Project Tektite I and the Birth of the Underwater Construction Teams

Dr. Frank A. Blazich Jr., Historian, U.S. Navy Seabee Museum 


Underwater view of the Tektite I habitat with aquanauts and accompanying divers egressing for research on the adjacent reef beneath Great Lameshur Bay, St. John, U.S. Virgin Islands. Source: NOAA

Tektite-I-logo_lowIn the annals of the U.S. Navy’s proud history, the Cold War witnessed the birth of many new units and capabilities to meet technological and geographical challenges. Within the Seabee community, the Underwater Construction Teams (UCTs) are one such example, born in the late 1960s amidst the converging threads of the space race, emerging technologies, ocean facilities and a yearning to conquer the last frontiers of the ocean’s depths.

From 1968 to 1969, Project Tektite I, a joint effort between government, industry and academia, presented the Naval Facilities and Engineering Command (NAVFAC) and the Seabees with new engineering and construction requirements needing underwater construction expertise. Through participation in Tektite, NAVFAC cemented the necessity for the permanent establishment and maintenance of Seabee underwater construction capability.


The AMMI pontoon barge is just starting to submerge below the waterline. Two of the pile winches are visible, along with divers at the far end. Source: TUHM-VIERS

For the Navy, the Cold War witnessed relentless advances in technology warranting increasing numbers of highly trained specialists in the service. In confronting the Soviet Navy, the American submarine and antisubmarine warfare capabilities grew in importance and reach as elements of the nation’s nuclear deterrent. By the mid-1960s, with the space race probing ever deeper, the nation turned inward to examine its commitment to explore and study the oceans.

The President’s Science Advisory Committee on Oceanography (PSACO) formed in May 1965 to draft goals for a national program of marine development, assess current and planned programs, identify opportunities for new programs in science and technology, and recommend measures “to effect an ocean science and technology program consonant with national needs and interests.” Among its findings, the committee recommended that the Navy, which bore primary responsibility for development of underwater capabilities, expand those “activities which will permit operation at any location and time within the oceans.”

Concurrent with advocacy for developing marine resources, the National Air and Space Administration (NASA) was engaged in manned exploration of outer space. Throughout 1965 to 1966, Project Gemini aggrandized the success of Project Mercury. One of Gemini’s key objectives sought to demonstrate human endurance for extended periods of spaceflight. While Gemini 12 splashed down in the Pacific Ocean in mid-November 1966 to successfully conclude the project, a Symposium on Isolation and Confinement in Washington, D.C., brought together NASA psychologists and counterparts from the Office of Naval Research (ONR). During discussions, both parties noted the similarities between crew behavioral aspects of long-duration spaceflight and saturation dives. Continuing talks in 1967 developed the working hypothesis that “behavioral, habitability and crew effectiveness data obtained in observations of undersea teams could be used to predict and understand similar problems involving space teams.”



The Project Tektite I habitat, consisting of essentially two vertical steel cylinders attached to a rectangular steel base. Each cylinder contained two large compartments for the crew, control, research and diving. The habitat itself was designed and built by General Electric in accordance with the American Society of Mechanical Engineers Boiler and Pressure Vessel Code for Unfired Pressure Vessels. Source: Office of Naval Research, U.S. Navy.


The Seabees involved in Project Tektite I bore responsibility not only for the launch and recovery of the underwater habitat, but also for construction of the support barge, base camp and other facilities for the two-month research and experiment phase. This map details the locations of the facilities, site of the habitat’s launch and eventual location on the bottom of Great Lameshur Bay, St. John, U.S. Virgin Islands. Source: U.S. Navy Seabee Museum

Further NASA-contracted research supported this hypothesis, but an actual mission would be essential to advance the study. In November 1967, the U.S. Department of the Interior, which reached agreement with the Navy for the “cooperative study of problems of mutual interest,” joined with NASA to develop a mission of mutual interest to all parties. The following month, the General Electric Company submitted to the ONR an unsolicited proposal to conduct an underwater space marine mission, designed to last 60 days exploring “the ability of a small group of saturated divers to successfully carry out a scientific mission under hazardous, isolated conditions.” For NASA, small-crew psychology and behavior in endurance spaceflight could be more affordably studied underwater to benefit post-Apollo missions. The Department of the Interior sought to evaluate saturation diving as a research technique while conducting an operational research program on the ocean floor demonstrating marine scientists could live and work effectively in said environment. The Navy, the lead agency of the three parties, stood to benefit tremendously from the mission, particularly in the areas of medicine, marine science, engineering and construction. The finalized project was christened “tektite” in reference to small particles of matter which survive a fiery plunge through the earth’s atmosphere to come to rest on the ocean’s floor.

NAVFAC understood the potential gains in capability and experience from Project Tektite participation. From May to September 1968, a NAVFAC task group worked to define the role of the command and the Naval Construction Force (NCF) in ocean engineering. Referencing the 1966 PSACO report and a more recent February 1968 report from the National Council on Marine Resources and Engineering Development, the task group concluded that “a void exists in development of capabilities for ocean bottom engineering which will be filled by others if NAVFAC does not aggressively take the initiative.”


The Project Tektite I habitat from aboard an AMMI pontoon barge in Great Lameshur Bay, prior to driving piles through the spud wells. Source: Tektite Underwater Habitat Museum, Virgin Islands Environmental Resource Station, Lameshur Bay, St. John, U.S. Virgin Islands. Source: TUHM-VIERSTemplate_low

A Seabee diver works with a template used to align the piles driven to anchor the AMMI pontoon barge-turned-underwater elevator. Source TUHM-VIERS 

In its summary report, Plan for Definition of NAVFAC/NCF Role in Ocean Engineering, the task group singled out Project Tektite as a chance to “demonstrate capability to carry total technical management as well as quality engineering.” The report further outlined a five-year plan whereby NAVFAC would organize two underwater construction units, one for each Construction Battalion Center, thus allowing the Seabees to “acquire appreciably improved capability in underwater construction,” developing the techniques, tools and equipment required for a variety of tasks. For Tektite, NAVFAC bore responsibility for the methods, operational installation and recovery of the habitat and surface and undersea support systems.

Within NAVFAC and the Seabee community, the personnel for Project Tektite began to assemble at Naval Amphibious Base, Little Creek, Norfolk, Va., in Autumn 1968. The command tasked Amphibious Construction Battalion (ACB) 2 with devising the method to install and recover the habitat, construction of the base camp, and operation of habitat support systems and support barges. To manage and direct the underwater construction aspects of Project Tektite, the Navy tapped Cmdr. Walter J. Eager, CEC, director of the Ocean Engineering Program Office and former head of the Navy’s Man-in-the-Sea section and chairman of the SEALAB Test Group, Deep Submergence Systems Project Office. The Butte, Mont., native brought a calm, professional civil and mechanical engineering background to the team, together with a robust knowledge of saturation diving. Eager tapped Senior Chief Utilitiesman Dick Miller as his Master Diver, and together they assembled a group of 12 highly skilled Seabee divers from Atlantic and Pacific Naval Mobile Construction Battalions (NMCBs) at Little Creek in September 1968. The need for extremely talented people meshed well with the project’s tight timetable.


Portrait of Cmdr. Walter J. Eager, CEC, NAVFAC’s officer in charge of underwater construction, Project Tektite I. Eager’s team of Seabee divers assigned to this project accomplished all aspects of emplacement and recovery of the habitat with a perfect safety record. Source: U.S. Navy Seabee Museum


 One of the many 3,000-pound anchors jetted into place to hold the habitat to the ocean floor. Source: TUHM-VIERS

Eager and Miller briefed the assembled dive team about Project Tektite, the habitat and technical requirements. General Electric’s Missile and Space Division designed and built the brilliantly white-painted habitat, characterized by two vertical steel cylinders, 18 feet high and 12.5 feet in diameter attached to a rectangular steel base. A crossover tunnel connected the cylinders, each featuring upper and lower compartments and three large hemispherical viewing ports. One cylinder featured a large observation cupola for crew enjoyment. The habitat base contained two passageways with barred gates, one serving as an open ingress/egress wet room, and the latter as a closed emergency escape hatch. Along the base, tanks for saltwater ballast and bins for pig iron ballast helped anchor the 160-ton habitat to the ocean floor. Umbilical lines extended from the habitat to the surface for water, air, electrical power and sewage outflow. For 60 days, from   Feb. 15 to April 15, 1969, four selected Department of the Interior scientists, christened “aquanauts,” would live in saturated conditions to a depth of 43 feet. The habitat would be emplaced 49 feet underwater in Great Lameshur Bay, St. John, U.S. Virgin Islands. The site afforded shallow water, vast biological diversity, shelter from storm, low subsurface water currents and logistical supportability.

For Eager, ACB 2 and the dive team, Project Tektite unfolded in four phases. For Phase I, ACB 2 and Eager devised a method to sink the habitat and emplace it before traveling to St. John from Oct. 22 to Nov. 26, 1968, to construct the project’s base camp. To sink and move the habitat, Eager and ACB 2 opted to use the AMMI pontoon barge, named in honor of its inventor, Dr. Arsham Amirikian. The 55-ton barge, introduced in 1966 and used extensively in South Vietnam, utilized unique bi-serrated orthotropic framing members for increased strength, measured 90 by 28 by 5 feet, and could support 290 tons of cargo. Among its many unique features, six 24-inch spud wells at the corners and two along the middle edges enabled 20-inch diameter steel piles to be driven in place to anchor the barge. For Tektite, one AMMI barge would be employed to lower the habitat into the water, while a second would be outfitted as a service barge for all the habitat support systems.


This diagram details the underwater elevator devised by NAVFAC to move the habitat into the sea. Using a standard AMMI pontoon barge, four piles were driven through the spud wells 17 feet into the bottom. The pontoon was modified with flood ports installed on the bottom and vent lines extended through the surface. Winches on the top of each piling, together with controlled submergence of the barge, allowed the habitat to be slowly lowered into the water. When it floated free, the habitat was towed into location and winched to the ocean floor. Source: U.S. Navy Seabee Museum


Once the habitat is free of the underwater elevator, it is towed to its final resting location, affixed to anchors and slowly winched to the bottom. Here several Seabee divers on one side of the habitat are bringing it down to the anchors. Source: TUHM-VIERS

As work commenced on assembling the service barge in the fall of 1968, ACB 2 and Eager tested pile driving operations in September and October for lowering Tektite. On an AMMI barge at the Philadelphia Navy Yard, technicians assembled the habitat and tested all systems. The barge floated the habitat into the Landing Ship, Dock (LSD) USS Hermitage for transport to Great Lameshur Bay, but once free of the ship’s well deck a “dry, integrated systems test” of the habitat and life support systems had to occur prior to installation. As a floating crane capable of listing 160 tons was cost-prohibitive, Eager and NAVFAC devised a method to use as an underwater elevator. Driving piles through the spud wells of the AMMI barge, the bottom of the pontoon had flood ports and vent lines installed to permit controlled submergence. Seabees affixed manual winches to the top of each pile, and by carefully flooding the pontoon symmetrically the divers carefully lowered the barge beneath the bay’s azure waters until the habitat floated free. Once free-floating, the habitat could be towed to its final emplacement site and manually winched to the bottom by divers using clump anchors and eight 3,000-pound chainfalls. When the habitat reached the bottom, divers would move 20 tons of pig iron ballast into trays on the habitat’s base platform to overcome Tektite’s 5,000-pound positive buoyancy. For the support barge, the Seabees jacked the pontoon out of the water on its anchor pilings to prevent machinery noises from entering the water and eliminate mooring line maintenance problems.


Now the barge is almost completely submerged and the habitat is entering the water at last. The flooding of the barge and the control of the winches have to be precisely managed to keep the barge and habitat perfectly level. Any deviation may cause the barge to jam up on one of the piles or lock up. Source: TUHM-VIERS


This photograph provides a clear view of the four piles and accompanying winch operators as the habitat cylinders begin to submerge. Source: TUHM-VIERS


The habitat seen midway into launch operations, with supporting AMMI pontoon barge having been carefully flooded and lowered into the water, a surface craft repurposed as an “underwater elevator.” Source: U.S. Navy Seabee Museum


At this stage in the lowering process the habitat is buoyant and floating free of the AMMI barge. Source: TUHM-VIERS

With the techniques determined to launch and emplace the habitat and all other aspects prepared, Phase II – the emplacement of the habitat – commenced. From Jan. 6 to Feb. 12, 1969, the combined team of ACB 2 personnel and a dozen Seabee divers (augmented by five other divers) arrived at Great Lameshur Bay. On Jan. 8, naval personnel loaded the habitat aboard the USS Hermitage, and Eager and his team arrived with the habitat on Jan. 13 at St. John and set to work. During the first eight days on site, divers cleared and leveled a portion of the sandy bottom for the habitat and installed the clump anchors to hold it in place. Other divers put templates on the ocean floor to emplace the AMMI barge underwater elevator piles, and installed moors and rock bolts in rock formations for use in stabilizing the support barge pilings.

Problems with the underwater elevator concept began early for Eager. The driving of the underwater elevator piles 17 feet into the sand caused several to fracture and fail due to the sands’ rigidity and surging action caused by ocean swells. Undeterred, Eager devised a simple solution of swinging the barge 90 degrees to seaward to reduce the surging effects of the swells. Additional piles were fabricated by ACB 2 in Little Creek and shipped out on Jan. 24 for St. John. On Jan. 27, 1969, the divers commenced lowering the habitat into the water. Recalling the event, Eager noted “there was a tendency, even with the winches, for the pontoon to jam up on the piles,” all the while working surrounded by “all kinds of newspapers [reporters]…As we were trying to do it, these people were circling around the launch platform, watching this going down, and we didn’t make it.”

Steelworker 2nd Class Jim Mennucci, one of the select Seabee divers at Tektite, explains that the underwater elevator itself “was straight forward applied engineering,” but “didn’t work reliably because of the free-surface effects on stability when the barge was close to immersion.” Working throughout the night, Eager devised a solution. He placed “one Seabee in a crow’s nest on each of the piles with his winch, and by commanding this thing in very, very tight increments, and very carefully controlling the manifolding, we got it down.”

Floating free, the divers helped move the habitat to the designated research site and carefully winched it to the bottom. A day of adding pig iron ballast completed the anchoring process at 49 feet below sea level. With the habitat anchored, divers worked with Seabees on the support barge to connect all the umbilical cables and install five underwater “safety stations” equipped with air pockets, spare air tanks and telephone communication to the surface at varying distances and locations from the habitat.

With construction completed, Phase III began with the four aquanauts entering the habitat on Feb. 15, 1969, for two months of research and habitation of the ocean floor. The divers and other Seabees of ACB 2 remained active monitoring the life support systems and base camp. Divers and NAVFAC personnel further tested and evaluated load-carrying capabilities of jetted anchors and a Naval Civil Engineering Laboratory underwater Laser Surveying System. Shortly after midnight on April 15, 1969, the aquanauts surfaced and began a 20-hour decompression period, emerging afterward without any ill-effects having established a new world record in extended saturation diving. The recovery of the Tektite habitat and support equipment – Phase IV – commenced on April 16 and was completed on June 10, 1969.


Once on the bottom, Seabee divers stack 20 tons of pig iron ballast to overcome the habitat’s 5,000-pound positive buoyancy. Source: TUHM-VIERS

Looking only at the underwater construction aspect of the $2.5 million Project Tektite I, Eager and his team of divers proved highly successful in the fulfillment of the mission. “We succeeded in everything that we had planned to do,” he proudly declared. Referencing the media attention of Tektite, the commander commented how “we had many prominent visitors from the Cousteaus to National Geographic and the whole works, and got lots of publicity throughout the country. That was helpful because it had some influence on how the command structure at NAVFAC viewed us. It was really important that we didn’t fail.” Under Miller’s careful guidance and with Eager’s thorough planning, the Seabees divers and aquanauts had a perfect safety record throughout Project Tektite I.

The ONR’s summary report of the project praised the divers and the Seabee element of Project Tektite. The report recommended that, “Based on the demonstrated capability of MCB/ACB divers in Tektite I, these personnel should be included in future Navy experimental/research activities where applicable.” On Dec. 10, 1969, NAVFAC requested assignment of one diving officer to the staff of the commander, 21st Naval Construction Regiment (NCR) at Davisville, RI, and one diving officer to the commander, 31st NCR at Port Hueneme, CA, to coordinate and manage a nucleus of Atlantic and Pacific area underwater construction teams, unofficially deemed UCT 1 and UCT 2. Eager and the Seabee divers of UCT 1 undertook additional underwater construction projects in 1970 and 1971 at the Atlantic Undersea Test and Evaluation Center installing underwater sound arrays and underwater cables off Andros Island, Bahamas and Santa Maria Island, Azores, as part of the Azores Fixed Acoustic Range (AFAR).

The successful underwater construction with Project Tektite I, followed by further success with AFAR, crystalized the permanence of Seabee underwater construction capability. Chief of Naval Operations Admiral Elmo R. Zumwalt declared UCT 1 and UCT 2 independent on Nov. 1, 1973, and on Feb. 15, 1974, the Navy commissioned each team with an officer in charge.

Today, the efforts of the 1960s to explore the world’s oceans and develop sustained underwater habitation remains but a footnote in the studies of Cold War naval history. Nevertheless, advances in dive medicine, ocean facilities and underwater technology owe much to the pioneering aquanauts who dared to brave the briny deep. For today’s Navy, the underwater construction teams of the NCF represent more than a mere extension of “Can Do” to beneath the earth’s oceans. Rather, the Seabee men and women who work underwater embody the continuation of a nation’s commitment to the development of its maritime resources and exploration of the Earth’s last frontiers.


A full bin after a hard day’s work underwater. Source: TUHM-VIERS

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