Reston, Va. — The American Society of Civil Engineers recognized the Union Chain Bridge that spans the River Tweed between Horncliffe, Northumberland, England and Fishwick, Scotland as an International Historic Civil Engineering Landmark. It is the world’s oldest operating suspension bridge. Construction on the Union Bridge started in 1819 and it was opened in July of 1820. At the time of its construction, the bridge was the world’s longest road carrying span and helped influence the use and development of suspension bridges across the globe. Steel cables and hangers were added to the bridge in 1903 to improve stability. Over the last few years, the bridge underwent an extensive restoration project.

The landmark was recognized at an event attended by members of the Northumberland County Council, The Scottish Borders Council, and representatives of ASCE, the UK Institution of Civil Engineers, and the Japan Society of Civil Engineers.

ASCE represents more than 150,000 members of the civil engineering profession worldwide. It is the oldest national engineering society in the United States. ASCE recognizes historically significant civil engineering projects, structures, and sites all over the world. More than 280 projects have earned the prestigious title for creativity and innovation.

“Bridges do so much more than help transport people and goods, they also help connect cultures and communities and help make the world feel a little bit smaller,” said Maria Lehman, ASCE President. “For centuries, civil engineers have been dedicated to improving health, safety, and quality of life. Projects like the Union Chain Bridge helped influence and inspire the infrastructure being designed and built right now.”

Construction of the Union Chain Bridge helped usher in a new era in bridge building. Workers completed the bridge in under one year and at approximately 25 percent of the cost of a masonry bridge, which was the most common kind of bridge in the early 19th century. The bridge faced an early structural test at its opening, when about 700 people broke through barriers to get onto the bridge. Engineers estimated the strength of the bridge at the time at 1,104 tons.

The bridge immediately helped local manufacturers, miners, and farmers get their products to market faster by greatly reducing the time and distance traveled on horse-drawn carts. The construction occurred during the Industrial Revolution, when moving heavy goods at increased frequency was becoming more prevalent in the region.

The bridge has been strengthened and restored several times over the last two centuries. In 2013, the Union Chain Bridge was put on Historic England’s Heritage at Risk register, which led to a community campaign to restore the bridge. Restoration work started in the fall of 2020 and the bridge reopened in April 2023. The dedication of the International Historic Civil Engineering Landmark coincides with a celebration of the restoration.

The Union Chain Bridge was nominated by the Institution of Civil Engineers and the Japan Society of Civil Engineers.

More information about ASCE's Historic Civil Engineering Landmark Program.

About the American Society of Civil Engineers

Founded in 1852, the American Society of Civil Engineers represents more than 150,000 civil engineers worldwide and is America's oldest national engineering society. ASCE works to raise awareness of the need to maintain and modernize the nation's infrastructure using sustainable and resilient practices, advocates for increasing and optimizing investment in infrastructure, and improve engineering knowledge and competency. For more information, visit or and follow us on Twitter, @ASCETweets and @ASCEGovRel.