The Georgetown Times November 05, 2006
Mine scare at Hobcaw Barony
By Clayton Stairs
Flashing lights at the entrance to Hobcaw Barony are an uncommon sight along Ocean Highway 17 just north of Georgetown. However, that was the scene at about 4:15 p.m. on Thursday after a nine-foot U.S. Navy MK 56 mine — which turned out to be inert — was found on the property.
Responding were crews from the Georgetown County Sheriff’s Office, Midway Fire and Rescue, the Horry County Bomb Squad and the State Law Enforcement Division (SLED). Sheriff’s Office Spokesman Sgt. Neil Johnson said that the emergency personnel at the scene initially didn’t know whether the device was dangerous or not, but they are trained to act as if it were a live explosive.
“Anytime we have a call like that, we treat it as if it is the real thing,” Johnson said. “We secured the area, got everybody back, and waited until the bomb squad arrived to determine if the device was explosive.”
According to Johnson, after an initial examination, the bomb squad found that the MK 56 Mine was inert and was, in fact, a practice mine belonging to the U.S. Navy. It had no explosive parts.
Research Specialist Tracy Buck and Nutrient Chemist Ben Lakish, both with the University of South Carolina (USC) Belle W. Baruch Marine Field Laboratory at Hobcaw Barony, discovered the “large cylindrical object with fins” floating in Clambank Creek in North Inlet about three months ago and dragged it to shore because it was a navigational hazard for boaters.
Lakish says he and Buck discovered the object while deploying an ISCO water sampler device and that they thought it was a buoy or perhaps some sort of “military ordinance.” Since it was encrusted with barnacles and oysters, they figured it had been in the water for a long time and was not dangerous.
“It was incredibly heavy and we couldn’t pull it out of the water, so we pulled it up as far as we could,” Lakish said. “We tied it to a dock at Clambank (Landing), which is our primary boat launch site for the USC lab here.”
He says they reported the find to the Director of the USC Lab, Dennis Allen who may have contacted the U.S. Coast Guard about it. Lakish says he did not give it much more thought.
“It is interesting that it turned out to be a mine,” Lakish said. “I would like to know where it was deployed, how long it was out there, and how it came to be in Clambank Creek.”
Bee Bessinger, with the Belle W. Baruch Foundation, reportedly began disassembling the device in the hanger at Hobcaw Barony to find out what was inside when, on Thursday, he found a plaque reading “U.S. Navy MK-56 Mine” and a warning reading “explosive section.” He then notified the proper authorities.
According to George Chastain, executive director of the Belle W. Baruch Foundation at Hobcaw Barony, after the bomb squad determined that the mine was inert, the U.S. Navy was called to claim their lost property. They picked up the mine by truck Friday morning, he said.
For Your Information
According to the website www.globalsecurity.org, the MK 56 ASW mine (the oldest still in use) was developed in 1966. The Mine MK 50 series includes the Mine MK 56, a 2000-pound aircraft-laid moored mine containing an explosive charge of 360 lb. of HBX-3, designed specifically for effectiveness against high-speed and deep-operating submarines.
The MK 56 has a magnetic firing mechanism that uses a total-field magnetometer as its detector. Total-field magnetometers are three dimensional target sensors that respond to changes in the earth's magnetic field as caused by the presence of a ship.
Consisting of a nonmagnetic stainless-steel case and a cast-steel anchor, the MK 56 is equipped with flight gear for launching from aircraft. When laid, the mine sinks to the bottom where case and anchor separation take place.
Should the mine become embedded in bottom sediment before case/anchor separation and mooring take place, a slow burning propellant in the anchor is ignited which frees the mine from any mud in which it may be buried. As the case rises, a hydrostat, which clamps to an 18-foot loose bight in the mooring cable, senses the preset mooring depth and falls free to release the loose bight. This permits the tension on the cable to relax and cause a pawling mechanism in the anchor to lock and stop further cable payout.
Should the mooring mechanism allow the mine to rise to a depth which is too shallow, the case will scuttle. This feature reduces the possibility of compromise and eliminates a navigational hazard. Scuttling will also occur upon sterilization or if the mooring cable breaks.
© Copyright 2006, Georgetown Times
