Unmanned Mine Spotter

Mechanical Engineering, Mar 2007 by Hutchinson, Harry

The U.S. Navy has signed The Boeing Co. to begin another round of tests of a defensive reconnaissance system that involves an autonomous underwater craft. Boeing has a new $11 million contract with U.S. Naval Sea Systems Command to refurbish and launch new tests of the technology, the AN/BLQ-11 Long-Term Mine Reconnaissance System.

The system is designed to send out an unmanned underwater vehicle, or UUV, from a submarine. The vehicle is capable of reaching programmed waypoints as it gathers data about mines. It can search an area for more than 12 hours at a stretch. Once the vehicle reaches its rendezvous position, it communicates acoustically with the submarine and operators on the submarine can command it to return and dock with a recovery arm. The craft uses inertial guidance and GPS tracking to reunite with the submarine, which retrieves it. Once the vehicle is back onboard, data can be downloaded and analyzed to reveal the existence of minefields and the positions of individual mines.

The purpose of the automated system, a Navy spokesman said, is to "keep the man out of the minefield."

The system was tested in January 2006, when a UUV was released through the torpedo tube of the USS Scranton and later returned to dock with the recovery arm. According to Boeing, the system's 60-foot robotic recovery arm suffered a mechanical failure during the test and, although docking was successful, the unmanned vehicle was not retrieved as planned.

The new contract covers repairs to the recovery arm, but the primary purpose of the refurbishment is to replace worn parts, Boeing said. The arm is designed to last 20 years, or about 300 cycles. During the test program, it was cycled more than 600 times.

Boeing will add cameras to the recovery arm so operators can observe the retrieval. Boeing said it also will modify the vehicle and the command and control software.

The AN/BLQ-11 system consists of the recovery arm, two UUVs, shipboard deployed equipment, and nondeployed shore support equipment. A spokesman for the Naval Sea Systems Command said the current configuration is designed to search for undersea mines, but the next phase of development may include "mission-configurable" vehicles with different payloads to carry out other missions.

HARRY HUTCHINSON