It's Time for a 'Sea-Control Frigate'

By Lieutenant (junior grade) Zachary Howitt, U.S. Navy

The Patrol Frigate Baseline

The Legend -class NSC is 418 feet long, displaces 4,500 metric tons, has a draft of 22 feet (the same as the Perry s), and operates with a combined diesel-and-gas propulsion system, which allows twin screw propulsion on a single engine. Its sprint speed can exceed 30 knots on full power and 18 knots with one engine online. It has a large 50 by 80 foot flight deck, twin hangar bays that accommodate two Sikorsky SH-60 Seahawks or four MQ-8B Fire Scout unmanned aerial vehicles, and a stern launch ramp for small boat operations. It’s equipped with a Phalanx close-in weapon system (CIWS), a Bofors 57-mm main gun, six .50 caliber machine guns, Mk 36 SRBOC (rapid chaff decoy launchers), Nulka active decoys, and the same SLQ-32v2 electronic-warfare suite found on Arleigh Burke- class destroyers (DDG-51s). 3

In 2012, Ingalls introduced the “Patrol Frigate 4921” concept ship with improved weapons and combat systems. It has an upgraded 76-mm main gun, a new CEAFAR 4th generation active-phased array radar, and both a hull mounted sonar and multi-functioned towed array (MFTA). Installed behind the main gun on the forecastle in a “reserved space” is a 12-cell Mk 56 Vertical Launch System (VLS) capable of holding 12 Evolved Sea Sparrow missiles (ESSMs) with up to a 30-mile engagement range. In lieu of the Phalanx is a more effective SeaRAM CIWS with 11 RIM-116 rolling airframe missiles. In place of the stern launch ramp is one Mk 32 triple torpedo tube set and eight Harpoon anti-ship missiles. It supports the SH-60 Light Airborne Multipurpose System Mk III with either Mk 54 Torpedoes for an ASW mission or AGM-114 Hellfire missiles for antisurface warfare. It has a 45-day endurance and a range of over 8,000 nautical miles at 12 knots. 4 (In comparison, LCS-1 and 2 have ranges of 3,500 nm and 4,300 nm with a 21-day endurance, and DDG-51 has a range of 4,400 nm with a 30-day endurance. 5 )

This “patrol frigate” concept is an interesting starting point, but it’s not exactly what we need. With the right research and a little creativity, a more ideal “sea control frigate” variant could be developed without additional hull modifications.

Sea-Control Frigate Transformation

To effectively transform the “patrol frigate” into the “sea-control frigate,” its weapon system must be upgraded. After careful analysis of the hull, adequate space is available to accommodate the installation of a centerpiece 16-cell Mk 41 tactical length VLS that takes the place of the proposed Mk 56 VLS on the forecastle, as well as an accompanying VLS and radar cooling and support system. 6 The VLS supports a multi-mission configuration of ESSMs, antisubmarine rockets (ASROCs),
and long-range antiship missiles (LRASMs). This brings a tremendous capability to the frigate, as ESSMs are quadpacked into each cell for an increased maximum of up to 64 missiles. A sizable ESSM loadout using CEA radar and illuminators is specifically designed to overcome the vulnerability of existing shipboard systems to saturation attacks by supersonic sea skimmers such as the SS-N-22 Sunburn or SS-N-27 Sizzler, which have reaches of several hundred miles. 7 Thus, this added capability is especially necessary to conduct tasking in these resulting anti-access areas, notable across several areas of operations. 

With an ever-increasing subsurface threat, ASROCs are an essential defense-in-depth element that hedge against the possibility of the presence of diesel-electric submarines in a vital area outside the range of over-the-side torpedoes. Moreover, the prospects of supporting the LRASM, slated to enter serial production in 2015 to replace the aging Harpoon, is an important future requisite to be a value-added in a surface action group. With a reach greater than 200 miles, and jam-resistant multimodal radio and electro-optical targeting systems, it has a truly effective over-the-horizon anti-surface capability. 8

Because of the added LRASM, the less effective Harpoon missiles are removed from the fantail, and the torpedo tube set is either moved to the port midships or removed completely. A clear fantail is then used to hold additional rigid-hull inflatable boats or serve as a flexible “creative space” for any future capabilities. For example, it could support special-operations equipment, unmanned surface and subsurface vehicles, or antisurface decoys. Furthermore, the fantail has the space to support small mission-module containers that have common roots with the NSC’s systems. 9 This opportunity allows for the installation of a plug-and-play variable-depth sonar, which greatly enhances deep-water ASW capability, especially in conjunction with the integrated MFTA. 10  

Another interesting possibility is a mine-countermeasures module that takes full advantage of the WLD-1 Remote Minehunting System technology, but with a smaller container footprint. Although not a primary mission, having the potential to install a mine-warfare capability would be invaluable in any future conflict. Both systems are already being designed for the LCS, which might rationalize spending the time and money needed to develop the mission packages while pursuing a plan that cuts the amount of LCSs in service.

On a final note, there is ample space to install two remotely operated Mk44 Bushmaster II 30-mm chain guns amidships, above the helo hangar, on either side of the SeaRAM. These guns have 50 percent more firepower than the smaller Mk 38 Mod 2 25-mm variant and are already integrated into the LCS surface-warfare mission package. 11 In addition to covering all axes of the ship with firepower, they also supplement the main 76-mm gun against crucial threats like swarm attacks.


The biggest potential drawback has been that while the hull is built to U.S. Navy structural design standards, other elements of the ship do not fully meet the frigate level II survivability requirements, defined in OPNAVINST 9070.1 as an “ability for sustained operations when in support of a Battle Group and in the general war-at-sea area” and “an ability for sustained combat operations following weapons impact.” 12 Additionally, the vessel does not fully comply with the American Bureau of Shipping’s naval vessel rules, controversially created after the NSC was designed, that established a code of specifications to militarize a ship. 13

A new frigate must be capable of taking and surviving hits similar to the two Exocet missiles that struck the USS Stark (FFG-31) in 1987 and the mine that crippled the USS Samuel B. Roberts (FFG-58) in 1988. That’s not to say NSCs aren’t highly survivable ships; they have a state-of-the-art damage-control system, a collective protection system for chemical, biological, and radiological protection, and various other comprehensive and redundant systems. 14 However, there are still some shortcomings, specifically in the area of shock and survivability, with no assurance that it could survive in a hostile environment. 15

In September 2012, a survivability revision came out that recognized the changing nature of ship design and system threats, measured against other objectives (such as cost, which eliminates the prescriptive survivability characteristics). 16 When asked, an Ingalls representative said the company would be willing to help define the needed survivability requirements and mitigate shortcomings with manageable design changes for a newly proposed sea-control frigate. 17 These enhancements include anti-vibration engine mounts and a passive countermeasures system to reduce acoustic and radar signatures, respectively, and installing ballistic resistant steel plating, side and bottom protection, additional system redundancies, and a variety of extra damage-control devices.

However, even with additional enhancements, it’s impractical to check off every minute box that may be requested for survivability, especially specific rules detailing things like the exact designs of firemain systems and other features established in the naval vessel rules that were not yet in existence when the hull was designed. Nevertheless, a holistic view of these modifications and the improved weapon system in accordance with the latest survivability instructions, for all practical purposes, show that a sea-control frigate can indeed become an extremely survivable combatant, even comparable to the Oliver Hazard Perry class. It’s also substantially more survivable than the aluminum-hulled LCS that was built to the lowest level I survivability standards and never intended for actual combat. 18


The last production cost for an NSC was $490 million, with a total average drive-away price of $684 million (the rest accounting for government-furnished equipment, post-delivery test and evaluations, etc.). 19 How much would a sea-control frigate cost? The Congressional Budget Office (CBO) has already explored limiting the purchase of the LCS and buying 20 of the aforementioned patrol frigate types as an option to reduce overall acquisition costs. 20 The report concluded it would cost $60 million per ship to upgrade the CIWS to a SeaRAM, install a Mk 54 VLS system, radar, illuminators, and ESSM missiles, and integrate the weapon systems. To further convert it to a sea-control frigate, additional costs would be incurred from other improvements: most notably, the larger VLS, and the survivability redesigns with comprehensive shock hardening. 

An exact price estimate is dependent on multiple factors such as timing, quantity, and contracting methodology. Although it can’t be determined without a formal feasibility study, information from the congressional report and the price of installing these weapon systems on other warships suggests that adding a likely $120 million would result in an end cost of $800 million. This is about half the price for a DDG-51 Flight IIA ($1.8 billion) and a third of the price for a DDG-51 Flight III ($2.3 billion). 21 Recent estimates put the final price of the LCS with mission modules at 70 percent of this cost, a comparable target price recently reported as a key requirement for a medium-sized surface combatant. 22

Design costs, upfront testing, and the learning curve are minimal; eight other similar hulls would have gone through production, and all the combat systems are operational on other Navy platforms. Efficiency and standardization are at their prime. Because of recognized deficiencies from the first three cutters, substantial changes to the structural design were made to achieve greater fatigue life. 23 Recently, NSCs have been operating in far-reaching places like the Arctic Ocean with no reported stress or fatigue issues, and the hull is now recognized by the Coast Guard as being able to support a 230-day-per-year underway operational tempo. 24 The Navy would be getting a proven product, and the class wouldn’t be plagued by as many delays and similar deficiencies typical in the introduction of ship classes. Likewise, industry sources acknowledged that a fixed-price contract can be established from the start, which would prevent any cost overruns—a rarity in present-day shipbuilding. 25

Even more features can be added when weighed appropriately against a higher cost. Some options include additional survivability enhancements, a composite deckhouse structure, upgrading the 76-mm gun to a 5-inch, substituting the radar with a SMART-S or a lighter Aegis SPY-1F (possibly modified to support ballistic-missile defense queuing), or even slightly lengthening the hull for more module or VLS room.

Operational Cost Savings

Manning is key. Because of the NSC’s state-of-the-art ship-control system that integrates machinery control, steering, and navigation, the NSC mans with a complement of 116 sailors, including the helo detachment. 26 Altogether, a sea-control frigate crew would consist of 120 to 130 personnel, with a possible berthing accommodation of up to 141. 27 This is well less than half the manpower of a DDG-51, and approximately the same total manpower required for an LCS with two 50-person crews and 40 more assigned to mission modules and helo detachments. 28 Unlike the LCS, which has grappled with the right “optimal-manning” numbers and has been described as “inefficient and uneconomical” for its reliance on contractors, NSCs have been deploying without any issues for several years with enough manpower for tasks, maintenance, and damage control. 29

Fuel cost savings are another important advantage. With ever-increasing gas prices and a priority to reduce dependency on oil, it’s important to be as efficient as possible. At most economical speeds, the sea-control frigate burns 17 gallons per nautical mile, a quarter as much as the DDG-51 (65 gallons), and about half as much as the LCS (32 to 42 gallons). 30 For example, an 8,000 nm trip from San Diego to Singapore at $4.00 per gallon costs $2 million for a DDG-51, versus $500,000 for a sea-control frigate. Furthermore, the CBO noted in a report that an NSC variant requires half the number of refueling and resupply visits from logistics ships than the LCS and DDG-51; if an LCS were to perform frigate-type missions, it would be “especially burdensome when operating places far from where logistics ships operate.” 31


Some have issued a call to upgrade our current Perry -class frigates. However, the modernization of four similar Australian Adelaide -class frigates ran four years late at a cost of $400 million per ship, and supports only a Mk 41 8-cell VLS. Despite the upgrade, the ships are still marred with problems and planning to decommission earlier than expected. 32 Another in-house option is building a scaled-down DDG-51 without Aegis, or taking away the LCS’s modularity, extending the hull, and increasing the 3,000-ton ship by 1,000 tons to install a 16-cell Mk 41 VLS. 33 But there is no telling how much either ship would ultimately cost, and the chances for a higher design cost are greater due to the more dramatic changes that need to be introduced. 

Several possible foreign design contenders are worth investigating as well, most notably ships with similar capabilities and manpower requirements such as Norway’s Fridtjof Nansen class and Denmark’s Iver Huitfeldt class. 34 While these designs are possible contenders, many still lack critical features unique to the sea-control frigate. For example, they have a small flight deck with room to berth only one helicopter. Besides, law requires them to be produced in American shipyards, which means the Navy would need to acquire the rights of the license to build the prospective ships. This has not been explored, and there is no guarantee that foreign companies would agree within reasonable terms. Moreover, our shipyards are unsubsidized when compared to foreign competitors, which likely erodes some cost advantage. 35

The Big Picture

In a September 2013 report, the Congressional Research Service denoted that a primary argument for truncating the LCS program is the refocus on sustained deep-water operations—namely antiship cruise-missile defense and countering submarines operating far from shore to contest China’s military modernization effort, an increasing concern since the LCS plan was announced over 12 years ago. 36 It goes on to state that “the LCS is not optimized for these missions,” and “in a period of constrained defense spending, resources must be balanced against ships with more closely aligned mission orientations.” It’s important to view a sea-control frigate not as a quid pro quo replacement, but as a blue-water complement that could potentially save the LCS’s legacy by keeping it in the littoral space and focused on the operations for which it was designed.

A sea-control frigate could even be an ideal partner, serving as an anti-air “shotgun” as an LCS performs specialized missions in a denial area too risky to enter alone. Additionally, every new frigate built takes a load off a destroyer, an important side benefit when the Navy’s betting on their 45-year service lives. 37 This also means a reduction in costly DDG-51 maintenance and surge manning requirements, and the opportunity to concentrate on higher-end missions like ballistic-missile defense that are becoming more frequent.  Perhaps more important, shortening the approaching nine-month deployment would be a welcome morale boost for sailors.

Still, there remains no formal requirement for a frigate from either the Navy or Congress. That may soon change; the Pentagon recently requested alternative procurement proposals for small surface combatants, and any plan that cuts the LCS alone would contradict Chief of Naval Operations Admiral Jonathan Greenert’s “presence is our mandate” ethos. 38  

The sea-control frigate is a well-positioned base platform to fit the Navy’s future needs. It may not be perfect, and it’s far from being a primary combatant. But it’s a capable and survivable blue-water multi-mission ship that has the flexibility to be upgraded over its 30-year service life. And it can be produced relatively quickly for a fixed price. Given our current financial constraints, it would pay to look at this creative option.

1. “Report: Surface Forces CO Wants One LCS Design, Scrap DDG-51 Flight III,” USNI News, , 18 March 2013. “Report: Pentagon to Trim LCS Total to 32,” USNI News, , 15 January 2014.

2. Norman Polmar, “U.S. Navy: ‘Where Are the Frigates?’” U.S. Naval Institute Proceedings , vol. 139, no. 6, June 2013.

3. U.S. Coast Guard Acquisition Directorate, “National Security Cutter Factsheet,”

4. Mrityunjoy Mazumdar, “Patrol Frigate Concepts from Huntington Ingalls Industries Gain Traction Internationally,” Defense Media Network , , 24 April 2012.

5. “US Navy Littoral Combat Ship Program,” RUSI Defense Systems , , 2010.

6. Material provided by Huntington Ingalls Industries between September and November 2013.

7. Carlo Kopp, PhD, “Killing the Vampire,” Defence Today Magazine , vol.7, no.3, , 2008.

8.  “Long Range Anti-Ship Missile (LRASM), United States of America,” Naval Technology ,

9. Huntington Ingalls Industries information from September to November 2013.

10. Kris Osborn, “LCS Pursues Next-Generation Submarine Sonar,” DefenseTech , , 30 May 2013.

11. “Mk 44 Bushmaster II 30/40-mm Automatic Cannon / Mk 46 Weapon Station,” Global Security ,

12. Office of the Chief of Naval Operations, “OPNAVINST 9070.1A,” 13 September 2012.

13. Mazumdar, “Patrol Frigate Concepts from Huntington Ingalls Industries Gain Traction Internationally.” 

14. United States Coast Guard Acquisition Directorate, “National Security Cutter Factsheet.”

15. Huntington Ingalls Industries.

16. Office of the Chief of Naval Operations, “OPNAVINST 9070.1A.”

17. Huntington Ingalls Industries.

18. Sydney J. Freedburg Jr., “LCS Couldn’t Survive War With China, But It Could Help Prevent It: CNO,” Breaking Defense , , 12 April 2012.

19. Ronald O’Rourke, “Coast Guard Cutter Procurement: Background and Issues for Congress,” Congressional Research Service, , 24 July 2013.

20. Congressional Budget Office, “Options for Combining the Navy’s and the Coast Guard’s Small Combatant Programs,” , July 2009.

21. O’Rourke, “DDG-51 and DDG-1000 Destroyer Programs: Background and Issues for Congress,” Congressional Research Service, , 22 October 2013.

22. Christopher P. Cavas, “U.S. Navy Weighs Halving LCS Order,” DefenseNews , , 17 May 2013.

23. “Acquisition of the National Security Cutter,” Department of Homeland Security Office of the Inspector General , p. 8,

24. Military Officer Association of America, “Interview with the Coast Guard Commandant,” , 21 February 2012.

25. Huntington Ingalls Industries.

26. U.S. Coast Guard Acquisition Directorate, “National Security Cutter Factsheet.”

27. Mazumdar, “Patrol Frigate Concepts from Huntington Ingalls Industries Gain Traction Internationally.” 

28. “US Navy Littoral Combat Ship Program,” RUSI Defense Systems.

29. O’Rourke, “Navy Littoral Combat Ship (LCS) Program: Background and Issues for Congress,” Congressional Research Service, , 27 September 2013.

30. Fuel consumption curve data (with stern flap) provided by the U.S. Navy and U.S. Coast Guard.

31. O’Rourke, “Coast Guard Cutter Procurement: Background and Issues for Congress.”

32. Alexadra Kirk and staff, “Dud Frigates are an Inherited Nightmare: Fitzgibbon,” ABC News Australia , , 2 January 2008.

33. O’Rourke, “DDG-51 and DDG-1000 Destroyer Programs: Background and Issues for Congress.”

34. “Industry Projects: Comparison of Frigates,” Naval Technology ,

35. “Industry Report: Ship Building and Repairing,” Highbeam Business , , 2013.

36. Cavas, “U.S. Navy Weighs Halving LCS Order.”

37. “Options for Combining the Navy’s and the Coast Guard’s Small Combatant Programs,” Congressional Budget Office , July 2009,

38. “Pentagon Caps LCS at 32 Hulls, Hagel Directs Navy to Evaluate ‘Capable and Lethal’ Frigate Designs,” USNI News , , 24 February 2014.O. Kreisher, “CNO Points to Alternatives to the ‘Gray Hull’ Amphibious Ships,” Seapower Magazine , , 25 October 2013.

Lieutenant (junior grade) Howitt has served as a surface warfare division officer on the USS Fitzgerald (DDG-62) and USS Stethem (DDG-63), both forward-deployed to Yokosuka, Japan. He is a designated operations analysis subspecialist and a member of CRIC[x], the CNO’s Rapid Innovation Cell Experimental Group.


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