HNSA Crest with photos of visitors at the ships.

My Experiences with the Sea Shadow, 1982-1994
By Steve Larson

In 1982, I was a design engineer working in San Francisco for Morris Guralnick Associates (MGA), Naval Architects and Marine Engineers. Lockheed Missiles and Space Company contacted us, saying they had a temporary job for personnel with our expertise. A few of us were sent down to Sunnyvale and briefed on a classified project, and they showed us some artist's renderings of a stealth ship. We started work in December of that year, and in February or March of 1983 we were moved to Redwood City, CA, in a secure building with dock access to the San Francisco Bay. Soon after, the Hughes Mining Barge (HMB) was brought in to the dock at this location, where the Sea Shadow would be assembled inside. Eventually, about 18 of us from MGA worked on the project.

There were two stress engineers (LMSC), two drafters (one MGA, one LMSC), and three design engineers (two from LMSC and myself) working on the structure of the vessel. Additionally, there were approximately 15-20 engineers working on the mechanical, piping, HVAC, arrangements and electrical designs of the vessel. We did not have computers or CAD packages; all the drawings were done on the drawing board. We were in a metal building with no air conditioning or heat, and it got into the 40's in winter and over 100 sometimes in the summer inside the building. Eventually they installed gas heaters for us, and that was wonderful! But no air conditioning.

The vessel was built in modules at three other locations, and trucked or barged in under cover of night. None of these other fabricators at the other locations had any idea of what we were doing, and sometimes we were just "Acme Engineering" to them. The roof of the HMB was opened at night, and a floating crane would lower each module into it. The roof would not be opened if any Russian satellites were known to be overhead.

There were approximately 200 workers inside the barge: welders, ship fitters, electricians, plumbers, etc. Each day at 1000, someone would go out and purchase several dozen doughnuts for the entire crew. We worked long hours, averaging over 100 hours per week. Along with the workers and engineering personnel, there was a cadre of purchasing agents, safety engineers, schedulers, security personnel, all going back and forth from the building to the HMB at all times of the day and night. The engineers would design the modules, do the drawings, send them to the fabricators, and start another design. We would also have to liaison with the fabricators, answering questions, etc. There were three outside fabricators, located in New York, Washington, and California, so we had to do some travelling as well.

There were also VIP's visiting from time to time. They were brought into the building in a vehicle with blacked out windows, driving into the building through one of the rollup doors. One day I encountered John Lehman (SecDef) in the building.

The structure is made up of high strength steel for the smaller shapes, and HY100 for all the plate (the same material that submarine hulls are made from). It is difficult to weld, and takes skilled workers to do it correctly. Amazingly, we had few problems in the assembly of the modules.

You will notice in the pictures of the interior all the HVAC (Heating Ventilation Air Conditioning) ducting. I had to work closely with the HVAC designer to make sure we could accommodate all that ducting without compromising the structure. He and I had worked together for years at MGA, so it was not a problem. He also wound up working for Lockheed permanently, until he left for Louisiana and went to work for Avondale Shipyard.

In the picture below of the Payload Space, you see what appears to be a stanchion all by itself. It is actually a large turnbuckle. It was installed in 1986 before a large cutout in the side was made for a radar installation. It was thought that there could be a structural problem with such a large cutout. As it turned out, the turnbuckle was installed, the cutout made, and everything was fine. However, the radar program was cancelled, but we left the turnbuckle in place.

Photo of empty payload bay.

The picture below of the HMB shows the MegaDoor at the stern of the barge. This was installed after the barge arrived at Redwood City. The engineering was done by MGA in San Francisco. Only a few at the company, besides the 18 of us, knew what we were up to.

Photo of HMB-1 in SBRF

If you look at the photo below, you will see the forward-most module, which included the deck of the bridge. The remainder of the upper structure was built and installed in RWC. One of my tasks was to come up with a drawing of that upper structure. One of my collegues had the task of building a fullsize mockup of the bridge, made of foam core material. I was having trouble picturing how all the structural members would come together in the forward area, so he and I worked together on it. We would go back and forth from the drawing board to his foam core model in determing how the structure came together. This method worked very well, and we succeeded in finishing the design/drawing and building the mockup. They used this mockup to custom build all the bridge consoles, which were later installed on the bridge, and fit perfectly. The structure came together perfectly as well. The drawing turned out to be a very long "R" size drawing, and was one of the few classified structural drawings due to the fact that it showed the final shape of the vessel.

Photo of Sea Shadow under construction without the bridge installed.

The entire vessel was designed and built in approximately two years time, which was an amazing feat. People from all walks of life worked as a team, and we had a great time doing it. There was a time when some of the guys stayed up all night roasting a whole pig for all of us to enjoy the next day.

Originally, the Sea Shadow was referred to either as the Demonstration Platform, or DP; or by it's Lockheed project number, P310. When it was nearing completion, management decided to have a naming contest. We were all invited to submit a name, which is how she was named. A logo was designed, as shown in the picture of the belt buckle, which was made with a sand casting. The casting was destroyed after about 200 buckles were made. The one shown is number 156, which I wear proudly. Several years later, the logo was slightly changed, as shown in the picture of the patch.

Photo of Sea Shadow twin sea horse buckle. Photo of Sea Shadow twin sea horse patch.

The Sea Shadow first went to sea in 1985. My work was done, so I went back to MGA, and in May of that year my supervisor at LMSC called to see if I would like to come and work permanently for Lockheed. I did, and retired earlier this year after 25 years. During those years, we worked on the Sea Shadow two other times, in 1986 as mentioned above, and 1994. During that time, it remained in the HMB in Redwood City.

The final time I was involved with the vessel was 1994, when it was declassified and shown off to the public. After various mods and sprucing up, it was moved to NAS Alameda, and docked adjacent to Carl Vinson, CVN-70.

Sea Shadow took some photo-op cruises around the bay, and some officers from Vinson were given a tour. They in turn gave us a tour of the Vinson. From there, the vessel was put back into HMB and was off to San Diego, where testing went on for several years. I can recall the time when I was able to tell my wife what I had been working on all those years. At first it was difficult to talk about, because it had been a highly classified project for such a long time.

It was an enjoyable and rewarding experience that I will never forget. I worked with some great people, and I have nothing but good memories. A lot of the technology from the Sea Shadow is being utilized in naval ship design today.

Photo of ship. Photo of ship. Photo of Zumwalt class destroyer.
US Navy ships utilizing stealth technology demonstrated by Sea Shadow
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