Category Archives: Naval ships & systems

Columbia – The Future of the U.S. FBM Submarine Fleet

On 14 December, 2016, the Secretary of the Navy, Ray Mabus, announced that the new class of U.S. fleet ballistic missile (FBM) submarines will be known as the Columbia-class, named after the lead ship, USS Columbia, SSBN-826 and the District of Columbia. Formerly, this submarine class was known simply as the “Ohio Replacement Program”.

USS ColumbiaColumbia-class SSBN. Source: U.S. Navy

There will be 12 Columbia-class SSBNs replacing 14 Ohio-class SSBNs. The Navy has designated this as its top priority program. All of the Columbia-class SSBNs will be built at the General Dynamics Electric Boat shipyard in Groton, CT.

Background – Ohio-class SSBNs

Ohio-class SSBNs make up the current fleet of U.S. FBM submarines, all of which were delivered to the Navy between 1981 and 1997. Here are some key points on the Ohio-class SSBNs:

  • Electric Boat’s FY89 original contract for construction of the lead ship, USS Ohio, was for about $1.1 billion. In 1996, the Navy estimated that constructing the original fleet of 18 Ohio-class SSBNs and outfitting them with the Trident weapons system cost $34.8 billion. That’s an average cost of about $1.9 billion per sub.
  • On average, each SSBN spend 77 days at sea, followed by 35 days in-port for maintenance.
  • Each crew consists of about 155 sailors.
  • The Ohio-class SSBNs will reach the ends of their service lives at a rate of about one per year between 2029 and 2040.

The Ohio SSBN fleet currently is carrying about 50% of the total U.S. active inventory of strategic nuclear warheads on Trident II submarine launched ballistic missiles (SLBMs). In 2018, when the New START nuclear force reduction treaty is fully implemented, the Ohio SSBN fleet will be carrying approximately 70% of that active inventory, increasing the strategic importance of the U.S. SSBN fleet.

It is notable that the Trident II missile initial operating capability (IOC) occurred in March 1990. The Trident D5LE (life-extension) version is expected to remain in service until 2042.

Columbia basic design features

Features of the new Columbia-class SSBN include:

  • 42 year ship operational life
  • Life-of-the-ship reactor core (no refueling)
  • 16 missile tubes vs. 24 on the Ohio-class
  • 43’ (13.1 m) beam vs. 42’ (13 m) on the Ohio-class
  • 560’ (170.7 m) long, same as Ohio-class
  • Slightly higher displacement (likely > 20,000 tons) than the Ohio class
  • Electric drive vs. mechanical drive on the Ohio-class
  • X-stern planes vs. cruciform stern planes on the Ohio-class
  • Accommodations for 155 sailors, same as Ohio

Design collaboration with the UK

The U.S. Navy and the UK’s Royal Navy are collaborating on design features that will be common between the Columbia-class and the UK’s Dreadnought-class SSBNs (formerly named “Successor” class). These features include:

  • Common Missile Compartment (CMC)
  • Common SLBM fire control system

The CMC is being designed as a structural “quad-pack”, with integrated missile tubes and submarine hull section. Each tube measures 86” (2.18 m) in diameter and 36’ (10.97 m) in length and can accommodate a Trident II SLBM, which is the type currently deployed on both the U.S. and UK FBM submarine fleets. In October 2016, General Dynamics received a $101.3 million contract to build the first set of CMCs.

CMC 4-packCMC “quad-pack.” Source: General Dynamics via U.S. Navy

The “Submarine Shaftless Drive” (SDD) concept that the UK is believed to be planning for their Dreadnought SSBN has been examined by the U.S. Navy, but there is no information on the choice of propulsor for the Columbia-class SSBN.

Design & construction cost

In the early 2000s, the Navy kicked off their future SSBN program with a “Material Solution Analysis” phase that included defining initial capabilities and development strategies, analyzing alternatives, and preparing cost estimates. The “Milestone A” decision point reached in 2011 allowed the program to move into the “Technology Maturation & Risk Reduction” phase, which focused on refining capability definitions and developing various strategies and plans needed for later phases. Low-rate initial production and testing of certain subsystems also is permitted in this phase. Work in these two “pre-acquisition” phases is funded from the Navy’s research & development (R&D) budget.

On 4 January 2017, the Navy announced that the Columbia-class submarine program passed its “Milestone B” decision review. The Acquisition Decision Memorandum (ADM) was signed by the Navy’s acquisition chief Frank Kendall. This means that the program legally can move into the Engineering & Manufacturing Development Phase, which is the first of two systems acquisition phases funded from the Navy’s shipbuilding budget. Detailed design is performed in this phase. In parallel, certain continuing technology development / risk reduction tasks are funded from the Navy’s R&D budget.

The Navy’s proposed FY2017 budget for the Columbia SSBN program includes $773.1 million in the shipbuilding budget for the first boat in the class, and $1,091.1 million in the R&D budget.

The total budget for the Columbia SSBN program is a bit elusive. In terms of 2010 dollars, the Navy had estimated that lead ship would cost $10.4 billion ($4.2 billion for detailed design and non-recurring engineering work, plus $6.2 billion for construction) and the 11 follow-on SSBNs will cost $5.2 billion each. Based on these cost estimates, construction of the new fleet of 12 SSBNs would cost $67.6 billion in 2010 dollars. Frank Kendall’s ADM provided a cost estimate in terms of 2017 dollars in which the detailed design and non-recurring engineering work was amortized across the fleet of 12 SSBNs. In this case, the “Average Procurement Unit Cost” was $8 billion per SSBN. The total program cost is expected to be about $100 billion in 2017 dollars for a fleet of 12 SSBNs. There’s quite a bit if inflation between the 2010 estimate and new 2017 estimate, and that doesn’t account for future inflation during the planned construction program that won’t start until 2021 and is expected to continue at a rate of one SSBN authorized per year.

The UK is contributing financially to common portions of the Columbia SSBN program.  I have not yet found a source for details on the UK’s contributions and how they add to the estimate for total program cost.

Operation & support (O&S) cost

The estimated average O&S cost target of each Columbia-class SSBN is $110 million per year in constant FY2010 dollars. For the fleet of 12 SSBNs, that puts the annual total O&S cost at $1.32 billion in constant FY2010 dollars.

Columbia schedule

An updated schedule for Columbia-class SSBN program was not included in the recent Navy announcements. Previously, the Navy identified the following milestones for the lead ship:

  • FY2017: Start advance procurement for lead ship
  • FY2021: Milestone C decision, which will enable the program to move into the Production and Deployment Phase and start construction of the lead ship
  • 2027: Deliver lead ship to the Navy
  • 2031: Lead ship ready to conduct 1st strategic deterrence patrol

Keeping the Columbia-class SSBN construction program on schedule is important to the nation’s, strategic deterrence capability. The first Ohio-class SSBNs are expected start retiring in 2029, two years before the first Columbia-class SSBN is delivered to the fleet. The net result of this poor timing will be a 6 – 7 year decline in the number of U.S. SSBNs from the current level of 14 SSBNs to 10 SSBNs in about 2032. The SSBN fleet will remain at this level for almost a decade while the last Ohio-class SSBNs are retiring and are being replaced one-for-one by new Columbia-class SSBNs. Finally, the U.S. SSBN fleet will reach its authorized level of 12 Columbia-class SSBNs in about 2042. This is about the same time when the Trident D5LE SLBMs arming the entire Columbia-class fleet will need to be replaced by a modern SLBM.

You can see the fleet size projections for all classes of Navy submarines in the following chart. The SSBN fleet is represented by the middle trend line.

Submarines-30-year-plan-2017 copy 2 Source: U.S. Navy 30-year Submarine Shipbuilding Plan 2017

Based on the Navy’s recent poor performance in other major new shipbuilding programs (Ford-class aircraft carrier, Nimitz-class destroyer, Littoral Combat Ship), their ability to meet the projected delivery schedule for the Columbia-class SSBN’s must be regarded with some skepticism. However, the Navy’s Virginia-class attack submarine (SSN) construction program has been performing very well, with some new SSNs being delivered ahead of schedule and below budget. Hopefully, the submarine community can maintain the good record of the Virginia-class SSNs program and deliver a similarly successful, on-time Columbia-class SSBN program.

Additional resources:

For more information, refer to the 25 October 2016 report by the Congressional Research Service, “Navy Columbia Class (Ohio Replacement) Ballistic Missile Submarine (SSBN[X]) Program: Background and Issues for Congress,” which you can download at the following link:

You can read the Navy’s, “Report to Congress on the Annual Long-Range Plan for Construction of Naval Vessels for Fiscal Year 2017,” at the following link:


Large Autonomous Vessels will Revolutionize the U.S. Navy

In this post, I will describe two large autonomous vessels that are likely to revolutionize the way the U.S. Navy operates. The first is the Sea Hunter, sponsored by Defense Advanced Projects Agency (DARPA), and the second is Echo Voyager developed by Boeing.

DARPA Anti-submarine warfare (ASW) Continuous Trail Unmanned Vessel (ACTUV)

ACTUV conceptSource: DARPA

DARPA explains that the program is structured around three primary goals:

  • Demonstrate the performance potential of a surface platform conceived originally as an unmanned vessel.
    • This new design paradigm reduces constraints on conventional naval architecture elements such as layout, accessibility, crew support systems, and reserve buoyancy.
    • The objective is to produce a vessel design that exceeds state-of-the art manned vessel performance for the specified mission at a fraction of the vessel size and cost.
  •  Advance the technology for unmanned maritime system autonomous operation.
    • Enable independently deploying vessels to conduct missions spanning thousands of kilometers of range and months of duration under a sparse remote supervisory control model.
    • This includes autonomous compliance with maritime laws and conventions for safe navigation, autonomous system management for operational reliability, and autonomous interactions with an intelligent adversary.
  • Demonstrate the capability of an ACTUV vessel to use its unique sensor suite to achieve robust, continuous track of the quietest submarine targets over their entire operating envelope.

While DARPA states that ACTUV vessel is intended to detect and trail quiet diesel electric submarines, including air-independent submarines, that are rapidly proliferating among the world’s navies, that detect and track capability also should be effective against quiet nuclear submarines. The ACTUV vessel also will have capabilities to conduct counter-mine missions.

The ACTUV program is consistent with the Department of Defense (DoD) “Third Offset Strategy,” which is intended to maintain U.S. military technical supremacy over the next 20 years in the face of increasing challenges from Russia and China. An “offset strategy” identifies particular technical breakthroughs that can give the U.S. an edge over potential adversaries. In the “Third Offset Strategy”, the priority technologies include:

  • Robotics and autonomous systems: capable of assessing situations and making decisions on their own, without constant human monitoring
  • Miniaturization: enabled by taking the human being out of the weapons system
  • Big data: data fusion, with advanced, automated filtering / processing before human involvement is required.
  • Advanced manufacturing: including composite materials and additive manufacturing (3-D printing) to enable faster design / build processes and to reduce traditionally long supply chains.

You can read more about the “Third Offset Strategy” at the following link:

You also may wish to read my 19 March 2016 post on Arthur C. Clarke’s short story “Superiority.” You can decide for yourself if it relates to the “Third Offset Strategy.”

Leidos (formerly SAIC) is the prime contractor for the ACTUV technology demonstrator vessel, Sea Hunter. In August 2012, Leidos was awarded a contract valued at about $58 million to design, build, and operationally test the vessel.

In 2014, Leidos used a 32-foot (9.8 meter) surrogate vessel to demonstrate the prototype maritime autonomy system designed to control all maneuvering and mission functions of an ACTUV vessel. The first voyage of 35 nautical miles (65.8 km) was conducted in February 2014. A total of 42 days of at-sea demonstrations were conducted to validate the autonomy system.

Sea Hunter is an unarmed 145-ton full load displacement, diesel-powered, twin-screw, 132 foot (40 meters) long, trimaran that is designed to a wide range of sea conditions. It is designed to be operational up to Sea State 5 [moderate waves to 6.6 feet (2 meters) height, winds 17 – 21 knots] and to be survivable in Sea State 7 [rough weather with heavy waves up to 20 feet (6 meters) height]. The vessel is expected to have a range of about 3,850 miles (6,200 km) without maintenance or refueling and be able to deploy on missions lasting 60 – 90 days.

Sea Hunter side view cropSource: DARPA

Raytheon’s Modular Scalable Sonar System (MS3) was selected as the primary search and detection sonar for Sea Hunter. MS3 is a medium frequency sonar that is capable of active and passive search, torpedo detection and alert, and small object avoidance. In the case of Sea Hunter, the sonar array is mounted in a bulbous housing at the end of a fin that extends from the bottom of the hull; looking a bit like a modern, high-performance sailboat’s keel.

Sea Hunter will include sensor technologies to facilitate the correct identification of surface ships and other objects on the sea surface. See my 8 March 2015 post on the use of inverse synthetic aperture radar (ISAR) in such maritime surveillance applications.

During a mission, an ACTUV vessel will not be limited by its own sensor suit. The ACTUV vessel will be linked via satellite to the Navy’s worldwide data network, enabling it to be in constant contact with other resources (i.e., other ships, aircraft, and land bases) and to share data.

Sea Hunter was built at the Vigor Shipyard in Portland, Oregon. Construction price of the Sea Hunter is expected to be in the range from $22 to $23 million. The target price for subsequent vessels is $20 million.

You can view a DARPA time-lapse video of the construction and launch of Sea Hunter at the following link:

Sea Hunter launch 1Source: DARPA

Sea Hunter lauunch 2Source: DARPA

In the above photo, you can see on the bottom of the composite hull, just forward of the propeller shafts, what appears to be a hatch. I’m just speculating, but this may be the location of a retractable sonar housing, which is shown in the first and second pictures, above.

You can get another perspective of the launch and the subsequent preliminary underway trials in the Puget Sound in the DARPA video at the following link:

During the speed run, Sea Hunter reached a top speed of 27 knots. Following the preliminary trials, Sea Hunter was christened on 7 April 2016. Now the vessel starts an operational test phase to be conducted jointly by DARPA and the Office of Naval Research (ONR). This phase is expected to run through September 2018.

DARPA reported that it expects an ACTUV vessel to cost about $15,000 – $20,000 per day to operate. In contrast, a manned destroyer costs about $700,000 per day to operate.

The autonomous ship "Sea Hunter", developed by DARPA, is shown docked in Portland, Oregon before its christening ceremonySource: DARPA

You can find more information on the ACTUV program on the DARPA website at the following link:

If ACTUV is successful in demonstrating the expected search and track capabilities against quiet submarines, it will become the bane of submarine commanders anywhere in the world. Imagine the frustration of a submarine commander who is unable to break the trail of an ACTUV vessel during peacetime. During a period of conflict, an ACTUV vessel may quickly become a target for the submarine being trailed. The Navy’s future conduct of operations may depend on having lots of ACTUV vessels.

Echo Voyager Unmanned Underwater Vehicle (UUV)

Echo Explorer - front quarter viewSource: BoeingEcho Explorer - top openSource: Boeing

Echo Voyager is the third in a family of UUVs developed by Boeing’s Phantom Works. The first two are:

  • Echo Ranger (circa 2002): 18 feet (5.5 meters) long, 5 tons displacement; maximum depth 10,000 feet; maximum mission duration about 28 hours
  • Echo Seeker (circa 2015): 32 feet (9.8 meter) long; maximum depth 20,000 feet; maximum mission duration about 3 days

Both Echo Ranger and Echo Seeker are battery powered and require a supporting surface vessel for launch and recovery at sea and for recharging the batteries. They successfully have demonstrated the ability to conduct a variety of autonomous underwater operations and to navigate safely around obstacles.

Echo Voyager, unveiled by Boeing in Huntington Beach, CA on 10 March 2016, is a much different UUV. It is designed to deploy from a pier, autonomously conduct long-duration, long-distance missions and return by itself to its departure point or some other designated destination. Development of Echo Voyager was self-funded by Boeing.

Echo Voyager is a 50-ton displacement, 51 foot (15.5 meters) long UUV that is capable of diving to a depth of 11,000 feet (3,352 meters). It has a range of about 6,500 nautical miles (12,038 km) and is expected to be capable of autonomous operations for three months or more. The vessel is designed to accommodate various “payload sections” that can extend the length of the vessel up to a maximum of 81 feet (24.7 meters).

You can view a Boeing video on the Echo Voyager at the following link:

The propulsion system is a hybrid diesel-electric rechargeable system. Batteries power the main electric motor, enabling a maximum speed is about 8 knots. Electrically powered auxiliary thrusters can be used to precisely position the vessel at slow speed. When the batteries require recharging,

The propulsion system is a hybrid diesel-electric rechargeable system. Batteries power the main electric motor, enabling a maximum speed is about 8 knots. Electrically powered auxiliary thrusters can be used to precisely position the vessel at slow speed. When the batteries require recharging, Echo Voyager will rise toward the surface, extend a folding mast as shown in the following pictures, and operate the diesel engine with the mast serving as a snorkel. The mast also contains sensors and antennae for communications and satellite navigation.

Echo Explorer - mast extendingSource: screenshot from Boeing video at link aboveEcho Explorer - snorkelingSource: screenshot from Boeing video at link above

The following image, also from the Boeing video, shows deployment of a payload onto the seabed.Echo Explorer - emplacing on seabedSource: screenshot from Boeing video at link above

Sea trials off the California coast are expected in mid-2016.

Boeing currently does not have a military customer for Echo Voyager, but foresees the following missions as being well-suited for this type of UUV:

  • Surface and subsurface intelligence, surveillance, and reconnaissance (ISR)
  • ASW search and barrier patrol
  • Submarine decoy
  • Critical infrastructure protection
  • Mine countermeasures
  • Weapons platform

Boeing also expects civilian applications for Echo Voyager in offshore oil and gas, marine engineering, hydrography and other scientific research.

28 July 2016 update: Sea Hunter ACTUV performance testing

On 1 May 2016, Sea Hunter arrived by barge in San Diego and then started initial performance trial in local waters.

ACTUV in San Diego BaySource: U.S. Navy

You can see a video of Sea Hunter in San Diego Bay at the following link:

On 26 July 2016, Leidos reported that it had completed initial performance trials in San Diego and that the ship met or surpassed all performance objectives for speed, maneuverability, stability, seakeeping, acceleration, deceleration and fuel consumption. These tests were the first milestone in the two-year test schedule.

Leidos indicated that upcoming tests will exercise the ship’s sensors and autonomy suite with the goals of demonstrating maritime collision regulations compliance capability and proof-of-concept for different Navy missions

Spearhead-class Joint High-speed Vessel (JHSV) Provides the Navy with an Express Delivery Service

Along San Diego Bay, you’ll see a great variety of military and civilian vessels. The San Diego Port District has posted a chart on Shelter Island to help tourists and locals identify the more common types of Navy ships that are based here. Occasionally, you might be treated to the sight of an uncommon vessel, such as the catamaran USNS Minninocket (JHSV-3), shown below. This ship is owned and operated for the Navy by the Military Sealift Command.

JHSV-3 pic 1 Source: Author

JHSV-3 pic 2 Source: Author

JHSV ships are fast, modest-sized, non-combatant vessels designed to transport about 600 tons troops and equipment. Their modular design enables rapid reconfiguration of the 20,000-ft2 cargo bay to support various missions. For example, a JHSV vessel can accommodate an Army or Marine Corps company-sized unit (typically 80 – 250 troops) and vehicles, or be reconfigured to transport up to 312 troops.

The vessel has a length of 338′ (103 m), a beam of 93’ 6” (28.5 m), and a draft of 12’ 7” (3.83 m), and a displacement of about 2,400 tons. The catamaran design of the hull and the location of the large cargo deck are evident in the following pictures:

JHSV hull Source: U.S. Navy

JHSV multi view Source: U.S. Navy

Ship propulsion is provided by four 12,200 hp (9.1 MW) diesel engines in the catamaran pods driving waterjets that deliver a maximum speed of about 43 kts. Range is about 1,200 miles at 35 kts. The ship has facilities for one helicopter. As of the FY 2015 budget, 11 JHSVs have been funded.

You can read a summary of this Navy ship program, including the status of resolving FY 2013 and FY 2014 recommendations for improvement and new FY 2015 recommendations, at the following link:

You can watch a short video on this intriguing vessel at the following link:

In 2016, the Navy plans to conduct shipboard tests of the BAE Systems prototype electromagnetic railgun aboard USNS Trenton (JHSV-5), including live firing GPS-guided hyper-velocity projectiles (HVP) at targets 20 miles or more away. While the JHSV is a non-combatant, it was chosen for this test program because of the availability of adequate space in the cargo hold and topside for the prototype weapon system. An artist rendering of the planned railgun installation is shown below.

JHSV railgun Source: U.S. Navy

4 September 2015 update:  Joint High-speed Vessel (JHSV) redesigned Expeditionary Fast Transport (EPF) 

Now there’s a new root designator for U.S. Navy vessels: “E” for “expeditionary support.”

Navy Secretary Ray Mabus and  Adm. Jon Greenert, Chief of Naval Operations,  changed the designations of three kinds of ships to the new expeditionary support category.  The JHSV joint high-speed vessels will become EPF, for expeditionary fast transport.

16 Feb 2016 Update: EPFs require structural upgrades to cope with heavy seas; operational suitability in question

The Navy has contracted for 10 of the shallow-draft Expeditionary Fast Transports (EPFs) from Austal USA, which constructs these ships at its Mobile, AL shipyard. Five EPFs have been delivered and have made deployments to Africa, the Middle East and the Far East. The 6th ship, USNS Brunswick, was just delivered to the Navy on 14 January 2016. Four more ships (EPF-7 to EPF-10) remain to be delivered under the current contract. EPF-11 and -12 have been funded by Congress in the 2015 and 2016 omnibus appropriations bills, but contracts with the Navy remain to be finalized.

Operating as part of the U.S. Navy’s Military Sealift Command, EPFs are intended primarily for use in littoral waters. However, they are expected to be able to make fast open ocean transits and operate with other Navy units in the open ocean.

The lead ship, USNS Spearhead, was damaged in moderate seas while transiting the Atlantic en route to Europe in September 2014. The ship took a significant pounding from wave slamming onto the “forepeak”, which is the bottom of the foremost part of the flat hull section spanning the two catamaran hulls. Repairs to the ship cost about $511,000. The repairs included structural reinforcement of the bow, which added 1,736 pounds to the ship’s weight and displaced about 250 gallons of fuel.

EPF forepeak Source:  U.S. Navy

On 22 September 2015, Michael Gilmore, Director, Operational Test and Evaluation, issued the following report to the Secretary of Defense: Follow-on Operational Test and Evaluation (FOT&E) Report on the Joint High Speed Vessel (JHSV).”

Key points in this report related to the weak bow are:

  • There is a serious problem with the bow structure related to the ship’s Safe Operating Envelope (SOE), which is designed to limit wave impact loads on the bow structure.
    • The Navy accepted compromises in the bow structure during construction of these ships.
    • Multiple ships of the class have suffered damage to the bow structure, and repairs/reinforcements are in progress class-wide.
  • Operating the ship outside of the SOE or encountering a rogue wave that is outside of the current sea state limits can result in sea slam events that cause structural damage to the bow structure of the ship.
  • The SOE operational restrictions are major limitation that must be accounted for in all missions assigned to these ships. The following limits apply:
    • At Sea State 3 or less (significant wave height up to 1.25 meters), the ship may operate up to its maximum speed
    • At Sea State 4 (significant wave height up to 2.5 meters) the ship must slow to 15 knots.
    • At Sea State 5 (significant wave height up to 4 meters) the ship must slow to 5 knots.
    • Above Sea State 5, the ship can only hold position and await calmer seas.
  • The Navy has spent almost $2.4 million strengthening the bows of the first four vessels delivered since late 2012.
    • The 5th operating ship, the USNS Trenton, will be modified during its next planned shipyard visit.
    • Later EPFs will be modified during construction, before delivery to the Navy.
  • There has been no heavy weather testing yet to verify if the fixes are sufficient.

In addition to the bow structural problems, Michael Gilmore’s report noted that the EPFs have the following significant problems:

  • The EPF cannot effectively inter-operate with a Mobile Landing Platform in the open ocean.
  • Unplanned limitations exist on launching a SEAL Delivery Vehicle (SDV) and associated support boats in the open ocean
  • Operational availability is limited primarily by the poor reliability of the Ship Service Diesel Generators, waterjets, and the Ride Control System (RCS).

You can download Michael Gilmore’s complete report at the following link:….pdf

Short summary articles on these matters are available at the following links to Bloomberg Business and Seapower:


Severe ship damage from very high sea states and rogue waves is always a possibility for ships operating in the open ocean. However, the bow damage experienced by the EPFs operating in the open ocean points to underlying design and operational issues for this type of ship.

For additional commentary on problems associated with bow damage to vessels operating in the open ocean, I refer you to the short video at the following link: