North Carolina’s Cape Hatteras Lighthouse, first constructed in 1870, is among the most popular and recognizable of its kind in the United States. For over 100 years now, it has helped safely guide ships traveling near the state’s eastern coast. But its entire existence once faced a big dilemma – something that actually quietly began shortly after the structure began operation during the 19th century.
When the Cape Hatteras Lighthouse was originally constructed, it stood a safe distance of 1,500 from the ocean’s shoreline. But as the years progressed, coastal erosion saw waters draw nearer to the lighthouse’s foundation. By 1919, ocean water had crept to within a few hundred feet from the lighthouse, and by 1970, water stood just 120 feet away.
The Cape Hatteras Lighthouse was originally constructed in a rather unique manner using what’s called a “floating foundation,” according to the National Park Service. Instead of using traditional pilings, it was something that featured a timber mat encased in fresh water around compacted sand, all covered by granite and brick on the top. This was a safe way to stabilize the lighthouse at first. However, if coastal erosion crept so close to the foundation and caused salt water to reach the lighthouse’s foundation, it would almost surely cause the floating foundation’s timber to rot – potentially causing the lighthouse to collapse and be destroyed.Over the years a variety of efforts had been made to attempt to slow down coastal erosion on the shoreline, including sea walls, beach nourishment, and other measures. However, by the mid 1990s, it was clear that in order to save the Cape Hatteras Lighthouse, a more sophisticated strategy was needed – something that would require engineers to physically move the structure 1,600 away from its original location and the threatening shoreline.
Moving the 4,830-ton lighthouse began in 1999 with a crew placing a steel beam mat over the original timber mat foundation, in addition to the using supports and shoring beams. From there, the lighthouse was lifted out of the ground via shoring jacks and moved atop the steal beam mat on a steel track that had been previously made ready. It was slowly moved with sensors constantly measuring the transfer load – assuring that everything remained safe. Once it reached its new location, it was slowly installed into a new concrete slab and brick foundation.
The successful relocation of the Cape Hatteras Lighthouse has been dubbed the “the move of the century” and defied skepticism from critics who feared the job would damage the famous structure. Today the lighthouse should be safe and sound for many years to come.