America's Littoral Combat Ships: Part II - Small Surface Combatant

Image 1: Pair of Independence class LCS 

Under the direction of Secretary of Defense Chuck Hagel, the Department of Defense has reduced its total LCS buys to 32 ships down from 52. The decision to limit LCS buys to 32 ships was influenced by scathing criticism from many Department of Defense officials, including former Deputy Defense Secretary Christine Fox, who argued the ship's lack of both the firepower and protection made it a "niche" platform with little relevance to the Pivot. 

"...we need to closely examine whether the LCS has the independent protection and firepower to operate and survive against a more advanced military adversary and emerging new technologies, especially in the Asia Pacific.  If we were to build out the LCS program to 52 ships, as previously planned, it would represent one-sixth of our future 300-ship Navy." - Defense Secretary Chuck Hagel, 2014

As part I discussed, the purpose of the LCS is not to engage high-end surface combatants in the South China Sea. Rather, the LCS is intended to preform Phase 0 & I such as providing training opportunities for US allies, routine maritime patrols, anti-piracy operations, etc. These basic peacetime duties are much more suited to $400 million dollar LCS ships over $1.8 billion dollar DDG-51 Destroyers. The use of LCS ships to fulfill routine peacetime duties near Africa and South America frees high-end surface combatants such as Arleigh Burke-class destroyers and Ticonderoga-class guided missile cruisers to transfer to the Pacific (Greenert, 2012). 

Even with these considerations, the decision to limit LCS procurement to 32 vessels is largely merited as it is a sufficient number of ships to free up high-end surface combatants for the Pacific and it allows the Navy to pursue a more heavily armed replacement to support the Pivot. The Small Surface Combatant (SSC) task force has been assigned with evaluating proposals for a more heavily armed surface combatant with capabilities consistent with a frigate. The task force would evaluate existing ship designs, upgraded LCS designs, and new designs with respect to the venerable Oliver Hazard Perry-class frigate (Cavas, 2014).  The task force's initial findings are due by the end of July. 

SSC Role,Objectives, and USN Needs 

Image 2: USS Taylor FFG-50 

In many respects, the existing LCS designs do not fully replace the Oliver Perry-class frigate and they notably are not integrated as part of carrier strike groups. Because the SSC task force will compare SSC proposals to the Oliver Perry-class frigate, understanding the role of the Oliver Perry-class frigate provides some basis of what can be expected from the SSC. The following is from Global Security: 

"These ships were originally conceived as a low-cost convoy escort (hence the original 'PF' hull number for the prototype). They are particularly well suited to be a convoy escort and are Link 11 capable...PERRY-class frigates are primarily Undersea Warfare ships intended to provide open-ocean escort of amphibious ships and convoys in low to moderate threat environments in a global war with the Soviet Union. They could also provide limited defense against anti-ship missiles extant in the 70's and 80's. The ships are equipped to escort and protect carrier battle groups, amphibious landing groups, underway replenishment groups and convoys." - Global Security, 2011

The future SSC needs to be able to fulfill the traditional escort and patrol role of the Oliver Perry-class in addition to providing some fleet defense capabilities for carrier strike groups within a hostile anti-access/area denial (A2/AD) environment. 

Relevant Capabilities Needed to Support the Pivot:

Anti-Surface Warfare: (ASuW) The SSC should be capable of engaging low and medium-end surface combatants such as the Type Jiangkai-class (Type 054A) and Type 056 corvette. Thus, the SSC needs VLS cells with capable long-range anti-ship missiles such as NSM, Tomahawks, or LRASM. VLS cells could be supplemented with two quad packs of Harpoon anti-ship missiles. A 76 mm main gun is standard for frigates of this size.

Image 3: The RIM-162 Evolved Sea Sparrow Missile (ESSM) serves as a medium range anti-aircraft and cruise missile weapon. The inclusion of the Mk 25 Quad-Pack allows four RIM-162 missiles to fit inside a standard MK 41 VLS cell. Thus, an SSC with 16 MK 41 VLS cells could provide effective air defense out to more than 27 nautical miles with 64 ESSMs. The quad pack configuration allows US carrier groups to field the large number of anti-cruise missile interceptors necessary for protecting a carrier group in an A2/AD environment. 

Anti-Aircraft Warfare (AAW):  The US Navy (USN) will deploy between 80 to 97 high-end surface combatants dedicated to fleet air-defense between FY 2015 – 2044 (O’Rouke, 2014). These ships will be supplemented with E-2D Hawkeyes, Aegis baseline 9, F-35Cs, F/A-18Es and 100 nm + capable SM-6 surface to air missiles. Thus, it would be cost prohibitive and redundant to spend money procuring heavy anti-air warfare frigates equipped with Aegis and ~48+ VLS cells. A limited fleet defense capability with quad packed RIM-162s and SM-2s supplemented with a SPY-1F would likely be sufficient to augment existing (and extensive) fleet AAW. The remaining cells could be filled with anti-ship missiles or anti-submarine weapons.        

Anti-Submarine Warfare (ASW): The rising threat of People's Liberation Army Navy (PLAN) diesel electric submarines remains among the most serious threats to US carrier groups in the Western-Pacific. The SSC could supplement destroyers and cruisers in ASW role with towed sonar array and anti-submarine weapons (e.g. RUM-139 ASROC) in VLS cells. Torpedoes such as the MK 54 could be added for additional ASW and ASuW capabilities.   

Extended range and endurance: long range needed for transit between US Pacific facilities e.g. Naval Station San Diego, Pearl Hickam, Naval Base Guam, United States Fleet Activities Yokosuka, etc. 

Image 4: FFG-37 USS Stark after being hit by two Exocet missiles 

Survivability: A2/AD environments are extremely hostile toward surface combatants, especially within the first island chain. The PLAN has 100,000 sea mines and thousands of anti-ship cruise missiles (Freedberg, 2014). A built-in survivability standard of Level II is required at a minimum (destroyers, cruisers, and carriers are built to Level III while minesweepers and replenishment ships are built to level I). Oliver Perry-class frigates demonstrated the value of Level II survivability when the USS Stark was hit with two Iraqi Exoset anti-ship missiles in 1987 (above) and in 1988 when Samuel B. Roberts was hit with a 500 pound Iranian sea mine. In both cases, the ships managed to stay afloat despite the damage. The aluminum hull of the independence-class LCS and the aluminum-steel hull of the freedom–class LCS limit the ships to Level I+ survivability status (O’Rouke, 2014). The SSC’s survivability can be augmented with SeaRAM, close-in weapon system (CIWS), and decoys but ensuring the SSC has a robust built-in survivability standard should be a non-negotiable requirement given the expected A2/AD environment.

It is important to note that definitions of ship survivability have changed overtime and fixating on the Level I, II, and III levels themselves is not necessarily constructive. Lazarus from the Information Dissemination blog wrote an article, Following in the Wake of the Frigate; Remarkable Continuity in the Postwar US Surface Combatant Force, which concludes the US warships have relied on defensive weapons, advanced sensors, and communication equipment over heavy armor since World War II:

"The Ticonderoga class cruiser, the Freedom and Independence LCS sea frames and even the large Zumwalt class DDG 1000 are differing examples of the same design ethos [operated by a small crew, reliant on on stealth and self defense weapons rather than armor] that has dominated U.S. surface combatant design since 1945. Any discussion of surface combatant 'survivability' must take into account this basic similarity among U.S. surface warships." - Lazarus, 2014

The argument for substantial built-in survivability measures within the SSC design is largely pragmatic as Level II survivability would serve as a fail-safe against threats defeating active ship defenses. In both the cases of FFG-37 and  FFG-58, the defensive weapons (e.g. CIWS) and sensors employed by the ships failed to neutralize the incoming threats. New technology, such as advanced ship defense weapons, should be employed in tandem with proven passive survivability measures like placing armor over key areas of the ship. 

Growth margins – A service life of 30 years requires the SSC design to be easily upgradable.  Ideally, the hull should be able to accommodate a larger displacement over its service life to allow for upgrades. A capable power plant is essential toward the accommodation of new systems such as solid state lasers, rail guns, or a more powerful radar. A hybrid-electric drive (HED) would ensure the SSC has adequate growth opportunities for the remainder of its service life. 

"Littoral Combat Ships have plenty of onboard power, plus accessible free space for capacitors etc. Switching the 57mm forward gun for a railgun, and adding laser weapons for air and surface defense, would give an LCS with the 'EM weapons' package unique Naval Fire Support and air-defense roles within the fleet." - Defense Industry Daily, 2014

Likely Candidates for SSC

While the task force is evaluating a number of designs, the most likely candidates will be upgraded variants of existing LCS models and Huntington Ingalls' patrol frigate submissions. Congress is highly unlikely to permit the purchase of a foreign design for political reasons (Cavas, 2014). European navies have increasingly procured 6,000 tonne plus high-end AAW "frigates" equipped with 48 VLS cells and powerful radars (e.g. the German Sachsen class, the Spanish Álvaro de Bazán-class (F100), and the British Type 26 Global Combat Ship). These ships have largely replaced the role of fleet defense destroyers within these countries or are intended to supplement a reduced destroyer force. Even if political calculations were not part of the Navy's procurement process, European frigate designs are in excess of US needs given the large number of more capable Arleigh Burke-class destroyers deployed by the USN. Given the constrained fiscal environment of sequestration, it is also highly unlikely for any completely new designs to be seriously evaluated. 

Huntington Ingalls' Patrol Frigate 4501 & 4921

Image 5: Pair of National Security Cutters (NSC) 

Huntington Ingalls has been actively marketing modified versions of its NSC for Navy's SSC. The base NSC has been constructed to 90% military standards, has a unit cost of $638 million dollars and features a 57 mm main gun (O'Rouke, 2014). Two modified variants of the NSC have been offered, the PF 4501 and PF 4921. The PF 4501's greatest asset is its range of 12,000 nautical miles and an endurance of 60 days compared to the 3,500-4,000 nautical mile range and 21 day endurance for existing LCS vessels. The design requirements for long range policing and endurance for the base NSC make it well suited towards traversing between distant US and allied facilities in the Pacific. The design philosophy behind the PF 4501, to limit cost increases above the NSC, limits the ships armament to only a 57 mm main gun with machine guns and defensive weapons. The limitations of the PF 4501's armament largely limits its prospects as a viable SSC candidate. 

The PF 4921 sacrifices 4,000 nautical miles worth of range on the base NSC for a heavily increased armament:  

"...the PF 4921 is a light frigate for executing anti-air, anti-surface and anti-submarine warfare...Armament is a 76 mm main gun, a vertical launch unit for the evolved Sea Sparrow Missile (ESSM), a Phalanx  or SeaRAM CIWS, and six crew-served as well as remotely operated machine guns. Mounted aft are two quad packed Harpoon surface-to-surface missile launchers and a triple torpedo tube launcher. Sensors shown on the concept ship include a CEAFAR radar system, a hull mounted sonar and a towed array sonar system." -  Mrityunjoy Mazumdar, 2012

Sources differ on the number of VLS cells carried on the PF4921, either 12 or 16 (LaGrone & Cavas, 2014). The combination of the aforementioned weapon systems and sensors in conjunction with a 8,000 nautical mile range and 60 day endurance makes the PF 4921 a viable candidate for the SSC. The only outstanding issue for the PF 4921 is its built-in survivability standard given the base NSC was designed for seakeeping not combat against capable surface combatants. (Cavas, 2014). The PF variants of the NSC have been enhanced to meet Navy standards but to the extent in which the ships feature higher survivability, in terms of Level I, II, III, etc., remains unclear. 

Austal USA & General Dynamic's Independence International Variant

Image 5: Independence-international 

As far as the aforementioned required capabilities are concerned, the Independence international variant features a substantially improved armament when compared to the existing domestic variant. The international variant has been marketed with several different configurations but many include: two eight VLS configurations for 16 VLS cell total, two quad harpoon mounts, torpedo launchers and a medium caliber gun (either 57 or 76 mm). With these weapons, the Independence-class would be more able to engage PLAN surface combatants. A major advantage the Independence-class vessels have over existing Freedom-class LCS boats is its more expansive mission module area which can in turn be used to house more equipment and armament for the SSC program. However, the major limitation of the Independence-class domestic variant is still present in the international variant, its aluminum hull. 

"The original concept for LCS was a ship whose damage resistance could save the crew, but not the ship, in the event if a significant strike. That was upgraded slightly to potentially saving the crew and the ship, but not continuing to fight while doing so. As the Exocet missile strikes on the HMS Sheffield (sank) and USS Stark (survived, barely) proved, even steel warships designed to keep fighting after a strike may find it challenging to meet their design specifications...The LCS-1 Freedom Class uses an aluminum superstructure, while the LCS-2 Independence Class is primarily an aluminum design. While both ships have had to certify to the same fire-proofing standards asked of other ships, aluminum conducts heat very well, and melts or deforms easily. If the ancillary fire-fighting systems, resistant coatings, etc. fail, or cannot handle a given situation at sea, structural integrity problems and secondary fires could become fatal concerns very quickly." - Defense Industry Daily, 2014

The argument that the LCS did not need high survivability to fulfill its intended mission legitimate, as discussed in part I. But, Level 1+ survivability is not acceptable if General Dynamics and Austal USA intend to market the international variant in a traditional frigate role. Therefore, the Independence international variant should not be pursued as a viable SSC candidate given its limited built-in survivability standards. 

Lockheed Martin's Multi-Mission Surface Combat Ship

Image 6: Multi Mission SCS proposals 

Lockheed Martin has proposed a series of major alternations to the existing Freedom-class LCS hull as part of the multi-mission surface combat ship (SCS). SCS proposals range from the current 118 meter variant up towards a 150 meters combatant with a SPY-1F radar, 48 VLS cells, and Aegis ballistic missile defense (BMD) capability. The high-end variants of the SCS are in excess of US needs similar to foreign heavy air defense frigates. Furthermore, the proposed high-end Aegis equipped SCS variants would cost around $1 billion dollars each making them unfeasible in the current fiscal environment (Cavas, 2014). However, a mid-range variant of the SCS with either 16 or 32 VLS cells, two quad harpoon missile launchers, a 76 mm main gun, SPY-1F radar and torpedo launchers would be sufficient to adequately meet most conceivable ASW and ASuW needs. As with the Independence-class LCS,  built-in survivability remains a serious concern. 

The Freedom-class LCS uses a combination of steel and aluminum as opposed to the all aluminium hull like the Independence-class LCS but it still has received a Level I+ rating. However, Lockheed’s vice president of littoral ship systems, Joe North, recently claimed that the international variants of the Freedom-class LCS had higher durability than the Level II Oliver Perry-class frigates: 

“Folks understand our hull, our structure...The analysis done by the American Bureau of Shipping told us our structure was stronger and more survivable than a FFG 7 [Oliver Perry-class frigate]. ” - Joe North, 2014

Conclusion 

If the SCS does have a higher built-in survivability standard as the Oliver Perry-class than it would likely become the front runner in the SSC selection process given its flexible design, significant armament, capable sensors, and the lowered developmental risk due to its commonality with existing Freedom-class ships. The PF 4921 is also a viable option for the SSC but it is likely the Navy has an institutional bias against adapting cutters in frigate roles: 

"Ingalls has dual challenges. Like the LCS builders, the company needs to show it can make the PF a creditable warship. But many naval officers and officials balk at considering a 'white hull' ship designed for the Coast Guard and not to the Navy’s more exacting combat standards.  Getting people to overlook those preconceptions and take a closer look at a design’s capabilities will be as much as challenge as fitting in more missiles and bigger guns." - Cavas, 2014

While the LCS' original concept remains valid, capping procurement at 32 ships is justified as it will allow the Navy to forward deploy more capable surface combatants to the Pacific. The Navy can further support the Pivot by procuring the SSC to support the Pivot in ASW, ASuW and AAW roles as part of conventional carrier strike groups.

Author's Note: I will continue to publish articles into the summer. About 1/2 of the article "Divergent Thinking: How Best to Employ Fighter Aircraft Part II - The American Approach" is completed and I'm in the process of working on articles relating to the DDG-51 Flight III & DDG-1000, US-Philippine defense ties, potential expansion for US-Vietnam ties, Divergent Thinking: How Best to Employ Fighter Aircraft - The Chinese Approach, as well as some other other topics. 

Sources (In addition to Part I)

1. ‘Is China Enemy No. 1?’ Debate Erupts at Marine War Game, Sydney J. Freedberg Jr., 2012. http://breakingdefense.com/2012/03/marines-debate-is-china-enemy-no-1/
2. Raytheon RIM-162 ESSM, Andreas Parsch, 2004.                                                   http://www.designation-systems.net/dusrm/m-162.html 
3. Navy Aegis Ballistic Missile Defense (BMD)   Program: Background and Issues for Congress, Ronald O'Rourke, 2014.                                                                                                                   https://www.fas.org/sgp/crs/weapons/RL33745.pdf
4. US Destroyers Get a HED: More Power to Them!, Defense Industry Daily, 2012. http://www.defenseindustrydaily.com/us-destroyers-get-a-hed-more-power-to-them-07142/
5. RIM-162 ESSM Missile: Naval Anti-Air in a Quad Pack, Defense Industry Daily, 2014. https://www.defenseindustrydaily.com/rim-162-essm-missile-naval-anti-air-in-a-quad-pack-03924/?utm_campaign=didsearch&utm_source=did&utm_medium=autosuggest&utm_term=RIM-162
6. Patrol Frigate Concepts from Huntington Ingalls Industries Gain Traction Internationally, Mrityunjoy Mazumdar, 2012.                                                         http://www.defensemedianetwork.com/stories/patrol-frigate-concepts-from-huntington-ingalls-industries-gain-traction-internationally/
7. Single Cell Launcher  Flexible and Adaptable for Today’s Navy, Lockheed Martin, 2014. http://www.lockheedmartin.com/content/dam/lockheed/data/ms2/documents/launchers/Single_Cell_Launcher_brochure.pdf
8. Lockheed Outlines Freedom-Class Improvements, Dave Majumdar, 2014. http://news.usni.org/2014/01/14/lockheed-outlines-freedom-class-improvements
9. US Navy Task Force Seeks Industry Ideas, Christopher Cavas, 2014. http://www.defensenews.com/apps/pbcs.dll/article?AID=2014304300042
10. CNO: Group Will Study New LCS Designs, Christopher Cavas, 2014. http://www.defensenews.com/apps/pbcs.dll/article?AID=2014303100028
11. Ready, Set, Go! Navy Gives Industry 21 Days For LCS Alternatives, Sydney J. Freedberg Jr., 2014.  http://breakingdefense.com/2014/04/ready-set-go-navy-gives-industry-21-days-to-propose-alternatives-to-lcs/
12. Following in the Wake of the Frigate; Remarkable Continuity in the Postwar US Surface Combatant Force, Lazarus, 2014.                                        http://www.informationdissemination.net/2014/05/following-in-wake-of-frigate-remarkable.html
13. Ship Study Should Favor Existing Designs, Christopher Cavas, 2014.  http://www.defensenews.com/article/20140419/DEFREG02/304190020/Ship-Study-Should-Favor-Existing-Designs