Thursday, November 8, 2012

3-D Sonar Imaging of the USS Hatteras successful

In mid September, archaeologists and computer technicians successfully imaged the undersea Civil War wreck of the USS Hatteras.  The Hatteras had been discovered in 1976, however, sediment did not allow for a proper survey of the wreck.  Recent storm and sea activity shifted some of the sand and allowed researchers to image the ship.  The team has been working against the clock since preservation laws do not allow the wreck to be excavated or salvaged and shifting undersea sands may soon cover the wreck again.  The researchers used advanced 3-D sonar imaging equipment which bounces sound waves off the shipwreck to create three-dimensional images of the structure.  Undersea visibility was poor during part of the mapping but since the technology does not use light to create images, but rather sound waves, the work proceeded smoothly.

USS Hatteras makes a name for a Confederate raider

The USS Hatteras had been the unfortunate victim of the notorious Confederate raider, the CSS Alabama.  Raphael Semmes commanded the CSS Alabama and in January 1863 the ship had been cruising towards the Texas coast to audaciously attack Union troop ships in port at Galveston, Texas.  Semmes was unaware his Confederate compatriots had not only recaptured the city but had also captured the USS Harriet Lane and three Union transports, had destroyed the USS Westfield and had killed Union commander John Wainwright. 

When Semmes arrived, he found five Union ships shelling Galveston.  Rather than fleeing, Semmes lured a Union gunboat, the USS Hatteras, from the main Union fleet by pretending to be a Union ship chasing a Confederate blockade runner.  Fifteen miles from the fleet, the Alabama turned on the Hatteras and in a 13 minute gun battle, fatally damaged the Hatteras below her waterline.  The Hatteras took on water as her crew surrendered to the Alabama and were taken aboard the Confederate ship.  The Hatteras sank soon thereafter.

The Hatteras was next encountered in 1976 by a salvage company.  The company requested permission from the Navy to salvage the Hatteras.  The Secretary of the Navy responded by essentially saying the Department of the Navy had abandoned the vessel.  The salvors recovered some artifacts but the government then demanded the items be returned.  In turn, the salvors sued for title of the items or in the alternative, salvage award.  The court held the Secretary of the Navy’s letter did not properly abandon the items because it did not comport with current Federal aw describing how the government may abandon its own property.  Title was retained in the government’s hands.  The salvors also did not receive salvage reward because the did not sue within two years of the salvaging which is required to win a suit for salvage reward under the Salvage Act of 1910.

Imaging reveals ship structures

Jim Delgado, director of maritime heritage for the National Oceanic and Atmospheric Administration's Office of National Marine Sanctuaries and the person overseeing the Hatteras imaging project, stated by email that the researchers were able to image some of the Hatteras’ engine machinery, especially the paddle wheel shafts and hubs.  The team also found clear evidence of the stern and rudder as well as iron plate armor the US Navy had installed on the ship for military use.  Trawling seems to have damaged some of the ship in the past and nets and gear appear to be snagged on the wreck. 

Mr. Delgado expects the team will be able to publish results of this survey by January 2013 to coincide with the 150th anniversary of the battle.   The USS Hatteras is currently US government property and located in waters administered by the Federal Bureau of Ocean Energy Management.

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