Scientist glimpse sub's propeller shaft

Thursday, January 25, 2001

By BRIAN HICKS
Of The Post and Courier staff

     Scientists excavating the Hunley's interior on Wednesday got their first look at the Confederate submarine's propeller shaft.
     Sure enough, it's a metal bar.
     Archaeologists removed another couple of buckets full of sediment from the hole in the submarine's starboard stern and Dr. Scott Harris, a scientist from Coastal Carolina checked out the layers of silt inside to see if it told anything about how long it took the submarine to sink into the sea bed.
     Dr. Bob Neyland, the project manager, said that after all this time, it's exciting to now be getting a first glimpse of the inside of the submarine that has held its secrets for 137 years.
     "It's pretty amazing to be at this point," Neyland said. "Looking in here raises questions about its construction. Did they have access to this area or was it sealed once the sub was built? And is this part of the ballast tank or is that tank forward of this area?"
     Right now, the interior excavation is confined to the aftmost compartment of the sub. Scientists expect to have all the sediment out of that area within the week. Then they will use fiber optics to take a peek forward. That should help them determine if they are in the rear ballast tank.
     With part of the rear hole in the sub cleaned out, scientists can see the shaft that turned the propeller and another one mounted along the top of the submarine that, somehow, controlled the rudder. That bar, which could contain smaller rods inside, is about four inches wide. No sightings, yet, of rivets or anything else that might supply a hint of how the Hunley was built. The inside walls of the submarine are concreted much like its exterior.
     The rest of the work at the Warren Lasch Conservation Center has focused on the upcoming excavation of the crew compartment. Scientists worked out bugs in their data systems computer, prepared to take a course on interpreting the load cell readings and had the tank swept out by a pool company.
     The load cells can tell scientists if there is any change in stress to the hull and can warn them ahead of time if a strap, which holds the sub in place, is weakening.
     They swept the tank to make sure there's no doubt that anything in it is from the sub. During tours, someone could have accidentally - or as a joke - dropped something in. Neyland said they don't want to be guessing about the origin of anything they find.
    

     Archaeologists are finding evidence of bilge water residue as they excavate the rear section of the sub.
     About 10 buckets of mud have so far been pulled from a three-foot long hole in the vessel's rear right side during the first phase of excavation at the Warren Lasch Conservation Lab.
     In the mud, scientists are discovering the presence of oil, organic material and other residue typically associated with a vessel's bilge. It has a sulphur-like smell.
     Also, there are small pieces of iron being found. When put together, the pieces may represent the section of hull that was ripped open when the mysterious hole was formed, possibly by a dragged anchor.