New Seabee Museum Features Navy Deep Sea Submersible Display

By Darrell E. Waller,Naval Facilities Engineering Command Public Affairs

PORT HUENEME, Calif. (NNS) -- Navy ocean engineers have delivered a treasured piece of naval history to the new Seabee Museum July 22, just in time for its official opening.

The Naval Experimental Manned Observatory (NEMO), a deep submergence vehicle created in the 1970s by the Naval Civil Engineering Laboratory (NCEL, a forerunner to today's Naval Facilities Engineering Command/Engineering Service Center) and the Southwest Research Institute, will be among the many featured exhibits at the new museum.

The Seabee Museum's gala coincides with the "Seabee Days" event this weekend at Naval Base Ventura County (NBVC). Thousands of local residents are expected to come out for a wide variety of free activities, including demonstrations of Seabee construction skills, displays of military construction equipment, weapons, and field camp construction.

"The NEMO exhibit is one of our proudest accomplishments and is fondly remembered years after its last deployment," said Naval Facilities Engineering Service Center Commanding Officer, Capt. Paz B. Gomez. "The unique, spherical construction of NEMO gave its occupants unfettered underwater vision while allowing Navy engineers and technicians to comfortably observe undersea construction without having to don bulky diving gear. It was an innovative system years ahead of its time that advanced ocean construction and demonstrated the effectiveness and limits of acrylic pressure hulls."

NEMO was one of four Navy Deep Submergence Vehicles (designated "DSV-3") within the Navy's "Man-in-the-Sea" Program during the 1970s. She carried one certified pilot and one observer and was fitted with a life support system that allowed its occupants to stay safely submerged for up to three days.

Unlike bathyspheres of the time, NEMO was not tethered to the surface, it was a true free-swimming submersible with its own thrusters and ballast system. NEMO measured 78 inches wide, with a height of 110 inches. She weighed 8,000 pounds in open air and was capable of taking a payload of up to 450 pounds down to a depth of 600 feet. NEMO also had the distinction of being the first deep submergence vehicle to test and demonstrate a spherical pressure hull made entirely out of acrylic. The properties of such a hull were largely unknown in the 1970s and the NCEL was tasked with analyzing, testing and designing the NEMO platform.

Three identical hulls were constructed in machine shops at Naval Air Station Point Mugu by bonding 12 pentagon sections. One hull became known as NEMO; a second was used for fatigue testing; the third was tested for failure by pressurizing it in a NCEL hyperbaric test chamber to a collapse depth of 4,150 feet.

During its naval service, NEMO made several hundred dives in the Bahamas and off the Channel Islands in California. The sphere's deepest recorded dive was officially recorded at 614 feet.