Field Research Facility
Coastal & Hydraulics Laboratory

The CRAB's Rise and Fall and Rise Again

The CRAB (Coastal Research Amphibious Buggy) is one of the oddest vehicles you might see on a vacation to the Outer Banks. If you are lucky, during your trip to the FRF, you may see this bright yellow tripod seafarer roll over the dune, across the beach, and into the deep ocean. Sometimes things do not go as planned. In 1987 the sturdy CRAB lost its balance in a trench next to the pier and landed on its side underwater. The following is that story.

The CRAB was custom built in Wilmington, NC for use around the Cape Fear area waters. The FRF later acquired the CRAB, but it was 10 feet shorter than it is now.

Once the new CRAB was put into position at the FRF it began to show its effectiveness right away. Here the CRAB is undergoing a storm performance test during Tropical Storm Dennis in August 1981.

In 1987 the CRAB veered too close to the pier and entered a trench created by longshore currents and began to slowly tip over. It was a slow fall that took minutes to complete.

Photo of the downed CRAB from the pier deck.

From Wilmington came the Debris Boat "Snell" to lift the CRAB out of the water.

For more information on the CRAB Click Here.

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Created by Clint Baron
North Carolina State University
Summer 2006

The original CRAB was too short to go around the pier and too tall to go under. This dilemma left the FRF without a means to deploy instruments on the North side of the pier. The CRAB was send back to Wilmington where modifications were made by raising its back support bar and lifting the platform 10 feet higher. The new and improved CRAB was flown in at night up the coast to its permanent home in Duck.

The CRAB has also gotten stuck on more than one occasion. Here on its first and only drive into the Currituck Sound its front wheel crossed a drop-off point and required bulldozers to haul it out. The FRF has a 2000 foot (the farthest distance out that the CRAB can go) rescue rope that can be used to pull the CRAB out of the ocean.

The CRAB rested gently on its side with only one wheel out of the water while a zodiac inspected it for damage.

Night came and went with the CRAB still submerged. The next morning at sunrise the CRAB had not moved.

The "Snell" lifted the CRAB completely out of the water to stand it upright. The LARC pulled in the now upright crab. The FRF had the CRAB up and running two days later. The CRAB has never tipped over again.