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On Saturday, June 5, 1999, the long-anticipated move of the Cape Hatteras lighthouse began. On that day, workers from the International Chimney Corporation and Expert House Movers began using hydraulic jacks (filled with highly pressurized but environmentally friendly vegetable oil) to lift the lighthouse from its former home just off the beach. By Wednesday, they had lifted its 4800 tons (4.35 million kilograms) about 6 feet (1.8 meters). North Carolinians are watching this move with awe and with anxiety. We're attached to the lighthouse; its graceful, spiral-banded tower is a symbol of our state and of the Outer Banks recognized around the world. The question has been, how should we preserve it? Cape Hatteras Light was 1600 feet (490 meters) from the ocean when it was completed in 1870. In June 1999 it stood just a few feet from the open beach, protected by rows of sandbags but vulnerable to the next passing summer hurricane or winter nor'easter. |
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Everyone agrees that if nothing is done the sea will destroy the lighthouse before our eyes within a very few years. The National Park Service, which owns most of Hatteras Island as part of the Cape Hatteras National Seashore, is moving the lighthouse and its associated buildings 2900 feet (about 880 meters) to the southwest. This move, diagonally away from the ocean, will place the lighthouse about as far from the sea as it was in 1870.
There was substantial opposition to the move, much of it coming from residents of Hatteras Island and of the Outer Banks. Opponents of the move were afraid the lighthouse was too large and too old to move; they feared it would crumble en route and be lost. They believed the lighthouse was historic where it stood, and some of that historical context will be lost in a new location. And they believed that the beach in front of the lighthouse could be preserved by building a new groin (a wall projecting into the ocean, designed to trap sand moving along the coast) and by installing other sand-catching devices in the surf.
In 1988, the National Research Council, an arm of the National Academy of Sciences, released a report, requested by the Park Service, which considered all the available options and recommended strongly that the lighthouse be moved. In 1997, Governor Hunt and other state leaders asked the NC State engineering and science faculties to review the NAS-NRC report and update it if needed. The faculty concluded the original report was correct and the lighthouse should be moved.
There's no doubt lighthouses can be moved. Three have been moved in recent years in New England: the Cape Cod Highland and Nauset lighthouses in Massachusetts and the Southeast Block Island lighthouse in Rhode Island. However, opponents of moving Cape Hatteras Light were correct in pointing out that North Carolina's lighthouse is a different animal from these New England structures.
New England lighthouses are typically built on top of cliffs overlooking the ocean, not on sandy beaches. These lighthouses don't need to be tall, since they are already up in the air. The three relocated lighthouses are from 48 to 62 feet tall (14.6-18.9 meters) and weigh around 500 tons (450 metric tons) each. Cape Hatteras is the nation's tallest and (probably) heaviest lighthouse; it is the tallest brick lighthouse in the world. At 208 feet tall (63.4 meters) it is four times the height and ten times the weight of its New England cousins.
Buildings the size of the Cape Hatteras Lighthouse have been moved many times, however. The methods used are robust, but relatively simple. The foundation of the building was excavated and a diamond-studded saw was used to cut through its granite foundation. As the granite was removed, steel pillars, called shoring towers, were substituted to support the structure. Hydraulic jacks are used to lift the building slowly from its old location. Steel rails are inserted under the base of the lighthouse to support the building during the move. Special rollers bolted to the rails give the building its mobility. The lighthouse is then eased very slowly towards its new location, pushed by five large hydraulic rams mounted on the rails behind the base. The expected rate of motion is about 25-100 feet or 8-30 meters per day: so slow the lighthouse will not appear to be moving at all. It will take more than a month for the lighthouse to reach its new home.
Because it has a heavy base and tapered shape, the lighthouse is not at all top heavy. This means it does not have any tendency to tip over. Although there has been a lot of concern about the lighthouse cracking when it is moved, engineers say the building is so massive in construction it is actually a very good candidate for being moved without any damage of this kind. The real problem is to be sure that the ground underneath is firm enough over the whole route to permit a smooth passage. For this purpose the soft surface sand is being removed along the route and replaced with a thick bed of gravel.
The two lightkeeper's houses and other associated structures around the base of the lighthouse have all been moved. They have been relocated so they will have exactly the same relationship to the lighthouse they have had since they were built. (However, in one important respect the new location will not be authentic: it is surrounded by dense shrubbery at the edge of the Buxton Woods maritime forest. Old photos show that since 1870 the lighthouse has always stood in a relatively open, sandy site.)
As famous as the lighthouse already is, the move is making it much more famous. It is amazing to think of moving such a structure, but perhaps not more amazing than to think of building it, on a sandy beach in one of the most exposed places in the world, in 1870. No doubt the builders of the lighthouse would be proud to see the level of concern and talent being concentrated on its preservation.
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Posted October 21, 1998. Last updated June 15, 1999. Features remain online as long as they remain current; they may be updated if new information becomes available.
Copyright © 1999, Center for Mathematics and Science Education. Teachers have permission to duplicate this page for use in teaching their own classes. All other rights reserved. You are welcome to link to this page, but do not copy its contents.
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