In this article:
Sea Shadow
Drawing inspiration from his work on the F-117 stealth aircraft, Ben Rich, then head of Lockheed’s Skunk Works, proposed applying the technology concepts he and his colleagues had learned for aircraft to submarines, with the idea of making these vessels undetectable via sonar. Initial tests on a small model suggested the stealth gains could be on the order of a thousandfold, albeit with a cost of speed due to the design.
The Department of Defense did not show interest in this line of investigation until Rich, with input from a colleague, adapted the idea to apply to surface ships. This led to a DARPA contract to apply stealth concepts and materials to surface vessels and to test the effects of seawater on the radar-absorbing materials.
At the time, one of the biggest threats against US surface vessels was the Soviet RORS satellite, which used X-band radar. Knowing that shape was the key to defeating such radar, Rich and team designed the ship using severe flat planes of 45-degree angles that bore a strong resemblance to the Nighthawk. The engineer team, led by Ugo Coty, tested their concept by taking the ship to an ancient lake bed deep within Death Valley, Calif. There, they filled a 100 by 80-foot plastic swimming pool and rigged a radar system that duplicated the Soviet radar satellite. Testing proved successful, resulting in additional funding by the Navy to create the prototype of the Sea Shadow.
Four-man crew
However, the Ocean Division of Lockheed caught wind of the project and managed to convince Rich to pass the project to them, as they were in dire need of new work at the time. Part of this agreement allowed chief engineer Ugo Coty to continue with the program to ensure the ship builders didn’t compromise stealth for performance.
Developed in great secrecy, a prototype, the Sea Shadow (also designated as IX-529) was assembled out of sight within a submersible barge (the Hughes Mining Barge 1) in Redwood City, Calif.
Ben Rich recalls in his book Skunk Works;
‘The Sea Shadow was made of very strong welded steel, displaced 560 tons, and was 70 feet wide. Our ship had a four-man crew—commander, helmsman, navigator, and engineer.
‘By contrast, a frigate doing a similar job had more than three hundred crewmen.
‘Viewed from head-on the ship looked like Darth Vader’s helmet. Some Navy brass who saw her clenched their teeth in disgust at the sight of the most futuristic ship ever to ply the seas. A future commander resented having only a four-man crew to boss around on a ship that was so secret.
‘Our stealth ship might be able to blast out of the sky a sizable Soviet attack force, but in terms of an officer’s future status and promotion prospects, it was about as glamorous as commanding a tugboat.
18 Sea Shadow stealth ships protecting the US Navy carrier fleet
‘We could arm it with 64 Patriot-type missiles and send it out 300 miles ahead of the carrier task force as an invisible, amphibious SAM missile site. We’d shoot down the Soviet attack aircraft before they got within missile range of the fleet. And because they couldn’t see the stealth ship electronically, they’d literally never know what hit them. We did an analysis and determined that the entire US Navy carrier fleet could be protected by only eighteen of our stealth defenders armed with SAMs. Since our ship would knock out most of the incoming air armada trying to attack our carriers, we would make the Aegis more effective by dramatically decreasing the number of incoming missiles it would be called upon to try to destroy at one time.
‘And we had compelling test data to prove our contentions. To accurately measure the low radar cross-section of a model ship under realistic ocean conditions, Ugo Coty went to one of the most remote areas of the western desert. There, within hailing distance of Death Valley, he built himself a miniature ocean. The place was about two days from Edwards Air Force Base by mule pack or by jeep crawling through deeply rutted roads. It was an ancient lake bed sitting at the foot of an 8,500-foot mountain, on top of which Ugo Coty planned to mount a radar system.’
The miniature ocean
Coty took my father, SR-71 Blackbird RSO Col. Richard “Butch” Sheffield, to see the miniature ocean.
Butch recalls in his book Ohio to Supersonic;
‘Ugo Coty was a real “Skunk.” This is a compliment to anyone who works in the Skunk Works. Ugo was an engineer who was considered brilliant by many. He worked on about 12 programs at the Skunk Works, and he kept them undercover from almost everybody there.
‘For some reason, he liked me and cleared me into all of his programs.
‘Ugo took me out to someplace north of Edwards Air Force Base and drove us high in the mountains on a narrow one-lane road. I was sitting in the front passenger seat and when I looked out of the window, all I could see was space. The road was just as wide as the vehicle. The road circled the mountain several times. When we reached the top, a large radar antenna was sitting on top of the mountain. He walked me over to the edge and pointed down on the desert floor thousands of feet below was an artificial lake with boats floating in it. The boats were about 10 to 20 feet long. Were in all shapes.’
Trials
The Sea Shadow’s first trials in 1981 proved greatly disappointing because the ship’s wake was unexpectedly huge and detectable with sonar and from the air. After discovering that the problem was due the motor propellers, which had been installed backwards, the project moved forward. The vessel was completed in 1984 and underwent night trials in 1985 and 1986.
Even so, the Sea Shadow never made it beyond the testing phase, though engineers applied lessons learned in such applications as submarine periscopes and some newer Navy destroyers, including the DDG 1000 Zumwalt-class ships.
The Navy was not impressed with this futuristic ship and it proved difficult for Ben Rich to work with the service. Legendary Lockheed Skunk Works founder Kelly Johnson who had 14 formally written management principles, but his unofficial 15th rule was blunt: “Starve before doing business with the damned Navy.”
In 1993, the public got it first view of the stealth ship, which eventually was scrapped in 2006.
Photo credit: U.S. Navy
