Grand Canyon Skywalk
Encyclopedia
The Grand Canyon Skywalk is a transparent horseshoe-shaped cantilever
Cantilever
A cantilever is a beam anchored at only one end. The beam carries the load to the support where it is resisted by moment and shear stress. Cantilever construction allows for overhanging structures without external bracing. Cantilevers can also be constructed with trusses or slabs.This is in...

 bridge and tourist attraction
Tourist attraction
A tourist attraction is a place of interest where tourists visit, typically for its inherent or exhibited cultural value, historical significance, natural or built beauty, or amusement opportunities....

 in Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...

 near the Colorado River
Colorado River
The Colorado River , is a river in the Southwestern United States and northwestern Mexico, approximately long, draining a part of the arid regions on the western slope of the Rocky Mountains. The watershed of the Colorado River covers in parts of seven U.S. states and two Mexican states...

 on the edge of a side canyon in the Grand Canyon West area of the main canyon. USGS topographic maps show the elevation at the Skywalk's location as 4770 ft (1,453.9 m) and the elevation of the Colorado River in the base of the canyon as 1160 ft (353.6 m), and they show that the height of the precisely vertical drop directly under the skywalk is between 500 ft (152.4 m) and 800 ft (243.8 m).

Commissioned and owned by the Hualapai Indian tribe
Hualapai
The Hualapai or Walapai are a tribe of Native Americans who live in the mountains of northwestern Arizona, United States. The name is derived from "hwa:l," the Hualapai word for ponderosa pine, "Hualapai" meaning "people of the ponderosa pine"...

, it was unveiled March 20, 2007, and opened to the general public on March 28, 2007. It is accessed via the Grand Canyon West Airport
Grand Canyon West Airport
Grand Canyon West Airport is a public airport located 60 miles northwest of the central business district of Peach Springs, in Mohave County, Arizona, United States. This particular location is known as Grand Canyon West...

 terminal or a 120-mile (190 km) drive from Las Vegas, which includes a 10 miles (16.1 km) stretch of dirt road which is currently under development. The Skywalk is east of Meadview
Meadview, Arizona
Meadview is an unincorporated community in Mohave County, Arizona, United States, located near Lake Mead. Despite its name, the townsite does not overlook the lake; a ridge to the west of town separates it from the lake. It has roughly 1500 residents...

 and north of Peach Springs
Peach Springs, Arizona
Peach Springs is a census-designated place in Mohave County, Arizona, United States. The population was 600 at the 2000 census. Peach Springs serves as the administrative headquarters of the Hualapai people, and is located on the Hualapai Reservation.-Geography:Peach Springs is located at ...

 with Kingman
Kingman, Arizona
Kingman is located in a desert climate on the edge of the Mojave Desert, but its higher elevation and location between the Colorado Plateau and the Lower Colorado River Valley tempers summer high temperatures and contributes to winter cold and rare snowfall. Summer daytime highs reach above 90 °F ...

 being the closest major city.

Technical achievement

David Jin, an entrepreneur who had been involved with tourism and the Hualapai Nation for some time, had the idea of extending a platform out over the edge of the Grand Canyon. With the help of architect Mark Ross Johnson, that idea evolved into a rectangular walkway and eventually the "U"-shaped walkway that has now been constructed.

The overall Skywalk width is 65 feet (19.8 m). The Skywalk length extending out from the post supports closest to the canyon wall is 70 feet (21.3 m). The outer and inner 32 inches (812.8 mm) by 72 inches (1,828.8 mm) bridge box beams are supported by eight 32 inch box posts having four posts on each side of the visitor’s center, once completed. The eight posts are anchored in pairs into four large concrete footings that are in turn anchored to the bedrock by ninety-six 2+1/2 in DYWIDAG
DYWIDAG Systems International
DYWIDAG-Systems International is a globally operating technology group that has its focus on the Construction and Underground markets.DSI was founded in 1979 as a Dyckerhoff & Widmann AG subsidiary to market licences for DYWIDAG-Products and Systems around the world.At the beginning, DSI’s focus...

 (acronym pronounced Doo-Wee-Dag) high strength steel threaded rod rock anchors grouted 46 feet (14 m) deep into the rock.

The deck of the Skywalk has been made with four layers of Saint-Gobain Diamant low iron glass with DuPont SentryGlas interlayer. Deck width is 10 in 2 in (3.1 m). The Skywalk glass railings were made with the same glass as the deck, but fewer layers (two) bent to follow the walkway’s curvature. The glass railings are 5 in 2 in (1.57 m) tall and have been designed for high wind pressures.

The Skywalk deck was designed for a 100-pound-per-square-foot live load along with code required seismic and wind forces. The foundation can support the equivalent of 71 loaded Boeing 747
Boeing 747
The Boeing 747 is a wide-body commercial airliner and cargo transport, often referred to by its original nickname, Jumbo Jet, or Queen of the Skies. It is among the world's most recognizable aircraft, and was the first wide-body ever produced...

 aircraft or an 8.0 magnitude earthquake within 50 miles (80.5 km). Fine-tuning of the project occurred after a wind loading and pedestrian induced vibration analysis. Two tuned mass dampers
Tuned mass damper
A tuned mass damper, also known as an active mass damper or harmonic absorber, is a device mounted in structures to reduce the amplitude of mechanical vibrations. Their application can prevent discomfort, damage, or outright structural failure...

 were installed inside the outer box beam as well as one inside the inner box beam at the furthest extension of the Skywalk to reduce pedestrian footfall vibration. The walkway could carry 822 people that weigh 200 pounds (90.7 kg) each without overstress, but maximum occupancy at one time is 120 people.

The Skywalk was assembled on top of the canyon wall in line with its final placement and moved into final position by a jack and roll rig. The Skywalk infrastructure itself weighs a little over 1000000 pounds (453,592.4 kg) without counterweights but including the tuned mass dampers, railing hardware, glass rails, glass deck and steel box beams. At the time of roll-out, the Skywalk weighed approximately 1.6 million pounds. The process was completed in two days.

The Skywalk glass itself was manufactured and imported from Saint-Gobain Deutsche Glas (Kinon in Aachen) and Glas Döring in Berlin, Germany.

Structural design was provided by Lochsa Engineering out of Las Vegas, Nevada. Contractor is Executive Construction Management also located in Las Vegas, Nevada. Foundation design was aided by John Peck (Geologist), Aaron Hastings, P.E. of Arroyo Engineering Consultants, Inc. (Geotechnical Engineer), DJ Scheffler, Inc and Crux Subsurface, Inc.

Astronauts Buzz Aldrin
Buzz Aldrin
Buzz Aldrin is an American mechanical engineer, retired United States Air Force pilot and astronaut who was the Lunar Module pilot on Apollo 11, the first manned lunar landing in history...

 and John Herrington
John Herrington
John Bennett Herrington is an American business executive, former US Navy officer and former NASA astronaut. He is a veteran of one Space Shuttle mission. He is the first enrolled member of a Native American tribe to fly in space....

 attended the opening ceremony on March 20, 2007.

Cornerstone of a larger plan

According to Hualapai officials, the cost of the Skywalk was $31 million. Future plans for the Grand Canyon Skywalk complex include a museum, movie theater, VIP lounge, gift shop, and several restaurants including a high-end restaurant called The Skywalk Café where visitors will be able to dine outdoors at the canyon's rim. The Skywalk is the cornerstone of a larger plan by the Hualapai tribe, which it hopes will be the catalyst for a 9000 acres (36.4 km²) development to be called Grand Canyon West; it would open up a 100 miles (160.9 km) stretch along the canyon's South Rim and include hotels, restaurants, a golf course, and a cable car
Aerial tramway
An aerial tramway , cable car , ropeway or aerial tram is a type of aerial lift which uses one or two stationary ropes for support while a third moving rope provides propulsion...

 to ferry visitors from the canyon rim to the Colorado River, which has been previously inaccessible.

Hualapai

Opponents within the tribe view the project as disturbing sacred ground. Supporters within the tribe counter that it is an opportunity to generate much-needed cash to combat serious problems that plague the small 2,000-resident reservation, including a 50% unemployment rate, widespread alcoholism
American Indian alcoholism
American Indians have historically had extreme difficulty with the use of alcohol. At times, American Indians have made paupers of themselves to obtain alcohol. Problems continue among contemporary Indians with 12% of the deaths among American Indians and Alaska Natives being alcohol related...

, and poverty. Other tribal members are happy with the Skywalk, but they have expressed concern over future over-development. They are also concerned about the potential lack of sustainability because the water used in both the development and the neighboring Grand Canyon National Park
Grand Canyon National Park
Grand Canyon National Park is the United States' 15th oldest national park and is located in Arizona. Within the park lies the Grand Canyon, a gorge of the Colorado River, considered to be one of the Wonders of the World. The park covers of unincorporated area in Coconino and Mohave counties.Most...

 is not taken from the Colorado River but piped or trucked in from elsewhere.

Environmentalists and others

People outside of the tribe, including Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...

 environmental groups and former National Park officials, have expressed concern about the project's obtrusiveness in the natural environment, considering it a defacement of a national treasure. Some have suggested it is ironic that the Hualapai had argued they were the best caregivers and stewards of the Grand Canyon, and yet decided to exploit it in this way. Tribal leaders counter that the 4.5 million people a year who visit the National Park portion are already overburdening an area and, further, that the tribe needs financial income. The tribe's 1 million-acre (4,000 km²) reservation attracts approximately 200,000 visitors a year and charges for rim-side weddings and stunt jumps, including one by Robbie Knievel
Robbie Knievel
Robert Edward "Robbie" Knievel is an American daredevil and son of stunt performer Evel Knievel.-Family:...

. The tribe made a foray into opening a casino but it has not been able to generate sufficient income.

Access and Protection

Access to the Skywalk can be made from Las Vegas, NV in the North or Kingman, AZ in the South, via Highway 93
U.S. Route 93
U.S. Route 93 is a major north–south United States highway in the western United States. The southern terminus is at U.S. Route 60 in Wickenburg, Arizona. The northern terminus is at the Canadian border north of Eureka in Lincoln County, Montana, where the roadway continues into Roosville,...

. Both routes converge (at CR 7/Buck and Doe Rd) near Diamond Bar Road, which was under construction as of Dec 7, 2009. At the time, Diamond Bar Road consisted of 10 miles (16.1 km) of an ungraded gravel and dirt road

Total cost to visit the attraction varies depending on how visitors arrive. In addition to a per person admission chart, visitors must pay for transportation to the remote site approximately 3 hours from Las Vegas, either via shuttle bus or for a travel permit from the Hualapai tribe. As of 2011, the final 14 miles (22.5 km) of road to the attraction were unpaved and travel guides caution visitors driving rental cars to verify that they are not violating rental agreements by traveling what may be considered "off-road". In addition to admission and transportation charges, visitors may purchase photographs of their party at the gift shop.

External links

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