BGuthrie Photos: NV -- Lake Mead NRA -- Mike O'Callaghan–Pat Tillman Memorial Bridge (incl views from...)

NV -- Lake Mead NRA -- Mike O'Callaghan–Pat Tillman Memorial Bridge (incl views from...):

Bruce Guthrie Photos Home Page: [Click here] to go to Bruce Guthrie Photos home page.

Description of Pictures: Including walking across the pedestrian bridge. Frankly, the informational signs in the area are hard to read since they're reflective. But you can read all of them on http://www.mtnmouse.com/nevada/hoover_dam_bridge_panels.html

Recognize anyone? If you recognize specific folks (or other stuff) and I haven't labeled them, please identify them for the world. Click the little pencil icon

underneath the file name (just above the picture). Spammers need not apply.

Copyrights: All pictures were taken by amateur photographer Bruce Guthrie (me!) who retains copyright on them. Free for non-commercial use with attribution. See the [Creative Commons] definition of what this means. "Photos (c) Bruce Guthrie" is fine for attribution. (Commercial use folks including AI scrapers can of course contact me.) Feel free to use in publications and pages with attribution but you don't have permission to sell the photos themselves. A free copy of any printed publication using any photographs is requested. Descriptive text, if any, is from a mixture of sources, quite frequently from signs at the location or from official web sites; copyrights, if any, are retained by their original owners.

Accessing as Spider: The system has identified your IP as being a spider.
IP Address: 3.16.81.94 -- Domain: Amazon Technologies
I love well-behaved spiders! They are, in fact, how most people find my site. Unfortunately, my network has a limited bandwidth and pictures take up bandwidth. Spiders ask for lots and lots of pages and chew up lots and lots of bandwidth which slows things down considerably for regular folk. To counter this, you'll see all the text on the page but the images are being suppressed. Also, some system options like merges are being blocked for you.
Note: Permission is NOT granted for spiders, robots, etc to use the site for AI-generation purposes. I'm sure you're thrilled by your ability to make revenue from my work but there's nothing in that for my human users or for me.
If you are in fact human, please email me at guthrie.bruce@gmail.com and I can check if your designation was made in error. Given your number of hits, that's unlikely but what the hell.

Help? The Medium (Email) links are for screen viewing and emailing. You'll want bigger sizes for printing. [Click here for additional help]

[1] TILLMN_150705_001_STITCH.JPG

[2] TILLMN_150705_003_STITCH.JPG

[3] TILLMN_150705_004.JPG	[4] TILLMN_150705_012.JPG	[5] TILLMN_150705_016.JPG
[6] TILLMN_150705_018.JPG	[7] TILLMN_150705_023.JPG	[8] TILLMN_150705_026.JPG
[9] TILLMN_150705_029.JPG	[10] TILLMN_150705_035.JPG	[11] TILLMN_150705_042.JPG
[12] TILLMN_150705_046.JPG	[13] TILLMN_150705_052.JPG	[14] TILLMN_150705_058.JPG
[15] TILLMN_150705_063.JPG	[16] TILLMN_150705_066.JPG	[17] TILLMN_150705_070.JPG
[18] TILLMN_150705_075.JPG	[19] TILLMN_150705_078.JPG	[20] TILLMN_150705_081.JPG
[21] TILLMN_150705_084.JPG	[22] TILLMN_150705_088.JPG	[23] TILLMN_150705_095.JPG
[24] TILLMN_150705_101.JPG	[25] TILLMN_150705_105.JPG	[26] TILLMN_150705_107.JPG
[27] TILLMN_150705_109.JPG	[28] TILLMN_150705_114.JPG	[29] TILLMN_150705_120.JPG
[30] TILLMN_150705_124.JPG	[31] TILLMN_150705_131.JPG	[32] TILLMN_150705_132.JPG
[33] TILLMN_150705_134.JPG	[34] TILLMN_150705_135.JPG	[35] TILLMN_150705_139.JPG
[36] TILLMN_150705_143.JPG	[37] TILLMN_150705_149.JPG	[38] TILLMN_150705_151.JPG
[39] TILLMN_150705_154.JPG	[40] TILLMN_150705_155.JPG	[41] TILLMN_150705_156.JPG
[42] TILLMN_150705_158.JPG	[43] TILLMN_150705_161.JPG	[44] TILLMN_150705_163.JPG
[45] TILLMN_150705_174.JPG	[46] TILLMN_150705_175.JPG	[47] TILLMN_150705_177.JPG
[48] TILLMN_150705_179.JPG	[49] TILLMN_150705_182.JPG	[50] TILLMN_150705_184.JPG
[51] TILLMN_150705_187.JPG	[52] TILLMN_150705_192.JPG	[53] TILLMN_150705_193.JPG
[54] TILLMN_150705_199.JPG	[55] TILLMN_150705_202.JPG	[56] TILLMN_150705_205.JPG
[57] TILLMN_150705_213.JPG	[58] TILLMN_150705_217.JPG	[59] TILLMN_150705_219.JPG
[60] TILLMN_150705_226.JPG	[61] TILLMN_150705_232.JPG	[62] TILLMN_150705_234.JPG
[63] TILLMN_150705_240.JPG	[64] TILLMN_150705_242.JPG	[65] TILLMN_150705_246.JPG
[66] TILLMN_150705_249.JPG	[67] TILLMN_150705_251.JPG	[68] TILLMN_150705_256.JPG
[69] TILLMN_150705_261.JPG	[70] TILLMN_150705_265.JPG	[71] TILLMN_150705_267.JPG
[72] TILLMN_150705_269.JPG	[73] TILLMN_150705_272.JPG	[74] TILLMN_150705_276.JPG
[75] TILLMN_150705_281.JPG	[76] TILLMN_150705_283.JPG	[77] TILLMN_150705_287.JPG
[78] TILLMN_150705_292.JPG	[79] TILLMN_150705_295.JPG	[80] TILLMN_150705_299.JPG
[81] TILLMN_150705_302.JPG	[82] TILLMN_150705_307.JPG	[83] TILLMN_150705_309.JPG
[84] TILLMN_150705_314.JPG	[85] TILLMN_150705_316.JPG	[86] TILLMN_150705_322.JPG
[87] TILLMN_150705_325.JPG	[88] TILLMN_150705_328.JPG	[89] TILLMN_150705_338.JPG
[90] TILLMN_150705_340.JPG	[91] TILLMN_150705_346.JPG	[92] TILLMN_150705_351.JPG
[93] TILLMN_150705_360.JPG	[94] TILLMN_150705_364.JPG	[95] TILLMN_150705_367.JPG
[96] TILLMN_150705_371.JPG	[97] TILLMN_150705_372.JPG	[98] TILLMN_150705_376.JPG
[99] TILLMN_150705_384.JPG	[100] TILLMN_150705_389.JPG	[101] TILLMN_150705_394.JPG
[102] TILLMN_150705_398.JPG	[103] TILLMN_150705_401.JPG	[104] TILLMN_150705_407.JPG
[105] TILLMN_150705_411.JPG	[106] TILLMN_150705_413.JPG	[107] TILLMN_150705_416.JPG
[108] TILLMN_150705_420.JPG	[109] TILLMN_150705_421.JPG	[110] TILLMN_150705_426.JPG
[111] TILLMN_150705_429.JPG	[112] TILLMN_150705_432.JPG	[113] TILLMN_150705_436.JPG
[114] TILLMN_150705_440.JPG	[115] TILLMN_150705_443.JPG	[116] TILLMN_150705_447.JPG

Specific picture descriptions: Photos above with "i" icons next to the bracketed sequence numbers (e.g. "[1] ") are described as follows:
1. TILLMN_150705_018.JPG: PROJECT FACTS The Bridge; At its completion in 2010, the Mike O'Callaghan-Pat Tillman Memorial Bridge had the longest concrete arch span in the western hemisphere. 1,060 feet -- length of the bridge arch span 1,900 feet -- Length of the bridge deck 880+/- feet -- Height of the bridge deck above the Colorado River 1,500 feet -- Approximate distance to the Hoover Dam from the bridge 2,000 tons -- Weight of steel in twin-rib concrete arches 9,000 cubic yards -- Volume of concrete in twin-rib concrete arches 290 feet -- Height of the tallest precast concrete columns on the arches 60 tons -- Weight of each steel strut between the paired columns 6,000 cubic yards -- Volume of concrete in the bridge deck The Approach Roadways: 1.2 miles -- Length of the Arizona roadway 2.3 miles -- Length of the Nevada roadway 26,000 linear feet -- Length of guardrails along the roadways 85,000 tons -- Weight of the aggregate base for the roadways 66,000 tons -- Weight of hot asphalt concrete for the roadways 3.6 million cubic yards -- Volume of rock excavation The Project: $240 million -- Cost of the Bypass Project, unchanged from original estimate 9 years -- Time to complete the project from designing to opening 2010 -- 1900 foot deck, 1060 foot span, 890 foot height -- Mike O'Callaghan-Pat Tillman Memorial Bridge on the Colorado River at Hoover Dam AZ-NV -- composite concrete arch & steel -- TransAmerica Pyramid 853 foot high, 48 stories + spire 1959 -- 1560 foot deck, 1028 foot span, 690 foot height -- Glen Canyon Dam Bridge on the Colorado River near Page, AZ -- steel truss arch -- Highest arch bridge in the world and second highest bridge in the world in 1959 1995 -- 909 foot deck, 725 foot span, 470 foot height -- New Navajo Bridge on the Colorado River at Navajo Crossing, AZ -- steel tross arch -- The original bridge was third highest bridge in North America in 1929
2. TILLMN_150705_023.JPG: WELCOME TO THE MIKE O'CALLAGHAN - PAT TILLMAN MEMORIAL BRIDGE
3. TILLMN_150705_026.JPG: SEEING DOUBLE IN A LAND OF CONTRASTS
4. TILLMN_150705_029.JPG: BYPASSED PLACE OF EMPTINESS & PROMISE You find nature hard at work here, sometimes in discord and at other times in harmony. Desert scorches yet river cools while water and wind carve canyon and crag. The sun and wind joined with sand and rock to make a place where few plants or animals can live. Hardy desert dwellers migrate through the deserts and hills seeking the few precious sources of food and water. The harsh desert and deep canyon made traveling through here almost impossible. Indians and pioneers bypassed this place to use easier crossings upstream and down. Long ago, this place gave no reason to travel or settle here; it was neither a passage nor a destination. The barren deserts and stony hills at Black Canyon had no precious minerals to mine or rich land to farm. Today, while you speed through this no-place, think of those heroes who first dared to blaze the trail.
5. TILLMN_150705_035.JPG: FOLLOW FOOTSTEPS OF EVERYDAY HEROES During 1857 and 1858 explorer Edward F. Beale led an experimental camel caravan from Texas to California to test their hardiness for Army service in the Southwest. Simultaneously, Captain George A. Johnson had been seeking the farthest navigable point on the Colorado River in his steamboat, General Jesup. At a remote crossing of the river, the explorers' camels and steamboat accidentally converged on 23 January 1858 to create one of the strangest scenes in Western history. ... In 1855, Brigham Young, president of The Church of Jesus Christ of Latter-day Saints, sent William Bringhurst and thirty pioneers to construct an adobe-walled fort and mission near Las Vegas Springs. The fort was meant to protect the water source and travelers along the wagon train from Salt Lake City to Los Angeles. The Mormon Fort was occupied until 1857 when the colonists were called back to Salt Lake City. The abandoned fort was adapted by Octavius D. Gass in 1865 as the Las Vegas Ranch, which was acquired and expanded by Archibald and Helen Stewart in 1880. ... William A. Clark, senator from Montana and mining magnate, built hte San Pedro, Los Angeles & Salt Lake Railroad to open new mines in Utah and to shorten the distance between his Montana mines and a seaport by 663 miles. In 1905, he founded the townsite of Las Vegas as an important stop for fuel and water for the locomotives.
6. TILLMN_150705_042.JPG: DAM TRAFFIC JAM FROM BONUS TO BOTTLENECK To those people with vision and spirit, obvious obstacles provided unseen opportunities. Most saw an impassable canyon; a few envisioned building an impossible dam. At last, Hoover Dam and a paved highway conquered canyon and wilderness. The once bypassed place had become a destination. Hoover Dam was built for water management and power generation but as a bonus provided recreation and highway transportation. The ideas of a few visionaries and the labors of many everyday heroes created an artistic engineering landmark to serve many purposes. Over time, highway traffic grew so great and fast that the dam crest crossing proved too narrow and slow. At first acclaimed as a major new thoroughfare, the dam later became criticized as a bottleneck. So the crossing that first conquered the bypassed place eventually had to be bypassed as well.
7. TILLMN_150705_046.JPG: BYPASS PROJECT BRIDGE & DAM IN TANDEM: The Bypass Project and its monumental River Bridge carries on the innovation and artistry of Hoover Dam. Envisioned as an inseparable visual and functional pair, the bridge gracefully takes on the transportation task of the dam. The Bypass Project partners worked toward two purposes -- for safe traffic flow and for resource protection. They successfully planned the project using an integrated management method and overlapping project phases. The ideal crossing site and bridge design were wisely chosen while natural and cultural resources were being protected. The road alignment was carefully cleared of existing features while new roadways smoothed the approach to the River Bridge. In building the River Bridge, solid rock and good foundations supported the concrete arch spanning the canyon. Pairs of columns atop the arch hold up the beams and girders of the roadway deck. The River Bridge is a functional structure and symbolic monument in this now passed-through place. Like the dam, the bridge was built for practical purposes; yet they are both symbols of those who conquered this impractical place. Everyday heroes worked through adversities and obstacles to make the envisioned River Bridge and roadways real.
8. TILLMN_150705_052.JPG: HONORS FOR HEROES SPAN TIME & PLACE The famous are not always heroes, but many heroes are not always famous. People are often called heroes for one great selfless deed, but they also can be heroes for their lifetime small commitments. Departed heroes, as guides for our personal journeys, leave us a legacy of their lessons in life. Tales of heroes, both the famous and the everyday kind, can inspire us to care and call us to act. Artistic monument arches have been used as tributes to heroes and events for two thousand years. Memorial arches span time and planes of existence, connecting us with the heroic spirit of those who led the way. The prehistoric rock art double spiral is the earliest memorial near this once by-passed place. Native people honored their ancestors and their journeys using petroglyphs along those trails. The modern deck arch bridge is the latest memorial in this now passed-through place. Modern Americans often commemorate heroes and their life journeys by naming a bridge in their honor. Find the marker at the center of the River Bridge where these ancient and modern symbols meet. Marvel at this place and reflect on the meaning of your own journeys and heroes.
9. TILLMN_150705_058.JPG: HEROIC JOURNEYS MIKE O'CALLAGHAN, 1929-2004: As an adventurous farm boy, he enlisted in the US armed forces and matured to be a courageous WAR HERO fighting in the Korean War and receiving the Silver Star, Bronze Star, and Purple Heart. As a scholar and athlete, he grew to be a caring and respected TEACHER and COACH working at Basic High School and the Boys Club in Henderson, Nevada. As a tolerant person, he won the regard of minorities as a fair, broadminded CIVIL SERVANT in Nevada hiring and helping the working poor and at-risk youth. As a politician with integrity, he rose to be hailed by some as Nevada's most popular GOVERNOR fighting for the little person by supporting programs for education, housing, energy, minorities, seniors, and the disabled. As a critic of governmental conduct, he was feared and loved as an influential NEWSPAPER EDITOR leading the editorial campaigns of the Las Vegas Sun. PAT TILLMAN, 1976-2004: As a natural student and athlete, he studied and trained hard to be a winning COLLEGE FOOTBALL COMPETITOR helping the Arizona State University Sun Devils to reach the Rose Bowl while earning his academic athlete recognitions. As a seeker of meaning and truth, he read continually to be a dedicated SCHOLAR and ADVOCATE debating vigorously a wide variety of current issues and philosophical ideas. As an aggressive sportsman, he strove to be a loyal and valued PROFESSIONAL FOOTBALL CHAMPION breaking records and pleasing fans of the Arizona Cardinals. As a patriotic citizen, he was willing to sacrifice his own career and life to be a SELFLESS SOLDIER declining a lucrative football contract and enlisting in the Army Rangers. Killed in Afghanistan, he was given the Silver Star and Purple Heart. HONORS FOR HEROES: There are many definitions for a hero. Most recognize a hero as someone who has dedicated and given his or her life to something bigger than oneself. This definition includes not only the gallant heroes who in a moment of glory win the day, but also the humble heroes quietly overcoming daily adversities in service to others. Heroes serve as examples to follow in putting high ideals into daily action. For thousands of years human cultures have devised ways of showing their respect for important individuals, groups of people or events. Songs, inscriptions, monuments, and buildings are dedicated as memorials to heroes. THE BRIDGE AS A MEMORIAL: For centuries, bridges have served as memorials throughout the world. A memorial bridge served practical and symbolic purposes, physically spanning space and symbolically spanning time. One who crosses a memorial bridge named after important persons is reminded of those heroes' journeys through life. At Mike O'Callaghan - Pat Tillman Memorial Bridge, we remember the life journeys of two men of heroic spirit by naming the bridge after them. Whenever we say their names in referring to the bridge, we remember and honor them. In life, these two humble men did not think of themselves, as being more heroic than anyone else is. However, perhaps now we may see each man as a "hero among heroes."
10. TILLMN_150705_063.JPG: PAT TILLMAN, 1976-2004: As a natural student and athlete, he studied and trained hard to be a winning COLLEGE FOOTBALL COMPETITOR helping the Arizona State University Sun Devils to reach the Rose Bowl while earning his academic athlete recognitions. As a seeker of meaning and truth, he read continually to be a dedicated SCHOLAR and ADVOCATE debating vigorously a wide variety of current issues and philosophical ideas. As an aggressive sportsman, he strove to be a loyal and valued PROFESSIONAL FOOTBALL CHAMPION breaking records and pleasing fans of the Arizona Cardinals. As a patriotic citizen, he was willing to sacrifice his own career and life to be a SELFLESS SOLDIER declining a lucrative football contract and enlisting in the Army Rangers. Killed in Afghanistan, he was given the Silver Star and Purple Heart.n as a "hero among heroes."
11. TILLMN_150705_066.JPG: Mike O'Callaghan - Pat Tillman Memorial Bridge Bridging Greatness In memory of Sherman Jones, who lost his life during construction. Dedicated by Iron Workers Local 416
12. TILLMN_150705_081.JPG: SEE THE VISION WITH PURPOSE & PARTNERS THE PURPOSE: Traffic Safety and Flow: Remove the traffic bottleneck atop Hoover Dam that slows interstate commerce and travel in the West on US 93, the major route between Phoenix and Las Vegas. * Replace the congested river crossing with a new bypass that meets current highway design criteria and increases traffic capacity at Hoover Dam. * Reduce the number of vehicular accidents along the routes to Hoover Dam. * Reduce the travel time across Black Canyon near Hoover Dam. * Minimize the potential for pedestrian-vehicle accidents at Hoover Dam. * Improve the visitor experience at Hoover Dam. Security: Protect Hoover Dam, employees, visitors, equipment, power generation capabilities and Colorado River water. * Help prevent hazardous conditions, spills or events at Hoover Dam. * Help prevent interruptions in electricity and water delivery. * Improve conditions to operate and maintain Hoover Dam facilities.
13. TILLMN_150705_084.JPG: PLAN FOR SUCCESS WITH PROCESS & PHASES The Design Challenge: The Hoover Dam Bypass joins one of the most famous civil engineering landmarks in the world. It pairs off in such proximity to Hoover Dam that the visual presence of each are tied together as one. This bond created a solemn duty for design -- to meet the high level of visual appeal and engineering excellence that the designers of Hoover Dam met in their day. The need to provide value and design within the project budget made this design challenge even greater. Project Management Process: Discussion of a Bypass Project began in the 1960s. A Project Management Team (PMT), representing each major stakeholder, studied design options and investigated technical and financial feasibility of the project. When the Central Federal Lands Highway Division of the Federal Highway Administration (CFLHD) stepped into the PMT leadership position in the mid-1990s, the Hoover Dam Bypass Project began to come together. In 2001, CFLHD hired a team of design firms known as the Hoover Support Team (HST). It included professionals in engineering, geotechnical and environmental investigation, and 20 other specialized consultants. CFLHD developed an organizational approach to manage the massive project set up by separate design disciplines with overlapping communication circles. This approach gave all disciplines a chance to work together toward a common goal from design through construction. This management method forged integration so the efforts of one discipline did not have unanticipated ripple effects on others. A Design Advisory Panel (DAP) consisting of designers, stakeholder agencies, State Historic Preservation Offices, and tribal representatives actively participated in developing design considerations for architectural, cultural and historic features. Project Phases: The Bypass Project consisted of eight overlapping phases planned to maximize efficiency and to minimize disruptions. The major design work began in late 2001 and continued to the end of 2003. Subsequent supporting design work occurred in 2006 and in 2010. The relocation of power lines preceded the work on the Arizona and Nevada highway approaches. The monumental bridge was constructed from 2005 to 2010. The paving project and visitor plaza construction completed the Bypass Project in October of 2010.
14. TILLMN_150705_088.JPG: DESIGN THE DREAM WITH SCIENCE & ART Design Philosophy of the Bypass Corridor: The Project's Corridor Design Manual presented principles for combining design aesthetics with efficient structural engineering to assure that the design excellence of today would honor that of Hoover Dam in its day. The Mission Statement called for delivering the cost-effective facility of the highest quality that is aesthetically pleasing; sensitive to environment, culture and history; that functions as intended; and is a source of pride to the nation. The Aesthetic Philosophy abides by the motto "form follows function." The design of project features was defined by appropriate engineering solutions as enhanced by architectural refinements to create a cohesive, coordinated corridor character. Furthermore, the corridor contains landforms in a natural state as well as modified by humans. The aesthetic approach to the new Bypass designs responds to the differing conditions. Thus, slopes, retaining walls, and structures near Hoover Dam received an "engineered" appearance, while those at the further extent of the project corridor received a more "natural" refinement. The Science of Engineering: The engineering solution for the River Bridge responds to the same unchanging principles of physics addressed at Hoover Dam while using the latest advances of science in construction methods and materials. The arch shape of the bridge spanning the canyon employs the same structural principles that the dam uses in holding back the lake. The upright bridge arch transfer vertical gravity forces downward into the canyon walls; the reposing dam arch transfers horizontal water pressure sideways the same way. The geometric symmetry of the arch balances the loads at both ends while locking together the tapered blocks composing the arch. Unlike the heavy, solid concrete dam, the lightweight bridge was built of hollow members combining steel and high-strength concrete. The off-site prefabrication of those members decreased the construction time and costs. The Art of Architecture: The architectural refinements of the River Bridge structural elements complement the twentieth-century Modern character of Hoover Dam by creating artistic forms that express structural functions. The shapes of the arch and column segments demonstrate how the engineers and architects blended science and art. To satisfy the functional need for a lightweight bridge structure, engineers developed a system of open box segments for the arch and stackable segments (like hollow building blocks) for the columns of the River Bridge. In detailing these enormous reinforced concrete units, the designers met structural and architectural needs by chamfering (cutting off) the corners of the rectangular segments. The chamfered edges are stronger than square corners and held "shed" the wind. The [sic] also create artistic highlighting of the bridge members in sunlight. This one seemingly simple detail unites the complexities of science and art.
15. TILLMN_150705_095.JPG: PROTECT THE PLACE OF NATURE & HISTORY
16. TILLMN_150705_101.JPG: CHOOSE THE SITE FOR CROSSING & BRIDGE Best Crossing Site: Selecting the best new bridge site was one of the first major decisions in bypassing the river crossing atop Hoover Dam. The Project Management Team (PMT) identified 13 alternative routes early in the project. These crossings ranged from as far south as Laughlin to as far north as Lake Mead. Only three crossing alternatives near Hoover Dam deserved further study: (1) Promontory Point, crossing Lake Mead 1,000 feet north of the dam; (2) Sugarloaf Mountain, crossing Black Canyon 1,500 feet south of the dam; (3) Gold Strike Canyon, crossing the Colorado River about 4,000 feet south and out of sight of the dam. The PMT compared the three alternatives to determine the best balance of highway approach and river crossing location. The Sugarloaf Mountain Alternative proved to be the best. Its site conditions allowed for optimal traffic flow, straightforward construction and minimal potential for environmental impact. Bridge Types: Truss: This truss type modifies the site to fit the bridge. 1,000 foot total span. Strange asymmetry. Also, the bridge shouldn't be locked into the canyon. It needs to move with heat expansion. Girder: This girder type would require expensive rock blasting over a large area. 875 feet required. Round peg in a square hole. World record span for this bridge type is 800 feet over a flat river bed site. Cable Stay: Site must be cut on AZ side to accept this type. 250 feet to the side of the tower, 1000 feet between towers. Winds will quickly wear out cables requiring very high maintenance costs. Visual profile pierces the skyline. Also, towers move inward to gorge & becomes more visible. Suspension: High wings will buffer cables during construction. Cable fatigue requires inspection often. Very light line on the skyline. High costs for construction and maintenance. Very expensive to build. Can't stage work from below as is usual economic method. Best Bridge Type: Then, the Project Team selected the Deck Arch design as best of the five possible bridge types for the Colorado River crossing. Deck Arch: Low maintenance. Extensive rock excavation. Easy construction staging. The Design Advisory Panel (DAP) also recommended guidelines for the new bridge design. They called for the design excellence of today to honor the achievements of the Hoover Dam designers in their day. This goal guided the design team's work through the further study of six deck arch alternatives. The final decision was to build a unique structure combining a modern steel superstructure with a long-span concrete arch to complement the historic Hoover Dam. The bridge design is distinctive not only for the setting and length of the arch span, but also for the combined use of steel and concrete to optimize construction and structural performance.
17. TILLMN_150705_114.JPG: FIND SOLID GROUND WITH SURVEYS & TESTS Land Surveying Above: The bridge engineers needed accurate measurements of the land surface to help them fit the River Bridge perfectly into the rugged canyon. Land surveyors carefully drew topographic maps to record the width of the canyon and the height of the cliffs where the roads meet the bridge. These contour maps were used to determine the location for placing the foundations on the canyon face. For the roadways approaching the River Bridge, the landform maps and cross sections showed the civil (highway) engineers where to cut the hills, fill the valleys, and bridge the canyons. Their goal was to balance the amount of rock that they had to move within the project area. They tried to avoid the great expense of moving rock to or from the site. Engineers used computer models of many possible earthwork designs to find the most practical and economical placement of the new roadways. Rock Core Boring Below: Geotechnical (rock and soil) engineers bored deep into the earth searching for solid bedrock upon which to build the River Bridge foundations. In some places, the upper layer of rock was not strong enough to support the heavy foundations. Only deeper solid bedrock could bear the structural loads. Large boring machines drilled deep into the earth to pull up rock cores. These two-and-one-half-inch-round rock cores were sometimes over thirty feet long. They showed the depths where layers change from fragile to firm. Dozens of borings were needed ot cover the foundation locations because the strength of rock can vary just yards apart. Engineers boxed and labeled the rock core segments as they removed them from the earth. They sent cores to the laboratory for strength testing. The geothechnical engineers compared the rock cores to determine the best type and depth of foundations to build. The rock cores displayed nearby are actual samples bored from the River Bridge foundation sites. These cores were used for guiding the design of excavations and foundations.
18. TILLMN_150705_120.JPG: GET GOOD FOOTING WITH ANCHORS & FOUNDATIONS Rock Anchors: To protect the foundations and stabilize the slopes, rock anchors tightly hold together the fractured rock faces on slopes and cliffs. Geotechnical (rock and soil) engineers determined where they Must stabilize the slopes by studying rock surfaces and testing rock core borings. If the fractured rock is deep, then they may install rock anchors into deeper solid rock. The rock anchor installations have a staggered pattern, like the stars on the American flag, at least five feet apart. This finished array of anchors locks the rock shape in place and helps to resist erosion. Each rock anchors includes a steel bar tendon grouted with concrete into a narrow drill hole. To reach solid rock the anchor hole may be more that sixty feet deep. A cylindrical metal cap protects the bar from corroding. The rock anchors in the heavily-fractured slopes in this passageway required a sheet of steel mesh fabric draped over the bar tendon extending out beyond the rock face. Thin layers of shotcrete have been sprayed to hold the rock in place under the mesh. Concrete Foundations: Each end of the River Bridge arch bears on a huge reinforced concrete foundation cut into the rock cliff face. To build each foundation on its rock shelf, the contractor created a cage of steel reinforcing bars enclosed in a boxlike form. The crew pumped concrete through a hose to fill up the foundation form in shallow layers or "lifts." A virtual forest of reinforcing bars projected out of the sloped face of the foundation to connect with the first segments of the twin-rib arch. The smaller foundations for the paired columns are built in a similar manner. The arch foundations, each the size of a two-story building, transfer the thrusting forces of the bridge arch into the earth. Within each foundation, a cage of steel reinforcing bars works in tension to help resist the forces of construction load, earthquake, and wind. The solid concrete works in compression to help resist for force of gravity. Great care was taken to get good footing, for a bridge is no better than its foundation.
19. TILLMN_150705_124.JPG: SPAN THE GAP WITH CABLES & ARCH Innovative Design for the Deck Arch Bridge: The Design Team worked through six deck arch options to find one for best form and function -- a unique hybrid structure with a concrete arch coupled with a composite steel superstructure. Engineers needed to find a bridge system that would perform well during high winds or a possible earthquake. The Design Team chose to use a pair of ribs for the arch instead of a single wide arch. Steel struts that flex in an earthquake or under high winds connect the twin ribs to protect the whole arch from damage. The arches transfer the forces to the canyon walls. The twin arch ribs support concrete columns which in turn support the bridge deck system. The bridge engineers used high-strength concrete when compression forces controlled the design in the arches and columns. Where flexing forces drove the design, they used steel for the struts and deck girders. How to build an arch bridge across a wide canyon: Get Solid Footing Lay the Path Span the Gap Raise the Road Enjoy the Ride Arch Construction Method: The bridge arches were constructed from both canyon wallsat once reaching toward the middle. The opposite halves of the twin-rib arch were each made of 26 segments that hung in mid-air from cables until the builders placed the concrete of the final, narrow closure. The cableway system lowered pre-made cages of steel reinforcing bars into place for each cast-in-place concrete segment. Fearless workers toiling 800 feet above the river connected the steel cages by hand. They set the forms, placed the concrete, and moved up for the next segment. High performance concrete with a compressive strength of 10,000 psi was needed to handle the massive loads.
20. TILLMN_150705_132.JPG: LAY THE PATH WITH CUT & FILL Hail & Frewell: US 93 enters and exits Nevada and Arizona near Hoover Dam in the most dramatic manner of any US highway crossing state lines. Before the River Bridge opened, the original highway twisted down and up the cliffs of the Black Canyon to cross over Hoover Dam. The River Bridge and its highway approached now eliminate traffic jams bypassing the original dam crossing. US 93 is a major highway within the north-south CANAMEX Corridor that crosses the United States. You can still get the feeling of the historic narrow, winding highway if you drive down the scenic canyon to the Hoover Dam Visitor Center. Make Straight in the Desert A Highway: The civil engineers made the highway approaches to the River Bridge more direct and level by cutting and filling the land and by installing bridges over valleys. The position of the River Bridge at the edge of the canyon allows a smoother, more direct approach to the crossing. The gently curved new highway and River Bridge allow the crossing of the canyon in a minute instead of an hour. The combined length of the approach bridges is greater than that o the River Bridge alone. The new approach highway retains the wildlife trails while overcoming landform obstacles. Underpasses and fences help to protect wildlife from highway traffic as they travel through the area. Bighorn sheep have quickly learned to use the broad underpasses while looking for food and water.
21. TILLMN_150705_135.JPG: CLEAR THE WAY OF SWITCHYARD & TOWERS From Water to Watts: The nearby swirtchyards, towers and high-voltage power lines deliver electricity from Hoover Dam generators to Southwestern cities. The Western Area Power Administration (WAPA) operates and maintains the Hoover-Basic Magnesium North and South transmission distribution system. They regular flow and direct hydroelectric energy to the power lines through switchyards near the dam. Dam Power Helps Win the War: Hoover Dam served a vital role during World War II by providing massive amounts of electricity to the defense plant south of Las Vegas. Two "sister" switchyards near the Nevada edge of Black Canyon were the starting points for the power lines serving the Basic Magnesium Inc. (BMI) complex. On 30 August 1942, for the first time, power from the southern Arizona-Nevada Switchyard ran through the Basic South line. At the height of defense plant operations in 1943, the BMI electrical system carried one-fourth of the power generated at Hoover Dam. Power to the People: After the war, the power lines were connected to the Nevada Power Company network to support continuing industrial production and the rapid growth of the Las Vegas Valley. The BMI plant stopped making incendiary bombs and anti-tank weapons by mid-1944. The Basic North and South lines continued to provide electricity for the remaining industrial functions at the complex and for Las Vegas, Henderson, and Boulder City. Switchyard Switch Over: To build the Hoover Dam Bypass, WAPA removed the Arizona-Nevada Switchyard and rerouted its lines through the "sister" switchyard. The Bridge Visitor Plaza parking area was once the Arizona-Nevada Switchyard. Two of its original nine towers still stand there. Its northern sister switchyard, card the Metropolitan Water District of Southern California (MWD) Switchyard, continues to support the transmission lines.
22. TILLMN_150705_139.JPG: ENJOY THE RIDE WITH CELEBRATION & PRIDE Respect the Landmark: The designers and builders of Hoover Dam showed pride in their creation and respect for the future generations that would marvel at the visual quality of their work. This artistic attitude, as much as any engineering success, separates Hoover Dam from other large dams around the world. Surpassing a minimal functional level of engineering, its builders expressed a grace of form and clarity of detail that has made Hoover Dam an enduring national landmark. Uphold the High Standards: The unmatched engineering triumph of Hoover Dam and the spectacular setting of the Black Canyon inspired the design for the Bypass Project. In the 1930s, architect Gordon Kaufmann guided the architectural character of the engineering marvel. He envisioned a Modernist dam of simple elegance contrasting the rugged texture of the desert canyon. The designers of the River Bridge shared the same aesthetic goal. Those involved with the Hoover Dam Bypass Project took pride in their 21st century engineering achievement and cared about its impact on those who follow. The River Bridge complements the Hoover Dam National Historic Landmark. It will be part of the landscape for the inspiration of future generations seeing the natural beauty and engineering excellence of the two monuments set in the Black Canyon. Compare & Contrast Images: The powerful image of these two monumental structures has now become inseparably one. The dam and bridge have visual qualities that are similar and different at the same time. They both share the clear-cut geometry of the arch form. Yet, the solid dam arch looks massive while the graceful bridge arch seems weightless. The architectural and artistic aspects of each monument are equal to their individual engineering achievements. Their combined visual images come full circle to make the vision a reality.
23. TILLMN_150705_149.JPG: RAISE THE ROAD ON COLUMNS & DECK Roadway Framing & Deck: The efficient bridge design that combines steel and concrete members does the same work as would an all-concrete bridge but at a much light weight. It also eliminates many braces between columns that would clutter the clean look of the bridge. An enormous concrete cap beam tops each pair of precast columns. Four pre-made steel box girders are connected between the concrete cap beams. The roadway deck slab spans across the girders. The deck slab and girders not only support the load of vehicles but also brace the tall concrete columns against wind and earthquake. Tall Precast Columns: The 290-foot-high approach columns at the River Bridge were the world's tallest precast concrete columns at the time of their construction. The contractor transported the ten-foot-tall, precast concrete column segments by truck to the staging area of the cableway system. Crews attached temporary platforms to the sides of each segment for worker access when it arrived in its place on the bridge. These huge hollow "building blocks" were stacked up and firmly connected to form the paired approach columns standing on the canyon walls and the spandrel columns bearing on the twin-rib arch. Efficient Construction Methods: To meet an aggressive construction schedule, the contractor premade many of the River Bridge parts while the foundations were being built. The fast-track construction method allowed premade components of the arch, columns and deck to be ready for installation the moment the contractor needed them. By making large structural parts of off-site work yards, the project needed fewer construction workers on the bridge. A giant cableway system spanning the canyon high above the River Bridge delivered the large structural parts of their finished locations. Concrete workers cast column segments nearby while excavations cut rock shelves into the steep canyon walls. When the foundations and the arch were finished, the column segments were ready to install. This process was economical and efficient.
24. TILLMN_150705_155.JPG: Welcome to Nevada The Silver State
25. TILLMN_150705_158.JPG: Mike O'Callaghan - Pat Tillman Memorial Brige
26. TILLMN_150705_161.JPG: Mike O'Callaghan – Pat Tillman Memorial Bridge May all who cross the canyon on this memorial bridge travel their life journeys with the strength and inspiration found in the high ideals and heroic deeds of these brave humble men. In Memory of these men of heroic spirit who overcame adversity throughout their life journeys to help people along the way and inspire those yet to come, grateful Americans respectfully dedicate this monumental bridge. 14 October 2010 Mike O'Callaghan 1929 – 2004 SGT USMC – CPL USAF – Governor of Nevada Donal Neil "Mike" O'Callaghan was a devoted family man who honored God and country in lifelong service to the public. He practiced high standards of conduct respect and diligence in his civic work to improve life for ordinary people. Pat Tillman 1976 – 2004 Football athlete - #42 ASU - #40 AZ Cardinals – CPL USA Patrick Daniel "Pat" Tillman was a loved son, brother, husband and loyal friend who was willing to sacrifice fame, fortune and his own life for his ideals. His family, friends, fans and nation lost Pat in military service to his country and his brothers-in-arms.
27. TILLMN_150705_163.JPG: THE LIFE & LEGACY OF MIKE O'CALLAGHAN, 1929-2004
28. TILLMN_150705_174.JPG: THE LIFE & LEGACY OF PAT TILLMAN, 1976-2004
29. TILLMN_150705_184.JPG: Mike O'Callaghan - Pat Tillman Memorial Bridge This multi-agency team was commissioned to manage and deliver the Hoover Dam Bypass from concept through completion. Goal: Construct a world-class facility fitting of this site, complementing the Hoover Dam where form follows function.
30. TILLMN_150705_193.JPG: Mike O'Callaghan - Pat Tillman Memorial Bridge Bridge Facts: * Construction -- 2005-2010 Dimensions: * Bridge Length -- 1905 Feet * Bridge Width -- 88 Feet * Roadway Height Above River -- 880 Feet * Roadway Height Above Dam -- 280 Feet * Arch Span Length -- 1060 Feet * Dimensions of Hollow Arches -- 20 Feet Wide by 14 Feet Tall with 1'-2" Thick Walls * Arch Rise -- 277 Feet * Maximum Column Height -- 287 Feet Materials: * Concrete -- 30,000 Cubic Yards * Steel -- 16,000,000 Pounds
31. TILLMN_150705_202.JPG: Mike O'Callaghan - Pat Tillman Memorial Bridge River Bridge Contractor ... Project Labor Agreement Unions ...
32. TILLMN_150705_219.JPG: Mike O'Callaghan - Pat Tillman Memorial Bridge Completing the bypass - a planned approach - After the design was completed, six separate yet overlapping projects were needed to complete the bypass - Projects were sequenced to increase competition and quality, matching industry capabilities with work requirements
33. TILLMN_150705_234.JPG: Mike O'Callaghan - Pat Tillman Memorial Bridge Completing the bypass - a team approach to funding - The project was completed on the original $240 million funding. - The project's funding reflected the federal and state partnership necessary to complete the project. - Pie chart: Arizona Funds $20M Nevada Funds $20M Federal Funds $100M Advanced from Bond Funds by Arizona and Nevada $100M
34. TILLMN_150705_265.JPG: Mike O'Callaghan - Pat Tillman Memorial Bridge Getting Started -- Tower cranes and highline cranes were utilized to excavate rock and construct foundations.
35. TILLMN_150705_276.JPG: Mike O'Callaghan - Pat Tillman Memorial Bridge Approach spans were completed to provide access for building the arches. The tallest columns are 290 feet tall.
36. TILLMN_150705_292.JPG: Mike O'Callaghan - Pat Tillman Memorial Bridge The first hollow arch segments were cast in place. Each segment is approximately 24 feet long, 20 feet wide and 14 feet tall with 14-inch-thick reinforced walls.
37. TILLMN_150705_299.JPG: Mike O'Callaghan - Pat Tillman Memorial Bridge Cable-stay construction supported 26 segments on each side of each arch rib coming together to join in the center.
38. TILLMN_150705_302.JPG: The state line. Hoover Dam Bypass Project US 93 -- Nevada-Arizona State Line -- 2010
39. TILLMN_150705_307.JPG: Mike O'Callaghan - Pat Tillman Memorial Bridge US 93 -- Apex of the Arch -- 2010
40. TILLMN_150705_309.JPG: Mike O'Callaghan - Pat Tillman Memorial Bridge The twin-rib arches were completed by connecting each side with a closure pour on August 10, 2009.
41. TILLMN_150705_322.JPG: Mike O'Callaghan - Pat Tillman Memorial Bridge Ten-foot-tall precast concrete segments were placed symmetrically on the arch to complete the columns.
42. TILLMN_150705_340.JPG: Mike O'Callaghan - Pat Tillman Memorial Bridge Steel box girders were placed symmetrically starting at the center spans. Each girder weighs 45 tons and is 115 feet long.
43. TILLMN_150705_346.JPG: Mike O'Callaghan - Pat Tillman Memorial Bridge The completed bridge includes a concrete deck, barriers and pedestrian sidewalk.
44. TILLMN_150705_351.JPG: Mike O'Callaghan - Pat Tillman Memorial Bridge Those involved with the Hoover Dam Bypass project take pride in building this modern civil engineering achievement in full respect of one of the most famous civil engineering landmarks in the world, the Hoover Dam. One of the major legacies of this project will be its under budget, quality construction which happened largely because of the incredible partnership that allowed everyone to come together in a structured, organized and systematic manner with hard accountability and commitment as good stewards of limits resources entrusted to us.
45. TILLMN_150705_360.JPG: Bridging Greatness Outstanding Civil Engineering Achievement Award, 2012 Hoover Dam Bypass / Mike O'Callaghan - Pat Tillman Memorial Bridge Recognizing the project that best illustrates superior civil engineering skills.
46. TILLMN_150705_416.JPG: FIND SOLID GROUND WITH SURVEYS & TESTS Rock Core Boring Below: Geotechnical (rock and soil) engineers bored deep into the earth searching for solid bedrock upon which to build the River Bridge foundations. In some places, the upper layer of rock was not strong enough to support the heavy foundations. Only deeper solid bedrock could bear the structural loads. Large boring machines drilled deep into the earth to pull up rock cores. These two-and-one-half-inch-round cores were sometimes over thirty feet long. They showed the depths where layers change from fragile to firm. Dozens of borings were needed to cover the foundation locations because the strength of rock can vary just yards apart. Engineers boxed and labeled the rock core segments as they removed them from the earth. They sent cores to the laboratory for strength testing. The geotechnical engineers compared the rock cores to determine the best type and depth of foundations to build. The rock cores displayed nearby are actual samples bored from the River Bridge foundation sites. These cores were used for guiding the design of excavations and foundations.
47. TILLMN_150705_420.JPG: Bridge Types: Truss: This truss type modifies the site to fit the bridge. 1,000 foot total span. Strange asymmetry. Also, the bridge shouldn't be locked into the canyon. It needs to move with heat expansion. Girder: This girder type would require expensive rock blasting over a large area. 875 feet required. Round peg in a square hole. World record span for this bridge type is 800 feet over a flat river bed site. Cable Stay: Site must be cut on AZ side to accept this type. 250 feet to the side of the tower, 1000 feet between towers. Winds will quickly wear out cables requiring very high maintenance costs. Visual profile pierces the skyline. Also, towers move inward to gorge & becomes more visible. Suspension: High wings will buffer cables during construction. Cable fatigue requires inspection often. Very light line on the skyline. High costs for construction and maintenance. Very expensive to build. Can't stage work from below as is usual economic method.
AAA "Gem": AAA considers this location to be a "must see" point of interest. To see pictures of other areas that AAA considers to be Gems, click here.
Wikipedia Description: Mike O'Callaghan–Pat Tillman Memorial Bridge
From Wikipedia, the free encyclopedia

The Mike O'Callaghan–Pat Tillman Memorial Bridge is an arch bridge in the United States that spans the Colorado River between the states of Arizona and Nevada. The bridge is located within the Lake Mead National Recreation Area approximately 30 miles (48 km) southeast of Las Vegas, Nevada, and carries U.S. Route 93 over the Colorado River. Opened in 2010, it was the key component of the Hoover Dam Bypass project, which rerouted US 93 from its previous routing along the top of Hoover Dam and removed several hairpin turns and blind curves from the route. It is jointly named for Mike O'Callaghan, Governor of Nevada from 1971–1979, and Pat Tillman, an American football player who left his career with the Arizona Cardinals to enlist in the United States Army and was later killed in Afghanistan by friendly fire.

As early as the 1960s, officials identified the US 93 route over Hoover Dam to be dangerous and inadequate for projected traffic volumes. From 1998–2001, officials from Arizona, Nevada, and several federal government agencies collaborated to determine the best routing for an alternative river crossing. In March 2001, the Federal Highway Administration selected the route, which crosses the Colorado River approximately 1,500 feet (460 m) downstream of Hoover Dam. Construction of the bridge approaches began in 2003, and construction of the bridge itself began in February 2005. The bridge was completed in 2010 and the entire bypass route opened to vehicle traffic on October 19, 2010.

The bridge was the first concrete-steel composite arch bridge built in the United States, and it incorporates the widest concrete arch in the Western Hemisphere. At 840 feet (260 m) above the Colorado River, it is the second-highest bridge in the United States, following the Royal Gorge Bridge. It is also the world's highest concrete arch bridge. The Hoover Dam Bypass project was completed within budget at a cost of $240 million; the bridge portion cost $114 million (2010 prices).

History

In 1935, the American Association of State Highway Officials (AASHO, later AASHTO) authorized a southward extension of U.S. Route 93 from its previous southern terminus in Glendale, Nevada to Kingman, Arizona by way of Las Vegas and Boulder City, crossing the Colorado River on the newly constructed Hoover Dam (also known then as Boulder Dam). Clark County was sparsely populated at the time, with a population of less than 9,000 at the 1930 U.S. Census (compared to an estimated 2 million in 2013). Development in and around Las Vegas in the latter half of the 20th century made Las Vegas and its surrounding area a tourist attraction, and US 93 became an important transportation corridor for passenger and commercial traffic between Las Vegas and Phoenix. In 1995, the portion of US 93 over Hoover Dam was included as part of the CANAMEX Corridor, a high-priority transportation corridor established under the North American Free Trade Agreement (NAFTA). This bridge is a key component of the proposed Interstate 11 project.

Through traffic on US 93 combined with pedestrian and tourist traffic at Hoover Dam itself led to major traffic congestion on the dam and on the approaches to the dam. The approaches featured hairpin turns on both the Nevada and Arizona sides of the dam, and the terrain caused limited sight distances around curves. In addition to traffic safety considerations, officials were also concerned about the safety and security of Hoover Dam, specifically the impact a vehicle accident could have on the dam's operation and the waters of Lake Mead. Officials first discussed the need for a new Colorado River crossing that would bypass the dam in the 1960s. The U.S. Bureau of Reclamation, which operates the dam, began work on the "Colorado River Bridge Project" in 1989, but the project was put on hold in 1995. In 1997 the Federal Highway Administration took over the project and released a draft environmental impact statement in 1998. From 1998–2001 state officials from Arizona and Nevada as well as several federal government agencies studied the feasibility of several alternative routes and river crossings, as well as the feasibility of modifying the roadway over the dam, restricting traffic over the dam, or doing nothing.

In March 2001 the Federal Highway Administration issued a Record of Decision indicating its selection of the "Sugarloaf Mountain Alternative" routing. The project called for approximately 2.2 miles (3.5 km) of highway in Nevada, 1.1 miles (1.8 km) of highway in Arizona, and a 1,900-foot (580 m) bridge that would cross the river 1,500 feet (460 m) downstream (south) of Hoover Dam. Design work began in July 2001. Security measures implemented following the September 11 attacks prohibited commercial truck traffic from driving across Hoover Dam; commercial vehicles were required to follow a 23-mile (37 km) detour to a river crossing between Laughlin, Nevada and Bullhead City, Arizona.

Design

Project design was by the Hoover Support team, led by HDR, Inc. and including T.Y. Lin International, Sverdrup Civil, Inc., and other specialist contributors.

The bridge has a length of 1,900 feet (579 m) and a 1,060 ft (320 m) span. The roadway is 900 ft (270 m) above the Colorado River and four lanes wide. This is the first concrete-and-steel composite arch bridge built in the United States. It includes the widest concrete arch in the Western Hemisphere and is also the second highest bridge in the nation, with the arch 840 ft (260 m) above the river. The twin arch ribs are connected by steel struts.

The composite design, using concrete for the arch and columns with steel construction for the roadway deck, was selected for schedule and cost control while being aesthetically compatible with the Hoover Dam. Sean Holstege in The Arizona Republic has called the bridge "an American triumph". USA Today called it "America's Newest Wonder" on October 18, 2010.

Pedestrian access is provided over the bridge to tourists who wish to take in a different view of the nearby dam and river below, but the dam is not visible for those driving across it. A parking area is provided near the bridge on the Nevada side at what was a staging area during construction. A set of stairs and disabled access ramps lead to the sidewalk across the bridge.

Construction

Work began in 2003 on the approaches in both states and the construction contract for the arch bridge was awarded in October 2004. The largest obstacle to the project was the river crossing. The bridge and the bypass were constructed by a consortium of different government agencies and contractors, among them the Federal Highway Administration, the Arizona Department of Transportation, and Nevada Department of Transportation, with RE Monks Construction and Vastco, Inc, constructing the Arizona Approach, Edward Kraemer & Sons, Inc, the Nevada Approach and Las Vegas Paving Corporation undertaking the roadway surfacing on both approaches. The bridge itself was built by Obayashi Corporation and PSM Construction USA, Inc., while Frehner Construction Company, Inc. was responsible for completing the final roadway installations. A permit problem between Clark County and the subcontractor Casino Ready Mix arose in May 2006 over the operation of a concrete-batch plant for the project, and this caused a four-month delay.
Construction of the arches, showing the diagonal cable stays and the high-line crane. June 2009

Construction required hoisting workers and up to 50 short tons (45 t) of materials 890 feet (270 m) above the Colorado River using 2,300 ft (700 m)-long steel cables held aloft by a "high-line" crane system. High winds caused a cableway failure in September 2006, resulting in a further two-year delay. The approach spans, consisting of seven pairs of concrete columns—five on the Nevada side and two on the Arizona side—were completed in March 2008. In November 2008, construction worker Sherman Jones died in an accident.

The arches are made of 106 pieces—53 per arch—mostly 24 ft (7.3 m) cast in place sections. The arch was constructed from both sides of the bridge concurrently, supported by diagonal cable stays strung from temporary towers. The twin arch spans were completed with the casting of the center segments in August 2009. That same month, the two halves of the arch were completed, and were 3⁄8 inch (9.5 mm) apart; the gap was filled with a block of reinforced concrete. The temporary cable stays were removed, leaving the arch self-supporting. By December, all eight of the vertical piers on the arch had been set and capped, and at the end of the month the first two of thirty-six 50-short-ton (45 t) steel girders had been set into place.

By mid-April 2010, all of the girders were set in place, and for the first time construction crews could walk across the structure from Arizona to Nevada. Shortly thereafter, the pouring of the bridge deck began. The bridge deck was fully paved in July, and the high-line cranes were removed from the site as the overall project neared completion. The bridge was completed with a dedication ceremony on October 14, 2010. and a grand opening party on October 16. It was opened to bicycle and pedestrian traffic on October 18 and to vehicular traffic on October 19, a few weeks earlier than estimated. The building of the bridge was featured in episode 5x02 of the TV series Extreme Engineering. The filming of this episode took place before the start of work on the arch.

When the bridge opened to traffic, the roadway over Hoover Dam was closed to through traffic, and all visitor access to the dam was routed to the Nevada side; vehicles are still allowed to drive across the dam to the Arizona side following a security inspection, but must return to the Nevada side to return to US 93. The former US 93 route between the dam and its junction with the present US 93 route has been re-designated as Nevada State Route 172.

Naming

In late 2004, the proposed bridge name honoring Mike O'Callaghan and Pat Tillman was announced at a ceremony by the Governor of Nevada, Kenny Guinn, and the Governor of Arizona, Janet Napolitano. O’Callaghan, a decorated Korean War veteran, was the Governor of Nevada from 1971 through 1979, and he was the executive editor at the Las Vegas Sun newspaper for many years until his death on March 5, 2004. Tillman had been a football player for the Arizona State University team and for the Arizona Cardinals team. He gave up his multimillion dollar career in the National Football League to enlist as an infantryman in the U.S. Army, but he was killed by friendly fire in Afghanistan on April 22, 2004.
Bigger photos? To save server space, the full-sized versions of these images have either not been loaded to the server or have been removed from the server. (Only some pages are loaded with full-sized images and those usually get removed after three months.) I still have them though. If you want me to email them to you, please send an email to guthrie.bruce@gmail.com and I can email them to you, or, depending on the number of images, just repost the page again will the full-sized images.
Connection Not Secure messages? Those warnings you get from your browser about this site not having secure connections worry some people. This means this site does not have SSL installed (the link is http:, not https:). That's bad if you're entering credit card numbers, passwords, or other personal information. But this site doesn't collect any personal information so SSL is not necessary. Life's good!
Photo Contact: [Email Bruce Guthrie].