The US Navy needs a sizable fleet of small but lethal combatant ships, suitable for either deep oceans or littoral waters, to provide sea control globally. A ship the length of a corvette but with the displacement of a frigate, which I’ll refer to as a “frigette,” could achieve lethality at a constrained length, with more emphasis on weapons, seaworthiness and survivability than on speed. A line drawing of this concept vessel is presented as Fig. 1.
Why We Need the Frigette
Currently, the U.S. Navy is mainly comprised of carrier strike groups (CSGs).[1] In a post-Cold War world, operating against countries lacking any appreciable missile capability, CSGs have performed successfully. But an aircraft carrier must operate from a relatively safe location. Even armed with Aegis and Phalanx antimissile systems, a carrier might be unable to defend against a peer or near-peer enemy launching repeated missile swarms. Other concerns include:
- Difficulty in moving CSGs quickly from one region to another.
- Inability to place CSGs in many locations at once due to their small numbers.
- Large crews that will suffer a devastatingly high loss of life if a carrier is destroyed.
- Extremely expensive and time-consuming replacement process.
Today we face growing threats that will challenge the effectiveness of CSGs soon. China is rapidly building a modern military, including a navy and weapon systems designed to counter ours. China’s encroachment into the South China Sea and its antiaccess/area denial (A2/AD) program threaten future conflict.[2] Russia is rebuilding its military capability and has demonstrated territorial ambitions by occupying Crimea, and Iran and North Korea are both building military assets that aspire to threaten the U.S. mainland. Finally, a proliferation of stateless terrorist organizations continues to create hotspots around the world that may require U.S. intervention. Against jihadists, CSGs constitute expensive overkill.
At any given time, our CSGs are needed in just a few places in the world—hotspots requiring considerable military strength. There are always other places a U.S. naval presence is needed, but where CSGs are grossly inappropriate. This is the basic argument for the frigette.
National security requires a military that can win a war against a peer or near-peer enemy. Such wars cannot be won by naval or air power alone, but only by full use of sufficient land forces. Those forces must have assured logistics, usually seaborne. Only the Navy can protect logistics shipping. The concept frigette is the sort of ship our Navy should have in considerable numbers, capable of many missions, and available at the beginning of any war to provide initial protection of logistics as we ramp up the war effort.
The Navy recognized its need for smaller craft to supplement its CSGs and developed the littoral combat ship (LCS). However, the LCS an oversized speedboat that is short on ruggedness and lethality.
Uses for the Frigette
If the Navy were to build a sizeable fleet of frigettes—perhaps 200 or more over a span of 15 or 20 years—they could serve in areas of the world’s oceans where our CSGs do not. Widely dispersed, each frigette would be capable of projecting power over a radius of about 1,200 nautical miles, allowing widely dispersed frigettes to concentrate projected force.
Peacetime roles would include:
- Suppressing piracy and keeping shipping lanes open for international navigation.
- Exhibiting the presence of the U.S. Navy worldwide.
- Providing “export of security” support to nations lacking adequate maritime security assets to fight terrorism in littoral environments.
- Providing a proportional, cost-effective response to international terrorism including the hosting and support of US antiterrrorist missions, coastal surveillance, interdiction, and vessel boardings.
Wartime functions of the frigette could include:
- Escorting merchant ships.
- Attacking land- or sea-based targets with missiles and guns.
- Using air assets to attack land- or sea-based targets.
- Defending against submarines, cruise and ballistic missiles, surface ships, and enemy fast boats.
- Operating in hunter-killer antisubmarine groups.
- Hosting mine-hunting systems.
- Conducting surveillance, reconnaissance, and intelligence missions.
- Helping maintain security of domestic waters.
- Disrupting enemy seaborne logistics.
- Concentrating force from widely dispersed frigettes within missile range of a target.
- Supporting special operations.
The frigette’s missile load would depend on its situation and mission. In case of a conflict with a major power, a fleet of frigettes could defend vital merchant shipping, which otherwise would be decimated early-on. In this regard, we should have learned from World War II. During the first six months of our involvement, (early 1942), 2,800 allied merchant ships were sunk by the Germans. That slaughter occurred because the U.S. Navy lacked proper vessels or a strategy for protecting those ships. It was not reduced substantially until our destroyer escorts came off the production lines in 1943. The Navy must never again fail to protect the merchant marine.
Today the U.S.-flag merchant marine is small, with only about 175 ships. But U.S. entities own almost 800 ships registered in other nations. In a near-peer war, where our merchant ships were under threat, all those U.S.-owned foreign-flag ships would likely come under U.S. registry, to qualify for U.S. Navy protection. So then our Navy would be responsible for protecting about 950 or more merchant ships, even before wartime construction brought additional ships online. If a fleet of frigettes were available at the early phase of such a war, it could prevent wholesale slaughter while both merchant ships and appropriate escort ships are being set up for production.
Advantages of the Frigette
The frigette will be fully capable of operating anywhere in ice-free oceans, independent most of the time or in small groups in high-threat areas. In large numbers frigettes will demonstrate Navy presence impressively, as their armament will be convincingly evident. Operating spread out around CSGs, they could expand antisubmarine coverage, provide antimissile defense, and could launch land-attack missiles out to the range of their missiles. The frigette will be too small to attract a swarm of antiship missiles, therefore, it needs only a few antimissile missiles for self-defense. The frigette’s missiles will be just as far-reaching and lethal as those of destroyers or cruisers. To attack or defend areas at closer range, the frigette’s air assets could be used to launch weapons and/or convey personnel into and out of inland positions. These air assets will consist of various types of mission-appropriate helicopters and/or other vertical-launch aircraft.
A large fleet of frigettes will produce many more competent officers and petty officers than our present fleet structured around aircraft CSGs. The small number of large ships comprising a CSG offers fewer opportunities for command than a large group of small ships. If serious war occurs, a larger group of competent professionals will be invaluable to a building a wartime Navy. Another advantage of maintaining a fleet of such small ships is that fewer crew will be lost if a frigette is sunk. The loss of one or two vessels from a large fleet of small ships would be less damaging than the loss of a larger ship from a smaller fleet.
Frigette Design Specifications
The concept frigette’s length is 330 feet at the waterline, 349 feet overall, and should only be longer if necessary to accommodate its essential weapons and features. Its beam is 64 feet. Though it seems a small, the frigette is only 27 feet shorter overall that a Fletcher-class (DD-445) destroyer of World War II. But it is 21 feet wider in beam and heaver in displacement. If more volume is needed, the beam should be widened before length is added. Practicability and mission goals should rule in design decisions.
The concept frigette has no funnel or mast. To elevate the surface search radar, there is a conic tower above the deckhouse with the antenna on top. The four inward-sloping sides of the deckhouse offer bulkhead areas for radar arrays for multifunction passive electronically scanned array radar for air and missile defense. Safety nets of stainless steel wire cable and tubular frames will be installed around the helicopter deck, like that of the Arleigh Burke-class (DDG-51) guided missile destroyer.
The ship should be built for a design speed of 24-26 knots and a range of about 12,000 miles, and should be rigged for underway replenishment. Its steel hulls, built a bit thicker than necessary for its size with armor around critical features, should anticipate an operating life of about 40 years.
The hull speed of a displacement hull is about 1.34 times the square root of its waterline length. So, the hull speed of a ship with a 330-foot waterline length is 24 knots. Powered for a speed of about 26 knots, slightly above hull speed at maximum power with propellers and waterjet, I assume a waterjet of about 25,000 horsepower mounted on the centerline between the two propellers. I prefer propulsion only by waterjets, as propellers are susceptible to damage in littoral environments. But with about 200 such ships, the cost of acquisition and of operation over a lifetime must be considered. I would compromise by providing two controllable- and reversible-pitch propellers and a centerline steerable waterjet with reversing bucket. They would be driven by electric motors, with electrical power provided by diesel engines and gas turbines, all driving alternators.
These ships should operate most of their lives at relatively low speeds, with electrical power provided by the diesel engines driving alternators. Propellers are more efficient at lower speeds, and waterjets at higher speeds. When operating in shallow and uncertain waters, safety would trump speed, so then it would be safer to proceed with waterjet for propulsion and steering, with the propellers stopped and feathered. Excess electrical power for weapons systems would be produced by gas turbines.
The frigette’s features should include as many as feasible in one design of the following: all-electric drive, a stern anchor and a stern-launched Willard 7-meter rigid hull inflatable boat (RHIB), and a strong bow thruster. It should have a relatively large flight deck to be used by various types of helicopters and other vertical-launch aircraft. Armament should include a 5-inch/62-caliber land attack gun forward, and two 76-mm Otobreda super rapid cannons, one forward of the bridge and one aft. The frigette also should have two laser turrets; one to port, another to starboard. It would have two autonomous SeaRAM missile launchers, each with 11 missiles, and four 25-mm M242 Bushmaster autocannon, two on each side.
If support of special operations is elected, then there will be two 11-meter RHIBs, one on each side, launched and recovered with dual point luffing davits. The davits stand 13-14 feet tall and are about 30 feet apart, nested inside recesses on the 01 deck, the forward end of the recesses that are about centered on the side of the deckhouse.
Instead of funnels for the exhaust gases of diesels and gas turbines, all exhaust gasses will go into a water spray cooler and thence into a horizontal duct and discharge out the side of the hull above the water line, providing thermal stealth. This system should be similar in principal to the German-built South African Valour-class frigate, as will the propulsion arrangement of propellers and a waterjet. But instead of direct drives, the propellers and waterjet will be driven by electric motors. There will also be a power storage system, probably using lithium ion batteries. It could power weapons, or power the ship for launch and recovery of boats alongside, to avoid exhaust gas effects on boat occupants.
The bottom of the hull will be highly compartmented, and there should be two engine rooms, not necessarily adjacent to one another. The sides of the engine rooms should be double-skinned, with the inner skin thicker than the outer skin, to deflect an explosion outward in case of a hit there. Principal bulkheads inside the hull should have water sprinkling systems for cooling in case of fire, so personnel would not need to man fire hoses for bulkhead cooling. A drainage system and pumps should be provided for dewatering during firefighting.
There should be hull-mounted mid and high frequency sonars, and a towed multi-frequency sonar array. The towed sonar array would emerge from one side of the stern transom, and a stern anchor from the other side.
The 5-inch/62-caliber gun has a range of about 21 nautical miles with standard ammunition. Rather than seeking extended range ammunition, the Navy should develop a relatively small missile with a range of 50-60 nautical miles. I see a clear need for such a missile, in lieu of rocket-boosted gun projectiles.
Atop the bridge will be two remotely controlled Griffen C missile launchers. Preferably in the forward peripheral vertical launch system (VLS) modules, it would carry six antiship missiles and ten antimissile missiles. It should have antisubmarine (ASW) sensors and weapons, including a couple of trainable triple torpedo tubes with Mark 54 torpedoes, and be capable of carrying, when appropriate, two ASW helicopters, or two vertical lift aircraft of suitable type.
The Mark 57 VLS for missiles is suggested. Its two-cell design allows for exhaust of the hot gases produced by a missile launch, unlike the one-cell Mark 41.
If calculations show that heat from the launching of forward missiles is a problem for the pilothouse, then an arrangement of quickly closing shutters would be devised for the pilothouse windows, to be closed before launch of forward missiles. When missiles are to be launched, the commanding officer and ship control team could step back into the combat information center (CIC) and control from there, where there are no windows and there is an electro-optical system for outside view.
When used primarily for anti-submarine work, I would expect the frigette to have a couple of vertical launch system cells normally holding Tomahawk missiles to be used instead for RUM-139 anti-submarine rocket (ASROC) torpedoes (the vertical launch version of the ASROC). The ASROC range is about 12 nautical miles, giving the ship a standoff capability for killing submarines.
If a suitable remote mine-hunting system is developed, the frigette should host that it, likely from the 03 deck, atop the aircraft hangars. Laser weapons such as the AN/SEQ-3 laser weapon system (XN-1 LaWS) directed energy weapon have been under testing and/or in use by the Navy since 2014.[3] The frigette should have the latest laser weapon available when the ship is designed.
It is too early to estimate the ship’s complement, but the goal would be a small crew for the vessel’s size. Using the basic principles that have been used by the world’s merchant fleets, navigation and engineering should require only about a dozen persons. Additional manning will depend on the degree of automation on weapons and sensors. I see no technical reason why about 60 qualified persons could not run this ship, including the air crew. If Aegis systems are installed, more people will be added: currently about 33, but that may be reduced over time. [4] Most of the ship’s weapons will be operated remotely, but not all at the same time. More automation means less crew.
The mooring arrangements are not shown on the concept drawing. There will be six mooring lines, each wound on a winch drum, with provision for locking the drum when automatic tensioning is not desired.
Because frigettes will typically operate alone, and may have to deal with pirates or jihadists, they should be equipped with appropriate small arms. Their crews should be continuously trained as shooters. This training should allow each crew member to attain his or her shooting potential. At least three crew-comprised sniper teams are suggested for each ship.
Summary
The concept frigette is about as short a ship with monohull that is likely to be equipped with all the armament and features I have suggested. My conceptual sketch of the ship shows the locations of the weapons I suggest, but does not venture into the internal design, which should be undertaken by naval architects and marine engineers. Ideally the design team should consist of Navy personnel, not contractors. That design team should follow these ships through their life of service in the Navy, so the design can be continually tweaked to enhance performance and achieve cost effectiveness.
In times of war or peace, the frigette will augment the Navy’s CSGs by projecting naval power in areas where CSGs cannot operate. Most of the time, frigettes will operate independently. But in wartime, they can also join CSGs or can be grouped into their own strike groups. Sometimes, in war or peacetime, frigettes can operate in groups that are widely dispersed, but with their capabilities concentrated. Either way, the frigette will fill a demonstrated need for which the littoral combat ship is inadequate.
END NOTES
[1] A CSG is an operational Naval formation usually consisting of an aircraft carrier, at least one cruiser, a destroyer squadron of at least two destroyers and a frigate; around 7,500 personnel, and a carrier air wing of 65 to 70 aircraft. It may also include submarines, as well a logistics and supply ships.
[2] Warfare strategy intended to defend against an opponent with superior military capabilities to prevent their ability to launch military missions near, into or within the Chinese mainland or nearby contested regions.
[3] Sam LaGrone, “U.S. Navy Allowed to Use Persian Gulf Laser for Defense,” USNI News, 10 December 2014.
[4] The Aegis Combat System is comprised of Aegis Weapon System (WS), the fast-reaction component of the Aegis Anti-Aircraft (AAW) capability, along with Phalanx Close In Weapons System (CIWS), with Mark 41 vertical launch system. As mentioned above, the Mark 41 should be replaced by the Mark 57, if feasible.
