Shopping on line can be easy, simple and save you lots of money. It can also take a lot of your time, frustrate you, and result in unwanted purchases. Now the same can be said for regular high street shopping, but with the vast opportunity presented by the Internet it will pay you to spend a few minutes reading this and understanding how to better optimize your Tunnels shopping experience:
1. Compare - without doubt the biggest advantage that the Tunnels offers shoppers today is the ability to compare thousands of Tunnels at a time. This is a great thing, but not necessarily all the time! Too much can be daunting at times so take advantage of the great comparison sites and where possible let them do the hard work for you.
2. Research - if it has been said it will be on the internet. Ignorance is no longer a justifiable reason for buying the wrong thing. Take the time to research in detail everything that you could possible want to know about
3. Testimonials - don't know anybody that has bought a Tunnels? Wrong! If the Tunnels is good the internet will let you know. Use the Internet as a friend and get testimonials before you buy.
4. Questions - Got a question about Tunnels then search the Forums, FAQ's, Blogs etc. Don't be afraid to ask .....
5. Reputation - Never heard of the company selling Tunnels? Don't worry, no reason why you should know every company in the world, but you know someone that does! Use the internet to find out what people are saying about Tunnels and build up a picture of their reputation for sales, returns, customer service, delivery etc.
6. Returns - still worried that even after all of the above your Tunnels wont be what you want? Check out the returns policy. There is so much competition now that someone, somewhere is bound to offer the terms that you are comfortable with.
7. Feedback - happy with your Tunnels then let people know, after all you are depending on others people input in your buying decision, so why not give a little back.
8. Security - check for the yellow padlock on the Tunnels site before you buy, and the s after http:/ /i.e. https:// = a secure site
9. Contact - got a question about Tunnels, or want to leave a comment then check out the sites contact page. Reputable companies have them and respond.
10. Payment - ready to pay for your Tunnels, then use your credit card or PayPal! Be aware of companies that don't accept them, there may be genuine reasons but given the huge amount of choice you have when buying online there is no reason at all not to buy via credit card or PayPal.
,
BelgiumA
tunnel is an underground passage. The definition of what constitutes a tunnel is not universally agreed upon. However, in general tunnels are at least twice as long as they are wide. In addition, they should be completely enclosed on all sides, save for the openings at each end.
A tunnel may be for pedestrians or
cyclists, for general road traffic, for
motor vehicles only, for rail transport traffic, or for a canal. Some are
aqueducts, constructed purely for
water supply — for consumption, for
hydroelectric purposes or as sewers — while others carry other services such as telecommunications cables. There are even tunnels designed as wildlife crossings for
European badgers and other
endangered species. Some
secret passage have also been made as a method of entrance or escape from an area, such as the
Cu Chi Tunnels or the Smuggling tunnel#Smuggling tunnels in Rafah, Gaza Strip connecting the
Gaza Strip to
Egypt.
In the United Kingdom a pedestrian tunnel or other underpass beneath a road is called a Subway (underpass). This term was used in the past in the
United States, but now refers to underground
rapid transit systems.
The longest canal tunnel is the
Standedge Tunnels in the United Kingdom, over three miles long.
In the Czech republic, the verb to 'tunnel' is a synonym for to embezzle. For example: the manager 'tunnelled' the company and now lives on the Bahamas; or, many banks collapsed because they were 'tunnelled'.
Tunneling (fraud) airport. in
Singapore is a fully-underground rail line.
The central part of a rapid transit network is usually built in tunnels. To allow non-level crossings, some lines run in deeper tunnels than others. At metro stations there are usually pedestrian tunnels from one
railway platform to another. Often, ground-level
train stations also have one or more pedestrian tunnels under the railway to enable passengers to reach the platforms without walking across the tracks. In the United Kingdom bridges are an equally popular for pedestrian access between two or more railway station platforms.
Geotechnical investigation
It is essential that any tunnel project starts with a comprehensive investigation of ground conditions. The results of the investigation will allow proper choice of machinery and methods for excavation and ground support, and will reduce the risk of encountering unforseen ground conditions. In the early stages, the horizontal and vertical alignment will be optimised to make use of the best ground and water conditions.
In some cases, conventional desk and site studies will not produce sufficient information to assess, for example, the blocky nature of rocks, the exact location of fault zones, or stand-up times of softer ground. This may be a particular concern in large diameter tunnels. To overcome these problems, a pilot tunnel, or drift, may be driven ahead of the main drive. This smaller diameter tunnel will be easier to support when unexpected conditions occur, and will be incorporated in the final tunnel. Alternatively, horizontal boreholes may sometimes be used ahead of the advancing tunnel face.
==Construction== under construction
Tunnels are dug in various types of materials, from soft clay to hard rock, and the method of excavation depends on the ground conditions.
Cut-and-cover
Cut-and-cover is a simple method of construction for shallow tunnels where a trench is excavated and roofed over. Strong supporting beams are necessary to avoid the danger of the tunnel collapsing due to over head pressure.
Two basic forms of cut-and-cover tunnelling are available:
- Bottom-up method: A trench is excavated, with ground support as necessary, and the tunnel is constructed within. The tunnel may be of insitu concrete, precast concrete, precast arches, corrugated steel arches and such, with brickwork used in early days. The trench is then backfilled, with precautions regarding balancing compaction of the backfill material, and the surface is reinstated.
- Top-down method: In this method, side support walls and capping beams are constructed from ground level, using slurry walling, contiguous bored piles, or some other method. A shallow excavation is then made to allow the tunnel roof to be constructed using precast beams or insitu concrete. The surface is then reinstated except for access openings. This allows early reinstatement of roadways, services and other surface features. Excavation machinery is then lowered into the access openings, and the main excavation is carried out under the permanent tunnel roof, followed by constructing the base slab.
Shallow tunnels are often of the cut-and-cover type (if under water, of the immersed-tube type), while deep tunnels are excavated, often using a
tunnelling shield. For intermediate levels, both methods are possible.
Boring machines
,
NevadaTunnel boring machines (TBMs) and associated back-up systems can be used to highly automate the entire tunneling process. There are a variety of TBMs that can operate in a variety of conditions, from hard rock to soft water-bearing ground. Some types, bentonite slurry and earth-pressure balance machines, have pressurised compartments at the front, allowing them to be used in difficult conditions below the water table. This pressurizes the ground ahead of the TBM cutter head to balance the water pressure. The operators work in normal air pressure behind the pressurised compartment, but may occasionally have to enter that compartment to renew or repair the cutters. This requires special precautions, such as local ground treatment or halting the TBM at a position free from water. Despite these difficulties, TBMs are now preferred to the older method of tunneling in compressed air, with an air lock/decompression chamber some way back from the TBM, which required operators to work in high pressure and go through decompression procedures at the end of their shifts, much like divers.
Until recently the biggest TBM built was used to bore the Green Heart Tunnel (Dutch: Tunnel Groene Hart) as part of the HSL-Zuid in the Netherlands. Its diameter is 14.87 m.
Nowadays 4 even larger machines exist: 2 for the M30 ringroad in Madrid, Spain, 2 for the Chong Ming tunnels in Shanghai, China. These machines are 15,2 m and 15,4m in diameter respectively. The two machines for Spain were built by Mitsubishi/Dura Fuelgo and Herrenknecht . The TBMs for China were built by Herrenknecht.
NATM
The
New Austrian Tunnelling method (NATM) was developed in the 1960s. The main idea of this method is to use the geological stress (physics) of the surrounding Rock (geology)
mass to stabilize the tunnel itself. Based on
geotechnical measurements, an optimal cross section (geometry) is computed. The excavation is immediately protected by thin
shotcrete, just behind the excavation. This creates a natural load-bearing ring, which minimizes the rock's
deformation.
By special Condition monitoring the NATM method is very flexible, even at surprising changes of the geomechanics rock consistency during the tunneling work. The measured rock properties lead to appropriate
tools for tunnel Strength of materials. In the last decades also soft ground excavations up to 10 km became usual.
Pipe jacking
Pipe Jacking, also known as
pipejacking or
pipe-jacking, is a method of tunnel construction where hydraulic jacks are used to push specially made pipes through the ground behind a tunnel boring machine or shield. This technique is commonly used to create tunnels under existing structures, such as roads or railways.
Underwater tunnels
There are also several approaches to underwater tunnels, for instance an immersed tube as in the
Sydney Harbour Tunnel, and the
Posey and Webster Street Tubes which connect the cities of
Oakland, California and Alameda, California, running beneath the Alameda-Oakland Estuary.
Other
Other tunneling methods include:
Choice of tunnels vs. bridges
For water crossings, a tunnel is generally more costly to construct than a bridge. Navigational considerations may limit the use of high bridges or drawbridge spans intersecting with shipping channels, necessitating a tunnel. Bridges usually require a larger footprint on each shore than tunnels. In areas with expensive real estate, such as
Manhattan and urban
Hong Kong, this is a strong factor in tunnels' favor. Boston's
Big Dig (Boston, Massachusetts) project replaced elevated roadways with a tunnel system to increase traffic capacity, hide traffic, reclaim land, redecorate, and reunite the city with the waterfront. Examples of water-crossing tunnels built instead of bridges include the Holland Tunnel and
Lincoln Tunnel between New Jersey and Manhattan in
New York City, and the
Elizabeth River (Virginia) tunnels between Norfolk, Virginia and
Portsmouth, Virginia and the Westerscheldetunnel, Zeeland, Netherlands. Other reasons for choosing a tunnel instead of a bridge include avoiding difficulties with tides, weather and shipping during construction (as in the 51.5 km Channel Tunnel), aesthetic reasons (preserving the above-ground view, landscape, and scenery), and also for weight capacity reasons (it may be more feasible to build a tunnel than a sufficiently strong bridge).
Some water crossings are a mixture of bridges and tunnels, such as the
Oresund Bridge and the
Chesapeake Bay Bridge-Tunnel in the eastern United States.
Short tunnels
A short tunnel can be built as an alternative to an overpass. One example of a short tunnel is the Croom Tunnel on the South Coast railway line, New South Wales.
Artificial tunnels
Overbridges can sometimes be built by covering a road or river or railway with brick or still arches, and then levelling the surface with earth. In railway parlance, a surface-level track which has been built or covered over is normally called a covered way.
Snow sheds are a kind of artificial tunnel built to protect a railway from avalanches of snow. Similarly the
Stanwell Park,
New South Wales steel tunnel, on the
South Coast railway line, New South Wales, which protects the line from rockfalls.
Common utility ducts are man-made tunnels created to carry two or more utility lines underground. Through co-location of different utilities in one tunnel, organizations are able to reduce the costs of building and maintaining utilities.
Examples of tunnels
In history
, London, mid 19th century
- The qanat or kareez of Persia is a water management system used to provide a reliable supply of water to human settlements or for irrigation in hot, arid and semi-arid climates. The oldest and largest known qanat is in the Iranian city of Gonabad which after 2700 years still provides drinking and agricultural water to nearly 40,000 people. Its main well depth is more than 360 meters and its length is 45 kilometers.
- The Eupalinian aqueduct on the island Samos Island (Ionia). Built 520 BC by the Ionian engineer Eupalinos. Eupalinos organised the work so that the tunnel was begun from both sides of the hill and the two teams met in the middle. The estimates for the time required range from 5 to 15 years: the mountain is solid limestone and one has to suppose that many of the slaves doing the work died. The tunnel's existence was recorded by Herodotus (as was the mole and harbour, and the third wonder of the island, the great temple to Hera, thought by many to be the largest in the Greek world). The precise location of the tunnel was only re-established in the 19th century by German archaeologists. The tunnel proper is 1030 metres (3,430 ft) long and visitors can still enter it Eupalinos tunnel.
- Sapperton Canal Tunnel on the Thames and Severn Canal in England, dug through hills, which opened in 1789, was 3.5 km long and allowed Canal boat transport of coal and other goods. Above it runs the Sapperton Long Tunnel which carries the "Golden Valley" railway line between Swindon and Gloucester.
- The tunnel created for the first true steam locomotive, the Penydarren locomotive, was built prior to Richard Trevithick was able to make his historic journey from Penydarren to Abercynon in 1804. Part of this tunnel can still be seen at Pentrebach, Merthyr Tydfil. This is arguably the oldest railway tunnel in the world, for self-propelled steam engines on rails.
- Box Tunnel in England, which opened in 1841, was the longest railway tunnel in the world at the time of construction. It was dug and has a length of 2.9 km.
- The Thames Tunnel, built by Marc Isambard Brunel and his son Isambard Kingdom Brunel and opened in 1843, was the first underwater tunnel and the first to use a tunnelling shield. Originally used as a foot-tunnel, it is now part of the East London Line of the London Underground.
- The Cobble Hill Tunnel and Murray Hill Tunnel in New York City are the world's oldest railway tunnels lying below streets, roofed over in 1850 and the 1850s, respectively.
- The oldest sections of the London Underground were built using the cut-and-cover method in the 1860s. The Metropolitan, Hammersmith & City, Circle and District lines were the first to prove the success of a metro or subway system.
- Col de Tende Road Tunnel, one of the first longer road tunnels under a pass
See also the
Rapid transit#History of
Rapid transit.
Longest
- The Seikan Tunnel in Japan is the longest rail tunnel in the world at 53.9 km (33.4 miles), of which 23.3 km (14.5 miles) is under the sea.
- The Channel Tunnel between France and the United Kingdom under the English Channel is the second-longest, with a total length of 50 km (31 miles), of which 39 km (24 miles) is under the sea.
- The Lötschberg Base Tunnel opened in June 2007 in Switzerland is the longest land tunnel, with a total of 34.5 km (21.5 miles).
- The Lærdal Tunnel in Norway from Lærdal to Aurland is the world's longest road tunnel, intended for cars and similar vehicles, at 24.5 km (15.2 miles).
- The Zhongnanshan Tunnel in People's Republic of China opened in January 2007 is the world's longest highway tunnel and the longest road tunnel in Asia, at 18.0 km (11.3 miles).
- Päijänne Water Tunnel is the world's longest complete tunnel that is bored into cliff. It is located in southern Finland and it is 120 km long. Its purpose is to provide the Greater Helsinki metropolitan area with fresh water.
Notable
- The Lincoln Tunnel between New Jersey and New York is one of the busiest vehicular tunnels in the world, at 120,000 vehicles/day.
- The Essingeleden in Stockholm, Sweden
- Williamson's tunnels in Liverpool, built by a wealthy eccentric are probably the largest underground folly in the world.
- New York City Water Tunnel No. 3, started in 1970, has an expected completion date of 2020.
- The Tunnel and Reservoir Plan is a network of 109 miles (197 km) of tunnels designed to reduce flooding in the Chicagoland. Started in the mid 1970s, the project is due to be completed in 2019.
- Moffat Tunnel in Colorado straddles the Continental Divide. The tunnel is 6.2 mi (10.0 km) long and at 9,239 feet (2,816 m) above sea level is the highest railroad tunnel in the United States.
- The Fenghuoshan tunnel on Qinghai-Tibet railway is the world's highest railway tunnel.
- The Houston Downtown Tunnel System is a system of tunnels about twenty feet below Houston's downtown street system. The system forms a network of subterranean, climate-controlled, pedestrian walkways that link twenty-five full city blocks.
- The Sydney Harbour Tunnel in Sydney, Australia was built in 1992 to augment the Sydney Harbour Bridge.
Other uses
Excavation techniques, as well as the construction of underground bunkers and other habitable areas, are often associated with
tunnel warfare, or civilian responses to threat of attack.
Media
Natural tunnel
Snow tunnels are created by voles, chipmunks and other rodents for protection and access to food sources. Larger versions are created by humans, usually for fun.
For more information regarding tunnels built by animals, see Burrow
See also
References
External links
- Trans Global Highway and proposed tunnels.
- Royal Engineers Museum British Army First World War Tunnelling.
- Directory of the world's longest tunnels by category
- ITA-AITES International Tunnelling Association
- Tunnels & Tunnelling International magazine
,
BelgiumA
tunnel is an underground passage. The definition of what constitutes a tunnel is not universally agreed upon. However, in general tunnels are at least twice as long as they are wide. In addition, they should be completely enclosed on all sides, save for the openings at each end.
A tunnel may be for
pedestrians or cyclists, for general road traffic, for motor vehicles only, for rail transport traffic, or for a canal. Some are
aqueducts, constructed purely for water supply — for consumption, for hydroelectric purposes or as sewers — while others carry other services such as telecommunications cables. There are even tunnels designed as wildlife crossings for European badgers and other endangered species. Some
secret passage have also been made as a method of entrance or escape from an area, such as the
Cu Chi Tunnels or the
Smuggling tunnel#Smuggling tunnels in Rafah, Gaza Strip connecting the Gaza Strip to
Egypt.
In the
United Kingdom a pedestrian tunnel or other underpass beneath a road is called a
Subway (underpass). This term was used in the past in the
United States, but now refers to underground rapid transit systems.
The longest canal tunnel is the
Standedge Tunnels in the United Kingdom, over three miles long.
In the Czech republic, the verb to 'tunnel' is a synonym for to embezzle. For example: the manager 'tunnelled' the company and now lives on the Bahamas; or, many banks collapsed because they were 'tunnelled'. Tunneling (fraud)
airport. in Singapore is a fully-underground rail line.
The central part of a rapid transit network is usually built in tunnels. To allow non-level crossings, some lines run in deeper tunnels than others. At metro stations there are usually pedestrian tunnels from one
railway platform to another. Often, ground-level train stations also have one or more pedestrian tunnels under the railway to enable passengers to reach the platforms without walking across the tracks. In the United Kingdom bridges are an equally popular for pedestrian access between two or more railway station platforms.
Geotechnical investigation
It is essential that any tunnel project starts with a comprehensive investigation of ground conditions. The results of the investigation will allow proper choice of machinery and methods for excavation and ground support, and will reduce the risk of encountering unforseen ground conditions. In the early stages, the horizontal and vertical alignment will be optimised to make use of the best ground and water conditions.
In some cases, conventional desk and site studies will not produce sufficient information to assess, for example, the blocky nature of rocks, the exact location of fault zones, or stand-up times of softer ground. This may be a particular concern in large diameter tunnels. To overcome these problems, a pilot tunnel, or drift, may be driven ahead of the main drive. This smaller diameter tunnel will be easier to support when unexpected conditions occur, and will be incorporated in the final tunnel. Alternatively, horizontal boreholes may sometimes be used ahead of the advancing tunnel face.
==Construction== under construction
Tunnels are dug in various types of materials, from soft clay to hard rock, and the method of excavation depends on the ground conditions.
Cut-and-cover
Cut-and-cover is a simple method of construction for shallow tunnels where a
trench is excavated and roofed over. Strong supporting beams are necessary to avoid the danger of the tunnel collapsing due to over head pressure.
Two basic forms of cut-and-cover tunnelling are available:
- Bottom-up method: A trench is excavated, with ground support as necessary, and the tunnel is constructed within. The tunnel may be of insitu concrete, precast concrete, precast arches, corrugated steel arches and such, with brickwork used in early days. The trench is then backfilled, with precautions regarding balancing compaction of the backfill material, and the surface is reinstated.
- Top-down method: In this method, side support walls and capping beams are constructed from ground level, using slurry walling, contiguous bored piles, or some other method. A shallow excavation is then made to allow the tunnel roof to be constructed using precast beams or insitu concrete. The surface is then reinstated except for access openings. This allows early reinstatement of roadways, services and other surface features. Excavation machinery is then lowered into the access openings, and the main excavation is carried out under the permanent tunnel roof, followed by constructing the base slab.
Shallow tunnels are often of the cut-and-cover type (if under water, of the immersed-tube type), while deep tunnels are excavated, often using a tunnelling shield. For intermediate levels, both methods are possible.
Boring machines
, Nevada
Tunnel boring machines (TBMs) and associated back-up systems can be used to highly automate the entire tunneling process. There are a variety of TBMs that can operate in a variety of conditions, from hard rock to soft water-bearing ground. Some types, bentonite slurry and earth-pressure balance machines, have pressurised compartments at the front, allowing them to be used in difficult conditions below the
water table. This pressurizes the ground ahead of the TBM cutter head to balance the water pressure. The operators work in normal air pressure behind the pressurised compartment, but may occasionally have to enter that compartment to renew or repair the cutters. This requires special precautions, such as local ground treatment or halting the TBM at a position free from water. Despite these difficulties, TBMs are now preferred to the older method of tunneling in compressed air, with an air lock/decompression chamber some way back from the TBM, which required operators to work in high pressure and go through decompression procedures at the end of their shifts, much like divers.
Until recently the biggest TBM built was used to bore the Green Heart Tunnel (Dutch: Tunnel Groene Hart) as part of the HSL-Zuid in the Netherlands. Its diameter is 14.87 m.
Nowadays 4 even larger machines exist: 2 for the M30 ringroad in Madrid, Spain, 2 for the Chong Ming tunnels in Shanghai, China. These machines are 15,2 m and 15,4m in diameter respectively. The two machines for Spain were built by Mitsubishi/Dura Fuelgo and Herrenknecht . The TBMs for China were built by Herrenknecht.
NATM
The
New Austrian Tunnelling method (NATM) was developed in the 1960s. The main idea of this method is to use the geological
stress (physics) of the surrounding Rock (geology) mass to stabilize the tunnel itself. Based on
geotechnical measurements, an optimal cross section (geometry) is computed. The excavation is immediately protected by thin shotcrete, just behind the excavation. This creates a natural load-bearing ring, which minimizes the rock's deformation.
By special
Condition monitoring the NATM method is very flexible, even at surprising changes of the geomechanics rock consistency during the tunneling work. The measured rock properties lead to appropriate
tools for tunnel Strength of materials. In the last decades also
soft ground excavations up to 10 km became usual.
Pipe jacking
Pipe Jacking, also known as
pipejacking or
pipe-jacking, is a method of tunnel construction where hydraulic jacks are used to push specially made pipes through the ground behind a tunnel boring machine or shield. This technique is commonly used to create tunnels under existing structures, such as roads or railways.
Underwater tunnels
There are also several approaches to underwater tunnels, for instance an immersed tube as in the
Sydney Harbour Tunnel, and the Posey and Webster Street Tubes which connect the cities of Oakland, California and Alameda, California, running beneath the
Alameda-Oakland Estuary.
Other
Other tunneling methods include:
Choice of tunnels vs. bridges
For water crossings, a tunnel is generally more costly to construct than a bridge. Navigational considerations may limit the use of high bridges or
drawbridge spans intersecting with shipping channels, necessitating a tunnel. Bridges usually require a larger footprint on each shore than tunnels. In areas with expensive real estate, such as
Manhattan and urban
Hong Kong, this is a strong factor in tunnels' favor. Boston's Big Dig (Boston, Massachusetts) project replaced elevated roadways with a tunnel system to increase traffic capacity, hide traffic, reclaim land, redecorate, and reunite the city with the waterfront. Examples of water-crossing tunnels built instead of bridges include the Holland Tunnel and
Lincoln Tunnel between New Jersey and Manhattan in
New York City, and the
Elizabeth River (Virginia) tunnels between
Norfolk, Virginia and Portsmouth, Virginia and the Westerscheldetunnel, Zeeland, Netherlands. Other reasons for choosing a tunnel instead of a bridge include avoiding difficulties with tides, weather and shipping during construction (as in the 51.5 km
Channel Tunnel), aesthetic reasons (preserving the above-ground view, landscape, and scenery), and also for weight capacity reasons (it may be more feasible to build a tunnel than a sufficiently strong bridge).
Some water crossings are a mixture of bridges and tunnels, such as the Oresund Bridge and the Chesapeake Bay Bridge-Tunnel in the eastern United States.
Short tunnels
A short tunnel can be built as an alternative to an overpass. One example of a short tunnel is the Croom Tunnel on the
South Coast railway line, New South Wales.
Artificial tunnels
Overbridges can sometimes be built by covering a road or river or railway with brick or still arches, and then levelling the surface with earth. In railway parlance, a surface-level track which has been built or covered over is normally called a covered way.
Snow sheds are a kind of artificial tunnel built to protect a railway from avalanches of snow. Similarly the
Stanwell Park,
New South Wales steel tunnel, on the South Coast railway line, New South Wales, which protects the line from rockfalls.
Common utility ducts are man-made tunnels created to carry two or more utility lines underground. Through co-location of different utilities in one tunnel, organizations are able to reduce the costs of building and maintaining utilities.
Examples of tunnels
In history
,
London, mid 19th century
- The qanat or kareez of Persia is a water management system used to provide a reliable supply of water to human settlements or for irrigation in hot, arid and semi-arid climates. The oldest and largest known qanat is in the Iranian city of Gonabad which after 2700 years still provides drinking and agricultural water to nearly 40,000 people. Its main well depth is more than 360 meters and its length is 45 kilometers.
- The Eupalinian aqueduct on the island Samos Island (Ionia). Built 520 BC by the Ionian engineer Eupalinos. Eupalinos organised the work so that the tunnel was begun from both sides of the hill and the two teams met in the middle. The estimates for the time required range from 5 to 15 years: the mountain is solid limestone and one has to suppose that many of the slaves doing the work died. The tunnel's existence was recorded by Herodotus (as was the mole and harbour, and the third wonder of the island, the great temple to Hera, thought by many to be the largest in the Greek world). The precise location of the tunnel was only re-established in the 19th century by German archaeologists. The tunnel proper is 1030 metres (3,430 ft) long and visitors can still enter it Eupalinos tunnel.
- Sapperton Canal Tunnel on the Thames and Severn Canal in England, dug through hills, which opened in 1789, was 3.5 km long and allowed Canal boat transport of coal and other goods. Above it runs the Sapperton Long Tunnel which carries the "Golden Valley" railway line between Swindon and Gloucester.
- The tunnel created for the first true steam locomotive, the Penydarren locomotive, was built prior to Richard Trevithick was able to make his historic journey from Penydarren to Abercynon in 1804. Part of this tunnel can still be seen at Pentrebach, Merthyr Tydfil. This is arguably the oldest railway tunnel in the world, for self-propelled steam engines on rails.
- Box Tunnel in England, which opened in 1841, was the longest railway tunnel in the world at the time of construction. It was dug and has a length of 2.9 km.
- The Thames Tunnel, built by Marc Isambard Brunel and his son Isambard Kingdom Brunel and opened in 1843, was the first underwater tunnel and the first to use a tunnelling shield. Originally used as a foot-tunnel, it is now part of the East London Line of the London Underground.
- The Cobble Hill Tunnel and Murray Hill Tunnel in New York City are the world's oldest railway tunnels lying below streets, roofed over in 1850 and the 1850s, respectively.
- The oldest sections of the London Underground were built using the cut-and-cover method in the 1860s. The Metropolitan, Hammersmith & City, Circle and District lines were the first to prove the success of a metro or subway system.
- Col de Tende Road Tunnel, one of the first longer road tunnels under a pass
See also the
Rapid transit#History of Rapid transit.
Longest
- The Seikan Tunnel in Japan is the longest rail tunnel in the world at 53.9 km (33.4 miles), of which 23.3 km (14.5 miles) is under the sea.
- The Channel Tunnel between France and the United Kingdom under the English Channel is the second-longest, with a total length of 50 km (31 miles), of which 39 km (24 miles) is under the sea.
- The Lötschberg Base Tunnel opened in June 2007 in Switzerland is the longest land tunnel, with a total of 34.5 km (21.5 miles).
- The Lærdal Tunnel in Norway from Lærdal to Aurland is the world's longest road tunnel, intended for cars and similar vehicles, at 24.5 km (15.2 miles).
- The Zhongnanshan Tunnel in People's Republic of China opened in January 2007 is the world's longest highway tunnel and the longest road tunnel in Asia, at 18.0 km (11.3 miles).
- Päijänne Water Tunnel is the world's longest complete tunnel that is bored into cliff. It is located in southern Finland and it is 120 km long. Its purpose is to provide the Greater Helsinki metropolitan area with fresh water.
Notable
- The Lincoln Tunnel between New Jersey and New York is one of the busiest vehicular tunnels in the world, at 120,000 vehicles/day.
- The Essingeleden in Stockholm, Sweden
- Williamson's tunnels in Liverpool, built by a wealthy eccentric are probably the largest underground folly in the world.
- New York City Water Tunnel No. 3, started in 1970, has an expected completion date of 2020.
- The Tunnel and Reservoir Plan is a network of 109 miles (197 km) of tunnels designed to reduce flooding in the Chicagoland. Started in the mid 1970s, the project is due to be completed in 2019.
- Moffat Tunnel in Colorado straddles the Continental Divide. The tunnel is 6.2 mi (10.0 km) long and at 9,239 feet (2,816 m) above sea level is the highest railroad tunnel in the United States.
- The Fenghuoshan tunnel on Qinghai-Tibet railway is the world's highest railway tunnel.
- The Houston Downtown Tunnel System is a system of tunnels about twenty feet below Houston's downtown street system. The system forms a network of subterranean, climate-controlled, pedestrian walkways that link twenty-five full city blocks.
- The Sydney Harbour Tunnel in Sydney, Australia was built in 1992 to augment the Sydney Harbour Bridge.
Other uses
Excavation techniques, as well as the construction of underground bunkers and other habitable areas, are often associated with tunnel warfare, or civilian responses to threat of attack.
Media
Natural tunnel
Snow tunnels are created by voles, chipmunks and other rodents for protection and access to food sources. Larger versions are created by humans, usually for fun.
For more information regarding tunnels built by animals, see
Burrow
See also
References
External links
- Trans Global Highway and proposed tunnels.
- Royal Engineers Museum British Army First World War Tunnelling.
- Directory of the world's longest tunnels by category
- ITA-AITES International Tunnelling Association
- Tunnels & Tunnelling International magazine
The Tunnels Aberdeen
Welcome to The Tunnels, Aberdeen's newest and most exciting independent music venue. From its subterranean home, The Tunnels aims to bring you the best in live music, from ...
Mersey Tunnels
Fast Tag scheme – the convenient way to travel through Mersey Tunnels
First Tunnels - Shop Online For Polytunnels
Order garden products from UK on-line garden superstore.
Amazon.co.uk: Tunnels (Tunnels 1): Roderick Gordon; Brian Williams ...
Amazon.co.uk: Tunnels (Tunnels 1): Roderick Gordon; Brian Williams: Books ... RRP: £6.99 : Price: £3.66 & eligible for Free UK delivery on orders over £15 with Super Saver ...
Friends of Williamson's Tunnels
Fan site for an odd collection of tunnels located under Liverpool.
tunnels beaches | ilfracombe | north devon
a network of hand carved tunnels leading to unique sheltered beaches and tidal victorian bathing pool
Williamson Tunnels Heritage Centre
Visitor information. Includes news, and details of their education programmes, the Tunnels Bar venue, and how you can help.
Tunnels | Mott MacDonald
Specialists in all forms of tunnel design and construction in soft ground and hard rock by TBM, drill and blast, immersed tunnel and jacked box techniques
Tunnel projects | Tunnels | Mott MacDonald
Specialists in all forms of tunnel design and construction in soft ground and hard rock by TBM, drill and blast, immersed tunnel and jacked box techniques
Polytunnels and Greenhouse Hybrids from Solar Tunnels based in Sussex
Offers a range of alternatives to glass greenhouses. Product details and specifications.
