Tag Archives: Destroyers

Japan’s Izumo-class Helicopter Destroyer: An Aircraft Carrier in Disguise?

By Matthew Gamble

The Land of the Rising Sun has been quietly strengthening its military capabilities and procuring advanced equipment amid the ongoing debate over whether to amend Article 9 of the country’s constitution. Though officially called the Japan Maritime Self-Defense Forces (JMSDF), the Japanese Navy boasts an impressive array of hardware and if the country’s ruling party has its way with the constitution, its capability will only get stronger.

To increase the potency of the JMSDF even further, the acquisition of aircraft carriers (CVs) would be a logical next step. Yet, as CVs can best be described as seagoing airbases with significant offensive capabilities, Japan’s pacifist constitution prohibits their use in its navy. Destroyers (DDs) on the other hand rely on speed and maneuverability and are easily employed in defensive roles, criteria deemed acceptable under the Japanese Constitution. Therefore, to accommodate this unique political limitation, the Japanese have designated one of their latest vessels as a “helicopter destroyer” (DDH) but with capabilities akin to those of an aircraft carrier.

American Nimitz class supercarrier besides Izumo and Hyuga class vessels of the JMSDF.

Enter the vessel in question: the JS Izumo (DDH-183), commissioned on March 25th, 2015. Officially classified as a $1.2 billion “helicopter destroyer”, this warship is the largest constructed by Japan since the Second World War, and at first glance bears a striking resemblance to a light aircraft carrier. With an impressive length of 248 meters and a beam of 38 meters, the vessel is larger than short take-off and vertical landing (STOVL) carriers operating in the Spanish and Italian navies. Likewise, its fully-loaded displacement of 24,000 tonnes and 7.3 meter draft put the Izumo class in a category similar to that of the Invincible class carriers commissioned by the Royal Navy. Altogether, the scale of these vessels represents a major advance in Japan’s maritime defense capabilities, significantly increasing the country’s ability to project force.

Equipped with the latest in electronic warfare, fire control, and radar systems, the Izumo class has been designed with the battlefield of the 21st century in mind. According to Janes Defense, the Izumo class will carry up to 14 helicopters- primarily Japanese-built MCH-101s and SH-60Ks equipped for anti-submarine warfare or search-and-rescue operations. For closer encounters, the Izumo is equipped with the Phalanx and SeaRam close-in weapons systems (CIWS), capable of defeating most forms of incoming ordnance.

Furthermore, the Izumo class boasts the exceptional capability of supporting amphibious assault operations as the ships have the capacity to embark up to 400 marines and approximately 50 light vehicles. However, unlike the American Wasp-class, the Izumo is not equipped with a well deck and relies on its compliment of helicopters to provide embarked marines with the ability to rapidly deploy in amphibious operations.

Izumo 1
Izumo with helicopters ready on the flight deck.

The Izumo will be supplemented by the JS Kaga (DDH-184), launched in late-August 2015 and expected to be commissioned sometime in 2017. Named after the Japanese province, the second ship of the Izumo class has the dubious honor of sharing the same designation as the infamous IJN Kaga- an aircraft carrier that took part in the surprise attack on Pearl Harbor in 1941 and served with the Imperial Japanese Navy until scuttled at the Battle of Midway in 1942. Unsurprisingly, the choice in name has raised eyebrows given the current Kaga’s aircraft carrier-like appearance.

Though the Izumo and her sister ship Kaga lack catapults or a “ski-jump” to assist conventional fixed-wing aircraft (such as the F/A-18) during take-off and arrestor cables for their recovery, the potential for operating STOVL aircraft from these vessels is high. For instance, in addition to greater size, major alterations were made to the design of the flight deck from Japan’s previous Hyuga class of helicopter destroyers. The new Izumos remove obstacles from the flight deck and rearrange equipment that would prevent the launch and recovery of fixed-wing aircraft. The CIWS system mounted on the foredeck of the Hyuga class has been moved well to the side, opening up the much needed space necessary for fixed-wing operations. Moreover, the aft vertical launch silo has also been removed, allowing for greater ease of aircraft recovery. By and large, changes such as these are critical for allowing the vessel to operate fixed-wing aircraft.

Should Japanese leaders decide to include a compliment of fixed-wing aircraft on the Izumo class, STOVL or vertical take-off and landing (VTOL) aircraft would be necessary as the ship’s basic design lacks the size of catapult assisted take-off barrier arrested recovery (CATOBAR) carriers. Though currently slated to be delivered to the country’s air force, domestic production of the Lockheed-Martin F-35A JSF is already underway in Nagoya. It is unclear, however, whether Japan will produce or purchase the F-35B- the model of the JSF with the STOVL capability necessary for the aircraft to operate from any Izumo class vessel.

A F-35B practices vertical take off and landing.

To accommodate the JSF, a few key modifications to the class would be necessary. Thermion coating, like that used on the Wasp class, would need to be applied to protect it from the extreme heat created by the F-35’s exhaust during vertical landing. Second, a ski-jump similar to those employed on most European carriers would likely be needed to assist the JSF during take-off, though this is not an absolute necessity as preliminary testing on the Wasp class has demonstrated. Moreover, since Japan has ordered the V-22 Osprey, its addition to the ship’s complement is likely. Should a complement of F-35’s and V-22’s be added to the Izumo and Kaga, Japan would boast an increased maritime strike capability, signaling Japan’s increasing military power to its rivals.

Overall, the capabilities of the new Izumo class “helicopter destroyers” represent a step up for the JMSDF. Though in their current configuration the vessels are not capable of fielding conventional fixed-wing aircraft, with minor adjustments and a compliment of STOVL aircraft, the Izumo class would boast similar capabilities to light aircraft carriers currently serving around the world.

Given this potential, simply calling these ships “helicopter destroyers” could be construed as misleading, or even deceptive. Therefore, we can surmise that the classification is largely for political purposes, as the inherently offensive capability of aircraft carriers would run counter to the values espoused in Article 9 of the Japanese Constitution. Whether the JMSDF decides to further develop the capability of these ships has yet to be seen; however, the potential is there and serves as a warning to China and the DPRK that Japan is indeed a maritime power to be reckoned with.

Matthew Gamble is an International Relations student at St. Thomas University, Fredericton, New Brunswick, Canada. His interests primarily focus on the foreign policy of Eurasian states, and new developments in warfighting capability.

Fit to be a Frigate?

LCS 3One of the most persistent complaints about the Littoral Combatant Ship (LCS) is that it is not fit to replace the retiring Perry class frigates. LCS has been characterized as under-armed in comparison with the Perry class, and not capable of assuming the roles and missions of a frigate. In light of these criticisms it’s useful to examine what constitutes a frigate in the second decade of the 21st century. What sort of frigate does the U.S. Navy need to meet present requirements? Finally, does the LCS, in both its current form, and as envisioned in the frigate upgrade meet those requirements, particularly in armament? The answers may surprise LCS critics who continue to call for a Cold War frigate as the solution for 21st century naval missions.

The definition of the frigate as a naval combatant has been in constant flux since the end of the Second World War. It appeared in the Second World War as a British Royal Navy (RN) classification for an independent antisubmarine warfare vessel. By 1945, the term “frigate” generally meant a ship of 1300-2000 tons; less than 350 feet in length; a speed of less than 25 knots, and an armament focused on antisubmarine weapons.

The U.S. Navy substantively changed the frigate designation after World War 2 with its first generation of purpose-built aircraft carrier escorts. The demise of the Axis surface fleets, the well-established threat from air attack, and the rise of a Soviet Navy based on submarines called for a new, affordable combatant that could meet these challenges. A ship roughly 6000 tons in displacement, a speed comparable to fleet carriers, and capable of mounting significant antiair (AAW) and antisubmarine (ASW) weapons was seen as an ideal cross between the expensive, man-power intensive cruiser and the cheaper, but less capable destroyer class. The new ship was designated first as a “hunter killer” (CL) and later as a “frigate” (DL) with missile armed versions classified as DLG’s. Destroyers, such as the Forrest Sherman class and their missile-armed immediate successors, the Charles Adams class remained general purpose combatants optimized for a variety of roles, but generally less capable than frigates. Smaller combatants optimized for antisubmarine warfare remained labeled as destroyer escorts (DE’s).

This condition persisted until the mid 1970’s. U.S. frigates had approached the size and capabilities of World War 2 cruisers in the California and Virginia class DLGN (nuclear-powered) frigates of 10000 tons and nearly 600 feet in length. The traditional antisubmarine warfare escort had also grown in size and capability. Many of these ships, such as the FF 1052 Knox class were significantly larger than the 1940’s-era ships they were replacing. These changes compelled the U.S. to re-designate a number of its warships in 1975 to better reflect the changes in the frigate classification since 1945, as well as to combat a persistent myth that the U.S. had less cruiser-designated ships than the Soviet Union. The frigates were divided into guided missile cruisers and destroyers based on size and capability. U.S. destroyer escorts were renamed as frigates.

The patrol frigate, later the FFG-7 Oliver Hazard Perry class was the zenith of American Cold War escort design. The Soviet Union was expected to deploy a significant force of subsurface, surface, and aviation platforms to destroy the expected Reforger re-supply convoys crossing the Atlantic to support embattled North Atlantic Treaty Organization (NATO) forces in Western Europe. Unlike previous escort classes, the FFG-7 was designed as a multimission combatant in order to better meet the expanding Soviet threat. It too, like the LCS,  ballooned in cost. According to a January 3, 1979 General Accounting Office (GAO) report, the cost per ship increased from 64.8 million dollars a ship in 1973, to 194 million a copy by 1979.

This general classification system of U.S. surface combatants persisted through the end of the Cold War and the first decade of the 2000’s. After 1991, however, the international definition of the frigate category again began to change. Falling defense budgets across the Western world in the wake of the Cold War’s end compelled many nations to put more capabilities into fewer hulls, often designated as frigates, as a cost savings measure. These ships now occupy a place in many European navies analogous to that of the U.S. Arleigh Burke class DDG as the primary surface warships of those nations’ navies. Japan and South Korea have made similar changes, but have retained the destroyer classification for these larger vessels. Russia maintained the Cold War classification structure throughout most of the last 20 years, but its recent frigates are smaller than their late Cold War cousins. The Chinese Navy has followed the Russian Cold War model and gradually increased the size of its frigates as general patrol and escort ships. Although there remain several descriptions of the frigate type warship, the post-Cold War ship now associated the frigate classification has generally grown into a large and capable surface combatant for many nations.

Does the U.S. Navy need a frigate as defined by these new standards? At the end of their service lives, the Perry class had lost much of their (AAW) and (ASUW) sensors and weapons. Their MK 92 fire control system, MK 13 single arm missile launchers, and medium range Standard Missile (SM-1 MR) systems were largely out of date against the growing antiship cruise missile threat by the turn of the century. They had become the early 21st century equivalent of the late 19th century colonial cruiser, whose chief purpose was to show the flag and conduct low-intensity combat operations.

The U.S. high capability combatant class is well filled by the CG 47, DDG 51 and DDG 1000 class ships. Such a mass of AAW capable ships was not in service when the Perry’s were conceived. While the U.S. Navy requires a replacement for the Perry’s “show the flag” role, there appears to be no requirement for another medium capability convoy escort in the tradition of past U.S. frigate designs. The cruise missile threat is considerable for even high capability warships such as the DDG 51. A supporting frigate similar in size and capability to current European designs could be built, but would provide little in the way of additional capability beyond present ships. It would also not be a cost effective product for low end presence missions. Unlike during the Cold War, no potential U.S. opponent yet deploys a global naval force capable of simultaneously effectively threatening U.S. seaborne communications in multiple geographic locations. The absence of this threat for now obviates the need for 21st century version of the FFG-7. If that threat develops, advances in missile and torpedo technology will require high capacity escorts like the DDG 51 rather than a new FFG-7.

The frigate needed for the present Navy is not another Cold War antisubmarine combatant, or an expensive, but less capable version of the DDG 51. It should instead be a general-purpose warship capable of multiple tasks. It must conduct low threat missions such as counter-piracy and presence operations in order to free the DDG force for offensive and defensive missions in high intensity combat. It should be able to perform escort missions for amphibious and logistics force ships for limited periods in appropriate threat environments. The addition of a surface to surface missile armament should allow the frigate to conduct limited ASUW under the Navy’s emerging concept of distributive lethality. LCS’ endurance is 70% of the FFG-7, but it’s still sufficient for extended operations in comparison with smaller corvettes or missile patrol craft. The LCS baseline platform with 57mm gun, Rolling Airframe Missile (RAM), electronic warfare gear, boats, and large flight deck and hangar is an excellent replacement for the FFG-7 in low threat, presence missions. The ship can accomplish escort and additional warfare missions with the weapons and sensors provided in its warfare modules and frigate upgrade. The ship’s modular design readily accepts additional weapons and associated equipment. The frigate upgrade to the basic LCS hull has been derided as insufficient, but only if a 21st century FFG 7 is the desired product. The modifications envisioned for the LCS-based frigate meet current requirements and definitions for the 21st century frigate the Navy requires.

No would deny the LCS program has suffered significant problems over the course of its history. It introduced multiple new technologies in one platform in order to replace three classes of ship. Problems associated with this effort remain and will likely persist for some time. In spite of these issues, the LCS and its frigate variant represent the best choice for replacing the retiring Perry class frigates in their current role as presence, patrol, and low intensity combat platforms, as well as emerging surface warfare missions. The Navy does not need a 21st century Perry class frigate.

Steve Wills is a retired surface warfare officer and a PhD student in military history at Ohio University. His focus areas are modern U.S. naval and military reorganization efforts and British naval strategy and policy from 1889-1941. He posts here at CIMSEC, sailorbob.com and at informationdissemination.org under the pen name of “Lazarus”.

LCS Survivability Debate: What the Data Doesn’t Tell Us

“Facts are meaningless.  You can use facts to prove anything that’s even remotely true. Facts, schmacts.”  

-Homer Simpson, from Lisa the Skeptic

100617-N-1200S-914Both Steven Wills in his USNI Blog opinion piece and Chuck Hill in his response trot out some interesting numbers in support of diametrically opposed positions on the survivability of LCS.  According to Wills, the US Navy lost ships under 3400 tons at a much higher rate than larger vessels in WWII.  Hill looks at the numbers and comes to the opposite conclusion.  The debate reminds me of the recent statistical dustup over the Patriots’ propensity to fumble that has accompanied Deflategate.  And the numbers are just about as meaningful.

Wills asserts that the US Navy lost 71 destroyers and 11 destroyer escorts in WWII.  Hill makes that number to be 58 destroyers and 9 destroyer escorts.  From what I can tell, they’re both wrong.  Using the summary report for ship losses to enemy action from 17 October 1941-7 December 1944, the US Navy lost 134 destroyers and 16 destroyer escorts through December 1944.  I could not easily find numbers from December 1944 through the war’s end, but the fact that these figures do not include losses from the Battle of Okinawa suggest that the actual number of destroyer losses for the whole war was closer to 150.  Over the period of the report, the US Navy also lost 51 cruisers (CA and CL), 22 battleships, and 39 aircraft carriers (combining CV, CVL, and CVE losses).   

After citing the number of losses, Hill uses the fate of vessels in commission at the start of the war to extrapolate survivability statistics for all vessels.  Statistically, this is highly suspect.  As Hill points out, the US fleet at the start of the war included just 233 major surface combatants.  But between 1941 and 1945, the US built over 1,300 more major surface combatants, including 349 DD’s and 498 DE’s.  Those ships in commission at the start of the war are a non-random sample, since they would tend to be older, slower, and less likely to incorporate new weapons, sensors, and other technologies that could affect survivability, unless backfitted during the war.  The US had no DE’s in commission at the start of the war, further skewing the sample.  

The numbers in the two reports point out some of the challenges with getting accurate data: since the US had no DE’s in commission at the start of the war, all 16 DE losses should come from those commissioned 1941-1945.  But only 9 are annotated as “sunk” in the shipbuilding report.  Similarly, 32 of the 349 DD’s commissioned during the war are listed as “sunk,” which when added to Hill’s figure of 29 destroyers in commission at the start of the war that were sunk comes nowhere close to the figure of 134 destroyers lost (nor even to Wills’ figure of 71, although it is over Hill’s figure of 58).  But it doesn’t matter.

falklands warThe most significant figure in the WWII ship loss data is zero.  That’s the number of ships lost to anti-ship cruise missiles.  While it’s tempting to try to draw equivalencies between threats in WWII and threats today, the simple fact is that war at sea looks different today than it did then.  The Falklands campaign, in which the Royal Navy lost two ships (a 5,000 ton destroyer and a 15,000 ton logistic ship) to Exocet missiles, and another five vessels (one LCU, two Type 21 frigates of 3,290 tons, a destroyer of 5,000 tons, and an auxiliary of 6,000 tons) to aerial bombs, may provide a more relevant frame of reference.  British ship losses in the Falkland campaign totaled two of 15 frigates and two of 12 destroyers or larger.  While these numbers are helpful, it’s worth remembering the facts behind the data: the RN were limited in their mobility by the need to protect the landing force; the Argentinians were operating at the outer limits of their range, limiting the duration of engagements.  And with such a small sample, it’s risky to draw too-strong conclusions.  

The most significant contributor to ship survivability is not getting hit.  Hill argues that LCS will not be a priority target due to its small size and relative unimportance.  Such an argument depends on the presence of perceived higher-value targets to draw fire.  But the whole nature of the A2/AD problem is that it creates too much risk to put high-value targets under the threat umbrella.  If LCS is the only surface platform we’ve got in the fight, it will be the platform that the adversary targets.  (Worse, if LCS is heavily dependent on the proximity of vulnerable combat logistics force ships to stay in the fight, an adversary may not need to target LCS at all, choosing instead to sink the oilers, rendering LCS immobile and irrelevant.)

The debate about LCS survivability is important, especially as we look to up-arm the ships and give them more offensive punch.  And, given the program’s history of overly-optimistic estimates of cost and capability, I understand why analysts would prefer to “go to the data,” rather than relying on assurances of improved survivability and defensive capability.  But unfortunately, we don’t have access to survivability data in an unclassified debate.  In the absence of the models and simulations that have been run on LCS versus modern threats, looking for examples from the past of different ship types versus different threats only clouds the picture.  In short, going back to World War II data to try to prove a point about the survivability of large ships versus small ships in modern combat is about as relevant as pointing out that USS Constitution, a ship of only 1,500 tons, was so survivable that she earned the name, “Old Ironsides.”  

Doyle Hodges is a retired Surface Warfare Officer currently pursuing PhD studies at Princeton’s Woodrow Wilson School of Public and International Affairs.

The LCS Survivability Debate

There has been a lot of discussion lately about the survivability of the LCS and smaller combatants in general. A recent US Naval Institute News opinion piece contends,

“Small warships are historically unsurvivable in combat. They have a shorter floodable length, reduced reserve buoyancy and are more likely to be affected by fire and smoke damage than larger combatants. In both World Wars, losses in ships below 3000 tons in displacement far exceeded those of larger vessels.

“In World War II, for example, the U.S. lost a total of 71 destroyers and 11 destroyer escorts — all under 3400 tons displacement and less than 400 feet in length.

“By comparison, only 23 larger ships were lost. Part of that figure is undoubtedly due to their operational employment, but in simple terms of engineering and physics, larger ships are inherently more survivable than their smaller counterparts.”

In the Coast Guard we once had a saying, “In our obscurity is our security.” I think that should be kept in mind when we consider the survivability of small surface combatants. No, they cannot take as much damage as major surface combatants, but the enemy gets a vote, and he will be less “excited” by the presence of smaller vessels, while he will normally choose to put more effort into destroying larger, more threatening ships. As in land warfare, tanks are more survivable than infantrymen, but they don’t necessarily last longer.

To look at how this factor might influence survivability, I looked at how many of the ships that were in commission at the beginning of World War II were sunk as a result of enemy action. My source is the Summary of War Damage to U.S. Battleships, Carriers, Cruisers, Destroyers, and Destroyer Escorts which is accessible here. The figures there do not correspond to those quoted above, rather they report 58 destroyers and 9 destroyer escorts sunk, along with 26 larger surface combatants, all listed by name. (The USNI post may have included constructive losses that were not actually sunk or losses to other than enemy action, and does not include the three battleships salvaged although they were out of action most of the war.)

If we look only at the US fleet at the beginning of the war, it included 233 major surface combatants of which 46 or 19.7% were sunk by enemy action during the course of the war. If we break it down by class it looks like this:

Type: Number in Commission, Dec. 7, 1941/Number sunk/% lost to enemy action
Aircraft Carriers (CV): 7/4/57.1%
Escort Carrier (CVE): 1/0/0%
Battleships (BB): 17/5/29.4% (of the 5 sunk, all were at Pearl Harbor, 3 were salvaged)
Heavy Cruisers (CA): 18/7/38.9%
Light Cruisers (CL): 19/1/5.3%
Destroyers (DD): 171/29/17%

(There were no Destroyer Escorts in commission at the beginning of the war.)

If we lump  all the cruisers together, 8 of 37 were lost or 21.6%

If we lump the lone escort carrier together with the fleet carriers then four of eight were sunk or 50%

Additionally three destroyers were lost to weather in a hurricane. They were not ballasted properly, because of the exigencies of impending combat operations.

Clearly, at least looking at the World War II experience, the US Navy did not lose a higher percentage of smaller ships. If anything it appears the opposite is true. A smaller percentage of smaller ships were lost (17% vs 27.4%). More small ships were lost simply because there were many more of them. Undoubtedly some of the DDs and DEs that were sunk, would have survived the damage they received, if they had been bigger, but presumably there would also have been fewer of them. If the decision criteria were an equal chance of being sunk, then probably taking greater risk with smaller ships is both reasonable and unavoidable.

I will note that the probability of personnel loss on small ships is probably higher because they are more likely to sink quickly and catastrophically, while larger ships are more likely to sink slowly.


Photo: USS Newcomb DD 586 was hit by as many as five kamikaze on 6 April 1945 as she was screening for the cruiser USS St. Louis off Okinawa. She survived but was not repaired.




I will add a bit of anecdotal evidence. As part of Operation Overlord, the Normandy Invasion, 60 US Coast Guard 83 foot patrol boats were assigned to rescue those unlucky enough to find themselves in the water or sinking. 30 went to the American beachheads and 30 went to the British and Canadian beachheads. Being wooden hulled and gasoline powered, they certainly would not have been considered “survivable.”

USCG 83 ft patrol boat, probably June 1944. Photographer unknown.

Apparently they were in the thick of it, because they rescued 1438 men from the water and sinking craft. In spite of all the fire from shore, not a single boat was sunk and not a single crewmen was killed. Apparently the German gunners were too busy with the landing craft hitting the beach and the warships that were shelling them. They simply were not a priority target.


This article can be found in its original form at Chuck Hill’s CG Blog.