway system|mountain railway]] with three rails. The railway, opened in June 1868, was 77 kilometres (48 miles) long, with a gauge of 1100 mm and a maximum inclination of 9 per cent. The [[Estrada de Ferro Cantagalo]] ([[Cantagalo, Brazil|Cantagalo]] railway) from Niterói to Nova Friburgo in [[Brazil]], which opened in 1873, re-used some of the equipment from the Mont Cenis Pass Railway. Brazil's first mountain railway, it was to the same gauge of 1100 mm, and operated until the 1960s.


==Fortifications==
==History==
===Background===
The Fréjus Tunnel was seen as a possible invasion route from Italy to France, avoiding the difficulties of the [[Mont Cenis]] pass. Accordingly, an extraordinary amount of fortification was placed around Modane. The [[Fort du Replaton]] and the [[Fort du Sapey]] were built in the late 19th century on the heights across the valley of the Arc. In the 1930s the [[Maginot Line]] fortifications [[Ouvrage Saint Gobain]], [[Ouvrage Saint Antoine]] and additional fortifications at Sapey were built.<ref name="fortiffbe0">{{cite web|url=http://www.fortiff.be/maginot/index.php?p=2709|title=Replaton (fort du)|last=Puelinckx|first=Jean|coauthors=Aublet, Jean-Louis & Mainguin, Sylvie|year=2010|work=Index de la fortification francaise 1874-1914|publisher=fortiff.be|language=French|accessdate=10 February 2010}}</ref>
The mountains of the [[Alps]] had posed long difficulties to any movements between Italy and its neighbours.<ref name = "open1871 michigan"/> Even with the arrival of new technologies such as the railway, the task of successfully traversing these peaks was viewed by numerous figures as a fool's errand, unfeasible to the point of being impossible. However, there was a strong political desire amongst officials in both Italy and France to establish a railway between the two which, if completed, would launch a new era of transit and bring new commercial opportunities for both nations.<ref name = "open1871 michigan"/> In Italy, the [[Victor Emmanuel Railway]], which included both the [[Culoz–Modane railway]] across [[Savoy]] and the [[Turin–Modane railway]] across [[Piedmont]], was largely constructed in the 1850s by the [[Kingdom of Sardinia (1720-1861)|Kingdom of Sardinia]] and named after its king, [[Victor Emmanuel II]]. Prior to 1860, Sardinia had included both Savoy and Piedmont.<ref name=R13>P. J. G. Ransom. ''The Mont Cenis Fell Railway.'' [[Truro]]: [[Twelveheads Press]], 1999. pp. 13, 14.</ref>


Even as it was being first envisioned, the Fréjus Tunnel, a necessary feature for traversing [[Mont Cenis]], was viewed as being the primary engineering challenge of the Turin–Modane railway by far; the initial length of its gallery was {{convert|12.8|km}}, which was twice as much as the previously longest tunnel in the world at that time.<ref name = "open1871 michigan"/> The Savoyard civil engineer [[Germain Sommeiller]] was appointed to head this undertaking. Considerable backing for the endeavor was forthcoming from individual Italians, not only in terms of funding, but also technical expertise, public endorsements, and labourers.<ref name = "open1871 michigan"/>
A blockhouse along the rail line to the east of the modern tunnel entrance has become a tourist attraction. The ''maison penchée'' ("leaning house") was built in 1939 to guard the tunnel entrance over an ammunition magazine connected to the tunnel by a gallery. In 1944 the retreating Germans exploded two rail wagons inside the tunnel entrance, causing the magazine to explode and blasting the blockhouse off its foundations, landing on a tilt.<ref name="maimod1"/>


===Construction===
==Monumental entry==
During August 1857, drilling work commenced on the [[Bardonecchia]] side; activity started on the Modane side in December 1857. It had been deemed impossible to increase the rate of excavation via intermediate shafts, thus the tunnel was driven entirely from either end.<ref name = "open1871 michigan"/> Serious challenges were encountered, including difficulty with providing sufficient ventilation. New methods of ventilation were successfully introduced, alongside other technological innovations.<ref name = "open1871 michigan"/> At the time, it was believed that, if the tunnel's construction had to rely upon traditional methods alone, it would have taken 71 years to complete.<ref>{{cite book |last1=West |first1=Graham |title=Innovation and the rise of the tunnelling industry |date=1988 |publisher=Cambridge University Press |isbn=9780521673358 |page=38}}</ref> Three years following the start of the tunnel's construction, unanticipated political interactions led to the transfer of Savoy from Sardinia to [[French Second Empire|France]] in 1860 under the [[Treaty of Turin (1860)|Treaty of Turin]]; the change of borders did not majorly disrupt the rate of work on the tunnel however. The tunnel took 14 years to construct, its rate of progress having been considerable increased via the use of new technical innovations such as [[Jackhammer|pneumatic drilling]] machines powered by compressed air.
The original monumental entry on the French side of the tunnel at Modane is now a tourist attraction, having been bypassed in 1881 in favor of a new entrance somewhat to the east in more stable ground. A steam locomotive has been placed in the entrance, which is now located along a roadside.<ref name="maimod1">{{cite web|url=http://www.modane-valfrejus.com/www-liste_monuments-37-FR-decouverte_et_tourisme.html|title=Monuments|publisher=Mairie de Modane|language=French|accessdate=11 February 2010}}</ref>


Ten drills were mounted in a frame to bore [[Drilling and blasting#Procedure|shot holes]] to receive [[Gunpowder#Other uses|blasting powder]] charges, with those in outermost positions aligned in a slight divergence from the centreline to increase the effective width. Air at a pressure of {{convert|7|atm|abbr=on|lk=on}} was conducted in iron pipes from [[hydraulic compressor]]s, powered by local streams at the mouths of the workings. There were separate pipes for water jets to remove waste from the holes. Each firing required up to eighty holes, taking between six and eight hours to drill.<ref>West (1988) pp. 39, 59</ref><ref>{{cite book |title=The Mont Cenis tunnel: its construction and probable consequences |date=1873 |publisher=Charles K. Skeet |location=London |oclc=547790 |page=28}} This is an account of construction from a contemporary Italian author.</ref><ref>{{cite book |last1=Drinker |first1=Henry Sturgis |title=A Treatise on Explosive Compounds, Machine Rock Drills and Blasting |date=1883 |publisher=[[Wiley (publisher)|Wiley]] |location=New York |oclc=833073516 |page=357}}</ref> On 26 December 1870, French and Italian workers shook hands as the two teams met halfway: the galleries were aligned to about {{convert|40|cm}} horizontally and {{convert|60|cm}} vertically.<ref>{{cite news |last1=<!--Staff writer(s)/no by-line.--> |title=Opening of the Mont Cenis tunnel |work=The Railway News & Joint-Stock Journal |date=23 September 1871 |location=London |page=446}}</ref>
== See also ==
* [[Fréjus Road Tunnel]]


On 17 September 1871, the Fréjus Tunnel was officially opened to traffic.<ref>{{cite book|title=Italian Railways|first=P. M. |last=Kalla-Bishop | year=1971 |publisher= David & Charles|location =Newton Abbott, Devon, England | isbn=0-7153-5168-0 |pages=41–42}}</ref> One foreign newspaper covering the occasion, the [[Michigan Argus]], described the tunnel as being "one of the greatest, if not the greatest, engineering feat of the age".<ref name = "open1871 michigan">{{cite web |url = https://aadl.org/node/289011 |title = The Mont Cenis Tunnel |publisher = [[Michigan Argus]] |date = 22 September 1871}}</ref> While further major tunnels through the Alps have since been constructed, it has remained active, the Fréjus Rail Tunnel being the oldest of the large tunnels through the Alps.
==References==
{{reflist}}


Between 1868 and 1871, the [[Mont Cenis Pass Railway]] was briefly operational as a temporary link over the Mont Cenis Pass. It was closed shortly after the opening of the Fréjus Railway. This railway was itself described as an engineering achievement in its own right.<ref name = "open1871 michigan"/>
{{LongestTunnel
| start = 1871
| end = 1882
| previous = Standedge Tunnel
| next = Gotthard Rail Tunnel
}}


===Alterations and improvements===
{{Coord|45|08|27|N|6|41|20|E|display=title|region:FR_type:landmark_source:dewiki}}
[[Image:Ligne Modane-Frontière - IMG 1230.jpg|thumb|The original portal on the French side of the tunnel]]

The original tunnel portal on the French side at Modane was only used for little over a decade before falling into disuse after having been bypassed during 1881. It was decided to redirect the tunnel to a new entrance positioned to the east of the original, where the ground was considerably more stable. The surplus portal was left in place as a monument, and has since become a minor tourist attraction. A steam locomotive has been placed in the disused portal, which is presently located adjacent to a road.<ref name="maimod1">{{cite web |url=http://www.modane-valfrejus.com/www-liste_monuments-37-FR-decouverte_et_tourisme.html |title=Monuments |publisher=Mairie de Modane |language=fr |access-date=11 February 2010 |archive-url=https://web.archive.org/web/20100327090508/http://www.modane-valfrejus.com/www-liste_monuments-37-FR-decouverte_et_tourisme.html |archive-date=27 March 2010 |url-status=dead}}</ref>

During the 2000s, the Fréjus Rail Tunnel underwent a programme of works to both modernise and improve it. One specific and major alteration performed during this period was the enlargement of the bore to facilitate an equivalent loading gauge of French [[High-speed rail in France#Network|Lignes à grande vitesse]]s (LGVs) throughout, thus enabling the tunnel to be traversed by wider rail vehicles, including container trucks on piggy-back wagons, as part of the [[Alpine rolling highway|Autoroute Ferroviaire Alpine]]. Various other enhancements were enacted, largely on the French side of the tunnel. The first package of work focused on civil works, while a follow-up package focused on electrical systems. During the former, the track was replaced and the track bed lowered, sections of masonry were repaired where applicable, new safety recesses created, along with other civil works around the tunnel's exterior, including a [[reservoir]].<ref>{{cite web |url = http://www.bouygues-tp.com/en/projects/mont-cenis-frejus-tunnel |title = Mont Cenis-Fréjus Tunnel |publisher = bouygues-tp.com |access-date = 3 January 2021}}</ref>

===Closure===
On 27 August 2023, a major landslide occurred on the line close to the tunnel at Saint-André à La Praz. All traffic through the tunnel, including the major [[TGV]] and [[Frecciarossa]] services between the [[Gare de Lyon]] and [[Milan Centrale]] / [[Milano Porta Garibaldi railway station|Porta Garibaldi]] were suspended. Repairs have been complicated and the line is not expected to re-open until spring 2025.<ref>{{cite news |last1=Raimondi |first1=Marco |title=Frejus Railway reopening might be delayed even further |url=https://www.railfreight.com/infrastructure/2024/01/30/frejus-railway-reopening-might-be-delayed-even-further/ |access-date=16 May 2024 |work=RailFreight.com |date=30 January 2024 |location=Rotterdam}}</ref><ref>{{cite news|url=https://www.railfreight.com/infrastructure/2024/10/29/frejus-railway-restoration-to-start-in-december/|title=Frejus Railway restoration to start in December|work=Rail Freight News|date=29 October 2024|accessdate=25 November 2024}}</ref>

==Neighbouring fortifications==
[[File:L'entrée mixte de l'ouvrage du Saint Antoine.jpg|thumb|[[Ouvrage Saint-Antoine]], overlooking the Fréjus Tunnel portal on the French side]]
Following the transfer of [[Savoy]] from Italy to France, the Fréjus Tunnel became a possible invasion route from Italy to France, particularly as it avoided the historical difficulties posed by the [[Mont Cenis]] pass. Accordingly, an extraordinary amount of defensive fortifications were constructed near to and around Modane. The [[Fort du Replaton]] and the [[Fort du Sapey]] were built in the late nineteenth century on the heights across the valley of the Arc. During the 1930s, the [[Alpine Line]] fortifications [[Ouvrage Saint-Gobain]], [[Ouvrage Saint-Antoine]] and additional fortifications at [[Le Sappey]] were also constructed.<ref name="fortiffbe0">{{cite web |url=http://www.fortiff.be/maginot/index.php?p=2709 |title=Replaton (fort du) |last=Puelinckx |first=Jean |author2=Aublet, Jean-Louis |author3=Mainguin, Sylvie |year=2010 |work=Index de la fortification francaise 1874-1914 |publisher=fortiff.be |language=fr |access-date=10 February 2010 |archive-date=18 October 2012 |archive-url=https://web.archive.org/web/20121018183237/http://www.fortiff.be/maginot/index.php?p=2709 |url-status=dead }}</ref>

A blockhouse along the rail line to the east of the modern tunnel entrance has become a tourist attraction. The ''maison penchée'' ("leaning house") was built in 1939 to guard the tunnel entrance over an ammunition magazine connected to the tunnel by a gallery. During 1944, the retreating Germans deliberately exploded two rail wagons inside the tunnel entrance, causing the magazine to explode and blasting the blockhouse off its foundations, leaving it on a tilt.<ref name="maimod1"/>

==See also==
* [[Hoosac Tunnel]]
* [[List of long tunnels by type]]

==References==
{{Reflist}}

{{s-start}}
{{s-ach|rec}}
{{s-bef|before=[[Standedge Tunnel]]}}
{{s-ttl|title=[[List of longest tunnels|Longest tunnel]]|years=1871–1882}}
{{s-aft|after=[[Gotthard Rail Tunnel]]}}
{{s-end}}
{{Authority control}}


{{DEFAULTSORT:Frejus Rail Tunnel}}
{{DEFAULTSORT:Frejus Rail Tunnel}}
[[Category:Tunnels in France]]
[[Category:Tunnels in the Alps]]
[[Category:Tunnels in Italy]]
[[Category:Alps]]
[[Category:Railway tunnels in Italy]]
[[Category:Railway tunnels in Italy]]
[[Category:Railway tunnels in France]]
[[Category:Railway tunnels in France]]
[[Category:Transport in Piedmont]]
[[Category:Transport in Piedmont]]
[[Category:France–Italy border crossings]]
[[Category:France–Italy border crossings]]
[[Category:Savoy]]
[[Category:Savoie]]
[[Category:Tunnels completed in 1871]]

[[Category:1871 establishments in Italy]]
[[da:Frejustunnelen]]
[[Category:1871 establishments in France]]
[[de:Mont-Cenis-Tunnel]]
[[Category:Bardonecchia]]
[[fr:Tunnel ferroviaire du Mont-Cenis]]
[[it:Traforo ferroviario del Frejus]]
[[hu:Fréjus-alagút]]
[[ja:フレジュス鉄道トンネル]]
[[no:Frejustunnelen]]
[[pms:Galarìa feroviaria dël Fréjus]]
[[pl:Tunel kolejowy Fréjus]]
[[ru:Мон-Сенисский туннель]]
[[sv:Fréjustunneln]]
[[tr:Fréjus Demiryolu Tüneli]]

Latest revision as of 20:35, 25 November 2024

"Mont Cenis Tunnel" redirects here. Not to be confused with Mont d'Ambin Base Tunnel.
Fréjus Rail Tunnel
The Italian Portal of the Fréjus Rail Tunnel
Overview
LocationMont Cenis
Coordinates45°08′27″N 6°41′20″E / 45.14083°N 6.68889°E / 45.14083; 6.68889
StartBardonecchia, Italy
EndModane, France
Operation
Opened17 September 1871
TrafficRailway
CharacterPassenger and freight
Technical
Line length13.7 km (8.5 mi)
No. of tracksTwo
Track gauge1,435 mm (4 ft 8+1⁄2 in)
Electrified3 kV DC

The Fréjus Rail Tunnel (also called Mont Cenis Tunnel) is a rail tunnel of 13.7 km (8.5 mi) length in the European Alps, carrying the Turin–Modane railway through Mont Cenis to an end-on connection with the Culoz–Modane railway and linking Bardonecchia in Italy to Modane in France. Its mean altitude is 1,123 metres (3,684 ft) and it passes beneath the Pointe du Fréjus (2,932 metres (9,619 ft)) and the Col du Fréjus (2,542 metres (8,340 ft)).

Headed by the Savoyard civil engineer Germain Sommeiller, construction of the tunnel commenced during August 1857, at a time when both ends of the future tunnel were in the Kingdom of Sardinia. From the onset, the tunnel was an ambitious engineering challenge, its gallery being twice the length of any tunnel previously constructed. Some figures believed that it would take as many as 40 years to complete; the total construction time was 13 years, the work having been greatly accelerated by the introduction of new technologies such as pneumatic drilling machines and dynamite. On 17 September 1871, the Fréjus Tunnel was opened to traffic for the first time, facilitating a new era of interaction between France and Italy.

The Fréjus tunnel remains an important link in the connection between Rome and Paris, via Turin and Chambéry. Following the development of car and truck transportation, the Fréjus Road Tunnel was built along the same path from 1974 to 1980. During the 2000s, the Fréjus Rail Tunnel underwent a series of works to modernise and improve it, including the increase of its bore to accommodate wider rail vehicles, such as container trucks on piggy-back wagons, as part of the Autoroute Ferroviaire Alpine. A future high-speed rail tunnel to improve transit capacity between France and Italy, called the Mont d'Ambin Base Tunnel, is being planned as part of the Turin–Lyon high-speed railway project.

History

[edit]

Background

[edit]

The mountains of the Alps had posed long difficulties to any movements between Italy and its neighbours.[1] Even with the arrival of new technologies such as the railway, the task of successfully traversing these peaks was viewed by numerous figures as a fool's errand, unfeasible to the point of being impossible. However, there was a strong political desire amongst officials in both Italy and France to establish a railway between the two which, if completed, would launch a new era of transit and bring new commercial opportunities for both nations.[1] In Italy, the Victor Emmanuel Railway, which included both the Culoz–Modane railway across Savoy and the Turin–Modane railway across Piedmont, was largely constructed in the 1850s by the Kingdom of Sardinia and named after its king, Victor Emmanuel II. Prior to 1860, Sardinia had included both Savoy and Piedmont.[2]

Even as it was being first envisioned, the Fréjus Tunnel, a necessary feature for traversing Mont Cenis, was viewed as being the primary engineering challenge of the Turin–Modane railway by far; the initial length of its gallery was 12.8 kilometres (8.0 mi), which was twice as much as the previously longest tunnel in the world at that time.[1] The Savoyard civil engineer Germain Sommeiller was appointed to head this undertaking. Considerable backing for the endeavor was forthcoming from individual Italians, not only in terms of funding, but also technical expertise, public endorsements, and labourers.[1]

Construction

[edit]

During August 1857, drilling work commenced on the Bardonecchia side; activity started on the Modane side in December 1857. It had been deemed impossible to increase the rate of excavation via intermediate shafts, thus the tunnel was driven entirely from either end.[1] Serious challenges were encountered, including difficulty with providing sufficient ventilation. New methods of ventilation were successfully introduced, alongside other technological innovations.[1] At the time, it was believed that, if the tunnel's construction had to rely upon traditional methods alone, it would have taken 71 years to complete.[3] Three years following the start of the tunnel's construction, unanticipated political interactions led to the transfer of Savoy from Sardinia to France in 1860 under the Treaty of Turin; the change of borders did not majorly disrupt the rate of work on the tunnel however. The tunnel took 14 years to construct, its rate of progress having been considerable increased via the use of new technical innovations such as pneumatic drilling machines powered by compressed air.

Ten drills were mounted in a frame to bore shot holes to receive blasting powder charges, with those in outermost positions aligned in a slight divergence from the centreline to increase the effective width. Air at a pressure of 7 atm (710 kPa) was conducted in iron pipes from hydraulic compressors, powered by local streams at the mouths of the workings. There were separate pipes for water jets to remove waste from the holes. Each firing required up to eighty holes, taking between six and eight hours to drill.[4][5][6] On 26 December 1870, French and Italian workers shook hands as the two teams met halfway: the galleries were aligned to about 40 centimetres (16 in) horizontally and 60 centimetres (24 in) vertically.[7]

On 17 September 1871, the Fréjus Tunnel was officially opened to traffic.[8] One foreign newspaper covering the occasion, the Michigan Argus, described the tunnel as being "one of the greatest, if not the greatest, engineering feat of the age".[1] While further major tunnels through the Alps have since been constructed, it has remained active, the Fréjus Rail Tunnel being the oldest of the large tunnels through the Alps.

Between 1868 and 1871, the Mont Cenis Pass Railway was briefly operational as a temporary link over the Mont Cenis Pass. It was closed shortly after the opening of the Fréjus Railway. This railway was itself described as an engineering achievement in its own right.[1]

Alterations and improvements

[edit]
The original portal on the French side of the tunnel

The original tunnel portal on the French side at Modane was only used for little over a decade before falling into disuse after having been bypassed during 1881. It was decided to redirect the tunnel to a new entrance positioned to the east of the original, where the ground was considerably more stable. The surplus portal was left in place as a monument, and has since become a minor tourist attraction. A steam locomotive has been placed in the disused portal, which is presently located adjacent to a road.[9]

During the 2000s, the Fréjus Rail Tunnel underwent a programme of works to both modernise and improve it. One specific and major alteration performed during this period was the enlargement of the bore to facilitate an equivalent loading gauge of French Lignes à grande vitesses (LGVs) throughout, thus enabling the tunnel to be traversed by wider rail vehicles, including container trucks on piggy-back wagons, as part of the Autoroute Ferroviaire Alpine. Various other enhancements were enacted, largely on the French side of the tunnel. The first package of work focused on civil works, while a follow-up package focused on electrical systems. During the former, the track was replaced and the track bed lowered, sections of masonry were repaired where applicable, new safety recesses created, along with other civil works around the tunnel's exterior, including a reservoir.[10]

Closure

[edit]

On 27 August 2023, a major landslide occurred on the line close to the tunnel at Saint-André à La Praz. All traffic through the tunnel, including the major TGV and Frecciarossa services between the Gare de Lyon and Milan Centrale / Porta Garibaldi were suspended. Repairs have been complicated and the line is not expected to re-open until spring 2025.[11][12]

Neighbouring fortifications

[edit]
Ouvrage Saint-Antoine, overlooking the Fréjus Tunnel portal on the French side

Following the transfer of Savoy from Italy to France, the Fréjus Tunnel became a possible invasion route from Italy to France, particularly as it avoided the historical difficulties posed by the Mont Cenis pass. Accordingly, an extraordinary amount of defensive fortifications were constructed near to and around Modane. The Fort du Replaton and the Fort du Sapey were built in the late nineteenth century on the heights across the valley of the Arc. During the 1930s, the Alpine Line fortifications Ouvrage Saint-Gobain, Ouvrage Saint-Antoine and additional fortifications at Le Sappey were also constructed.[13]

A blockhouse along the rail line to the east of the modern tunnel entrance has become a tourist attraction. The maison penchée ("leaning house") was built in 1939 to guard the tunnel entrance over an ammunition magazine connected to the tunnel by a gallery. During 1944, the retreating Germans deliberately exploded two rail wagons inside the tunnel entrance, causing the magazine to explode and blasting the blockhouse off its foundations, leaving it on a tilt.[9]

See also

[edit]

References

[edit]
  1. ^ a b c d e f g h "The Mont Cenis Tunnel". Michigan Argus. 22 September 1871.
  2. ^ P. J. G. Ransom. The Mont Cenis Fell Railway. Truro: Twelveheads Press, 1999. pp. 13, 14.
  3. ^ West, Graham (1988). Innovation and the rise of the tunnelling industry. Cambridge University Press. p. 38. ISBN 9780521673358.
  4. ^ West (1988) pp. 39, 59
  5. ^ The Mont Cenis tunnel: its construction and probable consequences. London: Charles K. Skeet. 1873. p. 28. OCLC 547790. This is an account of construction from a contemporary Italian author.
  6. ^ Drinker, Henry Sturgis (1883). A Treatise on Explosive Compounds, Machine Rock Drills and Blasting. New York: Wiley. p. 357. OCLC 833073516.
  7. ^ "Opening of the Mont Cenis tunnel". The Railway News & Joint-Stock Journal. London. 23 September 1871. p. 446.
  8. ^ Kalla-Bishop, P. M. (1971). Italian Railways. Newton Abbott, Devon, England: David & Charles. pp. 41–42. ISBN 0-7153-5168-0.
  9. ^ a b "Monuments" (in French). Mairie de Modane. Archived from the original on 27 March 2010. Retrieved 11 February 2010.
  10. ^ "Mont Cenis-Fréjus Tunnel". bouygues-tp.com. Retrieved 3 January 2021.
  11. ^ Raimondi, Marco (30 January 2024). "Frejus Railway reopening might be delayed even further". RailFreight.com. Rotterdam. Retrieved 16 May 2024.
  12. ^ "Frejus Railway restoration to start in December". Rail Freight News. 29 October 2024. Retrieved 25 November 2024.
  13. ^ Puelinckx, Jean; Aublet, Jean-Louis; Mainguin, Sylvie (2010). "Replaton (fort du)". Index de la fortification francaise 1874-1914 (in French). fortiff.be. Archived from the original on 18 October 2012. Retrieved 10 February 2010.
Records
Preceded by Longest tunnel
1871–1882 		Succeeded by
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