The USS Tennessee was in a precarious situation.
“We were somewhere deep in the middle of the Atlantic Ocean, gearing up to take on the role of the alert boat—the submarine that would launch nuclear warheads if called upon by the president to do so—when things took an unexpected turn,” recalls David Flores, who was an ensign in the U.S. Navy at that time. “A fellow sailor had suffered a severe injury; his potential for internal bleeding was high.”
The sailor needed urgent medical attention that would require the Tennessee to navigate to meet a rescue vessel, surface, and then transfer the sailor into the rescue vessel’s care. But as the upcoming on-alert submarine, the Tennessee had to hold its course. Breaking from that position would jeopardize the entire nuclear posture of the United States.
Communication went back to Kings Bay—the homebase for nuclear-armed submarines in the Atlantic Ocean. Almost immediately, another submarine was ordered to assume alert status. The Tennessee was ordered to alter course and meet a rescue vessel.
“At that moment, I started to grasp the communication, coordination, and time necessary to redirect a submarine,” says Flores, who now works as a manufacturing manager at Los Alamos National Laboratory. “In less than 48 hours, the Tennessee reached the waypoint, surfaced, and transferred the injured sailor to receive medical care. It was then that I truly appreciated the operational capability and flexibility of nuclear submarines.”
Getting his sea legs
As a high school student in Riverside, California, Flores was looking for a way to pay for college. A military recruiter encouraged Flores to apply for an ROTC scholarship, which would allow him to attend college and then commission into the U.S. Navy as an officer. Flores qualified for the scholarship and enrolled at the University of California, Los Angeles, intent on becoming a submarine officer.
After graduation, Flores was sent to the Naval Nuclear Power School in Charleston, South Carolina. There, officers are taught how to operate the nuclear reactors that power some of the Navy’s submarines. After a year of training, Flores was certified to operate the nuclear propulsion system used by Ohio-class submarines and was assigned to the gold crew aboard the USS Tennessee. (Each submarine has two crews—gold and blue—that alternate operating submarine patrols.) Flores started as a chemical and radiological controls officer, monitoring the nuclear reactor plant chemistry to ensure the nuclear propulsion system was operating properly. He also performed radiological work, including taking the dosimetry (radiation levels) of every sailor onboard.
During his seven years of active duty, Flores went on to work as a damage control assistant, a tactical systems officer, and a quality assurance officer. “Of those positions, I really enjoyed being a tactical systems officer,” Flores says. “In that role, I trained junior officers to drive the ship, read the combat control system, and navigate while submerged.” In fact, Flores enjoyed teaching so much that, after his active deployments ended, he worked at Kings Bay for two years as an instructor, training sailors and junior officers.
Boomers
Nuclear-armed Ohio-class submarines, which are often called boomers, currently serve as the sea-based arm of the nuclear triad, the three-pronged structure of U.S. nuclear armaments composed of land-launched intercontinental ballistic missiles, air-delivered bombs and missiles, and submarine-launched ballistic missiles. Submarines are considered the most survivable arm of the triad, meaning that if a nuclear strike is ever launched against the United States, submarines will likely be unharmed and capable of striking back.
Of the nation’s 18 Ohio-class submarines, 14 are denoted as SSBNs (SS for submarine, N for nuclear propulsion, and B for ballistic missiles), which means they are nuclear-armed. Six of these SSBNs submarines are based out of Kings Bay, in Georgia, and eight are based out of Naval Base Kitsap, in Washington state. Each boat carries 20 missiles topped with Los Alamos–designed W76 or W88 warheads.
Ohio-class submarines were designed to last 30 years. The first one—the USS Ohio—entered service in 1981. The newest boat—the USS Louisiana—entered service in 1997. Through maintenance and upgrades, the lifetimes of all boats have been extended to 42 years, but some submarines are already up against that limit. Flores’ boat, the Tennessee, will turn 36 years old in 2024. “The Ohio-class submarines, having been extended in life, have longer maintenance periods,” he says. “Things break a lot more often.”
Life on patrol
Patrols—the periods of time when a boat is at sea—are often planned out years in advance, creating predictable and routine cycles for sailors. Typically, each patrol is three months, but as Ohio-class submarines show more and more signs of aging, patrol lengths have started to vary. Some ships are forced into port early when things break, while others have their patrols extended if ships in port require longer maintenance periods.
According to Flores, the first week of a patrol is chaotic. The crew is getting reacquainted with snug living conditions while also wrapping up maintenance tasks left over from the previous patrol. All the while, the ship’s navigators are steering farther from shore to deeper water.
After the first week, a routine takes hold, and sailors get as comfortable as they can be in a 560-foot-long submerged metal tube. The ultimate source of comfort is a sailor’s bed, or rack. “It is very, very important to customize your rack and create whatever you need to make your piece of home,” Flores says. “I would bring in half of a queen memory foam topper, 900-count sheets, a memory foam pillow, and I thought I had a really comfortable rack until I found out that other people get even more creative. People were installing televisions and video games, fitting things in every crevice and corner of their racks.”
Flores explains that “your rack is your sanctuary. Disturbing people is called racking someone out, and we try to avoid racking out as much as possible because it can potentially ruin the only alone time the sailor may have that day.”
Without any windows and very limited contact with the outside world, the passage of time is largely dictated by routines. On submarines, everything is built around a 24-hour schedule where submariners have 8 hours on watch, 8 hours for administrative duties, and 8 hours to sleep. The 24-hour schedule was implemented in 2014.
Submarines used to operate on an 18-hour schedule where each shift lasted 6 hours instead of 8. “That was terrible for sleep,” Flores admits.
Another facet of life that is vital on submarines is what Flores calls a culture of quiet. So much of a submarine’s stealth, survivability, and threat capability is reliant on silence.
“From the very beginning, the moment we step on a submarine, sound silencing is the number one thing we do,” Flores says. “We do everything we can to keep our own ship noise at a low level.” This means gently closing doors and not dropping toilet seats.
Silence isn’t just a protective shield for submarines, though. It can be crucial for locating and identifying enemy ships. “We take sound analysis underwater; we look at the environment and at our own ship noise,” Flores explains. “Once we know the trends in the water of how sound propagates, we try to position ourselves in the best place to take advantage of the environment to amplify what we can hear.”
Another factor in stealth is visibility. To reduce visibility, submarines rarely surface during a patrol. Instead, they will come up to periscope depth—just high enough that a periscope can be used to help assess their surroundings. Coming up to periscope depth also allows the submarine to recirculate its atmosphere, release pressure, and get fresh oxygen into the ship before diving deeper again. Flores says the time between coming up to periscope depth typically ranges from several hours to several days, although the ships are capable of enduring longer stretches.
One drawback of maintaining stealth is that submarines are unable to restock supplies without giving away their location. This means the food the crew is eating three months into their patrol is the same food that was loaded onto the ship the day they left port. But Flores says he never had any complaints.
“Extended patrols are creating more proficient warfighters.”
—David Flores
“We had great cooks on the ship; I never had a bad meal,” Flores says. “My favorite was chicken and waffles with Chick-fil-A sauces.”
When a boat returns to port, the crews swap over, and the departing crew relinquishes all authority of the submarine. The departing crew has about a week to relax (and eat whatever they want) before getting back to work. Flores explains that a lot is demanded of sailors while on land. “You’re wearing three hats,” Flores says. “You’re trying to maintain your training, you’re trying to proceed in qualifications and still actively learn, and then you're trying to also plan maintenance and meetings, so once you take back the ship, you can see what can get done in the time before you go out to sea.”
Ready to act
During patrols, the 24-hour schedule is only interrupted by drills and maintenance that requires immediate attention. Sometimes these drills are missile launch drills. These “Wardays” are a way for the crew to test its readiness and response to likely launch scenarios.
When a message is received initiating a launch sequence, Flores says it becomes priority number one. The encrypted messages require two specially trained officers to work together to decode the incoming order. If the order is valid, it is then relayed to the captain who gives concurrence to follow the order.
“It could happen anytime,” Flores says. “So there were times where I’d be asleep, and I’d wake up to an alert going off saying that there was a receipt of a message. I would immediately have to get out of my rack.”
He continues. “The way that these scenarios go is you get one message that briefs a potential issue, then it escalates. You get another message that says to start navigating toward an area. Then you get another message saying this is a potential launch and then a final message to launch. And each of those messages comes throughout the day over a long period of time.”
At any given time, at least three ships are in the Pacific Ocean and three ships are in the Atlantic Ocean. In each hemisphere, one is on-alert and ready to launch. Another ship is mod-alert, meaning if the alert ship is unable to act on launch orders, the mod-alert ship can replace it within 24 hours. The final ship is non-alert and is in standby mode.
During Flores’ time on submarines, he never patrolled beyond the Atlantic Ocean, but he says now, things are starting to change.
“We are seeing kind of a show of force in response to the situation in Ukraine, and we’re also seeing China’s movements around Taiwan,” Flores explains. “We’re showing the capabilities and endurance of our submarines and an ability to not only execute strategic missions, but also show that the crews are proficient, experienced, and able to execute those missions.”
Flores says submarines are traveling to places they haven’t been in a long time—or ever. In October 2022, for example, the USS West Virginia embarked from Kings Bay to Diego Garcia in the Indian Ocean. In May 2023, the USS Maine resurfaced in the Philippine Sea after deploying out of Naval Base Kitsap, a journey of nearly 6,000 miles. In July 2023, the USS Kentucky made a port call to Busan, South Korea.
“I've fallen in love with the mission and what we're doing.” —David Flores
Flores says all crews have been trained to swap over at sea or at these distant bases. This allows the Navy to enact long-range patrols without requiring the crews to overexert themselves. And although much of the reasoning behind the extended patrols is the current geopolitical climate, Flores believes there is another factor. “Longer deployments do create a toll on the personnel, but crews are coming back a lot more proficient,” he says. “When a submarine’s back in port, you really can’t do much besides go to simulators and try to emulate what you see out at sea, so these extended patrols are creating more proficient warfighters.”
Building a more secure future
For decades, the United States Navy has maintained technological superiority over foreign countries with its Ohio-class submarines. Flores says in recent years, that gap has shrunk.
“Foreign countries are improving their combat control systems, their knowledge of the environment, their underwater acoustics, and their ability to operate submarines,” Flores says.
However, starting in 2031, the aging Ohio-class submarines will be replaced with new Columbia-class submarines, which are designed to be in service for 42 years. These boats will each carry 16 missiles topped with W76, W88, and perhaps eventually, W93 warheads. The W93, which is still in the early design phase, is slated for delivery in the mid-2030s, meaning that it will need to be compatible with both Ohio- and Columbia-class submarines.
Flores explains that the reduction in the number of submarines and missiles isn’t necessarily a reduction in force. “There’s not really a concern in terms of strategic readiness because the advancements in the Columbia boats—such as improved combat control systems—means they will still meet the intent of strategic deterrence.”
Fewer boats means fewer crews. Twelve Columbia submarines require a total of 24 crews—that’s compared to 14 Ohio SSBNs with 28 crews. The extra crews will be spread across the other SSBNs or shifted to new nonnuclear-armed fast-attack submarines that are in development. Flores also says the condensation of personnel may help crews that might’ve stretched thin previously.
“The Navy has a problem with retention on submarines,” Flores says. “I think having the extra personnel will actually satisfy and help meet some of the staffing requirements we have because right now we are understaffed.”
The personnel shortage is also a result of the Navy working with a limited talent pool for decades. That’s because until 2010, women were banned from serving on submarines. The Navy started incorporating female officers into crews in 2011, but it took more than a decade before enlisted women served on SSBNs. In 2022, 15 female enlistees completed a strategic patrol aboard the USS Wyoming. That number will likely increase in the coming years, which Flores says can only benefit the entire fleet.
“We are doubling the amount of talent that we can tap into for these submarines,” Flores says. “We were limiting ourselves before, and in a couple of years we’ll be able to have the first female commanding officer of a submarine.”
The inclusion of women on SSBN crews is also shaping the design process of the Columbia-class submarines. Previous iterations were designed with only male sailors in mind, meaning things like dimensions and the placement of controls and operating equipment were based on average male height. The Columbia-class submarines will be the first SSBNs with gender-neutral and more accessible operating systems.
“Now, when you go out on an SSBN, you have to have a step stool for shorter sailors to see on the periscope,” Flores says. “They wouldn’t be able to reach valves or use emergency equipment. The Columbia-class submarines won’t have these issues.”
Beyond integrating the operational systems on the submarines for all people, improvements will also be made to propulsion and combat control systems. According to a 2023 Congressional report, “The Columbia class is to be equipped with an electric-drive propulsion train, as opposed to the mechanical-drive propulsion train used on other Navy submarines. The electric-drive system is expected to be quieter (i.e., stealthier) than a mechanical-drive system.”
A 2022 news release from the U.S. Navy explained that the boat “will feature superior acoustic performance and state-of-the-art sensors to make it the most capable and quiet submarine ever built.”
In short, Flores says, “The Columbia is going to be a game changer.”
Extension of the mission
After leaving the Navy in 2023, Flores began looking for jobs that had a similar national security mission. “It was surprisingly very difficult,” he says. “I wasn’t having any luck, and it got to the point where I was debating going back to school or even staying in the Navy.”
That’s when he met a Los Alamos recruiter at King’s Bay. After one conversation, Flores thought perhaps a career at the Laboratory would allow him to continue serving the nation. In January 2023, he was hired into the Lab’s Power Supply Production group as a manufacturing manager where he helps develop power sources made with plutonium. These radioactive “heat sources” are used in everything from defense programs to NASA spacecraft, such as the Dragonfly rotorcraft that will attempt to land on Titan, Saturn’s largest moon.
“One of my biggest concerns when I left the Navy was leaving that collaborative work environment,” Flores says. “I feel I have that here. I’ve fallen in love with the mission and what we’re doing.”
But Flores can’t tear himself away from the Navy completely. He continues to serve his country as a reserve officer. ★
Want more? Listen to a former Los Alamos employee and Naval officer share his experiences on board the USS Nebraska: