Nuclear submarines

Metal is cut on the first steel plate for the lead boat of the USN’s new Columbia-class SSBN. (Photo: Huntington Ingalls Industries)

A juggling act

The USN is making ready for a once-in-a-generation submarine production run as it juggles both current and future requirements.

Jason Sherman

This summer, the USN’s submarine acquisition enterprise is girding itself for a once-in-a-generation challenge: beginning construction of a new ballistic missile boat while simultaneously cutting in a major upgrade of its attack sub production line and juggling long-term visions across four different submarine classes.

The lodestar for all these efforts is the Tactical Submarine Evolution Plan, what the navy calls a ‘holistic plan’ to maintain the right mix of nuclear-powered attack submarines, conventionally armed Ohio-class boats, submarine-launched intercontinental ballistic missile (ICBM) boats and a next-generation attack platform to meet current and future requirements for undersea warfare.

The classified document includes a near-term plan that accounts for needs of the coming decade and a long-term view that considers a 50-year perspective on what is needed to build, train and equip the submarine force of the future to maintain undersea dominance.

Seeking support

This summer, the Pentagon’s acquisition executive is set to consider a navy proposal to proceed with construction of the lead Columbia-class submarine, a replacement for the ageing Ohio-class boats that perform the US military’s undersea nuclear deterrence mission.

The navy is seeking to win support to proceed with building the lead boat as soon as Congress and the president enact an FY2021 defence policy and spending bill. The $127.6 billion Columbia-class programme is the navy’s top acquisition priority, which service officials have said explicitly will be funded at the expense of other projects in any budget pinch.

The programme includes $13 billion for R&D and $114.3 billion for procurement of 12 boats to replace 14 Ohio-class subs that are set to begin retiring at a rate of one per year in FY2027. The planned 12-boat fleet is slated to begin replacing the Ohio class with the first patrol in October 2030.

 

The planned 12-boat fleet is slated to begin replacing the Ohio class with the first patrol in October 2030.

 

The Columbia design – whose 20,815t displacement, 13m beam and 170m length is centred around integrating and deploying the Trident II D5 life-extended strategic weapon system – is slated to execute the US military’s undersea strategic mission while remaining survivable into the 2080s.

The project includes a joint effort with the UK to develop the Common Missile Compartment (CMC) for the submarine-launched ICBM for its Dreadnought programme, a £31 billion ($41 billion) submarine project to build four boats to replace its ageing Vanguard-class fleet.

The Columbia programme is the third project to build a new strategic missile submarine fleet; the Ohio fleet was built between 1974 and 1991, replacing the Polaris-class fleet that was built between 1958 and 1964.

The new submarine programme includes a number of simultaneous efforts that are rolled up in what the programme office calls the Integrated Enterprise Plan Initiatives, which include discrete efforts to reduce schedule risk through design, construction, material and the supplier base as well as through government-furnished equipment and acquisition. Lastly, the Columbia programme has an effort to identify options to reduce costs across the submarine enterprise.

It is working to reduce risks in the industrial base as well as with government-owned activities, such as the naval foundry and propeller centre. This spring, the navy advised Congress in a report that ‘the programme is proactively managing these risks and is confident it will achieve planned Columbia-class lead ship design, construction, and delivery schedules’.

Construction launch

In June, the navy awarded an $896 million contract modification to Groton, Connecticut-based prime contractor General Dynamics Electric Boat (EB) to continue design work, affordability studies and design support efforts on the new submarine class. The contract modification included a key provision, reflecting extensive negotiations between the navy and EB: a $9.5 billion option to begin construction.

‘That option, if we exercise it, will be the full construction for the first two Columbias,’ USN acquisition executive James ‘Hondo’ Geurts told reporters on 22 June. ‘Immediately, we’ll start into full construction for the first boat.’

The option calls for full construction on the second boat to begin in FY2024 with full-rate production set to begin with the third boat in FY2026 and a new boat annually thereafter. The June contract modification also provides additional UK Strategic Weapon Support System kit manufacturing and effort to support expansion of the domestic missile tube industrial base.

Top priority

In addition, the navy is using the contract modification to bolster the submarine industrial base, which is scaling up to expand production to support two production lines, including a nuclear enterprise that must also support the Gerald R Ford aircraft carrier programme.

The ‘start of the lead submarine construction for the Columbia class, combined with expanding Virginia-class construction, increases the demand for hiring and retaining skilled workers at levels not seen at EB since the 1980s’, company representatives told Congressional auditors last year, according to a 2019 Government Accountability Office (GAO) report. ‘Navy officials express concerns about the risk of adding a large number of new workers, including an influx of inexperienced welders and inspectors.’

EB plans to increase its workfare by 66% over the next decade at Quonset Point, Rhode Island, where individual submarine modules are constructed and by 174% at Groton, Connecticut, where the hulls are outfitted and assembled.

 

🜂 Block V Virginia-class subs will feature the VPM, a 25.6m-long mid-body section with four large-diameter vertical launch tubes. (Image: General Dynamics Electric Boat)

 

EB, which has a current workforce of more than 16,000, says it is investing $1.8 billion to construct and expand its facility to support construction of the Columbia class.

On 12 June, the shipbuilder inked a $544 million contract with AECOM of Los Angeles, California, to complete construction begun last year of the South Yard Assembly Building in Groton – an 18,580m2 building to support the Columbia programme that is a centrepiece of the biggest facility expansion at the Connecticut shipyard in five decades.

The company says it is also expanding and modernising other manufacturing spaces in Groton and building a floating dry dock. ‘General Dynamics Electric Boat continues to make investments – in facilities, in our supply chain and in the next generation of shipbuilders – to support the Columbia class, the navy’s top strategic priority,’ said EB president Kevin Graney.

Design progress

As of September 2019, EB had completed 100% of the basic and functional Columbia design, and the Pentagon’s acquisition executive has set a target that before construction begins, the shipbuilder completes 83% of detailed design. Problems with a new software design tool, however, hampered progress towards that target, GAO revealed in June.

According to the navy, EB increased design staff in an effort to get the project back on track. ‘However, delayed detail designs are impacting material orders, slowing construction progress, and jeopardising the design completion goal,’ according to GAO.

By locking in a high degree of design early in the programme, the navy is hoping to reduce the possibility of facing costly rework from design changes and associated schedule delays to the Columbia-class programme’s 84-month-per-boat plan, an aggressive target.

All but one of nine new systems being developed for Columbia deemed ‘critical’ to the new submarine have now reached an acceptable level of technological maturity to proceed with construction. The ‘stern area system’ remains a ‘four’ on the US government’s one-to-nine technology readiness level (TRL) spectrum; the navy estimates it will be declared TRL 7, meaning a prototype has been demonstrated in a realistic environment, in the spring of 2022.

Columbia’s nuclear reactor, propulsor, propulsor shaft and X-stern planes have all demonstrated TRL 7, while four other technologies – namely, the advanced carbon dioxide removal unit, advanced propulsor bearing, CMC and the integrated power system – are TRL 6, the statutory threshold needed to proceed with construction.

Quality control

Columbia has already encountered some growing pains. In July 2018, the navy revealed that the project encountered significant engineering problems as a result of defective missile tube weldings by subcontractor BWX Technologies. ‘Finding supplier quality issues after you’ve inserted them into final construction is really painful,’ said Geurts.

The navy deliberately began early construction of the CMC including missile tubes and first article quad pack, in anticipation that unforeseen technical challenges might surface and allow for on-time construction on the lead boat. The navy estimated the setback would consume ten months of a total of 23 months built into the plan to develop the compartment and quad pack.

‘I’m proud to say we’ve at least figured out how to solve those problems right now,’ RADM Scott Pappano, programme executive officer for Columbia, told reporters on 22 June. ‘We’ve turned around the industrial base; we’ve got to make sure we stay on cadence right now. The government has accepted 11 completed missile tubes. They’ve tactically outfitted and delivered five of those missile tubes for use on the ship.

‘So, we’re starting to turn the corner on the missile tubes right now. Now, it is all about maintaining cadence and quality as we proceed on. And we do that with much more instructive monitoring of the suppliers, with the government and Electric Boat.’

Modern missile

As the plan for Columbia construction solidifies, the USN is beginning to think about how to arm the new submarine in the early 2040s. The navy is proposing a $700 million, six-year project to define a second life extension of the Trident II D5 submarine-launched ballistic missile to keep the 27-year-old strategic weapon system in service for the life of the new Columbia-class fleet through 2083.

 

🜂 The Trident II D5 missile is undergoing a second life extension effort which will see it equip Columbia-class boats until the 2080s. (Photo: Lockheed Martin)

 

The navy’s FY2021 budget request details a new plan for a series of studies and requirements analyses that would culminate in FY2025 with beginning design of what the service has dubbed the D5LE2, a major follow-on modernisation project to the current D5 life extension meant to keep the submarine-launched ballistic missile operational into the early 2040s.

Marking milestones

The Columbia programme is gearing up as the Virginia-class programme is in its eighth consecutive year of full-rate production, with EB and its partner yard Huntington Ingalls Industries producing two boats annually.

The Virginia class is the USN’s project to modernise its attack submarine fleet, to replace retiring Los Angeles boats and supplement its mini-fleet of three Seawolf class – all three conduct a range of missions, including hunting enemy subs and surface ships, mine warfare, insertion and recovery of SF, as well as ISR.

The USN, which currently has 52 attack boats, has requirements for 66, a fleet target that would not be achieved until 2048. That requirement is subject to change as part of a force structure assessment update due soon. Just as the surface components are experimenting with unmanned technologies, the undersea component is exploring the potential for unmanned submarines.

Near-term Virginia-class milestones include the projected float off of USS Oregon (SSN 793) this summer, with delivery in November 2020. USS Montana (SSN 794) is projected to float off this summer too.

Costly contracts

Last December, the navy executed a $22.2 billion contract award to EB for the Virginia class – a five-year nine-boat acquisition with an option for a tenth – a banner event that marked the largest naval shipbuilding contract in US history.

The total value, when government-furnished equipment is added and a potential additional boat is included, raises the price tag of the package to $34 billion, according to Naval Systems Command spokesperson Bill Couch. ‘Block V Virginia-class submarines provide critical lethality improvements and will enable the navy to continue to modernise the nation’s fast-attack submarine fleet,’ he said.

Eight of the new subs under the December contract will be the latest Virginia Block V variant, which has a longer hull to accommodate the newly designed Virginia Payload Module (VPM). Boats equipped with the VPM are intended to compensate for the expected loss of strike capability when the navy’s four conventionally armed Ohio-class submarines phase out of service beginning in 2026.

The VPM is a 25.6m-long mid-body section composed of four large-diameter vertical launch tubes. These tubes can be used to store land attack cruise missiles and other large-diameter payloads, including unmanned systems; each can house up to seven Tomahawks. Earlier this year, the navy’s FY2021 budget revealed plans to begin incorporating an offensive hypersonic strike weapon, the Intermediate Range Conventional Prompt Strike, for VPM-equipped boats as soon as FY2028.

 

🜂 The USS South Dakota will be used to test classified new acoustic signature reduction technology for the Virginia class. (Photo: USN)

 

In the past, the navy has incurred major cost growth when modifying submarines: an initial $2.4 billion forecast to convert the four-boat SSGN fleet from a strategic to a conventional one eventually grew to $4 billion, a 60% hike; and $887 million in planned modifications to one of the Seawolf boats eventually drove costs up by nearly 40% to $3.3 billion.

The Block V variant will differ from the Block IV version by about 20%, according to Congressional auditors, but at this point, the VPM effort has not breached a cost cap set by Congress.

However, EB’s original plan to largely complete basic VPM designs before beginning construction is now behind schedule. The original target to complete 86% of the VPM design before proceeding construction was adjusted to a 75% goal, a delay due to challenges stemming from a new software design tool, according to the June GAO report.

The navy maintains that having three-quarters of the basic and functional VPM design in hand will be adequate to build the first hull within cost and schedule.

Acoustic superiority

On display outside the leadership offices of the programme executive officer for submarines in the Navy Yard in Washington, DC, is a model of the Severodvinsk – a constant reminder of Russia’s prowess in fielding very quiet submarines.

In 2016, USN leaders revealed a new technology was available to make the Virginia-class boats quieter and that they were launching a project to leap ahead. ‘We think we have found a significant opportunity that acoustic superiority is designed to exploit,’ then RADM Charles Richard, Undersea Warfare Director (N97), told a House panel in July 2016.

This technology initiative – details of which are classified – has been packaged in what the navy calls the South Dakota Insertion Program, a near-term acoustic superiority concept demonstration for the entire Virginia class.

This is set to be installed aboard USS South Dakota (SSN 790) during its post-shakedown availability, currently slated for early 2021, according to navy and industry officials.

This project marks the first significant investment in Virginia-class acoustic capability improvements since initial design of the submarine, which began in August 1992. The navy intends for all Block V boats to include acoustic superiority improvements.

Coming into focus

The USN is also beginning to think about a follow-on to the Virginia class. The FY2021 budget request includes a new project, SSN(X), funded at $1 million annually for early R&D of a faster, stealthier and more torpedo-packed boat than the Virginia. The goal is to develop a new class of attack subs to deal with future threats posed by China and Russia through the end of the century.

‘Unlike the Virginia-class submarine, which was designed for multi-mission dominance in the littoral, SSN(X) will be designed for greater transit speed under increased stealth conditions in all ocean environments, and carry a larger inventory of weapons and diverse payloads,’ states the budget request. ‘The primary goal of the SSN(X) programme element will be to evaluate a broad range of submarine technologies, sensors, and combat system components required to produce an affordable platform which supports these mission requirements,’ the documents continued. How the programme will progress remains to be seen.

 

🜂 Project 955 is set to become the main SSBN type of the Russian Navy. (Photo: Russian MoD)

Resurgent deterrent?

 

The Russian Navy maintains an active fleet of 33 nuclear-powered submarines, assigned to the Pacific and the Northern fleets. Despite limited funding and technical obstacles, Moscow relies heavily on this force, considering it as a primary strategic asset for nuclear deterrence, which is now active at levels last seen in the Cold War years.

Soviet survivors

Most of the boats, however, date from Soviet times. The ballistic missile submarine (SSBN) inventory, for example, consists of six Project 667BDRM Delfin (Delta IV-class) vessels and one Project 667BDR Kalmar (Delta III-class) submarine. All were commissioned between 1982 and 1989 and serve without any major upgrades, carrying 16 R-29P (SS-N-18 Stingray) submarine-launched ballistic missiles (SLBMs).

The SSBN force also includes the lone survivor of the Project 941 Akula (Typhoon-class), TK-208 Dmitry Donskoy. It was used as a long-term testing platform for the new R-30 Bulava (SS-N-32) SLBM and then underwent overhaul between 2018 and 2019 to extend service life and allow it to remain in the active inventory.

At the time of publication, the Russian Navy is operating four new-build Project 955 Borei (Borei-class) SSBNs. Design works were completed during Soviet times and the lead ship, Yury Dolgorukiy, was laid down in November 1996. The construction was heavily delayed, with launch reported in February 2008. The boat was then cycled through protracted trials, with the Bulava SLBM proving the most problematic piece of kit due to its low reliability.

As a result, Yury Dolgorukiy was commissioned with the navy only in January 2013. The following two Project 955 submarines, Alexander Nevsky and Vladimir Monomakh, were laid down in March 2004 and March 2006 respectively. The first was commissioned in December 2013 and the second boat followed suit in December 2014.

The first example of the improved Project 955A class, Knyaz Vladimir, was laid down in July 2012 and commissioned in June 2020.

🜂 Project 855M submarines have been built or ordered to replace the Russian Navy’s seven Oscar II-class boats. (Photo: Russian MoD)

 

Four further Project 955A SSBNs are in construction at present with two more contracted, expected to be laid down by year-end. There are also plans for a new contract covering two more Project 955As, also likely by year-end, to allow Moscow to renew in full its SSBN fleet.

The Russian Navy currently fields a plethora of cruise missile submarine (SSGN) and nuclear attack submarine (SSN) types. The fleet includes seven Project 949A Antey (Oscar II-class) boats, commissioned between 1988 and 1996. Two of these, Irkutsk and Chelyabinsk, are currently undergoing a deep upgrade to be made capable of launching Kalibr (SS-N-27 Sizzler) cruise missiles, P-800 Onyx (SS-N-26 Strobile) anti-ship missiles and the brand-new Tsirkon hypersonic missile, optimised for use against land and sea surface targets.

There are also nine Project 971 SSNs commissioned between 1989 and 1995, augmented by two Project 945A Condor (Sierra II-class) boats, added between 1990 and 1993, and two Project 671RTMK Shtuka (Victor III-class) vessels inducted in 1990 and 1992.

Designated successor

This wide variety of SSGNs and SSNs, a Soviet-era legacy, is set to be replaced by a single type – the Project 885 Yasen (Yasen class). The lead ship was laid down in 1993, but three years later works were interrupted and the hull was placed in deep storage. Its completion resumed only in 2004, with major design improvements compared to the original configuration. Named Severodvinsk, the boat was launched in June 2010 and commissioning took place in June 2014.

Project 885 is 139.5m long with a full displacement of 13,800t, while its underwater speed is 35kt and it can accommodate a crew of 90. Power is supplied by a single nuclear reactor rated at 190MW. Its armament is represented by ten 533mm torpedo launchers and the boat can take on board up to 40 Kalibr or 32 Onyx missiles.

Project 885, however, proved prohibitively expensive, which precluded its launch into mass production. To reduce costs, the Project 955M derivative is 10m shorter than its predecessor, with armament consisting of eight 533mm torpedo launchers but an increased number of missile silos – 50 Kalibr or 40 Onyx. Increasing onboard automation, meanwhile, enables the crew to be reduced to 64.

All these measures resulted in an estimated price reduction of 15-20%, while the vessel’s overall combat capability is more or less unchanged. Nevertheless, Project 855M boats remain expensive, believed to be priced at between $800 million and $1 billion a unit. In addition to the first submarine of this project – Kazan, laid out in July 2009, launched in March 2017 and set for commissioning in the near future – the Russian Navy plans to procure seven more, to replace the existing elderly Oscar II SSGNs. In contrast, the current SSNs are set to be cycled through upgrade and life extension, with their replacement postponed until the 2030s.

By Alexander Mladenov and Krassimir Grozev