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Mon May 6, 2019, 07:37 PM

25 Years Ago Today; The Channel Tunnel opens, linking the UK with France

https://en.wikipedia.org/wiki/Channel_Tunnel



The Channel Tunnel (French: Le tunnel sous la Manche; also nicknamed the Chunnel)[2][3] is a 50.45-kilometre (31.35 mi) rail tunnel linking Folkestone, Kent, in England, with Coquelles, Pas-de-Calais, near Calais in northern France, beneath the English Channel at the Strait of Dover. It is the only fixed link between the island of Great Britain and the European mainland. At its lowest point, it is 75 m (250 ft) deep below the sea bed and 115 m (380 ft) below sea level.[4][5][6] At 37.9 kilometres (23.5 mi), the tunnel has the longest underwater section of any tunnel in the world, although the Seikan Tunnel in Japan is both longer overall at 53.85 kilometres (33.46 mi) and deeper at 240 metres (790 ft) below sea level. The speed limit for trains through the tunnel is 160 kilometres per hour (99 mph).

The tunnel carries high-speed Eurostar passenger trains, the Eurotunnel Shuttle for road vehicles—the largest such transport in the world—and international goods trains. The tunnel connects end-to-end with the LGV Nord and High Speed 1 high-speed railway lines. In 2017 through rail services carried 10.3 million passengers and 1.22M tonnes of freight, and the Shuttle carried 10.4M passengers, 2.6M cars, 51,000 coaches, and 1.6M lorries (equivalent to 21.3M tonnes of freight). This compares with 11.7 million passengers, 2.6 million lorries and 2.2 million cars through the Port of Dover.

Plans for a cross-Channel fixed link appeared as early as 1802, but British political and press pressure over the compromising of national security had disrupted attempts to build a tunnel. An early attempt at building a Channel Tunnel was made in the late 19th century, on the English side, "in the hope of forcing the hand of the English Government". The eventual successful project, organised by Eurotunnel, began construction in 1988 and opened in 1994. At £5.5 billion (1985 prices), it was at the time the most expensive construction project ever proposed. The cost finally amounted to £9 billion ($21 billion), well over its predicted budget.

Since its construction, the tunnel has experienced a few mechanical problems. Both fires and cold weather have temporarily disrupted its operation.

People have been attempting to use the tunnel to illegally travel to the UK since 1997, creating the ongoing issue of the migrants around Calais on the French side, causing both diplomatic disagreement and violence.

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Construction
Working from both the English side and the French side of the Channel, eleven tunnel boring machines or TBMs cut through chalk marl to construct two rail tunnels and a service tunnel. The vehicle shuttle terminals are at Cheriton (part of Folkestone) and Coquelles, and are connected to the English M20 and French A16 motorways respectively.

Tunnelling commenced in 1988, and the tunnel began operating in 1994. In 1985 prices, the total construction cost was £4.65 billion (equivalent to £13 billion in 2015), an 80% cost overrun. At the peak of construction 15,000 people were employed with daily expenditure over £3 million. Ten workers, eight of them British, were killed during construction between 1987 and 1993, most in the first few months of boring.

Completion

Class 319 EMUs ran excursions trips into the tunnel from Sandling railway station on 7 May 1994, the first passenger trains to do so

A two-inch (50-mm) diameter pilot hole allowed the service tunnel to break through without ceremony on 30 October 1990. On 1 December 1990, Englishman Graham Fagg and Frenchman Phillippe Cozette broke through the service tunnel with the media watching. Eurotunnel completed the tunnel on time. (A BBC TV television commentator called Graham Fagg "the first man to cross the Channel by land for 8000 years".)

The tunnel was officially opened, one year later than originally planned, by Queen Elizabeth II and the French president, François Mitterrand, in a ceremony held in Calais on 6 May 1994. The Queen travelled through the tunnel to Calais on a Eurostar train, which stopped nose to nose with the train that carried President Mitterrand from Paris. Following the ceremony President Mitterrand and the Queen travelled on Le Shuttle to a similar ceremony in Folkestone. A full public service did not start for several months. The first freight train, however, ran on 1 June 1994 and carried Rover and Mini cars being exported to Italy.

The Channel Tunnel Rail Link (CTRL), now called High Speed 1, runs 69 miles (111 km) from St Pancras railway station in London to the tunnel portal at Folkestone in Kent. It cost £5.8 billion. On 16 September 2003 the prime minister, Tony Blair, opened the first section of High Speed 1, from Folkestone to north Kent. On 6 November 2007 the Queen officially opened High Speed 1 and St Pancras International station, replacing the original slower link to Waterloo International railway station. High Speed 1 trains travel at up to 300 km/h (186 mph), the journey from London to Paris taking 2 hours 15 minutes, to Brussels 1 hour 51 minutes.

In 1994, the American Society of Civil Engineers elected the tunnel as one of the seven modern Wonders of the World. In 1995, the American magazine Popular Mechanics published the results.

Tunnelling

Typical cross section, with the service tunnel between twin rail ones; shown linking the rail tunnels is a piston relief duct, necessary to manage changes in air pressure caused by the fast movement of trains

Tunnelling was a major engineering challenge, with the only precedent being the undersea Seikan Tunnel in Japan, which opened in 1988. A serious risk with underwater tunnels is major water inflow due to the pressure from the sea above, under weak ground conditions. The tunnel also had the challenge of time: being privately funded, early financial return was paramount.

The objective was to construct two 7.6-metre-diameter (25 ft) rail tunnels, 30 metres (98 ft) apart, 50 kilometres (31 mi) in length; a 4.8-metre-diameter (16 ft) service tunnel between the two main ones; pairs of 3.3-metre-diameter (11 ft) cross-passages linking the rail tunnels to the service one at 375-metre (1,230 ft) spacing; piston relief ducts 2 metres (7 ft) in diameter connecting the rail tunnels 250 metres (820 ft) apart; two undersea crossover caverns to connect the rail tunnels,[63] with the service tunnel always preceding the main ones by at least 1 kilometre (0.6 mi) to ascertain the ground conditions. There was plenty of experience with excavating through chalk in the mining industry, while the undersea crossover caverns were a complex engineering problem. The French one was based on the Mount Baker Ridge freeway tunnel in Seattle; the UK cavern was dug from the service tunnel ahead of the main ones, to avoid delay.

Precast segmental linings in the main TBM drives were used, but two different solutions were used. On the French side, neoprene and grout sealed bolted linings made of cast iron or high-strength reinforced concrete were used; on the English side, the main requirement was for speed so bolting of cast-iron lining segments was only carried out in areas of poor geology. In the UK rail tunnels, eight lining segments plus a key segment were used; in the French side, five segments plus a key.[64] On the French side, a 55-metre (180 ft) diameter 75-metre (246 ft) deep grout-curtained shaft at Sangatte was used for access. On the English side, a marshalling area was 140 metres (459 ft) below the top of Shakespeare Cliff, the New Austrian Tunnelling method (NATM) was first applied in the chalk marl here. On the English side, the land tunnels were driven from Shakespeare Cliff – same place as the marine tunnels – not from Folkestone. The platform at the base of the cliff was not large enough for all of the drives and, despite environmental objections, tunnel spoil was placed behind a reinforced concrete seawall, on condition of placing the chalk in an enclosed lagoon, to avoid wide dispersal of chalk fines. Owing to limited space, the precast lining factory was on the Isle of Grain in the Thames estuary,[63] which used Scottish granite aggregate delivered by ship from the Foster Yeoman coastal super quarry at Glensanda in Loch Linnhe on the west coast of Scotland.

On the French side, owing to the greater permeability to water, earth pressure balance TBMs with open and closed modes were used. The TBMs were of a closed nature during the initial 5 kilometres (3 mi), but then operated as open, boring through the chalk marl stratum.[63] This minimised the impact to the ground, allowed high water pressures to be withstood and it also alleviated the need to grout ahead of the tunnel. The French effort required five TBMs: two main marine machines, one main land machine (the short land drives of 3 km (2 mi) allowed one TBM to complete the first drive then reverse direction and complete the other), and two service tunnel machines. On the English side, the simpler geology allowed faster open-faced TBMs. Six machines were used; all commenced digging from Shakespeare Cliff, three marine-bound and three for the land tunnels. Towards the completion of the undersea drives, the UK TBMs were driven steeply downwards and buried clear of the tunnel. These buried TBMs were then used to provide an electrical earth. The French TBMs then completed the tunnel and were dismantled. A 900 mm (35 in) gauge railway was used on the English side during construction.

In contrast to the English machines, which were given alphanumeric names, the French tunnelling machines were all named after women: Brigitte, Europa, Catherine, Virginie, Pascaline, Séverine.

At the end of the tunnelling, one machine was on display at the side of the M20 motorway in Folkestone until Eurotunnel sold it on eBay for £39,999 to a scrap metal merchant.[69] Another machine (T4 "Virginie" still survives on the French side, adjacent to Junction 41 on the A16, in the middle of the D243E3/D243E4 roundabout. On it are the words "hommage aux bâtisseurs du tunnel", meaning "tribute to the builders of the tunnel".

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Reply 25 Years Ago Today; The Channel Tunnel opens, linking the UK with France (Original post)
Dennis Donovan May 2019 OP
dhol82 May 2019 #1
msongs May 2019 #2
musette_sf May 2019 #3
Liberal In Texas May 2019 #4

Response to Dennis Donovan (Original post)

Mon May 6, 2019, 07:49 PM

1. Rode it several times in the '90's and aughts.

Did some day trips from Paris.
Soooooooo fucking cool!!!

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Response to Dennis Donovan (Original post)

Mon May 6, 2019, 08:29 PM

2. honolulu is building an above ground rail since 2010, less than half done and NONE useable

yet

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Response to Dennis Donovan (Original post)

Mon May 6, 2019, 08:44 PM

3. "Chunnel: 32 Miles of Hell" and other great fake Seinfeld movies

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Response to Dennis Donovan (Original post)

Mon May 6, 2019, 10:23 PM

4. Which enabled a pretty darned good crime series produced in France and England

called "The Tunnel"



which was sadly ended after 3 seasons.

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