As of today, what is now currently known as the "Japanese Navy" by simplification could barely stand as "defensive" as its ships numbers and quality tends towards a regional blue water navy. As of particular interest are the latest "helicopter cruisers" like the izumo class (Izumo and Kaga), capable of operating the F-35 and succeeding to the Hyūga class. The main reasons are two folds: The new Abe government's own policy, encouraged by the Pentagon and of course the rapid rise of PLAN and regional ambitions of China.
Today the JMSDF boast a fleet of 154 ships and 346 aircraft manned by 45,800 personnel. Main missions are still to protect Japanese sea lanes and patrol territorial waters, also taking part in UN-led peacekeeping operations and Maritime Interdiction Operations. This naval force is one of the strongest in the world, with some of the largest and most powerful destroyers ever built, including some hybrids like the Hyūga and Izumo class helicopter destroyers and AEGIS-capable Kongo class DDs. Japan started early a policy of building standard destroyers assisted by a couple of helicopter destroyers of various capacities. These modern ships are just aircraft carriers in all but name, a considerable leap forward in blue water capabilities, well beyond a strict defensive framework. Indeed to this day Article 9 of the Japanese Constitution still forbid Japan to built any aircraft carrier.
Between 1945 and 1954, about ten years of American occupation, Japan started with little resources barely sufficient to protect fishing areas. Dissolved by the Potsdam Declaration acceptance, the fleet was reduced to a collection of disarmed ships, some taken away as war reparation (to be blasted in nuclear tests in the American case). Others provided means for the repatriation of Japanese soldiers throughout the whole asia-pacific, plus minesweeping the home waters. This dagerous and tiedous task was given to the supervision of the Second Bureau of the Demobilization Ministry. The minesweers were transferred afterwards to the newly formed Maritime Safety Agency, maintaining resources adnd skills for the navy.
Japan's 1947 Constitution Article 9 in particular stated "The Japanese people forever renounce war as a sovereign right of the nation and the threat or use of force as a means of settling international disputes." This was interpreted as to allow only a self-defense force. But under Cold War pressures and forced United States alliance, Japan had to bring its own maritme assets to the local defence rather than relying only on the US Navy. At last in 1952, the Coastal Safety Force was created, as part of the Japanese Maritime Safety Agency. It included the minesweeping fleet and auxiliary vessels including American transferred destroyers. Two years later, this Force was separated to become the core of the JMSDF, a simple branch of the Japanese Self-Defense Force (JSDF), fixated by a law.
In 1956, the JMSDF at last commissioned its first domestically produced destroyer, Harukaze. As the Cold War intensified, the JMSDF main task became the anti-submarine role. Both destroyers and frigates developed for the JMSDF were tailored for ASW warfare in priority. By 1970, this navy was sufficient in this frame to nor depend of the US Navy, which kept a permanent task force centered around a nuclear aircraft carrier. With Japan's economy booming, the Navy also gradually benefited from constant increased in budget and by 1991 had achieved by tonnage an historical peak, both in quantity and quality of ships. They were perfectly able to take head on the Soviet Pacific fleet.
This chapter has been already thoroughly examined in the cold war page, but in the space of 40 years, the fleet scrapped her US-built or supplied ships and restarted naval construction with its own industrial giants, like Mitsubishi, already responsible for Japan's tanks and some of her planes. The main doctrine that dominated Japanese cold war thinking was its role of a shield against any infiltration of the Soviet Pacific fleet submarines, in particular SNA and SSBNs.
Early japanese DDs were clearly tailored for ASW warfare, a role that was pushed forward as a condition to benefit from the MDAP program. Japan therefore accessed in the 1950s to the latest in weapons and sensors tech. The strenght of the Japanese cold war navy rested on destroyers, gradually built into two major types: Helicopter destroyer, generally two ships dedicated to ASW warfare, and more versatile escort destroyers, still helicopter capable, more standard. While the Harukaze, Ayanami, Murasame of the 1950s has been retired in 1990, the oldest Japanese DDs still active were the 1959 Akizuki class, of this early design (discarded 1993), and sole Amatsukaze (1963) that introduced a brand new Japanese DD design (discarded 1995). It was followed by the first class of ASW "escort destroyers", the six Yamagumo class (1965-77). Moderately slow with their diesels, they were still capable of 27 knots and heavily armed for ASW warfare. Two became training ships in 1991, one an auxiliary, the others were still in service in the early 2000s.
The late 1960s will saw again a double class of four standard and three escort destroyers, the Takatsuki (1966-69) and Minegumo (1967-69). The first displaced 3100 tons, the second 2100 tons, 32 knots versus 27 knots. The first were heavily armed, but with slightly better antiship capabilities and more powerful electronics. The Minegumo were again ASW destroyers made for long range patrols. All were in service by 1990.
1971 saw the arrival of the first Japanese Helicopter destroyer, Hiei. With on-board electronics being refined, airborne ASW warfare seemed a better solution and authorized the test of two massive destroyers, the largest postwar Japanese ships so far, bearing famous names also (used by former battleships): Hiei and Haruna. At 4700 tons standard, 6300 fully loaded, they were the largest and most powerful DDs in asia, capable of operating three large ASW HSS-2 heavy-duty long range helicopters.
AA | Anti-Aircraft |
AAW | // warfare |
AAS | Amphibious Assault Ship |
Adm | Admiral |
AEW | Airbone early warning |
AG | Air Group |
AFV | Armored Fighting Vehicle |
AMGB | armoured motor gunboat |
AP | Armor Piercing |
APC | Armored Personal Carrier |
AS | Antisubmarine |
ASM | Air-to-surface Missile |
ASMD | Anti Ship Missile Defence |
ASROC | ASW Rockets |
ASW | // Warfare |
ASWRL | /// rocket launcher |
ATW | ahead thrown weapon |
avgas | Aviation Gasoline |
aw | Above Waterline |
AWACS | Airborne warning & control system |
BB | Battleship |
bhp | brake horsepower |
BL | Breach-loader (gun) |
BLR | Breach-loading, Rifled (gun) |
BU | Broken Up |
c | circa |
CA | Armoured/Heavy cruiser |
Capt. | Captain |
Cal | Caliber or ".php" |
CG | Missile Cruiser |
CIC | Combat Information Center |
C-in-C | Commander in Chief |
CIWS | Close-in weapon system |
CE | Compound Expansion (engine) |
Ch | Chantiers ("Yard", FR) |
CL | Cruiser, Light |
cm | centimeter(s) |
CMB | Coastal Motor Boat |
CMS | Coastal Minesweeper |
CNO | Chief of Naval Operations |
Cp | Compound (armor) |
Co | Company |
COB | Compound Overhad Beam |
CODAG | Combined Diesel & Gas |
CODOG | Combined Diesel/Gas |
COGAG | Combined Gas and Gas |
COGOG | Combined Gas/Gas |
comm | commissioned |
comp | completed |
conv | converted |
convl | conventional |
COSAG | Combined Steam & Gas |
CR | Compound Reciprocating |
CRCR | Same, connecting rod |
CruDiv | Cruiser Division |
CP | Controlled Pitch |
CT | Conning Tower |
CTL | constructive total loss |
CTOL | Conv. Take off & landing |
CTp | Compound Trunk |
cu | cubic |
Cyl | Cylinder(s) |
CV | Aircraft Carrier |
CVA | // Attack |
CVE | // Escort |
CVL | // Light |
CVS | // ASW support |
cwt | Hundredweight |
DA | Direct Action |
DASH | Drone ASW Helicopter |
DC | Depht Charge |
DCT | // Track |
DCR | // Rack |
DCT | // Thrower |
DD | Destroyer/drydock |
DE | Double Expansion |
DE | Destroyer Escort |
DDE | // Converted |
DesRon | Destroyer Squadron |
DF | Double Flux |
D/F | Direction(finding) |
DP | Dual Purpose |
DUKW | Amphibious truck |
DyD | Dockyard |
EOC | Elswick Ordnance Co. |
ECM | Electronic Warfare |
ESM | Electronic support measure |
F | Farenheit |
FCS | Fire Control System |
FF | Frigate |
fps | Feet Per Second |
ft | Feets |
FY | Fiscal Year |
gal | gallons |
GM | Metacentric Height |
GPMG | General Purpose Machine-gun |
GRP | Fiberglass |
GRT | Gross Tonnage |
GUPPY | Greater Underwater Prop.Pow. |
HA | High Angle |
HC | Horizontal Compound |
HCR | // Reciprocating |
HCDA | // Direct Acting |
HCDCR | // connecting rod |
HDA | // direct acting |
HDAC | // acting compound |
HDAG | // acting geared |
HDAR | // acting reciprocating |
HDML | Harbor def. Motor Launch |
H/F | High Frequency |
HF/DF | // Directional Finding |
HMS | Her Majesty Ship |
HN | Harvey Nickel |
HNC | Horizontal non-condensing hp |
HP | High Pressure |
hp | horizontal |
HQ | Headquarter |
HR | Horizontal reciprocating |
HRCR | // connecting rod |
HS | Harbor Service |
HS(E) | Horizontal single (expansion) |
HSET | // trunk |
HT | Horizontal trunk |
HTE | // expansion |
IC | Inverted Compound |
IDA | Inverted direct acting |
IFF | Identification Friend or Foe |
ihp | indicated horsepower |
IMF | Inshore Minesweeper |
in | Inche(s) |
irc | ironclad |
KC | Krupp, cemented |
kg | Kilogram |
KNC | // non cemented |
km | Kilometer |
kt(s) | Knot(s) |
kw | kilowatt |
ib | pound(s) |
LA | Low Angle |
LC | Landing Craft |
LCA | // Assault |
LCAC | // Air Cushion |
LFC | // Flak (AA) |
LCG | // Gunboat |
LCG(L) | /// Large |
LCG(M) | /// Medium |
LCG(S) | /// Small |
LCI | // Infantry |
LCM | // Mechanized |
LCP | // Personel |
LCP(R) | /// Rocket |
LCS | // Support |
LCT | // Tanks |
LCV | // Vehicles |
LCVP | /// Personal |
LCU | // Utility |
loco | locomotive (boiler) |
LSC | Landing ship, support |
LSD | // Dock |
LSF | // Fighter (direction) |
LSM | // Medium |
LSS | // Stern chute |
LST | // Tank |
LSV | // Vehicle |
LP | low pressure |
lwl | lenght waterline |
m | metre(s) |
M | Model |
MA/SB | motor AS boat |
max | maximum |
MG | Machine Gun |
MGB | Motor Gunboat |
MLS | Minelayer/Sweeper |
ML | Motor Launch |
MMS | Motor Minesweper |
MT | Military Transport |
MTB | Motor Torpedo Boat |
HMG | Heavy Machine Gun |
MCM(V) | Mine countermeasure Vessel |
min | minute(s) |
Mk | Mark |
ML | Muzzle loading |
MLR | // rifled |
MSO | Ocean Minesweeper |
mm | millimetre |
NC | non condensing |
nhp | nominal horsepower |
nm | Nautical miles |
N° | Number |
NBC/ABC | Nuc. Bact. Nuclear |
NS | Nickel steel |
NTDS | Nav.Tactical Def.System |
NyD | Naval Yard |
oa | Overall |
OPV | Offshore Patrol Vessel |
PC | Patrol Craft |
PDMS | Point Defence Missile System |
pdr | pounder |
pp | perpendicular |
psi | pounds per square inch |
PVDS | Propelled variable-depth sonar |
QF | Quick Fire |
QFC | // converted |
RAdm | Rear Admiral |
RC | Radio-control/led |
RCR | return connecting rod |
rec | Rectangular |
rev | Revolver |
RF | Rapid Fire |
RPC | Remote Control |
rpg | Round per gun |
SAM | Surface to air Missile |
SAR | Search Air Rescue |
sb | Smoothbore |
SB | Ship Builder |
SC | Sub-chaser (hunter) |
SSBN | Ballistic Missile sub.Nuclear |
SE | Simple Expansion |
SET | // trunk |
SG | Steeple-geared |
shp | Shaft horsepower |
SH | simple horizontal |
SOSUS | Sound Surv. System |
SPR | simple pressure horiz. |
sq | square |
SS | Submarine (Conv.) |
SSM | Surface-surface Missile |
sub | submerged |
sf | steam frigate |
SLBM | Sub.Launched Ballistic Missile |
spf | steam paddle frigate |
STOVL | Short Take off/landing |
SUBROC | Sub.Fired ASW Rocket |
t | ton, long (short in bracket) |
TACAN | Tactical Air Nav. |
TB | Torpedo Boat |
TBD | // destroyer |
TC | Torpedo carriage |
TE | Triple expansion |
TER | // reciprocating |
TF | Task Force |
TGB | Torpedo gunboat |
TG | Task Group |
TL | Torpedo launcher |
TLC | // carriage |
TNT | Trinitroluene |
TS | Training Ship |
TT | Torpedo Tube |
UDT | Underwater Demolition Team |
UHF | Ultra High Frequency |
Vadm | Vice Admiral |
VC | Vertical compound |
VCE | // expansion |
VDE | / double expansion |
VDS | Variable Depth Sonar |
VIC | / inverted compound |
VLF | Very Low Frequency |
VQL | / quadruple expansion |
VSTOL | Vertical/short take off/landing |
VTE | / triple expansion |
VTOL | Vertical take off/landing |
VSE | / Simple Expansion |
wks | Works |
wl | waterline |
WT | Wireless Telegraphy |
x | number of |
Yd | Yard |
Organizations | |
GIUK | Greenland-Iceland-UK |
BuShips | Bureau of Ships |
DBM | German Navy League |
GB | Great Britain |
DNC | Directorate of Naval Construction |
EEZ | Exclusive Economic Zone |
FAA | Fleet Air Arm |
FNFL | Free French Navy |
JMSDF | Jap.Mar.Self-Def.Force |
MDAP | Mutual Def.Assistance Prog. |
MSA | Maritime Safety Agency |
NATO | |
RAF | Royal Air Force |
RAN | Royal Australian Navy |
RCN | Royal Canadian Navy |
R&D | Research & Development |
RN | Royal Navy |
RNZN | Royal New Zealand Navy |
USSR | Union of Socialist Republics |
UE/EEC | European Union/Comunity |
UN | United Nations Org. |
USN | United States Navy |
WaPac | Warsaw Pact |