“Inactive idle time describes when a [U.S. Navy] attack submarine designated for decommissioning cannot be inducted into a dry dock in a shipyard. As a result, the submarine and its crew must remain pier-side until a shipyard has the capacity in a dry dock to defuel their nuclear reactor.”

That’s a quote from a Government Accountability Office (GAO) report released last Thursday titled, Actions Needed to Address Costly Attack Submarine Maintenance Challenges, which describes lost operational days for the Navy’s 44 nuclear attack submarines (20 Los Angeles class and 24 Virginia class), including those spent awaiting depot maintenance or what’s called active idle time.

The Navy, according to the GAO report, said that as of fiscal year 2025, its 44 attack submarines “provide the United States an asymmetric advantage to gather intelligence undetected and attack enemy targets, among other missions. These capabilities make attack submarines some of the most requested assets by the global combatant commanders.”

However, the GAO found, “Over the last 10 years, the U.S. Navy has lost more than 15,000 operational days due to maintenance delays and idle time on active attack submarines. These delays resulted in an estimated $3.4 billion in costs to sustain crews and submarines that provided no operational capability.”

Along with the inactive idle time illustrated earlier, active idle time is a period when an attack submarine and its crew must remain pier-side because they cannot be taken in by a shipyard for maintenance and are no longer certified to conduct normal underwater operations.

Attack submarines follow the Fleet Response Training Plan which calls for a 12-month training and then a complex certification process that leads to deployment. Deployments are normally six months, although one could be longer, but the result is generally an 18-month cycle.

Thereafter, a nuclear attack sub goes through three or four operational cycles – around six years of operations – before the next major overhaul.

“From fiscal years 2016 through 2025, “ the GAO report said, “the U.S. Navy incurred 8,906 days of active idle time for active attack submarines, hitting its peak in fiscal year 2022 with 1,518 days. Since this peak, the U.S. Navy reduced active idle time to 166 days in fiscal year 2025.”

From fiscal years 2021 through 2025, according to the GAO report, the average depot-level maintenance period was 809 days. “Further, the U.S. Navy only completed about 11 percent of attack submarine depot maintenance on time at the public shipyards, from fiscal years 2016 through 2025,” the GAO report added.

For Los Angeles-class subs, active idle time is costing almost $220,000 per day for the entire group. For the Virginia-class, that figure is more than $237,000 per day.

Los Angeles class attack submarines have an expected life of 30 to 33 years, while the planned life for the newer Virginia class is 33 years.

According to the GAO, only U.S. public naval shipyards -- Portsmouth Naval Shipyard, Norfolk Naval Shipyard, Puget Sound Naval Shipyard, and Pearl Harbor Naval Shipyard -- provide depot maintenance for attack submarines, along with two private shipyards -- General Dynamics Electric Boat at Groton, Connecticut and Huntington Ingalls Industries Newport News Shipbuilding at Newport News, Virginia.

Inactive idle time for older Los Angeles class attack submarines is a growing problem.

This period, when an attack submarine designated for decommissioning cannot be taken into a dry dock in a qualified shipyard, requires that its crew must remain pier-side, according to the GAO report. That’s because “those required to maintain and supervise the nuclear reactor…must wait until a shipyard has the capacity in a dry dock to defuel their nuclear reactor,” the report said.

The decommissioning attack submarines “take limited dry dock space away from the operational fleet,” the GAO said, but added, “For most fiscal years prior [to 2025], one or two attack submarines entered inactive idle time each year. However, without mitigation, the U.S. Navy projects a significant increase of inactive idle time through fiscal year 2030.”

In fact, over the past five fiscal years, the Navy has had seven attack submarines waiting to decommission and has “incurred 2,216 days of idle time resulting in more than $480 million in operating and support costs,” according to the GAO.

“As of January 2026,” the GAO report added, “without mitigation, the U.S. Navy projects that 15 more attack submarines and their crews will enter inactive idle time from fiscal years 2026 through 2030.” That could see the Navy incurring “more than 14,000 days of inactive idle time and $3.1 billion in operating and support costs, according to our [GAO] analysis.”

Perhaps the worst example of inactive idle time, according to the GAO report, is the Los Angeles-class submarine USS Pasadena, which became inactive in January 2025, but is not expected to enter Norfolk Naval Shipyard for decommissioning until November 2028.

During this inactive idle time, which could run nearly four years, the Pasadena remains fully crewed and is being utilized by the Navy as a training platform. The inactive Pasadena has also been used in videos – in November 2024 for a promotional video for the 2024 Army-Navy Game, and in February 2025 for the Netflix TV series The Recruit.

A small group from the Pasadena crew remains on the submarine at all times to monitor security, nuclear reactor status, and safety systems. These crew members sleep in the submarine's cramped quarters during their off-watch hours, while on duty. The remainder of off-duty crew members may live on a tender ship, a submarine base barracks, or at their own off-base homes rather than on the submarine.

According to the GAO, the Navy “has not fully evaluated or established plans for implementing…alternative options for decommissioning attack submarines more efficiently and optimizing shipyard capacity for the operational fleet.”

For example, what about pier-side nuclear reactor defueling of inactive attack submarines which would not require now-limited dry dock space?

According to the GAO, “Navy officials stated pier-side defueling of the Los Angeles-class attack submarine nuclear reactors is not cost effective,” but those “officials were unable to provide documentation of detailed analyses conducted on the feasibility and cost-effectiveness of this option.” However, pier-side defueling is under study when it comes to the new Ohio-class strategic nuclear submarines, according to the GAO.

Another defueling option would be using floating dry docks, which the Navy officials told the GAO “requires additional study.”

Also under study by the Navy is to release a portion of the inactive attack submarine crew back to the operational fleet “over three phases: (1) the first month during system turnover to the public shipyard; (2) the first 6 months when idle conditions begin; and (3) nuclear reactor defueling once a dry dock is available.”

This approach has been used for two out of 18 Los Angeles-class subs set for decommissioning between 2014 and 2025, and, according to Navy officials, only “a limited number of attack submarines are planned to use this construct in the next five years.”

Asked why, “Navy officials cited public shipyard pier capacity constraints,” but again “did not provide documentation on any analyses conducted to reach this conclusion,” according to the GAO.

The Navy is studying whether the service life of two of its attack submarines by shifting, shortening or removing idle times. “As of September 2025, the U.S. Navy projected that it can reduce inactive idle time by 1,715 days for fiscal years 2026 through 2029 for [these] two attack submarines. However, these service life extensions are still pending approval,” the GAO said.

The GAO after this study concluded in its report, “While the U.S. Navy has recently made some progress in reducing attack submarine active idle time, inactive idle time has grown and will continue to grow with the impending wave of Los Angeles-class inactivations over the next 5 years.”

It then recommended the obvious: “The Secretary of the Navy should ensure that the Chief of Naval Operations directs the Naval Sea Systems Command to fully evaluate alternative options for decommissioning attack submarines more efficiently to optimize shipyard capacity for the operational fleet. Such options may include, but are not limited to, defueling outside of dry docks and reducing crewing for attack submarines awaiting decommissioning.”

I agree.

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“During its 11-month deployment [mostly in the Middle East] which ended in May, and was the longest for a[n aircraft] carrier since the Vietnam War, the USS Gerald R. Ford conducted more than 11,000 aircraft carrier launches using electromagnetic catapults, more than carriers with steam [aircraft launching] systems could achieve…But perhaps the biggest benefit of the electromagnetic catapults are their lower cost and lighter personnel requirements. With the Navy running out of operating funds, and retention likely to plummet in the aftermath of the war with Iran, the fleet needs to make the most of every dollar and sailor.”

Writing that opinion piece in The Washington Post last Wednesday was Bryan Clark, a former Navy officer who at one time served as Special Assistant to the Chief of Naval Operations and Director of his Commander’s Action Group. Currently, Clark is a Senior Fellow and Director of the Center for Defense Concepts and Technology at the Hudson Institute.

I am using Clark’s article because it provides information that challenges a recent military step contained in an August 13, President Trump Presidential Memorandum which ordered “the Secretary of War, in consultation with the Secretary of the Navy, shall provide to the President… a plan on the required measures to replace the Electromagnetic Aircraft Launch System and Advanced Weapons Elevators with steam and hydraulic systems for the construction of [aircraft carrier] CVN-81[USS Doris Miller], including timelines and resourcing requirements.”

Electromagnetic catapult systems accelerate aircraft more smoothly and gradually, thus putting less stress on airframes. They also recharge faster than steam catapults which need to pressurize gases and they eliminate the need for boilers and other plumbing equipment needed to create steam.

Trump, who never served in the military, has been obsessed for years with the way that steam propels fighter jets off the decks of carriers and where a carrier’s tower structure or “island” is located.

I will point out, according to former Defense Department officials the Navy designers moved the island from the middle of the carriers to the back of the vessel to make more space for moving jet fighter aircraft around on the flight deck, in order to increase the number of flights or “sorties” that the carrier could generate.

These Trump aircraft carrier views apparently first came to him less than two months after he took office based on a March 2, 2017, tour he had on the then-under-construction USS Gerald Ford being built at the Newport News shipyard in Virginia.

Two months later, in a May 8, 2017 wide-ranging, 100-minute interview over dinner with Time Magazine editors and reporters, Trump at one point apparently brought up his visit to the Gerald Ford at Newport News where he was shown the catapult system for launching aircraft from the deck.

According to TIME, the conversation went, “Sir, this is our digital catapult system…we’re going to this because we wanted to keep up with modern [technology]. I [Trump] said, ‘You don’t use steam anymore for catapult? No sir. I [Trump] said, Ah, how is it working? Sir, not good. Not good. Doesn’t have the power. You know the steam is just brutal. You see that sucker going and steam’s going all over the place, there’s planes thrown in the air.’”

The TIME transcript then has Trump saying, “It sounded bad to me. Digital. They have digital. What is digital? And it’s very complicated, you have to be Albert Einstein to figure it out. And I [Trump] said -- and now they want to buy more aircraft carriers. I [Trump] said what system are you going to buy -- Sir, we’re staying with digital. I [Trump] said no you’re not. You going to goddamned steam, the digital costs hundreds of millions of dollars more money and it’s no good.”

I should note, at the time Trump visited and for months thereafter, there were issues with ghe new electromagnetic catapults, but fixes were made, although not in Trump’s mind.

Before I continue with Trump, let’s turn back to Heritage’s Bryan Clark, a real Navy expert, who wrote, “The biggest benefit of the electromagnetic catapults are their lower cost and lighter personnel requirements.”

Clark also noted, “The Ford’s crew is about 500 sailors smaller than its predecessors, largely because it is an all-electric ship outside of the engine room. Because they needed steam for catapults, older carriers also used steam for a variety of other functions throughout the ship — such as cooking equipment and water purification…And the steam catapults have so many moving parts and failure modes that they require about 10 more sailors per catapult — there are four catapults on a modern carrier — than electromagnetic systems.”

A Navy February press release said preliminary reports from the Sortie Generation Rate test program for aircraft show that the flight deck design in conjunction with electromagnetic systems and arresting gear “have contributed to an increased sortie generation rate compared to that of a Nimitz-class carrier.”

However, Trump over the years has kept calling for a return to steam catapults and retelling the story of his 2017 visit to the Gerald Ford.

For example, at a November 2, 2023 campaign rally in Houston, Texas, Trump was talking about shipbuilding and veered off to tell about a ship that was “in trouble” because “it was $10 billion over budget, and I wanted to go and see this ship that was costing so much money.”

At that Houston rally, Trump went on, “And I landed with a helicopter on top of this massive, incredible ship [USS Gerald Ford] being made in Newport News. And I said to the people…I want to meet the catapult people, the people that have done the catapulting.”

Trump continued, “I want to find out what the hell happened because the catapults weren't working. So for 50 years, we used steam more. And that beautiful scene, that steam goes off, and that plane gets thrown the hell off, the power, beautiful, and it's cheap.”

Trump said he asked a catapulter “Which is better, steam or electric? ‘Steam, sir.’ I [Trump] said why did they design electric? ‘Because it can keep going like this all day long, but it takes us 59 seconds to reload a plane. And when we reload the plane, the steam builds up, and it's all set, sir. It's perfect. It works so well. And we can fix it with a blowtorch if something happens. And if a wave hits it, it actually cools us down, sir. We love the waves hitting us. If a wave hits the electric [catapult], we're out of business, sir. We might -- we'll die with this thing.’"

Last July 15, at the U.S. Army War College in Carlisle, Penn., Trump again was talking about shipbuilding and switched saying, “I went to the ship [USS Gerald Ford], because I came into office and the ship was way over budget, built in Newport News, unfortunately, was way over budget.”

Trump went on, “I said, I want to meet the ‘catapultier’ and a man came over, along with four of his assistants. And I said, what's better, electric catapult or steam? He's been there for 25 years. He said, ‘Steam is better, sir. We can fix it with a hammer and a blowtorch. When the electric [catapult] goes bad, I have to send to MIT to get geniuses over here’…But I [Trump] said, so you're saying we spend billions of dollars extra to build electric catapults instead of using steam.”

Bryan Clark concluded his Post article saying, “Steam power was cutting-edge technology in the 19th century. It is the wrong choice for a Pentagon that is leaning into artificial intelligence and autonomous systems. The Navy should stay the course with electromagnetic catapults to keep the carrier fleet strong and deliver more firepower. It could use the savings to help refill the fleet’s weapons magazines.”

Clark told CNN the cost of changing catapults on the USS Doris Miller, already under construction, “will probably be into the billions” and it could delay the carrier — which was expected to be in service around 2034 — “until the end of the next decade.”

Clark also Clark said, “Nobody builds them anymore. There’s no steam catapult manufacturers in the…U.S. anymore so they’d have to restart that production line, which would cost tens of millions of dollars to get going and that’ll be, it’ll take years to start that up again and build the first catapult.”

To add insult to injury, various recent news reports have said Navy senior staffers are reviewing the name USS Doris Miller for CV-81.

Named on January 20, 2020 -- during the Trump first administration -- by then-Acting Navy Secretary Thomas B. Modly during a Martin Luther King, Jr. Day ceremony, it honored African-American Mess Attendant Third Class Doris “Dorie” Miller, who received the Navy Cross for extraordinary heroism during the attack on Pearl Harbor on December 7, 1941, where he manned an anti-aircraft machine gun without prior training and aided wounded crewmates.

In giving the new aircraft carrier Miller’s name, acting-Navy Secretary Modly said, “In selecting this name, we honor the contributions of all our enlisted ranks, past and present, men and women, of every race, religion and background.”

One name said to be under study to replace Miller’s is that of President Trump.

The Cipher Brief is committed to publishing a range of perspectives on national security issues submitted by deeply experienced national security professionals. Opinions expressed are those of the author and do not represent the views or opinions of The Cipher Brief.

Have a perspective to share based on your experience in the national security field? Send it to Editor@thecipherbrief.com for publication consideration.

Read more expert-driven national security insights, perspective and analysis in The Cipher Brief