Lockheed Sea Shadow IX-529

Sea Shadow (IX-529) is an experimental stealth ship built by Lockheed for the United States Navy to determine how a low radar profile might be achieved and to test high stability hull configurations which have been used in oceanographic ships.

Development

Sea Shadow was built in 1984 and used in secret but normal service until her public debut in 1993, to examine the application of stealth technology on naval vessels. In addition, the ship was designed to test the use of automation to enable the reduction of crew size. The ship was created by the Defense Advanced Research Projects Agency (DARPA), the U.S. Navy and Lockheed. Sea Shadow was developed at Lockheed's Redwood City, California, facility, inside the Hughes Mining Barge (HMB-1), which functioned as a floating drydock during construction and testing. It is sometimes referred to as "USS Sea Shadow" however, this designation is inappropriate as it was never a fully commissioned ship of the U.S. Navy.

Overview

Sea Shadow has a SWATH hull design. Below the water are submerged twin hulls, each with a propeller, aft stabilizer, and inboard hydrofoil. The portion of the ship above water is connected to the hulls via the two angled struts. The SWATH design helps the ship remain stable even in very rough water of up to sea state 6 (wave height of 18 feet (5.5 m) or "very rough" sea). The shape of the superstructure has sometimes been compared to the casemate of the ironclad ram CSS Virginia of the American Civil War.

The T-AGOS 19-and-23-class oceanographic ships have inherited the stabilizer and canard method to help perform their stability-sensitive surveillance missions.

Sea Shadow has only 12 bunks aboard, one small microwave oven, a refrigerator and table. It was never intended to be mission capable and was never commissioned, although it is listed in the Naval Vessel Register.

Sea Shadow was revealed to the public in 1993, and was housed at the San Diego Naval Station until September 2006, when it was relocated with the Hughes Mining Barge - inside which it still resides - to the Suisun Bay Reserve Fleet in Benicia, CA. The vessels are available for donation to a maritime museum.

In 2006, the U.S Navy began to try to sell the Sea Shadow to the highest bidder;[1][2] after the initial offering met with a lack of interest, it was listed for dismantling sale on gsaauctions.gov.[3] The U.S. Government requires that the buyer cannot sail the ship and is required to dumped the ship for recycling scraps.[4] The ship was finally sold in 2012 for $3.2 million.

Specifications
Builder Lockheed Martin
Power Plant Diesel electric
Length 164 feet (49.99 meters)
Beam 68 feet (20.73 meters)
Draft 14.5 feet (4.42 meters)
Displacement 560 tons (568.99 metric tons) full load
Speed 10 knots ( mph)
Crew 10