Engineering the Outer Banks

Even on vacation, civil engineers have a unique ability to recognize engineering accomplishments that somehow our spouses failed to see. As my wife and I are spending a few days in the outer banks, a number of unique engineering challenges are apparent. Some that are similar to what we see in New England, others that are unique to this region.

The ones most evident are the light houses. Touring any local shop in town will provide calendars and pictures of these often photographed features in every possible light from every possible angle. The size of these large brick structures is impressive. Many have been moved since they were active to inland locations less susceptible to erosion, wind, and ocean tides. Lately public access to many national landmarks are slowly disappearing either due a function of maintenance needs or security issues.

These are still impressive structures and important landmarks along the shore roads even if they no longer guide mariners safely home. They are especially impressive when considering the time period when they were designed and constructed. Many long before the high rise buildings began gracing the sky lines of this country's major cities. There are many stories on how they were built, events that they witnessed, and even in some cases the storms in which they met their demise. Minot Light comes to mind for New Englanders.

Similar to the Cog Railroad in New Hampshire, the Cape Hatteras light house (upper photo) was recognized as an ASCE civil engineering national landmark. Equally impressive, but probably held back by limited vantage points for photographs is the Currituck Beach lighthouse. Both are valuable features for navigating the roads of the Outer Banks if you didn't bring your GPS unit.

A less publicized engineering feat is the constant battle between the dunes and the ocean. The Outer Banks is a narrow ribbon of land that has been built up with a series of large beautiful vacation houses. On one side of the banks is the ocean and on the other is the sound. The natural world is intent on reconnecting these two large water features at the cost of any structures constructed in between. Every couple of decades the ocean reexerts itself by carving a new channel through the banks taking out any man-made features that exist in between. Signs along the dunes strictly prohibit trespass on the dunes. Special programs have been organized to establish and maintain vegetation to minimize erosion.

Walking along the beach, sections of fencing can be seen oriented to foster the health of the dunes. The fencing would recall for New Englanders the fences set up during the winter to discourage the drifting of snow in exposed sections of highway.

The dunes provide a natural barrier between the ocean and the inland features. They also provide a haven for many of the wildlife in the area. Patrolling the dunes are a number of wild horses that have adapted to the coarse grasses that grow along the dunes. The horses look as tough as the grasses that grow with a higher tolerance for salt, stomachs adapted to the limited vegetation and an acceptance of the many vehicles that share the beach environment.

The sand below the waves also changes continuously and sometimes radically. On lazy days on the beach, one can witness daily changes in the way the waves come ashore as sands under the water shift constantly and create new patterns for the waves rising and breaking on shore. This was very evident following a storm where this large object was spotted for a few days. It was a distance off shore so I didn't have an opportunity to inspect it up close. It appeared to be a large anchor with the head and two spines sticking out of the water. It was visible for two days, but completely gone the third day. It had disappeared before I had a chance to investigate.

Looking at the houses in the outer bank, it is interesting that as spectacular as the architecture and stature of the buildings, the bottom floors are built almost sacrificially. These large structures are built almost like pole buildings with the main living spaces usually on the second or third floor. The bottom floors are often sided with lattice work with the basement rooms almost anticipating a day when the waters could wash through the house.

As with the devastation that recently visited New England, the outer banks can count on being visited by seasonal storms including tropical storms and hurricanes. The recent hurricane that hit Vermont and northern New Hampshire also took its toll on North Carolina. The main road that connects Cape Hatteras to Kitty Hawk (made famous by the Wright  Brothers flight). The road was stabilized with over-sized sand bags about four feet in diameter and about eight feet long. Bridges foundations were hastily made out of steel casings for the piers and sheet piling and concrete for the abutments.

In previous years, we had came south to this area to watch the kite surfing. This year it was a very sobering as we passed through the devastation. Piles of debris lined the road from flooded items removed from the first floors. The worst hit area was a series of beautiful homes with the adjacent road and patios collapsed into a newly formed canal. One house listed precariously to one side leaving no doubt that its foundation had passed the point where simple repairs could restore the building structure. On the ocean side there were a few homes founded on piles with the leading columns touching the water. The failure of these columns had led to deck failures several levels above the water. Posted to the doors were the condemnation papers from the county announcing to the world that they structures were no longer suitable for human habitation.

We drove through very somberly knowing that only a slight change of fates in either North Carolina or even at our home in New Hampshire and we would share the fate of these property owners. Our trips to the Outer Banks are spent with good friends with a lot of stories told and a great deal of laughter. It would be hard to imagine the loss of the vacation home that has been our home away from home for more than five years now.