Global Records
The World's Ten Longest Continuous Truss Bridges
1. Ikitsuki Bridge, 400-meter main span, Japan, opened 1991.
The Ikitsuki Bridge connects Hirado Island in southern Japan with smaller Ikitsuki Island, population 7,500. It is located about 70 miles northwest of Nagasaki. The bridge crosses the narrow Tatsuno-Seto Strait. A tidal-power turbine has been installed on one of the bridge piers.
Photo Courtesy Wikimedia Commons
2. Astoria-Megler Bridge, 376-meter main span, Oregon and Washington, United States, 1966.
A steel through-truss bridge, the Astoria-Megler Bridge spans the Columbia River between Astoria, Ore., and Megler, Wash. Situated 23 kilometers from the mouth of the river, it is 6.6 km long. Engineer William Adair Bugge designed the bridge, which is jointly owned and operated by the Oregon and Washington departments of transportation. In effect, the structure comprises two steel-truss bridges, which span the river and its shipping channels. The bridges are linked by a prestressed-concrete roadway on hollow concrete piles across a stretch of sandy shallows, the so-called Desdemona Sands, which is barely awash at low tide. The larger span, near the Oregon side, crosses the main ship channel and is 205 ft above mean low water.
Photo Courtesy Wikimedia Commons
3. Francis Scott Key Bridge, 366-meter main span, Maryland, United States, 1977.
A steel arch-shaped, continuous through-truss bridge totaling 8,636 ft, it carries four lanes of Interstate 695 across the Patapsco River in Baltimore. The central truss spans were designed by Singstad, Kehart, November & Hurka. Superstructure contractor Pittsburgh-Des Moines Steel Corp. fabricated the main truss. It was erected by a 100-ton traveling guy derrick and what may have been, at that time, the world’s tallest stiff-leg derrick. Standing 425 ft high, the barge-borne, 200-ton-capacity derrick was used to help erect approach spans and the 722-ft-long anchor arms. The floating derrick was designed by the project’s steel erector, the John F. Beasley Construction Co. Owned and operated by the Maryland Transportation Authority, the bridge cost $110 million to build. Also known as the Outer Harbor Bridge, the bridge is believed to pass within 100 meters of the site at which Francis Scott Key witnessed, in 1814, the bombardment of Fort McHenry, a battle during the War of 1812 that inspired him to write the words of "The Star-Spangled Banner," the U.S. national anthem (ENR 1/15/76 p.14).
Photo Courtesy Wikimedia Commons
4. Dashengguan Bridge, two 336-meter main spans, China, 2010.
The double continuous-steel truss-girder bridge carries six rail lines across the Yangtze River in Nanjing: four high-speed rail lines and two Nanjing metro lines. Owned by the Ministry of Railways, it has the highest loading capacity of any bridge in China. BHC Global served as the main contractor, with China Major Bridge Engineering and China Railway Baoji Bridge Group also participating. The steel-arch trusses were erected with the double-cantilever method, using crawler cranes. The foundation rests on bored piles up to 112 meters long and 2.89 m in dia. The construction cost was $537 million.
Photo Courtesy Wikimedia Commons
5. Oshima Bridge, 325-meter main span, Japan, 1976.
Developed by the Japan Highway Public Corp. and designed by Japan Bridge & Structure Institute Inc., the bridge began construction in 1970. The foundation was constructed by the Taisei Corp. & Obayashi Corp. joint venture. The bridge’s superstructure was built by the NKK Corp. and Yokogawa (Bridge) Corp. joint venture. NKK Corp. currently is named the JFE Steel Corp. The construction cost was 9.9 billion yen.
Photo Courtesy Wikimedia Commons
6. (tie) Tenmon Bridge, 300-meter main span, Japan, 1966.
A flattened, almost feathery-looking cantilever truss bridge that connects Oyono Island and the Uto peninsula, which is part of the major island of Kyushu, it is located 20 miles southwest of the city of Kumamoto. The Japan Public Highway Corp. was the designer. The foundation was constructed by Nishimatsu Kensetsu Corp., and the superstructure was constructed by Yokogawa Bridge Corp. The construction cost was 570 million yen.
Photo Courtesy Wikimedia Commons
6. (tie) Kuronoseto Bridge, 300-meter main span, Japan, 1974.
The bridge’s superstructure was designed and built by Kawasaki Heavy Industries Ltd. The foundation was built by Kajima Corp. Construction began in 1970, and the construction cost was 3.7 billion yen.
Photo Courtesy Wikimedia Commons
8. U.S. 60 Bridge/New Ledbetter Bridge, 274 meter main span, Kentucky, USA, 2013.
A Warren truss, the bridge carries four lanes of U.S. Highway 60 across the Tennessee River near Paducah. The piers were built by C.J. Mahan Construction. A joint venture comprised of URS and Stantec designed the superstructure, which was constructed by a joint venture of Haydon Bridge Co. and Kan and Kay Construction Co. C.J. Mahan Construction also worked with Haydon and Kay and Kay as a subcontractor and performed the steel erection for the truss. The project was broken into an initial substructure contract and a superstructure contract that followed later, to help spread out the cost. While the substructures were under construction, the administration in charge at that time wanted to change the appearance of the truss, reduce the truss depth and eliminate some of the truss bracing to give a more open appearance to the bridge from what was originally proposed. The design team faced challenges arising from the demands of a long main span on a relatively shallow truss. These challenges were compounded by rigorous seismic loading on piers designed to accommodate a different structure. The design team overcame the challenge by finding a solution that did not require retrofitting the existing foundations or piers. The final construction cost was $95 million, and it was completed 11 months ahead of schedule.
9. Taylor-Southgate Bridge, 259-meter main span, Ohio and Kentucky, United States, 1995.
This continuous-truss bridge carries U.S. Route 27 across the Ohio River, linking Newport, Ky., and Cincinnati, Ohio. It was designed by Hazelet + Erdal.
Photo Courtesy Wikimedia Commons
10. Julien Dubuque Bridge, 258-meter main span, Iowa and Illinois, United States, 1943.
The Julien Dubuque Bridge is a 5,760-ft-long continuous steel-arch truss bridge that crosses the Mississippi River, connecting Dubuque, Iowa, and East Dubuque, Ill. It is believed to be the longest continuous-tied arch bridge in the world. It was designed by Howard, Needles, Tammen and Bergendorff (HNTB). The Bethlehem Steel Co. fabricated and built the superstructure, and the substructure was built by a joint venture comprising the Fred J. Robers Construction Co. and the La Crosse Dredging Corp. It was built using the balanced-cantilever construction method, with the trusses constructed outward from each pier and only a single steel bent next to the pier to provide temporary support. Because it was built during wartime, the project experienced several delays of materials and labor. The original construction cost was $3.2 million. The bridge was extensively renovated in the early 1990s, getting a new deck and a pedestrian walkway.
Photo Courtesy Wikimedia Commons
Truss bridges have a long pedigree. The first ones were made of wood and erected in various European countries at least as early as the 16th century. Beginning in the late 1700s, many of them were built throughout the United States. “Combination trusses,” which included both wood and metal bridge components, began to appear in the 1840s. Beginning in the late 1860s, all-metal truss bridges became widespread, particularly within the railroad industry.
Trusses are assemblies of beams or other supports, typically arranged in combinations of triangles. Truss bridges take many forms. One early truss-bridge design, the bowstring-arch truss, was patented in 1841 by Squire Whipple, a Massachusetts engineer who is considered the father of iron bridge building in the U.S. He also invented the Whipple Truss, a design employed on the Cairo Rail Bridge, which was completed in 1889 and spanned the Ohio River, near Cairo, Ill. Its two longest spans each measured 158 meters. At 3,220 m overall, it was, at the time, the longest metallic structure in the world. Truss bridges were a popular choice of bridge designers in the U.S. from the 1870s through the 1930s.
One variety of truss bridge played an important role in World War II. A civil engineer working in the British War Office, Donald Bailey, designed a portable, prefabricated truss bridge in 1941. Its modular components were 10-ft x 12-ft rectangular units that, once assembled, formed bridges that were strong enough to support 35-ton Sherman tanks. They did not require special tools or equipment to assemble. It was first used by British forces in North Africa in 1942. Known as the Bailey Bridge, it was widely used by British, American and Canadian forces on the move, often in situations in which retreating German and Italian armies had destroyed bridges.
Over 3,000 Bailey Bridges were employed by the advancing Allied armies in Sicily and Italy alone, and many others enabled Allied forces to advance on battlefronts in Asia against Japanese forces. Gen. Eisenhower, commander of Allied forces in Europe, gave this tribute: “The three major inventions of the war were radar, the heavy bomber, and the Bailey Bridge.” Bailey Bridges continue to be used widely, both by military units and civilian contractors.
“Truss bridges have long been important to the rail industry—six Ohio River crossings and one Mississippi River crossing are all functioning trusses that are over 100 years old,” says James N. Carter Jr., chief engineer of bridges and structures at Norfolk Southern Corp. “After 100 years, we see that the main trusses are in pretty good condition, but we have problems with the brace members and the floor systems. [With proper rebuilding] I believe they’ll be there 100 years from now. The last major river crossing we redid was a bridge across the Mississippi River at Hannibal, Mo., with six truss spans." The spans ranged in length from 180 ft to 409 ft, and the project was completed in 1993.
“The essential value of a truss is that it’s a very efficient use of a material: You use the distance between the material to give you strength. [The distance] makes it more stable, more rigid," he adds. "Also, trusses lend themselves to repair and replacement of individual members. Members are riveted together and replaced with bolts, and it can be done fairly easily. In the rail industry, we don’t have the luxury of putting up a detour sign. When we have to do a repair, we’re looking for a way to get in and out quickly to reduce interruption to our network."
"We’re to the point in the highway industry where we’re pushing steel girders out to 150 ft. In the rail industry, over 150 ft, we’re probably going to choose a truss. Below that, girders are much more economical,” says Carter.
Truss bridges continue to play a significant role in highway construction. “There’s still a place for truss bridges for highways, but less so than in the past," says Jamey Barbas, a long-span bridge expert. “Truss bridges are very stiff bridges. There’s a lot of steel in them and, therefore, inherently, a lot of maintenance. [When] comparing your options, cable-stayed or suspension bridges are usually more economical choices.”
“Usually, truss bridges are older and, oftentimes, conservatively designed with extra capacity, allowing for the flexibility of adding to them. Also, trusses may be favored for double-decker or combined highway-rail bridges,” Barbas adds.
Barbas has worked in the New York City area on several major bridge rehabilitation projects involving bridges with truss components. “On the Williamsburg Bridge [a suspension bridge with truss components], we had to reinforce the truss chords with reinforcing plates to give it extra strength to deal with increased truck weight and comply with modern codes. The Williamsburg Bridge is a utilitarian workhorse. It was able to be retrofitted 100 years later for an additional 100 years of service life."
“The Bronx-Whitestone Bridge was a suspension bridge that utilized a stiffening truss," Barbas also notes. "When they wanted to reduce the load, they removed the truss and added wind-faring elements for aerodynamic stability.”
