Japanese Maritime Self Defense Force Thread

gf0012-aust

Grumpy Old Man
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New Helicopter Carrier for Japanese Navy
By Keith Henderson at October 11, 2011 07:35
Filed Under: Research & Development

Details of the propulsion system for the new Helicopter Carrier of the Japanese Navy / Maritime Self-Defence Force (JMSDF) have been announced. To be built by IHI of Tokyo, the LOA 814 ft (248 m) and beam of 124 ft (38 m) vessel will have a fully loaded displacement of around 27,500 tons. The official Japanese 22DDH designation of the ship is of a “destroyer” but in reality it is a helicopter carrier. The reason for the diplomatic designation lies in the post World War 2 constitution which prohibits Japan to own aircraft carriers.

Japan already has two smaller Hyuga Class helicopter carriers of 18,000 tons full displacement and the new ship will become the largest vessels in the Japanese Navy.

The propulsion system comprises four GE LM2500 gas turbines of 33,600 hp (25 MW) each giving a total power of around 135,000 hp (100 MW) in a COGAG arrangement giving a speed of 30 kt. The ships will also be using GE’s smaller turbine, the LM500 with an output of approximately 6,000 hp (4.5MW) in a turbo-electric configuration for on board power generation.

The turbines will be built by GE licensee IHI with a delivery date of late 2012 for the LM500s and early 2013 for the LM2500 engines.

The LM2500 and LM500 gas turbines have been in service on a number of other ships of the JMSDF. LM2500s presently power the Hyuga helicopter carrier class, the destroyer classes Atago , Takanami, Murasame and Kongou: LM500 are in service on the Hayabusa class patrol boats and Sparviero fast attack class hydrofoils.
 

Belesari

New Member
Nice its basicly just a tiny bit smaller in tonage and dimensions as a Essex class carrier of WW2.

[ame="http://en.wikipedia.org/wiki/Essex_class_aircraft_carrier"]Essex class aircraft carrier - Wikipedia, the free encyclopedia[/ame]

This is also the class that introduced the angled flight deck.

Nice maybe the Japanese will buy some F-35B's.



New Helicopter Carrier for Japanese Navy
By Keith Henderson at October 11, 2011 07:35
Filed Under: Research & Development

Details of the propulsion system for the new Helicopter Carrier of the Japanese Navy / Maritime Self-Defence Force (JMSDF) have been announced. To be built by IHI of Tokyo, the LOA 814 ft (248 m) and beam of 124 ft (38 m) vessel will have a fully loaded displacement of around 27,500 tons. The official Japanese 22DDH designation of the ship is of a “destroyer” but in reality it is a helicopter carrier. The reason for the diplomatic designation lies in the post World War 2 constitution which prohibits Japan to own aircraft carriers.

Japan already has two smaller Hyuga Class helicopter carriers of 18,000 tons full displacement and the new ship will become the largest vessels in the Japanese Navy.

The propulsion system comprises four GE LM2500 gas turbines of 33,600 hp (25 MW) each giving a total power of around 135,000 hp (100 MW) in a COGAG arrangement giving a speed of 30 kt. The ships will also be using GE’s smaller turbine, the LM500 with an output of approximately 6,000 hp (4.5MW) in a turbo-electric configuration for on board power generation.

The turbines will be built by GE licensee IHI with a delivery date of late 2012 for the LM500s and early 2013 for the LM2500 engines.

The LM2500 and LM500 gas turbines have been in service on a number of other ships of the JMSDF. LM2500s presently power the Hyuga helicopter carrier class, the destroyer classes Atago , Takanami, Murasame and Kongou: LM500 are in service on the Hayabusa class patrol boats and Sparviero fast attack class hydrofoils.
 

Abraham Gubler

Defense Professional
Verified Defense Pro
It’s interesting to gauge why the JMSDF has upsized their DDH (aka carrier) from the Hyuga class. There is nothing officially that the 022DDH can do that the Hyuga can’t. But the Invincible sized 022DDH has a lot more storage capacity. Ostensibly this is for carriage of passengers, troops and cargo for troop deployment or emergency relief. But all this could just as easily accommodate an air wing and stores for a STOVL fighter. The JSMDF fleet air force operates their P-3s so could easily introduce the F-35B into service.
 

Corsair96

New Member
Wouldnt introducing this carrier into service be breaking the treat of 1945? It states that Japan cannot have carriers or offensive weapons, and trying to build a carrier that could handle F-35b's would be breaking both of these rules. Does this treaty still apply at all?
 

StevoJH

Active Member
Wouldnt introducing this carrier into service be breaking the treat of 1945? It states that Japan cannot have carriers or offensive weapons, and trying to build a carrier that could handle F-35b's would be breaking both of these rules. Does this treaty still apply at all?
Nope. I'll try to pre-empt swerve on this....

From memory their constitution (not the peace treaty) prevents them from getting "offensive aircraft carriers".

So all they have to do is say that it is a defensive aircraft carrier.
 

swerve

Super Moderator
Nope. I'll try to pre-empt swerve on this....

From memory their constitution (not the peace treaty) prevents them from getting "offensive aircraft carriers".

So all they have to do is say that it is a defensive aircraft carrier.
Absolutely right.

The constitution isn't at all specific, & doesn't mention any particular weapons at all, but the official interpretation of it, as given on the MoD web site, is that Japan can't have offensive weapons, & IIRC it cites as examples nuclear weapons & "offensive aircraft carriers". I'm sure that "offensive" is not accidental.

The peace treaty doesn't say anything.


Am I really that famous? I'm embarrassed.
 
Last edited:

gf0012-aust

Grumpy Old Man
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Am I really that famous? I'm embarrassed.
I've almost lost count on the number of times that you've had to give a lesson on the japanese constitutional issues of acquiring gear for self defence
 

swerve

Super Moderator
New Helicopter Carrier for Japanese Navy
By Keith Henderson at October 11, 2011 07:35
Filed Under: Research & Development

Details of the propulsion system for the new Helicopter Carrier of the Japanese Navy / Maritime Self-Defence Force (JMSDF) have been announced. To be built by IHI of Tokyo, the LOA 814 ft (248 m) and beam of 124 ft (38 m) vessel will have a fully loaded displacement of around 27,500 tons....

The propulsion system comprises four GE LM2500 gas turbines of 33,600 hp (25 MW) each giving a total power of around 135,000 hp (100 MW) in a COGAG arrangement giving a speed of 30 kt. The ships will also be using GE’s smaller turbine, the LM500 with an output of approximately 6,000 hp (4.5MW) in a turbo-electric configuration for on board power generation.
...
The LM2500 and LM500 gas turbines have been in service on a number of other ships of the JMSDF. LM2500s presently power the Hyuga helicopter carrier class, the destroyer classes Atago , Takanami, Murasame and Kongou: LM500 are in service on the Hayabusa class patrol boats and Sparviero fast attack class hydrofoils.
4 x LM2500 is the same as the main power plant of Cavour, which has almost the same dimensions (4 metres shorter, 1 metre wider).
 

kato

Defense Professional
Verified Defense Pro
The funky part about the propulsion is that IHI always has to order the LM2500 for JMSDF ships straight from GE Marine because they only have the license to build the 20 MW and 30 MW variants - and the JMSDF uses the 25 MW standard version.

Nothing to do with FMS money at all ;)
 

StingrayOZ

Super Moderator
Staff member
4 x LM2500 is the same as the main power plant of Cavour, which has almost the same dimensions (4 metres shorter, 1 metre wider).
Seems like a very fast helo ship. It is sounding more and more like a carrier.

But I doubt the Japanese getting F-35B immediately. There are quiet a few hurdles to get over before they can operate this ship as a carrier.
 

swerve

Super Moderator
Seems like a very fast helo ship. It is sounding more and more like a carrier.
Same as Hyuuga & Ise, & they really are helicopter ships. There have been plenty of other helicopter carriers around that speed, e.g. the non-through deck helicopter cruisers Jeanne d'Arc & Vittorio Veneto. You could also count Andrea Doria & Caio Duilio, though they'd be thought of as just destroyers (or even frigates) with large flight decks now.

Even the Invincible class was originally intended for helicopters only, with a Vittorio Veneto style deck being considered before the through deck configuration was adopted.

All of the above were fast.
 

Abraham Gubler

Defense Professional
Verified Defense Pro
Same as Hyuuga & Ise, & they really are helicopter ships. There have been plenty of other helicopter carriers around that speed, e.g. the non-through deck helicopter cruisers Jeanne d'Arc & Vittorio Veneto. You could also count Andrea Doria & Caio Duilio, though they'd be thought of as just destroyers (or even frigates) with large flight decks now.

Even the Invincible class was originally intended for helicopters only, with a Vittorio Veneto style deck being considered before the through deck configuration was adopted.
The speed of the ship is all about how it is meant to be used. Helicopter carriers for use in amphibious assaults like the Iwo Jima class only have ~20 knot speeds because this is the post war fast convoy requirement. A helicopter carrier like the ships Swerve has mentioned above are conceived to operate as part of the fleet so are as fast as the other combatant ships. Just because they all carry helicopters doesn’t mean all such ships need to be similar across the board.
 

StingrayOZ

Super Moderator
Staff member
Well I would imagine these are to be used for ASW. They don't appear to be designed around amphibious operations. However thats pretty big for a pure asw helo carrier.

I wonder if we will see this ship, the Canberra class and the Korean Dokdo class operating together.
 

gf0012-aust

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  • #18
Well I would imagine these are to be used for ASW. They don't appear to be designed around amphibious operations. However thats pretty big for a pure asw helo carrier.
Actually, if you look at the desicated ASW Hunter Killer Task Forces from the cold war, the carriers dedicated to ASW support were much bigger.

the reason for having a large carrier or capacity for rotors is because it increases your saturation and ipso facto, persistence footprint.

3 helos working a sub in unison is not a jolly time for the sub.
3 flights of 3 working the area is the equiv of sending in the cleaners...
 

swerve

Super Moderator
Well I would imagine these are to be used for ASW. They don't appear to be designed around amphibious operations. However thats pretty big for a pure asw helo carrier.
ASW is exactly what Hyuuga & Ise (BTW, I'll be in the city of Ise 3 weeks from now) are designed for.

The reasoning seems to be very similar to that which produced the Invincible class (slightly larger than Hyuuga). The Japanese have some light frigates/DEs with limited helicopter support facilities. One Hyuuga can not only be an effective ASW ship on its own, but extend the reach of those smaller ships, as a flotilla leader. Here we get something like the reasoning behind early iterations of the Type 23, a relatively low-end ASW vessel operating with a mothership.

Thus we see that for the 16DDH class there is no need to imagine that the ships are some kind of proto STOVL carrier.

The new ships are more of the same, but apparently designed to be more general purpose. I wouldn't be at all surprised if the possibility of future F-35B operations was considered when deciding on their size, but they don't depend on F-35B to be valuable. Think of it as prudence, allowing for possible future requirements in ways that don't compromise current needs.
 

Volkodav

Defense Professional
Verified Defense Pro
Actually, if you look at the desicated ASW Hunter Killer Task Forces from the cold war, the carriers dedicated to ASW support were much bigger.

the reason for having a large carrier or capacity for rotors is because it increases your saturation and ipso facto, persistence footprint.

3 helos working a sub in unison is not a jolly time for the sub.
3 flights of 3 working the area is the equiv of sending in the cleaners...
I have read that in 1950s planning the RN saw each ASW helo on station as equivalent to a specialist ASW frigate and could replace such in the taskforce screen. i.e. three ASW helos were worth an ASW frigate. The fact that a modern ASW helo can dip and sprint so efficiently makes them even more effective. Submariners don't fear skimmers, its the helos that give them issues.
 
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