Since the vessel was experimental, it didn’t have auxiliary power, so all the work was done in the dark with flashlights and the water removed from the ship by bucket brigade.Biden and Kadhimi seal agreement at White House to end US combat mission in Iraq Read More » The crew was especially note-worthy as the ship’s fuel tanks once took on water, and instead of a Navy tow, the crew spent 12 hours without power to restore one of the engines and make it home. The vessel was so experimental that it didn’t even have a rudder and relied on stabilizers to steer, making the docking process even more impressive.

Save for testing, the vessel never sailed for any other purpose, the sole function of Sea Shadow was to test technologies that were then applied to submarines and new Navy Destroyers. After construction, the vessel was also used to test advanced combat systems prototypes for passive identification and targeting, according to San Francisco Maritime National Park Association. The entire ship was wired with cameras to reduce the need for a large crew, and it had plenty of space for experiments. The Sea Shadow wasn’t just built to test stealth technology – it also tested the SWATH hull, automation to reduce crew, rough weather seakeeping improvements, and radar and sonar control. The vessel was offered up for sale and even for donation to museums without interest, and in 2012 the vessel was sold along with HMB-1 with the requirement that Sea Shadow be dismantled for scrap. Additional testing was done in 1999, and vessel operations were completed in 2006. Testing was suspended from 1986 to 1993 when the Sea Shadow was unveiled to the public, with testing concluding only a year later. During trials, the crew saw huge wakes behind the ship that stood out on radar and from above, finding when they returned that the propellers were installed backward. During the day, the vessel was safely secured inside HMB-1 for repair and maintenance. Sea Shadow was delivered in March of 1985, followed by nighttime test voyages in 19 near the Santa Cruz Islands in Southern California. According to Maritime National Park Association, to maintain complete secrecy, any operation that required opening the roof of HMB-1 was timed to avoid spying Soviet satellites overhead. The modules were made by four different manufacturers to ensure no one company had a clear picture of the final product. According to Lockheed Martin, a four man crew built the ship in pieces before they were taken to the submersible barge and assembled.

To keep the project super-secret (even many military officers with top secret level clearance didn’t know about the construction of Sea Shadow), the ship was built completely inside a floating dry dock vessel called Hughes Mining Barge I, or HMB-1. After going back to Washington to talk with the Defense Undersecretary about the idea in a meeting that was supposed to be about the F-117, he was approved a contract through the Defense Advanced Research Projects Agency, or DARPA to work on the vessel. This new vessel was quicker than a normal ship and very stable with its catamaran design, a nice match for stealth technology. Another Skunk Works engineer told Rich about a new naval ship design he had just seen, the Small Water Area Twin Hull (SWATH). The captain was not convinced, worried about loss of speed even with the prospect of invisibility. Acoustic tests confirmed huge improvements in sound deadening, prompting Rich to approach a Navy captain at the Pentagon in charge of submarine research and development, according to Lockheed Martin. They got to work and the first design was cigar shaped like a normal submarine, but with angular outer surfaces like the F-117 to deflect sonar and dampen internal noise from the crew. What they discovered was an improvement in sonar return of three orders of magnitude, 1000 times better with just a simple model. In engineering, an improvement of one magnitude, or 10x, is considered a huge improvement and worthy of celebration. Realizing he had something by bringing stealth aircraft technology to the water, Rich’s team purchased a model submarine and added faceted fairings for sonic chamber testing.

Voltage bomber crew