WASHINGTON — This fiscal year was expected to be the first in which the U.S. Navy dipped into a “trough” in its submarine force, falling below the previous requirement for 48 attack subs and facing two decades of reduced numbers, with as few as 41 at times.

Instead, the Navy is holding steady at 50 and plans to only grow the fleet, thanks to efforts to extend the lives of many aging Los Angeles-class SSNs by about three years each and to refuel five of them altogether for additional years of operations.

Still, the remaining 27 Los Angeles boats will retire by the mid-2030s, putting pressure on the industrial base to continue building at least two Virginia-class attack subs a year, if not more, as the Navy looks to grow the size of its submarine force to its new requirement of 66 to 72 SSNs.

“We are currently forecast to sustain a force of 50 SSNs throughout this decade, and that’s almost a 20% improvement over previous assessments,” Rear Adm. Doug Perry, the director of undersea warfare on the chief of naval operations’ staff (OPNAV N97), said in November at the Naval Submarine League annual conference.

Navy leaders say avoiding this trough — which was previously expected to start when the Navy hit 48 boats in fiscal 2022 and finally end when the submarine force grew to 49 in FY42 — is a testament both to the high-quality design and construction of the Los Angeles-class submarines and sheer luck in finding five unused nuclear reactor cores that could refuel some LA attack subs.

Michael Breslin, an executive director at the Program Executive Office for Attack Submarines, said at the Sub League conference the Los Angeles subs were planned to last for 30 years, but the Navy previously extended the class to 33 years after an engineering effort confirmed the hulls could handle it. Now, he said, the Navy is assessing hull by hull and regularly approving boats in this class for another three years, for a total of 36.

For five boats whose hulls are in good shape but whose nuclear reactors are low on fuel, the Navy will perform engineered refueling overhauls at Portsmouth Naval Shipyard in Maine and replace the reactor cores with the ones sitting unused in storage. This decision was approved in FY21 and helps avoid the trough, Perry said.

But, he noted, in 2016 the Navy upped its requirement to 66 SSNs. The outgoing Trump administration then proposed a goal of 72 to 78 attack subs, and the Biden administration has since settled on a range of 66 to 72 — still far out of reach for the Navy unless something changes.

The Navy’s newest attack submarine, the future Oregon, is christened in a ceremony at Electric Boat in Groton, Conn. (Dana Jensen/The Day via AP)

The industrial base, led by prime contractor General Dynamics Electric Boat and supporting shipbuilder Huntington Ingalls Industries’ Newport News Shipbuilding, has struggled to deliver two Virginia-class attack subs a year on schedule. The two yards each build different portions of the boats and then alternate who performs final assembly and delivery. For boat after boat, the contractors have delivered them to the Navy late.

Each block of Virginias has had successively shorter construction schedules. Block IV, of which only one has been delivered to the Navy so far, was supposed to get down to a 60-month timeline, though the industrial base has not been able to achieve and sustain that pace. The second boat in the block, the future Oregon, has still not delivered despite its schedule previously calling for a fall 2020 delivery date.

Electric Boat President Kevin Graney told Defense News in a Nov. 17 interview construction times today are in the “low 70 [month]s” and that the company is looking module by module for ideas to cut that to 67 or 68 months.

The first Block V with the Virginia Payload Module, the future Arizona, is under construction already. These boats will have an additional mid-body section that holds 28 missiles, helping the Block V Virginias make up for the loss of the retiring guided-missile submarines that provide significant land-attack and surface-ship strike capacity.

Virginia submarine program manager Capt. Todd Weeks said at the Sub League event the industrial base in total puts in about 750,000 man-hours of work on the Block IV Virginia program each year, which will increase to about 1 million man-hours of work in the next two or three years for Block V.

“We are doing some pretty innovative things that are collapsing the schedules back to the left. They had grown excessively, and we’ve been focused on driving them back,” Graney said, noting Electric Boat has put special emphasis on finding efficiencies in the final assembly and test portions.

In general, he said, the company has not done a great job inserting lessons learned into build plans and other documents and has seen significant workforce turnover. The new employees have been good at questioning old processes and suggesting new ones, he said, but successful ideas haven’t always been codified.

Graney said the company is being more diligent about, as simple as it sounds, writing things down to ensure efficiencies are gained from boat to boat.

“We’re not out of the woods by any stretch of the imagination, but I think the continued focus on those things is starting to move the needle in a good way.”

Still, some issues, like the COVID-19 pandemic, remain out of his direct control.

The pandemic is “a drag on the system, it’s slowed us down,” he said, but vaccines and masks have helped ease some of the strain.

Beyond COVID, the yard is struggling to find new recruits who want to work in manufacturing, a challenge across the industry.

With the Columbia-class ballistic missile submarine the Pentagon’s top acquisition priority — and therefore Electric Boat’s top priority — many of the best and most experienced employees are being moved to that project.

“If we’re short people, we’re going to be short people on Virginia,” Graney said.

A Virginia-class submarine under construction on July 24, 2015. The Virginia class is the first U.S. Navy warship designed from the keel up for the full range of mission requirements in the post-Cold War era. (General Dynamics Electric Boat)

And there’s also the broader submarine industrial base.

“The concern I would have would be with the supply base: we’re stretching them. Two Virginia submarines was a stretch from one. Lead ship Columbia has been a stretch. And I think, in order to get into serial production [on Columbia], we’ve got to really increase the volume and the throughput through the supply base,” Graney said.

“Let’s face it, that supply base is brittle,” he added. “Just as we’re teaching the next generation of shipbuilders, every one of our suppliers is teaching the next generation of what it is they do, whether it’s turbine manufacturing or valves and components.”

He noted the Navy and industrial base recently went through the fifth critical supplier review, which showed improvements.

“I would say our critical suppliers are ready today for the work that we have on our plate.” Graney said. “How we extend that to get to serial production on Columbia, I think, is the next hurdle for us to get through.”

Even as Electric Boat and its subcontractors are struggling to get the Virginia program back on schedule, the next challenge is already lurking in the background: the next-generation attack submarine, or SSN(X), that will follow.

Vice Adm. William Houston, the commander of Naval Submarine Forces, said at the Sub League conference “we have to go fast, because our adversaries are not going slow” when it comes to bringing new capabilities to undersea warfare.

“Even at the fastest we go on SSN(X), we won’t have that platform until the early ‘40s. We need to continue to invest in the research and development so we can get SSN(X) because it takes so long, over 12 years of [research and development before construction begins],” Houston said. “But if we don’t have that R&D and we don’t maintain the advantage we have with Virginia, we will lose our undersea advantage.”

Perry added in his remarks that the design work, not just the research and development of SSN(X) sensors, networks and weapons, needs to begin now.

“We know we need to start that work today to make sure we can deliver SSN(X) in time to meet [growing global threats] and without lots of technical and schedule risks,” Perry said. “With Columbia 95% design complete, now is the time to begin transitioning that experienced design team … from Columbia over to the next submarine.”

For Graney, that design work can’t start soon enough. Electric Boat is looking for innovative ways to keep engineers busy, including embedding engineers within Columbia production teams. In that case, the benefit is twofold: the engineers stay gainfully employed, and the shipbuilders building components and modules for the first time can ask questions of designers and do the new work right the first time.

Additionally, Electric Boat has been designing a new seabed warfare module for the Navy, akin to the Virginia Payload module that adds surface strike lethality to the submarine with a mid-body insert. Still, Graney said the new module only keeps some of the engineering workforce employed because the module doesn’t touch the propulsion system and other technical components of the submarine.

“Right now, we’ve got kind of the hot hand coming off of Columbia: we just did it, we’ve got all of those resources coming off. And I think it’s important that we, just like we did coming off of Virginia into Columbia, look at that critical skillset and make sure we’re keeping that skillset well fed,” Graney said. “We’re going to have to leverage the guys who just came off it to really train the next generation of designers and engineers.”