The sea is a wondrous place with
countless stories to tell and even more secrets to reveal within its murky
depths. There are many research submersibles designed to explore the depths
and unlock those secrets – but none have the capabilities offered by the
Navy’s only nuclear-powered deep submergence vessel, NR-1.
Other submersibles operate on
battery power, which restricts their range, limits their time on the sea floor
to approximately eight hours, and requires long periods of recharging on the
surface. NR-1’s nuclear power source frees the boat from those restrictions.
The submarine can travel great distances underwater and remain submerged for
as long as provisions for the crew hold out. With an 11-man crew, NR-1
has been able to stay submerged as long as 30 days.
|Family members of
NR-1’s crew watch
from the historic submarine Nautilus in Groton, Connecticut, as NR-1
transits down the Thames River towed by the Chouest.
NR-1 was to put all these
capabilities to the test this summer as they departed Naval Submarine Base New
London in Groton, Connecticut on 11 June, under tow by the Submarine Support
Vessel (SSV) Carolyn Chouest, to conduct ten different missions on the
Atlantic coast and in the Gulf of Mexico. Because the submarine’s average
cruising speed is only 4.5 knots, or about five miles per hour, NR-1 depends
on the Carolyn Chouest to tow it for long-distance transits.
“We did a mixture of scientific
and military missions and were able to get some great data for the Navy and
the scientific community,” said LCDR Dennis McKelvey, NR-1’s
Officer-in-Charge. “Because of our unique ability to go down to 3,000 feet
and look with our cameras and out of our viewing windows at deep-water life
forms and other features on the bottom of the ocean, we were really the only
people who could provide that [service] to a variety of customers this summer.”
The first stop for NR-1 and
its crew was off the coast of New Jersey at the site where the Navy dirigible
USS Akron (ZRS-4) crashed shortly after midnight on 4 April, 1933. Akron
was one of two 6.5 million cubic-foot rigid airships built for the Navy in
Akron, Ohio in the early 1930s. The airships were used for technical
and operational development of new naval aviation concepts and for exploring
the potential of rigid airships as a naval weapon system. Between January and
March 1933, Akron made two trips to the Southeast, visiting Florida,
Cuba, and Panama to explore basing sites in the U.S. fleet’s southern
operating zone. While en route to the New England area, Akron
encountered a violent storm over the New Jersey coast and crashed, tail-first,
into the sea. Only three of the 76 men onboard survived the tragic accident.
NR-1 made a single pass along the wreckage of the airship at a depth of approximately 120 feet, while the crew obtained imagery of the hulk using the submarine’s side-looking
“It was neat to see something of historical significance like that,” McKelvey said. “Akron was really a very technologically advanced weapon system for the Navy at the time.
“We were able to get some very good images of the wreck,” McKelvey continued, “but the visibility was too poor to do very extensive surveys. We saw that the actual ship itself was built of an aluminum alloy called duraluminum and we were able to see some of the girders. They looked like I-beams with holes drilled out of them to make them lighter and still retain their strength.”
NR-1 then continued southward to the Florida Straits, where the crew worked first with scientists from Texas A&M University examining deep-water marine habitats called lithoherms – large carbonate sediment mounds in the Gulf Stream colonized by coral and other deep-sea life forms. Then, in conjunction with the Naval Underwater Systems Center,
NR-1 located two bottom-implanted test packages near a simulated minefield associated with the AUTEC range and brought them to the surface for a failure analysis. Recovering these objects from an area of a square nautical mile took less than four hours.
(above left) NR-1’s
crew used their side-looking sonar to capture this image of the
airship USS Akron (ZRS-4) that crashed off the coast of New
Jersey in 1933.
(above right) MMC(SS) Shawn R. Wolfgong
stares out one of NR-1’s three viewports on the underside of the
submarine. Crewmembers crawl into this narrow area to stand a six-hour
watch lying down. The watchstanders look out for anything sonars may
not pick up that could present a hazard to the submarine. This section
of the boat can hold no more than three people at a time.
“After that, we got to have a much-enjoyed port visit in Pensacola, Florida, which was great,” McKelvey said. “There was a lot to do down there, and Florida in the summertime is certainly a nice place to be.”
NR-1 spent approximately five days in Pensacola during the first of three port visits to that Navy town before returning to the Gulf of Mexico to survey an underwater test vehicle range now under construction for the Naval Oceanographic Office to test future autonomous underwater vehicle (AUV) technology. This required a side-scan sonar survey over an area of four by four nautical miles to establish “ground truth” when future AUVs are deployed to test their ability to map bottom features such as minefields. During the
NR-1 survey – with RADM Tom Donaldson, Commander Naval Meteorology and Oceanography Command, onboard for part of the mission – the crew found two shipwrecks, cables, several oil pipelines, and an unused well-head.
(right) NR-1 departs Pensacola, Florida, under-tow from the Carolyn Chouest, after enjoying some liberty in the Navy town. During the submarine’s underway period, they made three stops in Pensacola for approximately five to seven days each.
USS Akron (ZRS-4) flying off the Panama Canal Zone 15 March,
NR-1’s next assignment in the Gulf of Mexico was to conduct various marine research surveys for other deep-water corals and life forms. “In the three missions we did involving deep-water biology or geology for the Geochemical Environmental Research Group (GERG), the first thing we were looking for is called
Lophelia Pertusa, which grows in deep water, greater than 1,500 feet, and looks a lot like other fan corals,” McKelvey said. “They’re looking at how broadly these corals are distributed in the Gulf of Mexico, at what depths, and what exactly supports them.”
These particular organisms had the potential to lead the scientists and crew aboard
NR-1 to gas and oil pockets in the sea floor.
“Few people recognize how much gas and oil naturally leaks into the ocean from the deep water of the Gulf of Mexico,” said Dr. Roger Sassen, a research scientist, adjunct professor of geology and geophysics at Texas A&M University, and undersea explorer on
NR-1 during the submarine’s summer underway period. “In the Gulf of Mexico, life appears to have adapted to the presence of gas and oil, and unique sea floor communities occur near the natural gas vents and gas hydrates. I could see tube worms, mussels, corals and other unusual life forms that colonize oases on the sea floor near gas hydrate deposits.”
Sassen’s role aboard NR-1 was to follow up on a recent gas hydrate discovery approximately 60 miles off the coast of Louisiana in about 3,000 feet of water. Gas hydrate is a crystalline substance that forms naturally under the high pressures and low temperatures of the deep sea floor.
“The gas hydrate is generally white to bright orange in color, so it’s easy to see in contrast to the gray colored mud of the sea floor,” Sassen said. “Gas hydrate could be a future energy mineral. If it’s collected at the sea floor, and then allowed to decompose at the surface, its gas volume expands by a factor of 160. Gas hydrate is found almost everywhere across the Gulf of Mexico in the deep water of the continental slope and in deep water off the U.S. Atlantic and Pacific coasts,” he continued. “It’s thought that there is more energy held in sea-floor gas hydrates than in all conventional reserves of gas, oil and coal. Our country will someday need this new energy source.”
Sassen used NR-1’s side-looking sonars to map the bottom, which he said is usually flat and featureless. “However, the sea floor is irregular and broken up near big gas hydrate accumulations, so likely sites are visible on the sea floor imagery. We found several sites and then went back to look at them through the portholes on the bottom of the submarine,” he continued. “I was able to confirm visually that they were active sites for venting of hydrocarbons to the water, [indicating] areas where gas hydrate was likely to exist.”
On a battery-powered submersible, such extensive exploration would not have been possible due to limited power reserves.
NR-1’s range and endurance vastly surpass the capabilities of other submersibles, and that proved to be an invaluable advantage for Sassen and the Texas A&M research team.
“If I did not have the services of NR-1, my particular mission could not have been done,” Sassen said.
“NR-1 provides a unique perspective on ocean exploration. The submarine can cover large areas on the bottom and gather important scientific data 24 hours a day. The officers and crew are totally professional, and the research is excellent. There is no other research submarine anywhere with that immensely useful
The research conducted by Sassen and the other scientists also proved to be a valuable educational experience for
NR-1’s crew. “We saw some interesting geological features and learned a lot about the actual geology of the Gulf of Mexico from all the scientists aboard
NR-1,” LCDR McKelvey noted. “One feature [we saw] was called a brine pool. It’s a depression in the bottom where [there are] local concentrations of brine. There’s a lot of salt underneath the bottom of the Gulf of Mexico, and it actually seeps up near the bottom and you get a brine pool. It almost looked like a pool of dry ice in the bottom when we approached it.”
While still in the Gulf of Mexico, NR-1 got a look at another sunken wreck – a 65-foot long wooden-hulled sailing vessel dating back approximately to the 1820s.
NR-1 surveyed the wreck and a pipeline that was constructed on top of it at a depth of 2,650 feet for the Minerals Management Office of the
Department of the Interior.
Robert Hanna, NR-1’s Executive Officer, sits at the Officer of the
Deck position on the submarine. The Executive Officer and the Engineer
Officer alternate at this station in six-hour rotations.
“After the pipeline got laid, they were doing their post-survey, and they discovered they had laid it over the top of the shipwreck,” McKelvey said. “Our main objective was to photo-document the wreck, do a photo mosaic and [obtain] some side looking sonar images.”
To obtain their images, the crew used a capability unique to NR-1. The submarine is equipped with two retractable rubber-tired bottoming wheels. The wheels allow the platform to set down on the sea floor and drive around the bottom.
“We drove up to [the wreck], and with our cameras we were able to zoom in to where the head of a nail was two or three inches across our video screens,” McKelvey noted. “We just sat there and did extensive video surveys of the condition of the wreck so that scientists and archeologists can go back, study it, and try to determine the details of its construction.”
NR-1’s crew collected between 75 and 90 hours of photo-documentation. But even as they performed a mission similar to many they had done before, they still felt a sense of astonishment
at the display before them.
“It’s a once in a lifetime experience to see this stuff,” McKelvey said. “You sit down there and look at the
ship and you [imagine] that sometime in the past that ship was out working and sailing in the oceans, people were walking and eating on the decks and being jolly
like you see in the movies. You’re just in awe that this was a working ship seven or eight lifetimes ago and you’re one of the first people to look at it.”
As NR-1 completed all its assignments in the Gulf of Mexico and started home with the help of the Carolyn Chouest, the Texas A&M scientists reflected on how they had met the objectives they set before the underway period.
(above) Crewmembers crowd around the sail of the submarine
NR-1 as the tug C-Tractor 6
eases her into her berth at Naval Submarine Base New London in Groton, Connecticut.
(left) MM1(SS/DV) David Krug was the first Sailor to disembark NR-1 and to receive the
traditional first kiss after the submarine returned to her homeport. Krug’s wife Allison
waited with several other family members for their loved ones to come home after a
three-month underway period to the Gulf of Mexico.
“My scientific mission was a success, because NR-1 was able to record sea floor imagery over such a large area in direct support of my objectives,” Sassen said. “The submarine is the best vehicle I’ve used for covering a lot of territory. I felt a personal bond with everyone onboard, and I’m certainly looking forward to doing another cruise with the NR-1 when it [returns] to the Gulf of Mexico.”
Before returning to Connecticut, NR-1 stopped off Norfolk, Virginia for two more tasks. The first was a survey of another underwater test and training range for the Naval Oceanographic Office. Developed in 1988-89 by arraying 100 separate training targets on the ocean bottom, the range occupies an area of four by ten nautical miles and had to be re-surveyed to determine the condition and location of the test objects, many of which had been buried, trawled away, or otherwise destroyed. The mission took seven days.
“There are sonar targets on the bottom of the ocean and we went in, found them, and verified their locations,” McKelvey said. “Since we had the ability to get right down and look at them, we went to all the targets, found them on sonar, visually identified them, took pictures, and brought it all back.”
For their final mission of this underway period, NR-1 and its crew assisted the National Undersea Research Center at the University of Connecticut in looking for additional deep-water habitats, but this time not connected to any oil or gas deposits.
“We were looking for fish and deep-water corals in the Norfolk Canyon, where it starts to drop off
to deep water.” said McKelvey. “The University of Connecticut has done several of these studies
in various canyons up and down the east coast and they wanted to take another look at the
With all of their missions complete, NR-1 and Carolyn Chouest set course for Groton, where family members gathered in the compound to welcome their returning loved ones.
“The missions were a complete success. My crew got some great training and several members earned their deep submergence pins,” McKelvey said. “They found the missions we did this summer to be very satisfying and now they’re all happy to be back home with their families.”
JO1 Savage is a Navy Journalist assigned to Commander, Submarine Group TWO.