SPECIAL OPERATIONS

Down where it’s wetter

Artist's rendering of Virginia-class submarine courtesy U.S. Navy

Nearly six years since it last updated plans for the development of unmanned undersea vehicles (UUVs), the U.S. Navy is taking another look at the largest variant of underwater craft as a way to extend its reach into shallow areas along hostile or restricted shorelines.

The Navy’s update of its 2004 Master Plan for UUVs – expected to be released later this year – will focus more attention on the largest of four classes of UUVs which can go farther, carry bigger payloads and tackle longer-range missions than the next largest in size. One Large UUV mission being studied is the capability to ferry Navy SEALS or other Special Ops forces in an autonomous underwater vehicle from a submarine to shore.

Until recently, smaller UUVs — classified Heavy Weight Vehicles by the Navy (see photo below) — had been getting most of the attention because, at up to 3,000 pounds, they were the largest that could fit in the 21-inch diameter of a standard submarine torpedo tube, the primary launch method.

Bluefin-21 Battlespace Preparation Autonomous Underwater Vehicle (BPAUV) Photo Courtesy of Bluefin Robotics

But with Navy plans to acquire eight new Virginia-class nuclear-powered subs equipped with large vertical launch systems that could accommodate bigger UUVs, attention turned to the largest class of undersea robot vehicle. And four Ohio-class Trident missile boats, converted to fire conventional cruise missiles, also have capacity to launch the biggest UUVs.

The 2004 Master Plan — itself an update of a 2000 plan — broke down the profusion of underwater robots into four categories by weight and size: Man Portable Vehicles weighing between 25 and 100 pounds, Light Weight Vehicles, weighing up to 500 pounds with a diameter of 12.75 inches; the Heavy Weight Vehicles and Large UUVs weighing 20,000 pounds or more.

For more details see my story in the January 2010 issue of Unmanned Systems (subscription required), the monthly magazine of the Association for Unmanned Vehicle Systems International (AUVSI).