Tag Archives: submarine

Time to Re-Task, Downsize, and Re-Engineer the SSN, Part II

Read Part One here.

By Duane J. Truitt

As discussed in Part I, it is clear that NAVSEA needs to undertake a project now to completely re-engineer the next generation of SSNs. The old bloated SSN(X) (now “New SSN”) concept should be rejected entirely because it is more of the same, but bigger and more expensive. Instead, the Navy should go for a new class of SSN that is far smaller and cheaper than the current Block 5 Virginias. 

The key components of a reimagined, redesigned “compact” SSN include four major changes from existing SSN designs. Namely, it can refocus the SSN and its systems on its original roles of anti-shipping and ISR, eliminating the vertical launch tubes and enhancing the horizontal launch tube systems. It can re-engineer the nuclear power plants to result in power plants that are safer, simpler, more compact, and cheaper to build and operate. It can also re-engineer the rest of the SSN systems to increase automation, optimize crew work processes, and to reduce the total required ship’s complement. Finally, it can modernize and revise the SSN’s weapons system to provide a wider range of weapons capability and increase the number of warshots deployable in a compact hull form

The net result of the proposed changes should be a more effective, more capable, yet smaller and cheaper SSN that the U.S. Navy can afford to build and operate in numbers sufficient to meet existing and growing near-peer naval challenges of the mid-21st century. Such a submarine would be expected to displace well under 5,000 tons.

In recognition that major ship class redesigns with “great leap forward” technology improvements carry additional development risk and incur longer development timeframes, it is good practice for the Navy to pursue these advances in a relatively small block build or in technology insertion increments (as used on the Virginia-class boats).

The proposed Next Gen “New SSN” class should consist of the following minimum of two blocks.

Block I

Set an overall objective for Block I to build a new SSN of not more than 4,500 tons, but less if feasible, and a crew size of not more than 70 officers and sailors, and less if achievable. The design should strive to reduce the volume of operations spaces, engineering spaces, crews’ quarters, storage, and support spaces accordingly. Total construction cost should aim for significantly less than $2 billion each in 2019 dollars. 

The ship should include a new secondary propulsion plant system utilizing hybrid drive – i.e., eliminating the main propulsion turbines and reduction gears, and utilizing only two relatively large turbo-generators with electric drive, as used on the Colombia SSBN class design. This design provides a significant noise reduction and propulsion plant size reduction. It can also consider using a shrouded propulsor with built-in electric motor external to the pressure hull. The new design can include a new reactor plant with next-gen automation and design simplification, as a scaled-down version of the USS Gerald R. Ford A1B plant design.Consider, and develop as available, alternatives to conventional lead acid battery banks for emergency power generation, including use of next-gen hydrogen fuel cells and/or advanced battery technology to increase power availability in event of a prolonged reactor shutdown, and/or to provide enhanced quiet operations for limited periods of time.

The new design should retain the standard 21-inch torpedo tubes for use with heavyweight torpedoes (Mk 48 ADCAP) and submarine launched cruise missiles (i.e., Maritime Tomahawk ASCMs, Naval Strike Missiles, etc.) relevant to surface ship attack. It should also add new 13-inch torpedo tubes to deploy Mk 46/54 lightweight torpedoes relevant to ASW. This will result in an overall increase in the number of warshots that a submarine can carry per unit hull volume. The design should also include next generation torpedo defenses including both towed passive softkill systems and hardkill kinetic weapons with respective launch tubes, as already in use on surface combatants.

Eliminate the vertical launch tubes. For those who say the Navy still cannot afford to give up the deep strike land attack mission (because of now-obsolete fears of naval irrelevance in 21st century warfare), we still have all of the existing Virginia-class boats that already have been delivered, and those that have already been ordered, including those Block 5s with VPM – which still provide a robust deep strike land attack capability in the SSN fleet today and for the next 40 years. If it is really thought necessary that the Navy provide the deep strike land attack capability from submarines, then build new SSGNs to provide that capability starting in the early 2030s as the existing SSGNs retire– that mission, however, does not require SSNs as platforms. If there is any resulting temporary “gap” in needed launchers it may be filled with surface warships and aircraft.

To be ready for unmanned systems and networked warfighting capabilities the new design should account for modularity and open architecture in submarine system interfaces (communications and combat data management systems) to enable effective networking with off-ship platforms including unmanned undersea vessels (UUV), unmanned surface vessels (USV), and aircraft, both manned and unmanned. Submarine systems must be interoperable within the evolving architecture of Naval Integrated Fire Control – Counter Air (NIFC-CA) and Cooperative Engagement Capability (CEC), and be flexible within the Navy’s Distributed Maritime Operations (DMO) doctrine.

Block 2 – Next-Gen Reactor Plant Technology Insertion

While developing and building the Block 1 new SSN, the Navy can launch a new reactor design program to adapt a generation four reactor plant to provide numerous advantages for naval submarine power over current technology pressurized water reactor (PWR) plants. Perhaps the most likely candidate is a molten salt reactor (MSR)2, which is part of the current crop of commercial generation four reactor plants already under development in the U.S. and elsewhere including the People’s Republic of China. Liquid MSR technology, in experimental reactor use since the 1960s, has several advantages over PWR plants. The reactor does not have a solid “core” that requires replacement in order to refuel the reactor, and the reactor can be refueled at will during regular maintenance availabilities. It also does not require cutting open the pressure hull or making other intrusive openings to the plant to “gas up.”  This design still delivers extremely long endurance between refueling operations, and results in a significant reduction in hull lifetime operating cost. It also provides extended hull operating lifetime without enlarging the hull to accommodate a larger reactor plant needed to yield a life-of-ship reactor.

MSR reactors are intrinsically safe unlike PWRs (there is no meltdown risk because the reactor itself, along with its fuel, is already molten), thus significantly reducing the safety requirements and operating limitations necessary with PWRs. MSR reactors also operate at one atmosphere of pressure, eliminating the need for very heavy steel reactor pressure vessels and primary coolant system components, thus significantly reducing the weight and size of the nuclear power plant. This greatly reduces the effects of thermal stress due to rapid cooldown associated with thickly walled steel pressure vessels.

MSR reactors operate at far higher temperatures than PWRs, thus allowing the use of more efficient high temperature steam secondary plants, reducing both the size and weight of the secondary plant. This also yields a much higher overall thermal efficiency for the entire power plant, meaning that a MSR plant of a given capacity in MW thermal power (MWt) produces the same motive power as a much larger PWR plant. 

MSR reactors do not need high speed main coolant pumps as do PWRs, hence are intrinsically quieter than today’s submarine power plants. MSR reactors can use a wide variety of cheaper and more widely available reactor fissionable fuels, including, amazingly enough, spent fuel from conventional PWRs, lower enriched uranium fuel, depleted uranium, and thorium. When the MSR fuel is completely spent and discarded as waste, it is far less radioactive over far shorter decay timeframes than spent fuel from conventional PWRs.

Overall, MSR reactors are significantly safer, smaller, lighter, simpler, more efficient, and cheaper than PWRs – all of which will contribute significantly to reducing the size and cost (both construction, and operating) of next gen SSNs. The end result of a successful integration of MSR technology into SSNs will be a much more compact, simplified, and capable sub in addition to being much less costly to build and operate. 

This investment in a new nuclear propulsion technology approach will undoubtedly generate lots of pushback.  People, including professionals, find comfort with the familiar, and more people than not simply dislike change because it creates uncertainty. However, nuclear propulsion itself was perceived as a big threat to the status quo by many senior leaders in the fleet and at Pentagon in the late 1940s and 1950s when Admiral Rickover upset their apple carts. Rickover managed to keep his program operational and funded by going over the heads of the senior uniforms, and cultivated “protection” from the senior uniforms via senior members of Congress who controlled naval budgets and authorizations for ship construction.

Rickover actually considered several alternative technology approaches before finally settling on a single approach via PWRs. His team developed a liquid sodium cooled reactor plant, or “Liquid Metal Fast Reactor” (LMFR) first as a prototype (S1G) in West Milton, New York, and then installed the reactor (S2G)  in a SSN, the USS Seawolf (SSN-575).  These liquid metal reactor plants enjoyed several but not all of the same advantages listed above for MSR plants, but also suffered significant limitations particular to liquid sodium that are not issues with MSR plants, including a tendency to leak, and the fire hazard presented by such leaks of liquid sodium metal. This reactor design was abandoned in 1956, and the liquid sodium reactor in Seawolf was later replaced with a PWR reactor. But today’s fourth generation MSR technology is both very different from and more advanced than that used in the early liquid sodium plants.

It is clearly time for Naval Reactors to give MSRs a very hard look, including designing, building, and operating a prototype. If it works out well, then design one into the second or a subsequent block of the new SSN submarines, likely by the late 2020s to early 2030s.  It would likely result in a smaller displacement hull with greater capability, quieter, and lower cost to build and operate than those based on traditional PWR propulsion technology. Even if MSRs are not able to deliver all that is expected, there are other fourth generation reactor technologies that may be feasible.  Even a next generation LMFR may be worth reconsideration, given what we know now that Admiral Rickover and his team at Naval Reactors did not know in the mid-1950s.

Conclusion

This block development approach to a new SSN, a next generation of smaller, more capable, and far cheaper to build and operate SSNs, will lead the U.S. Navy to building a numerically larger yet more capable SSN force. Instead of the age old “capacity vs. capability” argument between opposing sects of naval planners and advocates, the result will be both much more capacity and more capability. The proposed smaller, cheaper, yet more capable sea-control focused attack SSNs will help the U.S. cost-effectively meet the immediate and growing threat of peer naval adversary submarine fleets today and for decades to come.

Mr. Truitt is a veteran Cold War era SSN sailor, qualified nuclear reactor operator, and civilian nuclear test engineer as well as a degreed civil engineer, environmental scientist, and civil/environmental project manager with extensive experience at both naval and civilian nuclear facilities as well as military and civilian facilities development.  His interest today as an author is in forward looking military preparedness and improvements in both capacity and capability of U.S. naval forces.

Endnotes

1. A1B Reactor; https://www.globalsecurity.org/military/systems/ship/systems/a1b.htm

2. Albert J. Juhasz, NASA Glenn Research Center, Cleveland, Ohio 44135; Richard A. Rarick and Rajmohan Rangarajan Cleveland State University, Cleveland, Ohio 44115; “High Efficiency Nuclear Power Plants Using Liquid Fluoride Thorium Reactor Technology; https://ntrs.nasa.gov/search.jsp?R=20090029904 2019-04-02T18:59:43+00:00Z

Featured Image: Virginia-class submarine USS Missouri. (General Dynamics Electric Boat photo courtesy of Edward S. Gray, Secretary, Missouri (SSN-780) Commissioning Committee.)

Time to Re-Task, Downsize, and Re-Engineer the SSN, Part 1

By Duane J. Truitt

The U.S. Navy is faced with several big challenges in maintaining undersea warfare dominance – the domain of the fast attack nuclear submarine or “SSN.”

These challenges include the reemergence of a near peer naval threat that is a direct challenge to the entire U.S. Navy, including our SSN force. The current and growing undersea threat includes both advanced technology attack submarines (including nuclear, diesel-electric, and air independent propulsion variants) with advanced torpedoes and cruise missiles, and much increased numbers of adversary submarines, particularly in the Indo-Pacific theater. Another challenge comes from the rapidly escalating procurement and sustainment costs of ever-larger and more complex U.S. SSNs since the end of the Cold War.

These two challenges have resulted in a very large immediate deficit in U.S. SSN numbers,1 if not capabilities, that is expected to continue for decades. The Navy’s current planned way out seems to be to simply hope for the best, that the funding will materialize to build many more of today’s very large and expensive SSNs. That plan is increasingly seen as unlikely if not impossible given existing serious constraints on U.S. defense spending.

This situation is not unique to the submarine force. The Navy’s overall force structure assessment (FSA) is undergoing a significant revision due for release later this year.2 Navy leaders including outgoing CNO ADM John Richardson and VADM Bill Merz have stated on multiple occasions that the surface fleet is going to evolve with many more small surface combatants, with enhanced capabilities, and many fewer large surface combatants. Admiral Merz stated:

“You may see the evolution over time where frigates start replacing destroyers, the Large Surface Combatant starts replacing destroyers, and in the end, as the destroyers blend away, you’re going to get this healthier mix of small and large surface combatants.”

What is driving this mix to an overall surface fleet weighted toward smaller vessels? Cost. The cost to build, and then the cost to operate and maintain vessels is necessitating this shift from the current generation of surface warships dominated by large surface combatants. The same cost factors also inhibit submarine construction and operations, too. This is in fact a rebalancing in the age-old naval argument of capability versus capacity. The rebalancing is made possible by emerging technologies that allow the Navy to package enhanced capability into smaller hull forms, and to take advantage of new capabilities in cheap yet capable unmanned vessels. Yet today, the U.S. Navy still has no “small subsurface combatant” – just the very large Virginia-class SSNs that are evolving into even larger and more expensive hulls with the Block 5 and subsequent block versions.

The U.S. has relied on its total undersea dominance for nearly three decades since the collapse of the Soviet Union, but that dominance is already fading, and is projected to flip upside down within the next decade. While perversely, due to the projected retirement of the rest of the aging Los Angeles-class SSNs, U.S. submarine forces will continue to fall over the same period, from 51 boats today to a projected 42 within a decade. The principle reason for the inability to build and operate the much larger SSN fleet of 66 subs that the Navy now says it needs is lack of funding. Some suggest that the answer is extending the service lives (SLEPing) of the Los Angeles-class boats, but that is not a practical solution, even in the short term, let alone the long term, since the maintenance burden for very old submarines is much higher than for new vessels. SLEPing old SSNs would only exacerbate the existing near-crisis of maintaining our these SSNs in operable condition.

Some say our small SSN fleet size is also due to a lack of “industrial capacity,” but the ability of the United States of America to ramp up its industrial capacity in times of severe military need is clearly proven in actual U.S. history throughout both World War Two, and during the long Cold War. If the funds to build all the subs that we need are actually made available, American industry will almost certainly respond, and ramp up accordingly, as proven time and time again. Make the construction dollars available on a predictable, multi-year contracting basis, and existing yards will open new lines, and/or new yards will be built, workers trained, and supply chains expanded.

In the 1960s through the mid-1970s there were six U.S. shipyards building SSNs and SSBNs, and in just 13 years of production the yards produced 39 boats, an average of three per year while at the same time producing 31 boats in multiple classes of Polaris and Poseidon SSBNs over just a five-year period. That came to on average of more than nine nuke submarines delivered per year at its peak in the mid-1960s.

As to the dollars needed for an expanded SSN fleet, the current full construction cost of a Virginia-class Block 5 SSN with Virginia Payload Module (VPM) stands at $3.2 billion in 2018 dollars. For comparison, the Sturgeon class-SSNs were built in the late 1960s for approx. $130 million each – in 2019 dollars that would be approximately $726 million – about a fourth of the cost of a Block 5 Virginia boat.

These behemoth Block 5 Virginia SSNs, at approximately 10,000 tons submerged, are more than twice the displacement of Cold War SSNs in the Skipjack-class, Permit-class, and the numerically large Sturgeon-class boats (4,300 tons submerged displacement). And to make matters more challenging, current naval plans for the next generation SSN, now dubbed “New SSN”3 suggest an even larger attack submarine, perhaps 12,000 tons and likely to cost $4 billion to $6 billion or more in 2018 dollars (and not entering the fleet for a decade or more) to build, and similarly expensive to operate. The Seawolf-class of SSNs were of approximately the same displacement, and the very high cost associated with building and operating the Seawolf SSNs encouraged limiting the class of boats to three hulls after the end of the Cold War.

The attack submarine Seawolf (SSN-21) conducts her first at-sea trial operation, following her early morning departure 3 July 1996, from the Naval Submarine Base, Groton, Conn. (General Dynamics photo)

Note that not only does raw displacement drive up the construction cost of a SSN (the rule of thumb is you pay for ships by the ton), but it also drives up the lifetime operating costs of the SSN. Manning a Block 5 Virginia-class SSN with its 42 vertical launch cells requires a crew of approximately 140 officers and sailors, as compared to the  99 officers and sailors of a Sturgeon-class SSN. 

So why are the current class American SSNs so large?

The answer includes land attack – the new mission assigned to SSNs by the Navy in the aftermath of the end of the Cold War, with the virtually overnight disappearance of its main naval adversary, the Soviet Navy. By the early to mid 1990s the U.S. Navy was busy retiring aged-out Cold War boats by the dozens and was still building as replacements the last Los Angeles-class SSNs. These boats were larger than their predecessors, primarily to make them faster and capable of keeping up as escorts with CVN carrier battle groups and later on, carrier strike groups. Such high cruising speeds were not a requirement for anti-shipping warfare (both ASW and anti-surface ship) and ISR – the two primary missions of Cold War era SSNs.

Later on, the more advanced Virginia SSNs – as a smaller, cheaper, and slightly reduced capability version of the small class of Seawolf SSNs – came along by the mid-2000s, adding length, tonnage, and  vertical launch tubes capable of putting up as many as 12 Tomahawk missiles (a similar vertical launch tube arrangement by then had also been added to some of the last Los Angeles-class boats). However, those post-Cold War Tomahawks on SSNs were not, like their Cold War predecessors, equipped to engage moving naval targets as long range anti-ship missiles, but instead were Tomahawk Land Attack Missiles (TLAM), capable only of engaging fixed land targets. The Navy was also busy deploying large numbers of TLAMs on large surface combatants, both Ticonderoga-class cruisers and Arleigh Burke-class destroyers, for the same deep strike land attack mission the Navy had taken on in the 1990s and beyond.

The latest Block 5 Virginias add a new “Virginia Payload Module” that adds yet another 84-foot section to the hull aft of the sail containing four more vertical launchers carrying as many as 28 additional TLAMs for land attack. The stated purpose of the VPM was to attempt to make up for the planned retirement of four SSGNs (converted Ohio-class SSBNs that were “denuclearized” per the START strategic nuclear arms reduction treaty). But of course that conversion of SSBN to SSGN was a “make work” solution for the resulting excess Ohio SSBNs above treaty limits, which has now begat a “make work” mission for SSNs. All of which bloats the boat itself and makes it much more expensive to build and operate.

Adopting the deep strike land attack mission was an understandable response to the drastic and virtually overnight elimination of a significant near peer naval threat in the 1990s. Thus the Navy and its supporters in Congress converted the navy virtually overnight to a deep strike land attack force in order to become more relevant to evolving national security interests, but at the expense of full-spectrum competence. Otherwise, naval leaders and proponents feared an even more drastic fleet reduction than the 50 percent cut that was actually made after the end of the Cold War.

This “keep the Navy relevant in the Post Cold War era” mindset was also aided and abetted by the Intermediate Range Nuclear Forces (INF) Treaty of 1987 limits on “land based” intermediate range cruise missiles (IRCM) that strangely did not apply to “surface launched” (i.e., naval platforms). (Both the U.S. and Russia have now withdrawn from this treaty, effective later this year.) In any event, INF encouraged both the Russian and U.S. navies to deploy large numbers of land attack cruise missiles on surface warships.

Clearly a lot has changed since the Post Cold War-era began. The U.S. military today is no longer simply tasked with combating low-capability insurgent forces in various and sundry developing nations often situated well inland, nor does the INF treaty apply as of this year either.

With the well-documented fast growing maritime threat posed especially by China (whose fleet of attack submarines is currently estimated to number over 70 vessels, and is expected to continue to grow at a rapid rate thereafter), as well as a resurgent Russian Navy, the world of naval warfare has now transformed from a low threat environment into a serious challenge to U.S. naval dominance. The U.S. Navy now has a clear and overriding mission – to deter and if necessary fight and win a naval war against capable near peer forces. Projecting sea power ashore continues as a U.S. Navy mission, but that mission is best and most cost-effectively performed by naval aircraft (both carrier-based and land-based), not by submarines. Given all of the above factors, then, and the fact that naval shipbuilding budgets are constrained, including demands to simultaneously recapitalize aging CVNs and Ohio-class SSBNs, the Navy must go back to the drawing boards.

Chairman of the Joint Chiefs of Staff Adm. Mike Mullen visits the Chinese People’s Liberation Army-Navy submarine Yuan at the Zhoushan Naval Base in China on July 13, 2011. (DoD photo by Mass Communication Specialist 1st Class Chad J. McNeeley/Released)

The Navy should consider designing a new SSN that is smaller and cheaper, and focused entirely on the anti-shipping and ISR roles – the historic roles of the SSN throughout the Cold War – with particular attention paid to building and operating many more new boats at a far faster build rate.

Size as measured in tons displacement, however, is not the only requirement and means of controlling cost – there is also the matter of modernization and capability.  Obviously the technologies available today are far more advanced compared to those available in the 1960s and 1970s when the bulk of our Cold War era SSN fleet was built. For example, the later generations of U.S. submarines incorporated new propulsors – pump jets, rather than the older and noisier seven-bladed open screws on the Cold War era boats. Better sensors are also going into today’s boats, both sonars and “above the water” sensors, with photonic masts rather than periscopes, which allows more efficient interior hull design and better distribution of sensor data to various locations within the crew area. Better electronic warfare capabilities are also part of today’s fleet, and cyber warfare is increasingly a key area of focus in the 21st century.

Better weapons are also available today, although advancements in deployed submarine-launched weaponry have clearly lagged behind both our adversaries and even of USN surface forces and naval air wings in recent years. Existing SSNs are still using the old Mk 48 ADCAP 21-inch torpedo first deployed in the mid-1970s, though significantly upgraded over the decades. But as of today the only submarine-launched anti-ship cruise missile available is still the old Harpoon Block 1C that was developed in the 1970s, and as of today only one of our existing SSNs has even re-integrated the Harpoon, as of last year. A new “Maritime Strike Tomahawk” refit kit is slated to become available in 2021 which will provide a new very long range ASCM capability to both submarines and surface warships with VLS. Perhaps other existing ASCMs such as the new Naval Strike Missile, now slated for deployment on LCS and FFGX, can and may also be integrated onto U.S. submarines, along with LRASM in the coming years.

Additionally, it should also be recognized that for purposes of anti-submarine warfare which was the primary role of the Cold War SSN, and which is now becoming a priority again, the Mk48 ADCAP torpedo is likely “overkill” for use against submerged submarines. The power of a 650 pound warhead on the Mk 48 certainly is helpful for attacking large surface ships, with the ability to literally break a ship in half when detonated under the keel. Submerged submarines, however, do not require such explosive power because of the effect of submergence sea pressure.

The lightweight ASW torpedoes such as the Mk 46 and Mk 54 (12.75 inches diameter by 8 feet 6 inches long, and weighing just 508 pounds vs. 21 inches, 19 feet, and 3,695 pounds respectively for a Mk 48) have for decades been in use by the US Navy and our NATO allies deployed on surface warships and ASW aircraft. The lightweight torpedoes have warheads with weights of slightly less than 100 pounds – demonstrably sufficient to sink a submerged submarine. Indeed, one of the most effective ASW weapons in WWII, the “hedgehog,” had a much smaller warhead of just 35 pounds of TORPEX. It was demonstrated that typically only one or two hedgehog detonations were needed to sink a submerged submarine.

An exercise Mark 54 Mod 0 torpedo is launched from the U.S. Navy Arleigh Burke-class guided-missile destroyer USS Roosevelt (DDG-80). (U.S. Navy Photo by Mass Communication Specialist 2nd Class Justin Wolpert)

Therefore, the Navy needs to give strong consideration to adapting existing lightweight ASW torpedoes to our next generation of SSNs. Doing so would facilitate the ASW capability of our SSNs while significantly increasing the sub’s capacity to store and deploy much smaller torpedoes. Not as a total replacement for the Mk 48, but rather, as a supplement to the Mk 48 to enable much larger total magazine depth without increasing the displacement of the submarine, to accommodate the ability to attack both surface ships and submarines. Instead of just four 21-inch torpedo tubes on a Virginia-class boat, a combination of 21 inch and 13 inch horizontal tubes optimized for a typical mission profile could work very well.

Finally, whatever combination of horizontal tubes and torpedoes is determined optimal, the weapons themselves need to continue to be updated to the latest technological capabilities as to sensors, self-contained computing (and artificial intelligence) as necessary to track and target submarines and defeat enemy countermeasures, and improved warheads. Hard kill anti-torpedo torpedoes as well as other torpedo countermeasures are also a prime area of development that needs to continue, despite a recent setback with the CAT weapon systems deployed on CVNs.

Nuclear propulsion technology is also advanced today over the old Cold War power plants. The latest generation of naval nuclear reactors as used on the new Ford class CVNs known as the A1B reactor are much more automated and simplified than the previous plants, allowing the highly trained and certified nuclear plant operator crew size to be cut in half as compared to the 1960s era reactors of the Nimitz class CVNs.4 Even more revolutionary nuclear power plant designs are going to be available to submarine designers in the next decade.

Similar technological opportunities abound to more heavily automate every work process throughout the next generation submarines, including artificial intelligence capabilities, and thus can significantly reduce overall crew manning requirements in a submarine. This has already been achieved on the latest surface combatants including the Ford CVNs and the Zumwalt DDGs, which respectively achieved overall manning reductions of 33 percent and 50 percent over their predecessor classes. A similar reduction in SSN crew size also ought to be achievable using the same design approaches and modern automation technology. Reductions in crew size also lead to reductions in hull volume.

Additional technology “insertions” are also available in other areas of submarine design that should be able to create significant impacts in both cost reduction as well as improving the capabilities of our next gen SSNs.

Conclusion

In consequence of all of the considerations described above, it is clear that NAVSEA needs to undertake a project to re-engineer the next generation of SSNs. Navy leadership has publicly stated its intent to reconfigure the surface fleet to significantly reduce the ratio of large surface combatants (LSCs) to small surface combatants (SSCs). The Navy now needs to similarly reconfigure the SSN fleet in favor of smaller boats optimized for sea control over long-range land attack. They must reject the bloated SSN(X) concept which is more of the same, but bigger and more expensive, and go for a new class of SSN that is far smaller and cheaper and thus affordable in much larger numbers than currently planned submarines. 

Mr. Truitt is a veteran Cold War-era SSN sailor, qualified nuclear reactor operator, and civilian nuclear test engineer. He is also a degreed civil engineer, environmental scientist, and civil/environmental project manager with extensive experience at both naval and civilian nuclear facilities as well as military and civilian facilities development. His interest today as an author is in forward-looking military preparedness and improvements in both capacity and capability of U.S. naval forces.

Notes

1. USNI News, Ben Werner, March 27, 2019: “Indo-PACOM Commander Says Only Half of Sub Requests are Met”

2. USNI News, Megan Eckstein, April 8, 2019: “Navy Sees No Easy Answer to Balance Future Surface Fleet”.

3. USNI News, Megan Eckstein, May 13, 2019: “Virginia Block VI Subs Will Focus on Special Operations, Unmanned”

4. A1B Reactor; https://www.globalsecurity.org/military/systems/ship/systems/a1b.htm

Featured Image: YOKOSUKA, Japan (Sept. 3, 2010) The Virginia-class attack submarine USS Hawaii (SSN 776) transits Tokyo Bay on the way to Fleet Activities Yokosuka, marking the first time in the history of the U.S. 7th Fleet that a Virginia-class submarine visited the region. This is Hawaii’s first scheduled deployment to the western Pacific Ocean. (U.S. Navy photo by Lt. Lara Bollinger/Released)

The Deep Ocean: Seabed Warfare and the Defense of Undersea Infrastructure, Pt. 2

Read Part One here.

By Bill Glenney

Concepts from the CNO SSG

From 1998 to 2016, the CNO Strategic Studies Group (SSG) consistently recognized and accounted for the challenge of cross-domain maritime warfare, including the deep ocean. The Group generated several operational concepts that would give the Navy significant capabilities for the deep ocean part of the maritime battle.

Vehicles and Systems

Within the body of SSG concepts were reasonably detailed descriptions of a range of unmanned underwater vehicles, undersea sensors, and undersea weapons such as the towed payload modules, extra-large UUVs, logistics packages, and bottom-moored weapons. All would use the seabed and undersea for sensing, attacking, and sustaining in support of maritime forces.

One vehicle worth discussing is the armed UUV for single-sortie obstacle neutralization that would provide the Navy with the capability to counter armed UUVs, or conduct search for and clearance of fixed and mobile mines without the need for local air/surface superiority, or a manned support ship.1 It could plausibly do so at tactical sweep rates higher than today’s MCM forces. This can be achieved well before 2030, yet this capability is something neither the existing nor planned MCM forces can do.

The SSG XXXII concept can be achieved by integrating the following capabilities on the conceptualized extra-large UUV (XLUUV):

  • A synthetic aperture sonar – a capability the Navy had in 2013 
  • Automatic target-recognition software – a capability the Navy was developing
  • A 30 mm cannon that shoots super-cavitating rounds – a capability previously funded but not developed by the Navy

But, instead of focusing on the vehicles, there are two examples of operational-level concepts that exploit these vehicles and systems in recognition of the fact that the deep ocean is a critical yet misunderstood and underutilized part of maritime warfighting. 

Blitz MCM

In 1999, the SSG generated a concept called “Blitz MCM.”2 This work has stood the test of time technically and analytically, but has not been adopted by the Navy. And, while the SSG described it in terms of mine countermeasures, this same approach can be applied to deep ocean warfighting and the defense of undersea infrastructure.

At its most basic level, Blitz MCM resulted from the recognition that sensor performance in the undersea was not going to improve significantly from a tactical perspective over the period of 2000-2030. For clarity, yes, the accuracy of various undersea sensors has improved routinely, providing accuracy down to fractions of a meter and able to produce fairly detailed pictures of objects. But the effective range of these sensors has not and will not dramatically increase, still being measured in hundreds and maybe a thousand yards at best. These short ranges preclude their use as a single sensor when it comes to tactical maneuver in the maritime environment.

The SSG solution was to use large numbers of these individual sensors.

In order to enable the rapid maneuver by maritime forces, the force must be able to conduct in-stride mine reconnaissance and clearance of approach routes and intended areas of operations. In order to avoid lengthy operational pauses to search large areas and neutralize mines or armed UUVs or undersea explosives, Blitz MCM uses relatively autonomous UUVs that rely on sensing technology only moderately advanced beyond that available to the fleet 20 years ago. However, unlike today’s operations where small numbers of mine-hunting vehicles and aircraft are involved, Blitz MCM relies on the deployment of large numbers of unmanned vehicles out ahead of the force to rapidly work through the areas of interest to find, tag, or clear threats. Hundreds of small UUVs can work together as an intelligent swarm to clear thousands of square miles of ocean per day.

In some cases, based on the information provided by the vehicles, alternate approach routes or operating areas would be chosen, and the movements of closing units can be rapidly redirected accordingly. In other cases, the required paths will be cleared with a level of confidence that allows force elements to safely continue through to their intended operating areas.

As illustrated in figure 7, UUV-Ms use conformal, wide-band active/passive sonar arrays, magnetic sensors, electric field sensors, blue-green active/passive lasers, and trace chemical “sniffing” capabilities to detect mines. Onboard automatic target recognition capabilities are essential to the classification and identification effort. Acoustic and laser communications to near-surface relays or seabed fiber-optic gateways maintain connectivity.

Figure 7 – Mine Hunting and Clearance Operations (CNO SSG XIX Final Report)

Unmanned air vehicles are critical in their role as UUV carriers, especially when rapid deployment of UUVs is required across a large space. UCAV-Ms contribute to the effort with their mine-hunting lasers. They also serve as communications gateways from the “swimmer” UUVs to the network.

The UUV-Ms will generally operate in notional minehunting groups of several dozen to over a hundred vehicles. Teams of vehicles will swim in line abreast formations or in echelons with overlapping fields of sonar coverage. Normally they will swim at about 8-10 knots approximately 50 feet above the bottom. Following in trail would be additional UUVs assigned a “linebacker” function to approach closely and examine any suspicious objects detected. Tasking and team coordination will be conducted by the UUVs over acoustic or laser modems. Once a linebacker classifies and identifies a probable mine, its usual protocol will be to report the contact, standoff a short distance, and then send in a self-propelled mine clearing charge to destroy or neutralize the mine. Each UUV-M could carry approximately 16 of these micro-torpedoes. When one linebacker has exhausted its supply, it will automatically trade places with another UUV-M in the hunting team.

Rapid neutralization of mine threats is key to the clearance effort. Today, this dangerous task is often performed by human divers. 

Blitz MCM uses a “leapfrog laydown” of UUV-Ms, as illustrated in Figure 8. Analogous to the manner that sonobuoys are employed in an area for ASW coverage, the force would saturate an area of interest with UUV-Ms to maximize minehunting and clearance capabilities. Once dropped into the water, the UUV-Ms quickly form into echelons and begin their hunting efforts. Navigation and communication nodes will be dropped along with the Hunter UUV-Ms.

Figure 8 – Leapfrog Laydown of UUVs (CNO SSG XIX Final Report)

Large delivery rates will be possible with multiple sorties of UCAV-Ms each dropping two to four UUV-Ms on a single load and then rapidly returning with more. Upon completion of their missions, the Hunter UUV-Ms will be recovered by UCAVs or USVs and returned to the appropriate platforms for refueling, servicing, and re-deployment.

First order analysis indicates that with approximately 150 UUV-Ms in the water and a favorable oceanographic and bottom environment, reconnaissance and clearance rates of about 6,000 to 10,000 square miles per day (a 20-mile wide swath moving at 12-20 knots) should be achievable. This capability is several orders of magnitude over current MCM capabilities.

Naval Warfighting Bases

The SSG XXXII concept called Naval Warfighting Bases3 requires the Navy to think about sea power and undersea dominance in an entirely new way. And this new thinking goes against the grain of culture and training for most naval officers and is unconventional in two ways:

  • First, in Naval Warfighting Bases, forces ashore will have a direct and decisive role in establishing permanent undersea superiority in high interest areas
  • Second, “playing the away game” – the purview of forward deployed naval forces − is not sufficient to establish and sustain undersea dominance at home

As shown in Figure  9, afloat forces – CSGs, ESGs, SAGs, and submarines – do not have the capacity or the capabilities to establish permanent undersea dominance of the waters adjacent to the U.S. homeland and its territories (shown in yellow) and of key maritime choke points (shown with white circles), while simultaneously reacting to multiple crisis spots around the world (shown in red). The Navy must discard its current model of undersea dominance derived solely from mobile, forward deployed at-sea forces and replace it with one that is more inclusive − one that looks beyond just afloat forces. This new model must capitalize on the permanent access the Navy already has from shore-based installations at home and abroad (shown with yellow stars).

Figure 9 – Global Requirements for Undersea Superiority

Naval Warfighting Bases builds on detailed local understanding of the undersea, coupled with the projection of combat power from the land to control the sea; thereby providing permanent undersea dominance to defend undersea critical infrastructure near the homeland, protect major naval bases and ports of interest, and to control strategic chokepoints. Naval Warfighting Bases also provides the critical benefit of freeing up afloat Navy forces for missions only they can conduct.

At home, the U.S. Navy could establish something called an Undersea Defense Identification Zone, akin to the Air Defense Identification Zone, to detect and classify all deep sea contacts prior to their entry into the U.S. exclusive economic zone (EEZ). By enhancing the capabilities of key coastal installations, the Navy will transform each into a Naval Warfighting Base. The base commander will be a warfighter with the responsibility, authority, and capability to establish and maintain permanent undersea superiority out to a nominal range of 300 nautical miles seaward from the base to include the majority of U.S. undersea and maritime critical infrastructure.

Figure 10 – Undersea Defense Identification Zones Provide Permanent Undersea Superiority

Base commanders will have the capability to detect and track large numbers of contacts as small as wave-glider sized UUVs. Each Naval Warfighting Base will have a detachment of forces to actively patrol its sector. Naval Warfighting Base commanders will be able to maintain continuous undersea understanding, enabling control of the deep ocean.

Naval Warfighting Base commanders will also have an integrated set of shore-based and mobile weapons systems with the capability to neutralize adversary undersea systems, such as UUVs, mines, and sensors. Naval Warfighting Base commanders will be capable of disabling or destroying all undersea threats in their sector, employing armed unmanned systems, and employing undersea warfare missiles fired from ashore.

An undersea warfare missile is a tactical concept that combines a missile and a torpedo, similar to modern ASROC missiles. The missile portion would provide the range and speed of response, while the torpedo portion would provide the undersea killing power. Broadly integrating undersea warfare missiles into a variety of platforms would provide a tremendous capability to cover larger areas without having to tap manned aviation or surface assets for weapon delivery. These missiles would provide responsive, high volume, and lethal capabilities. And they could be fired from land installations, submarines, surface combatants, and aircraft.

As practiced today, waterspace management (WSM) and prevention of mutual interference (PMI) result in a highly centralized authority, and extremely tight control and execution for undersea forces. This type of C2 would prevent undersea forces and Naval Warfighting Bases from becoming operational realities, and it would eliminate the warfighting capabilities from a balanced force of manned and unmanned systems. Undersea dominance is not possible without more deconflicted C2. The submarine force in particular must get over the fear of putting manned submarines in the same water as UUVs, and develop the related procedures and tactics to do so.

Defense of Undersea Infrastructure as a Navy Mission

As early as 2008 in their final report to the CNO, after having spent a second year of deep study on the convergence of sea power and cyber power, the SSG gave the CNO the immediately actionable step to:

take the lead in developing the nation’s deep seabed defense (emphasis in the original), given the absolute criticality of seabed infrastructure to cyberspace. Challenge maritime forces and the research establishment to identify actions and technologies that will extend maritime domain awareness to the ocean bottom, from the U.S. coastline to the outer continental shelf and beyond. Prepare now for a future in which U.S. commercial exploitation of the deep seabed – including the Arctic – is both commercially feasible and urgently required, making deep seabed defense a national necessity.”4

In 2008 and again in 2013, Navy leadership offered that there is no requirement for the U.S. Navy to defend undersea infrastructure except for some very specific, small area locations.5 In this context, the term requirement is as it relates to formally approved DON missions, functions, tasks, budgeting and acquisition, but not actual warfighting necessity.

Conclusion

The force must have the capabilities to sense, understand, and act in the deep ocean. The capabilities to do so are already available to anyone with a reasonable amount of money to buy them. Operationally speaking, hiding things on the seabed is fairly easy. On the other hand, finding things on the seabed is relatively difficult unless one is looking all the time, and has an accurate baseline from which to start the search and compare the results. The deep ocean presents an “area” challenge and a “point” challenge simultaneously, and both must be addressed by the maritime force. Understanding the deep ocean and fighting within it is also a matter of numbers and time – requiring lots of vehicles, sensors, and time.

The U. S. Navy is not currently in the game. With a variety of unmanned vehicles, sensors, and weapons coupled with Blitz MCM, Naval Warfighting Bases, and making undersea infrastructure defense a core U.S. Navy mission, the fleet can make the deep ocean – the entire undersea and seabed – a critical advantage in cross-domain warfighting at sea.

Professor William G. Glenney, IV, is a researcher in the Institute for Future Warfare Studies at the U. S. Naval War College.

The views presented here are personal and do not reflect official positions of the Naval War College, DON or DOD.

References

1. Chief of Naval Operations Strategic Studies Group XXXII Final Report, Own the Undersea (March 2014, Newport, RI), pp 4-6 to 4-9.

2. Chief of Naval Operations Strategic Studies Group XIX Final Report, Naval Power Forward (September 2000, Newport, RI), pp 6-8 to 6-12.

3. Chief of Naval Operations Strategic Studies Group XXXII Final Report, Own the Undersea (March 2014, Newport, RI), pp 2-15 to 2-20.

4. Chief of Naval Operations Strategic Studies Group XXVII Final Report Collaborate & Compel – Maritime Force Operations in the Interconnected Age (December 2008), pp 8-1 and 8-4.

5. Author’s personal notes from attendance at SSG XXVII briefings to the CNO on 19 July 2008 and SECNAV on 24 July 2008, and SSG XXXII briefing to the CNO on 25 July 2013.

Featured Image: Pioneer ROV (Blueye Robotics AS)

The Deep Ocean: Seabed Warfare and the Defense of Undersea Infrastructure, Pt. 1

By Bill Glenney

Introduction

Given recent activities by the PLA(N) and the Russian Navy, the matters of seabed warfare and the defense of undersea infrastructure have emerged as topics of interest to the U. S. Navy.1,2 Part One of this paper presents several significant considerations, arguably contrary to common thinking, that highlight the challenges of bringing the deep sea and benthic realm into cross-domain warfighting in the maritime environment. Part Two presents three warfighting concepts drawn from the body of work done by the CNO Strategic Studies Group (SSG) that would give the Navy capabilities of value for the potential battlespace.

The Deep Ocean Environment

For clarity the term “deep ocean” will be used to cover the ocean bottom, beneath the ocean bottom to some unspecified depth, and the ocean water column deeper than about 3,000 feet.3 The deep ocean is where the U.S. Navy and the submarine force are not. Undersea infrastructures are in the deep ocean and on or under the seabed for various purposes.

How does the maritime fight on the ocean surface change when there must be a comparable fight for the deep ocean? In the maritime environment, it is long past time for the U.S. Navy to be mindful of and develop capabilities that account for effects in, from, and into the deep ocean, including effects on the ocean floor. Cross-domain warfighting demands this kind of completeness and specificity. As the Army had to learn about and embrace the air domain for its Air-Land battle in the 1980s, the Navy must do the same with the deep ocean for maritime warfare today and for the future.

However, the current frameworks of mine warfare, undersea warfare, and anti-submarine warfare as practiced by the Navy today are by no means sufficient to even deny the deep ocean to an adversary let alone control the deep ocean.  To “own” a domain, a force must have the capability to sense and understand what is in and what is happening in that domain. The force must also have the capability to act in a timely manner throughout that domain.

Today, the Navy and many nations around the world have radars and other sensors that can detect, track, and classify most of anything and everything that exists and happens in the atmosphere from the surface of the ocean and land up to an altitude of 90,000 feet altitude or higher, even into outer space. The Navy and many nations also have weapons – on the surface and on land, and in the air – that can act anywhere within the atmosphere. Some nations even have weapons that can act in the atmosphere from below the ocean surface. In short, with regard to the air domain, relevant maritime capabilities abound, including  fixed or mobile, unmanned or manned, precise or area. Naval forces can readily affect the air domain with capabilities that can cover the entire atmosphere.

But the same cannot be said for the deep ocean. Figure 1 below is based on information drawn from unclassified sources. Consider this depiction of the undersea in comparison with the air domain. Notice that there is a lot of light blue space – space where the Navy apparently does not have any capability to sense, understand, and act. The Navy’s capability to effect in, from, and into the deep ocean is at best extremely limited, but for the most part non-existent. Capabilities specifically relative to the seabed are even less, and with the Navy’s mine countermeasures capabilities also being very limited. What systems does the Navy have to detect unmanned underwater vehicles at very deep depths? What systems does the Navy have to surveil large ocean areas and the resident seabed infrastructure? What systems does the Navy have to act, defend, or attack, in the deep ocean?

Figure 1 – The Deep Ocean

Arguably, the Navy has built an approach to maritime warfighting that dismisses the deep ocean, and done so based on the assumption that dominating the top 3,000 feet of the waterspace is sufficient to dominating the entire waterspace – ocean floor to ocean surface. Undersea infrastructure is presumably safe and protected because the ceiling over it is locked up.

However, the force must have the capabilities to sense, understand, and act in the deep ocean.

While the assumption for dominating the deep ocean by dominating the ceiling may have been useful in the past, it clearly is no longer valid. In the past, it was very expensive to do anything in the deep ocean. The technology was not readily available, residing only in the hands of two or three nations or big oil companies. This no longer holds true. The cost of undersea technology for even the deepest known parts of the ocean has dropped dramatically, and also widely proliferated. If one has a couple hundred million dollars or maybe a billion dollars, they can sense, understand, and act in the deep ocean without any help from a nation or military. Unlike the U.S. government-funded search for the SS Titanic by Robert Ballard, Microsoft co-founder Paul Allen independently found USS Indianapolis in over 15,000 feet of water in the Philippine Sea. The capabilities to sense, understand, and act in the deep ocean are available to anyone with a reasonable amount of money to buy them.

Figure 1 is misleading in one perspective. At the level of scale in figure 1, the ocean floor looks flat and smooth. If something is placed on the ocean bottom, such as a towed payload module, a logistics cache, sensors, or a weapon system, could it be easily found?

Figure 2 is a picture of survey results from the vicinity of the Diamantina Trench approximately 700 miles west of Perth, Australia in the Indian Ocean. The red line over the undersea mountain is about 17 miles in length. The water depth on the red line varies from 13,800 feet to 9,500 feet as shown on the right.4

Figure 2 – Diamantina Trench

Consider figure 3. The red line is just under three miles in length. The depth variation ranges from 12,100 feet to 11,900 feet.5 These figures provide examples of evidence that the abyssal is not featureless. The assumption of a flat and smooth ocean floor is simply wrong, and severely understates the challenge of sensing and acting in the deep sea.

Figure 3 – A Closer View in the Diamantina Trench

How hard would it be to find a standard-sized shipping container (8ft x 8ft x 20ft or even 40ft) on this floor? It could be incredibly difficult, requiring days or weeks or even months with many survey vehicles, especially if the area had not been previously surveyed. This is a lesson the U. S. Navy learned in the Cold War and has long since forgotten from its “Q routes” for port access. And it would be harder still if one were purposefully trying to hide whatever they placed on the ocean floor, such as in the pockmarks of figure 3.

Based on reported results from a two-year search for Malaysian Airlines flight MH-370, approximately 1.8 million square miles of the ocean floor were searched and mapped to a horizontal resolution on the order of 100 meters and vertical resolution of less than one meter.6 Yet, the plane remains unlocated.

Hiding things on the seabed is fairly easy, while finding things on the seabed is incredibly difficult. Unless one is looking all the time, and has an accurate baseline from which to start the search and compare the results, sensing in the deep sea is significant challenge. The next consideration is that of the matter of scale of the geographic area and what resides within it. This is what makes numbers matter.

Figure 4 provides a view of the Gulf of Mexico covering about 600,000 square miles in area and with waters as deep as 14,000 feet. There are about 3,500 platforms and rigs, and approximately 43,000 miles of pipeline spread across the Gulf.

Figure 4. – The Gulf of Mexico (National Geographic)

Of note, the global economy and worldwide demands for energy have caused the emergence of a strategic asymmetry exemplified by this figure. China gets most of its energy imports by surface shipping which is vulnerable to traditional anti-shipping campaigns. The U. S. gets much of its energy from undersea systems in the Gulf of Mexico. While immune from anti-shipping, this infrastructure is vulnerable to seabed attack. In late 2017, the Mexican government leased part of their Gulf of Mexico Exclusive Economic Zone seafloor to the Chinese for oil exploration.

Figure 5 provides a depiction of global undersea communication cables with some 300 cables and about 550,000 miles of cabling.

Figure 5 – Global Undersea Telecommunications Cables

Figure 6 provides a view of the South China Sea near Natuna Besar. This area is about 1.35 million square miles with waters as deep as 8,500 feet. Recall that in the two-year search for Malaysian Air flight MH 370 they surveyed only 1.8 million square miles, and did so in a militarily-benign environment. 

Figure 6 – The South China Sea

The deep ocean demands that a maritime force be capable of surveilling and acting in and over large geographic areas just like the ocean surface above it. Undersea infrastructure is already dispersed throughout those large areas. In addition, because the components of undersea infrastructure are finite in size, the deep ocean also demands that a maritime force be capable of surveilling and acting in discrete places. While it is arguable that defense in the deep ocean is a wide-area challenge and offense is a discrete challenge, the deep ocean demands that a maritime force be capable of doing both as part of the maritime battle. Therefore, the deep ocean presents an “area” challenge and a “point” challenge simultaneously, and both must be addressed by maritime forces.

In addition, the size of the area and the number of points of interest means that a dozen UUVs or a couple of nuclear submarines are not in any way sufficient to address the maritime warfighting challenge of defending the deep ocean and undersea infrastructure of this scale. Furthermore, the situation is exacerbated by systems and vehicles in the deep ocean above the seabed. The threat is not a few, large, manned platforms, but many small unmanned vehicles and weapons.

The historical demarcation among torpedoes, mines, and vehicles is no longer productive except maybe for purposes of international law and OPNAV programmatics. Operationally and tactically, the differentiation is arbitrary and a distraction from operational thinking. The Navy should be talking in terms of unmanned systems – some armed or weaponized, and some not; some mobile and some not; some intelligent and some not. Torpedoes can easily become mobile, armed UUVs with limited intelligence. Mines can also become mobile or fixed UUVs with very limited intelligence.

In the course of the author’s research and in research conducted by the CNO SSG, there were no situations or considerations where reclassifying mines and torpedoes as UUVs was problematic with regard to envisioning war at sea. Doing so eliminated a significant tactical and operational seam and opened up operational thinking. The systems for the detection and neutralization of UUVs are the same as those needed to detect and neutralize torpedoes and mines, and the same for surveilling or attacking undersea infrastructure.

Conclusion

Ultimately, understanding the deep ocean and warfare in the deep ocean is a matter of numbers and time – requiring plenty of sensors, and plenty of time. Part Two will present three warfighting concepts drawn from the body of work done by the CNO Strategic Studies Group (SSG) that would give the Navy capabilities for the deep sea battlespace.

Professor William G. Glenney, IV, is a researcher in the Institute for Future Warfare Studies at the U. S. Naval War College.

The views presented here are personal and do not reflect official positions of the Naval War College, DON or DOD.

References 

1. This article is based on the author’s remarks given at the Naval Postgraduate School Warfare Innovation Continuum Workshop on 19 September 2018. All information and conclusions are based entirely on unclassified information.

2. See for example Rishi Sunak, MP, Undersea Cables:  Indispensable, Insecure, Policy Exchange (2017, London, UK);  Morgan Chalfant and Olivia Beavers, “Spotlight Falls on Russian Threat to Undersea Cables”, The Hill, 17 June 2018 accessed at http://thehill.com/policy/cybersecurity/392577-spotlight-falls-on-russian-threat-to-undersea-cables;  Victor Abramowicz, “Moscow’s other navy”, The Interpreter, 21 June 2018 accessed at https://www.lowyinstitute.org/the-interpreter/moscows-other-navy?utm_source=RC+Defense+Morning+Recon&utm_campaign=314b587fab-EMAIL;  Stephen Chen, “Beijing plans an AI Atlantis for the South China Sea – without a human in sight”, South China Morning Post, 26 November 2018 accessed at https://www.scmp.com/news/china/science/article/2174738/beijing-plans-ai-atlantis-south-china-sea-without-human-sight;  and Asia Times Staff, “Taiwan undersea cables ‘priority targets’ by PLA in war”, Asia Times, 6 December 2017 accessed at http://www.atimes.com/article/taiwan-undersea-cables-priority-targets-pla-war.

3. Based on unclassified sources, manned nuclear submarines can operate to water depth of 1,000-1,500 feet, manned diesel submarines somewhat shallower, and existing undersea weapons to depths approaching 3,000 feet.

4. Kim Picard, et. al., “Malaysia Airlines flight MH370 search data reveal geomorphology and seafloor processes in the remote southeast Indian Ocean,” Marine Geology 395 (2018) 301-319, pg 316.

5. Kim Picard, et. al., “Malaysia Airlines flight MH370 search data reveal geomorphology and seafloor processes in the remote southeast Indian Ocean,” Marine Geology 395 (2018) 301-319, pg 317.

6. Kim Picard, Walter Smith, Maggie Tran, Justy Siwabessy and Paul Kennedy, “Increased-resolution Bathymetry in the Southeast Indian Ocean”, Hydro International, https://www.hydro-international.com/content/article/increased-resolution-bathymetry-in-the-southeast-indian-ocean, accessed 13 December 2017.

Featured Image: Deep Discoverer, a remotely operated vehicle, explores a cultural heritage site during Dive 02 of the Gulf of Mexico 2018 expedition. (Image courtesy of the NOAA/OER)