Eisenhower Tunnel
Encyclopedia
The Eisenhower Tunnel, officially the Eisenhower–Johnson Memorial Tunnel, is a dual-bore, four-lane vehicular tunnel
approximately 50 mi (80 km) west of Denver, Colorado
, United States. The tunnel carries Interstate 70
under the Continental Divide
in the Rocky Mountains
. With a maximum elevation of 11158 ft (3,401 m) above sea level, it is one of the highest vehicular tunnels in the world. The tunnel is the longest mountain tunnel and highest point on the Interstate Highway system
. Completed in 1979, it was one of the last major pieces of the Interstate Highway system to be completed. The westbound bore is named after Dwight D. Eisenhower
, the U.S. President for whom the Interstate system is also named. The eastbound bore is named for Edwin C. Johnson
, a governor
and U.S. Senator
who lobbied for an Interstate Highway to be built across Colorado.
(westbound tunnel) is 1.693 mi (2.72 km) long while the Johnson bore (eastbound tunnel) is 1.697 mi (2.73 km) long. The tunnels are sloped with a 1.64% grade, with an elevation of 11013 feet (3,356.8 m) at the east portal and 11158 feet (3,401 m) at the west portal. At the time of dedication, they were the highest vehicular tunnels in the world. The Eisenhower Tunnel remains the highest vehicular tunnel in the United States, however higher tunnels have since been constructed elsewhere, such as the Fenghuoshan Tunnel
, a rail tunnel in China. The Eisenhower tunnel is noted as the longest mountain tunnel and highest point on the Interstate Highway system
. The tunnel bores measure 48 feet (14.6 m) by 40 feet (12.2 m); however, the portion accessible to the public is a square shape measuring just over 16 feet (4.9 m) tall. The rest of the bore is used for forced air ventilation and water drainage systems.
Due to additional height restrictions from variable message signs and lighting systems, the original posted clearance of the tunnels was 13.5 feet (4.1 m). The trucking industry lobbied the Colorado Department of Transportation (CDOT) to increase the vertical clearance of the tunnel. With a 2007 retrofit that used lower profile lighting and signs, it is now possible for trucks 13.92 feet (4.2 m) to navigate the tunnel, an increase of 5 inches (12.7 cm) over the original limit. Sensors will activate audible sirens near each entrance of the tunnel if a vehicle above the posted height attempts to enter the tunnel. Traffic signals at that entrance will turn red, stopping all traffic. The entrance will remain closed until the over-height vehicle is removed from the freeway, sometimes causing severe delays for all traffic. CDOT noted that prior to the retrofit, about 20,000 vehicles per year tripped the alarm. The trucking industry argued that many of these trucks were under the height requirement but tripped the alarm due to their air suspensions (which can be manually lowered for the duration of the journey through the tunnel) or due to winter snow and ice on top of the trailer. During this time, the trucking industry estimated the number of alarms would drop by as much as 80% if the clearance could be raised even a few inches. Another feature of the retrofit monitors truck weight—a safe speed for each truck on the 7% grades and curves just outside the tunnel is calculated and displayed for each driver.
s, pedestrian
s and those who wish to stop and view the scenery must take the longer and steeper climb and descent of the older U.S. Highway 6
across Loveland Pass
, 834 ft (254 m) higher at 11992 ft (3,655 m) above sea level. Other than the above exceptions, the tunnel has replaced the pass
for general vehicular traffic. While less formidable than the older route, the approach to the tunnel on both sides is steep, and runaway truck ramp
s are available for truckers who lose control.
During construction or winter storms that require closing Loveland Pass, there is a procedure in place to allow hazardous material trucks to use the tunnel. Once per hour, the tunnel bores will be closed to regular traffic, and the trucks will be guided through the tunnel in a convoy
with escorts.
As of December 2009, almost 276 million vehicles have passed through the tunnel. This figure includes a significant number of visitors to Colorado's ski resort
s.
officials, it was decided the best option was to follow the US 6 corridor. Engineers recommended to tunnel under the pass rather than attempt to build a route across it that conformed to Interstate Highway standards
.
The Eisenhower–Johnson Memorial Tunnel was known as the Straight Creek Tunnel during construction, named for the waterway that runs along the western approach to the tunnel. Before the tunnel was dedicated it was renamed to honor Dwight D. Eisenhower and Edwin C. Johnson. Construction on the first bore of the tunnel was started on March 15, 1968. Construction efforts suffered many setbacks and the project went well over time and budget. One of the biggest setbacks was the discovery of fault lines
in the path of the tunnel that were not discovered during the pilot
bores. These faults began to slip during construction and emergency measures had to be taken to protect the tunnels and workers from cave-ins and collapses. Despite the best efforts of engineers, three workers were killed boring the first tube, and six in boring the second. Further complicating construction, the boring machines could not work as fast as expected at such high altitudes; the productivity was significantly less than planned. The frustration prompted one engineer to comment, "We were going by the book, but the damned mountain couldn't read". Though the project was supposed to take three years, the tunnel was not opened to traffic until March 8, 1973. Initially this tunnel (the Eisenhower bore) was used for two way traffic, with one lane for each direction. The amount of traffic through the tunnel exceeded predictions, and efforts soon began to expedite construction on the second tube (the Johnson bore). Construction began on the eastbound tunnel on August 18, 1975 and finished on December 21, 1979. The initial engineering cost estimate for the Eisenhower bore was $42 million; the actual cost was $108 million (equivalent to $ million in ). Approximately 90% of the funds were paid by the federal government, with the state of Colorado paying the rest. At the time, this figure set a record for the most expensive federally aided project. The excavation cost for the Johnson bore was $102.8 million (equivalent to $ million in ). Not included in these figures is about $50 million in non-boring expenses in the construction of both tunnels.
The tunnel construction became unintentionally involved in the women's rights movement when Janet Bonnema applied for work with the Colorado Department of Transportation. She was given an assignment on the Straight Creek Tunnels project, however her supervisor misread her resume and thought he was hiring "James". When the supervisor discovered the department had hired a woman, she was instead tasked with doing support work from the office. There was opposition to a woman entering the construction site: one supervisor stated that if she entered, "Those workers would flat walk out of that there tunnel and they'd never come back". The workers, most of whom had a mining
background, expressed a common superstition that a woman brought bad luck to a mine. One worker insisted, "It's a jinx. I've seen too many die after a woman was in the tunnel."
Janet sued the department for the right to work in the tunnel itself. She countered that she was in better shape and more agile than most of the men working on the tunnel. Emboldened by the passage of an equal rights law in Colorado, she finally entered the tunnel, with an entourage of reporters, on November 9, 1972. Some workers did walk off the job, at least one yelled, "Get those women out of here". She remained determined and re-entered the tunnel a few days later. The next time she dressed in coveralls, and was even assigned tasks on the roof of the tunnel overlooking the men below. Surprised that nobody apparently noticed she was a woman, she stated, "I had a good disguise".
Tunnel
A tunnel is an underground passageway, completely enclosed except for openings for egress, commonly at each end.A tunnel may be for foot or vehicular road traffic, for rail traffic, or for a canal. Some tunnels are aqueducts to supply water for consumption or for hydroelectric stations or are sewers...
approximately 50 mi (80 km) west of Denver, Colorado
Colorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...
, United States. The tunnel carries Interstate 70
Interstate 70 in Colorado
Interstate 70 is a transcontinental Interstate Highway in the United States, stretching from Cove Fort, Utah to Baltimore, Maryland. In Colorado, the highway traverses an east–west route across the center of the state. In western Colorado, the highway connects the metropolitan areas of Grand...
under the Continental Divide
Continental Divide
The Continental Divide of the Americas, or merely the Continental Gulf of Division or Great Divide, is the name given to the principal, and largely mountainous, hydrological divide of the Americas that separates the watersheds that drain into the Pacific Ocean from those river systems that drain...
in the Rocky Mountains
Rocky Mountains
The Rocky Mountains are a major mountain range in western North America. The Rocky Mountains stretch more than from the northernmost part of British Columbia, in western Canada, to New Mexico, in the southwestern United States...
. With a maximum elevation of 11158 ft (3,401 m) above sea level, it is one of the highest vehicular tunnels in the world. The tunnel is the longest mountain tunnel and highest point on the Interstate Highway system
Interstate Highway System
The Dwight D. Eisenhower National System of Interstate and Defense Highways, , is a network of limited-access roads including freeways, highways, and expressways forming part of the National Highway System of the United States of America...
. Completed in 1979, it was one of the last major pieces of the Interstate Highway system to be completed. The westbound bore is named after Dwight D. Eisenhower
Dwight D. Eisenhower
Dwight David "Ike" Eisenhower was the 34th President of the United States, from 1953 until 1961. He was a five-star general in the United States Army...
, the U.S. President for whom the Interstate system is also named. The eastbound bore is named for Edwin C. Johnson
Edwin C. Johnson
Edwin Carl Johnson was a Democratic Party politician who served as Governor of the state of Colorado.-Background:...
, a governor
Governor
A governor is a governing official, usually the executive of a non-sovereign level of government, ranking under the head of state...
and U.S. Senator
United States Senate
The United States Senate is the upper house of the bicameral legislature of the United States, and together with the United States House of Representatives comprises the United States Congress. The composition and powers of the Senate are established in Article One of the U.S. Constitution. Each...
who lobbied for an Interstate Highway to be built across Colorado.
Description
The Eisenhower boreBoring (earth)
Boring is drilling a hole, tunnel, or well in the earth.-Earth boring:Boring is used for a wide variety of applications in geology, agriculture, hydrology, civil engineering, and oil and natural gas industries...
(westbound tunnel) is 1.693 mi (2.72 km) long while the Johnson bore (eastbound tunnel) is 1.697 mi (2.73 km) long. The tunnels are sloped with a 1.64% grade, with an elevation of 11013 feet (3,356.8 m) at the east portal and 11158 feet (3,401 m) at the west portal. At the time of dedication, they were the highest vehicular tunnels in the world. The Eisenhower Tunnel remains the highest vehicular tunnel in the United States, however higher tunnels have since been constructed elsewhere, such as the Fenghuoshan Tunnel
Fenghuoshan tunnel
The Fenghuoshan Tunnel is the highest railway tunnel in the world. It is 1,338 metres long, and stands 4,905 meters above sea level...
, a rail tunnel in China. The Eisenhower tunnel is noted as the longest mountain tunnel and highest point on the Interstate Highway system
Interstate Highway System
The Dwight D. Eisenhower National System of Interstate and Defense Highways, , is a network of limited-access roads including freeways, highways, and expressways forming part of the National Highway System of the United States of America...
. The tunnel bores measure 48 feet (14.6 m) by 40 feet (12.2 m); however, the portion accessible to the public is a square shape measuring just over 16 feet (4.9 m) tall. The rest of the bore is used for forced air ventilation and water drainage systems.
Height restriction
Alternate route
To mitigate the dangers posed by a fire inside the tunnel, trucks hauling hazardous materials are also prohibited from using the tunnel. Prohibited trucks, bicycleBicycle
A bicycle, also known as a bike, pushbike or cycle, is a human-powered, pedal-driven, single-track vehicle, having two wheels attached to a frame, one behind the other. A person who rides a bicycle is called a cyclist, or bicyclist....
s, pedestrian
Pedestrian
A pedestrian is a person traveling on foot, whether walking or running. In some communities, those traveling using roller skates or skateboards are also considered to be pedestrians. In modern times, the term mostly refers to someone walking on a road or footpath, but this was not the case...
s and those who wish to stop and view the scenery must take the longer and steeper climb and descent of the older U.S. Highway 6
U.S. Route 6 in Colorado
In the U.S. state of Colorado, U.S. Route 6 is an east–west highway stretching from Colorado to Nebraska. Much of the route overlaps other highways in Colorado, and as a result, much of US 6 is unsigned.- Route description :...
across Loveland Pass
Loveland Pass
Loveland Pass, elevation 11,990 ft. above sea level, is a high mountain pass in the Rocky Mountains of north-central Colorado, U.S.A.....
, 834 ft (254 m) higher at 11992 ft (3,655 m) above sea level. Other than the above exceptions, the tunnel has replaced the pass
Mountain pass
A mountain pass is a route through a mountain range or over a ridge. If following the lowest possible route, a pass is locally the highest point on that route...
for general vehicular traffic. While less formidable than the older route, the approach to the tunnel on both sides is steep, and runaway truck ramp
Runaway truck ramp
A runaway truck ramp, runaway truck lane, emergency escape ramp or truck arrester bed is a traffic device that enables vehicles that are having braking problems to safely stop. It is typically a long, sand or gravel-filled lane adjacent to a road with a steep grade, and is designed to accommodate...
s are available for truckers who lose control.
During construction or winter storms that require closing Loveland Pass, there is a procedure in place to allow hazardous material trucks to use the tunnel. Once per hour, the tunnel bores will be closed to regular traffic, and the trucks will be guided through the tunnel in a convoy
Convoy
A convoy is a group of vehicles, typically motor vehicles or ships, traveling together for mutual support and protection. Often, a convoy is organized with armed defensive support, though it may also be used in a non-military sense, for example when driving through remote areas.-Age of Sail:Naval...
with escorts.
As of December 2009, almost 276 million vehicles have passed through the tunnel. This figure includes a significant number of visitors to Colorado's ski resort
Ski resort
A ski resort is a resort developed for skiing and other winter sports. In Europe a ski resort is a town or village in a ski area - a mountainous area, where there are ski trails and supporting services such as hotels and other accommodation, restaurants, equipment rental and a ski lift system...
s.
History
The idea for a tunnel under Loveland Pass has existed at least since the 1940s. Serious discussion began when the state of Colorado lobbied for the Interstate Highway System to route a transcontinental interstate across Colorado. After a round of negotiations with UtahUtah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
officials, it was decided the best option was to follow the US 6 corridor. Engineers recommended to tunnel under the pass rather than attempt to build a route across it that conformed to Interstate Highway standards
Interstate Highway standards
Standards for Interstate Highways in the United States are defined by the American Association of State Highway and Transportation Officials in the publication A Policy on Design Standards - Interstate System...
.
The Eisenhower–Johnson Memorial Tunnel was known as the Straight Creek Tunnel during construction, named for the waterway that runs along the western approach to the tunnel. Before the tunnel was dedicated it was renamed to honor Dwight D. Eisenhower and Edwin C. Johnson. Construction on the first bore of the tunnel was started on March 15, 1968. Construction efforts suffered many setbacks and the project went well over time and budget. One of the biggest setbacks was the discovery of fault lines
Fault Lines
Fault Lines, a documentary series produced and broadcasted by Al Jazeera English, is the channel's flagship program about the Americas.Josh Rushing, Zeina Awad and Sebastian Walker host the series, currently enjoying it's third season....
in the path of the tunnel that were not discovered during the pilot
Pilot (experiment)
A pilot experiment, also called a pilot study, is a small scale preliminary study conducted in order to evaluate feasibility, time, cost, adverse events, and effect size in an attempt to predict an appropriate sample size and improve upon the study design prior to performance of a full-scale...
bores. These faults began to slip during construction and emergency measures had to be taken to protect the tunnels and workers from cave-ins and collapses. Despite the best efforts of engineers, three workers were killed boring the first tube, and six in boring the second. Further complicating construction, the boring machines could not work as fast as expected at such high altitudes; the productivity was significantly less than planned. The frustration prompted one engineer to comment, "We were going by the book, but the damned mountain couldn't read". Though the project was supposed to take three years, the tunnel was not opened to traffic until March 8, 1973. Initially this tunnel (the Eisenhower bore) was used for two way traffic, with one lane for each direction. The amount of traffic through the tunnel exceeded predictions, and efforts soon began to expedite construction on the second tube (the Johnson bore). Construction began on the eastbound tunnel on August 18, 1975 and finished on December 21, 1979. The initial engineering cost estimate for the Eisenhower bore was $42 million; the actual cost was $108 million (equivalent to $ million in ). Approximately 90% of the funds were paid by the federal government, with the state of Colorado paying the rest. At the time, this figure set a record for the most expensive federally aided project. The excavation cost for the Johnson bore was $102.8 million (equivalent to $ million in ). Not included in these figures is about $50 million in non-boring expenses in the construction of both tunnels.
The tunnel construction became unintentionally involved in the women's rights movement when Janet Bonnema applied for work with the Colorado Department of Transportation. She was given an assignment on the Straight Creek Tunnels project, however her supervisor misread her resume and thought he was hiring "James". When the supervisor discovered the department had hired a woman, she was instead tasked with doing support work from the office. There was opposition to a woman entering the construction site: one supervisor stated that if she entered, "Those workers would flat walk out of that there tunnel and they'd never come back". The workers, most of whom had a mining
Mining
Mining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...
background, expressed a common superstition that a woman brought bad luck to a mine. One worker insisted, "It's a jinx. I've seen too many die after a woman was in the tunnel."
Janet sued the department for the right to work in the tunnel itself. She countered that she was in better shape and more agile than most of the men working on the tunnel. Emboldened by the passage of an equal rights law in Colorado, she finally entered the tunnel, with an entourage of reporters, on November 9, 1972. Some workers did walk off the job, at least one yelled, "Get those women out of here". She remained determined and re-entered the tunnel a few days later. The next time she dressed in coveralls, and was even assigned tasks on the roof of the tunnel overlooking the men below. Surprised that nobody apparently noticed she was a woman, she stated, "I had a good disguise".
External links
- Eisenhower Tunnel by Colorado Department of Transportation
- Eisenhower Tunnel traffic camera by Colorado Department of Transportation