A melhor analise dos porta-aviões que já vi!

Assuntos em discussão: Marinha do Brasil e marinhas estrangeiras, forças de superfície e submarinas, aviação naval e tecnologia naval.

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Re: A melhor analise dos porta-aviões que já vi!

#91 Mensagem por Bolovo » Dom Nov 23, 2008 1:25 am

PARTE NOVA

I'll post some "bluffer's guide" type stuff I've done as a starting point but please add any photos/illustrations or narartive and opinions. Carriers already has an excellent pics thread but small carriers deserve some focus.

STOVL Carriers compared

I was writing a long narrative for this but it was just a load of waffle so I’ll let the illustrations do most of the speaking. As per my other threads all the illustrations are by me, photos found on the web. And this is strictly amateur web research so apologies if I got anything wrong. Hopefully there’s something of interest!


Part 1: Comparison on contemporary and near-future STOVL carriers

Meet the contenders for the crown
These are the ‘Harrier Carrier’ types currently in service or just entering service.
Brief intros:
Wasp Class: Characterized by tall slab sides to facilitate a large floodable well-deck at the stern for landing craft and hovercraft. Among the class of eight the exact weapons fit and placement varies so I’ve used USS Wasp as the example. I’ve taken the Wasp class as representative of the Tawara class also.
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Cavour: Just entering service. Has an air-defence fit similar to a destroyer.
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Juan Carlos I: Amphibious dock like the Wasp, but with prominent ski jump on starboard bow. Noticeably light armament though design could mount more. Two derived ships are being purchased by Australia where they almost certainly will deploy JSF fighters at least on occasion, although that is some years off and beyond the scope of this comparison.
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Note that in the photo the ship has only just been launched and is missing much equipment.

INS Virant: Formerly HMS Hermes of Royal Navy. Some armament modifications since sale to India.
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Invincible class:
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The above pic is the now retired HMS Invincible at a late stage of her active career but whilst Sea Dart was still fitted. The example ship I use in this comparison is Ark Royal which differs in armament and has the Sea Dart removed. But I love the pic and it illustrates the Harrier capacity.

Principe de Asturias: Spanish light carriers built to US Sea Control Ship concept of 1970s.
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Giuseppe Garibaldi: Italian light carrier.
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Chakri Naruebet: Thai light carrier built in Spain. Often described as a smaller version of the older Principe de Asturias, the design also has some refinements. Thailand cannot afford to operate this ship at anything light the tempo of the Western carriers and has not bought more recent models of the Harrier (relying on a handful f ex-Spanish early model Harriers) so the ship is more of a prestige symbol than a fully utilized warship.
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Orientation:
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Defensive weapons:
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Air wings:
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Air defence fighter fit:
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Deck facilities:
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An observation about the trade-off between jet ops and amphibious assault role: Some of the STOVL carriers are also Landing Platform Docks (LPD). This means that they have a large floodable well-deck at the rear for landing craft/hovercraft/amphibious vehicles to come in and out off. Generally in a hybrid carrier/LPD you end up with the hanger deck above the well-deck which results in a rather tall ship, in turn limiting the width of the flight deck. For instance, the 40,000 ton Wasp class LPD has a flight deck of about 8067m2 which equates to 0.17m2 per ton. Whereas Cavour, which is amphibious logistic capable (both air-assault and RORO) but lacks the dock, has a flight deck to tonnage ratio of about 0.26m2 per ton, over 50% more! Clearly this is an advantage for the Cavour as a “Harrier carrier”.
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Side by side comparison of ‘pure’ carrier with LPD carrier:
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And also, the assault ships tend to be much slower than the ‘pure’ carriers which reduces survivability when they operate as light fleet carriers because they are less mobile and cannot keep up with maneuvering warships (so the whole fleet would have to go slower to protect them).
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The reckoning:
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Whilst Wasp has by far the best amphibious capability (rivaled only by Juan Carlos I?), it’s not much of a Harrier Carrier without a Ski-Jump. Cavour overall is the most capable. The argument should be how the best of the harrier carriers (Cavour) matches up to the much larger CTOL carriers (and RN’s Queen Elizabeth class quasi-CTOL) carriers. It’s the newest and the best in a 1:1 comparison. I think any navy, including the USN/USMC would be proud to have a Cavour class carrier.
In fact, going by what has been released about the USMC’s next amphibious assault carriers (USS America class) they too seem inferior to Cavour as ‘pure’ carriers because they are essentially a Wasp class ship without the dock, retaining the smallish flight deck and missing a ski-jump in favour of helicopter landing spots.


2. Large through-deck helicopter carriers that could be used as STOVL or VTOL carriers
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Re: A melhor analise dos porta-aviões que já vi!

#92 Mensagem por Bolovo » Dom Nov 23, 2008 1:29 am

3. Some Harrier carrier history
You could be forgiven for thinking that Britain invented the STOVL carrier concept, and we certainly were forerunners in applying the concept, but it was a widespread idea even in the 1970s. Really, the Royal Navy (RN) didn’t want Harrier Carriers, that was until the politicians forced them out of the “real” carrier game at which point a Harrier Carrier became better than nothing. Where Britain can claim a lot of credit however is in providing the Harrier jump jet. Whilst several countries tried to develop Vertical take-off and landing jets in the 1950s and 60s, only two countries were successful in making operational types (Harrier in UK and Forger in USSR) and only the Harrier was really combat credible. Even the USMC purchased the Harrier for deployment on Helicopter carriers. In fact, ironically the USMC appears to have been the first Harrier user to routinely deploy Harriers operationally on warships from around 1971 onwards (the UK did plenty of demo flights prior). And even Spain deployed its Harriers to its small WWII vintage carrier Dedalo before the Royal Navy did its. So the Royal Navy was not alone, and not the first, but in some respects I suppose we can claim credit; The British Invincible class was the first purpose-built STOVL carrier to enter service and the second with a ski-jump. 2nd??? – yep HMS Hermes beat her there! And just to throw a couple more spanners into the works, Italy was already designing their own Harrier Carrier in the 1970s too, which ultimately became the Giuseppe Garibaldi and entered service in the early 1980s.

Also, both the Spanish and Russian navy’s deployed jump jets on warships operationally before the Royal Navy!
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The Russian Yak-38 Forger was however an operational failure and certainly inferior to the Harrier. Its successor, the Yak-41 (/141) was much better however and easily a match (if not somewhat superior to!) any version of the Harrier, at least in air-air role (the Yak was not designed for an air-to ground role).
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The Yak-41 was however a 1980s design, but we can assume that had the USSR continued to exist and/or it entered service, then it would have been upgraded with AA-12 Adder and AA-11 Archer missiles. Yak wanted to follow it up with a much more capable Yak-43 stealthy design (Yak was noteworthy among Russian design bureaus for their inclusion of US style stealth alignment in their concept designs of 1990s). The Yak-43 would have been equivalent to (though probably inferior to) the JSF:
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Analogous with the Yak-41 programme, both UK and US considered improved Jump jets in the 1970s/80s (UK actually planned a supersonic follow-on in 1960s!). Ultimately they plumbed for the Harrier-II which was essentially the old Harrier with updated engine and new bigger (and slower!) wings. However, one of several Hawker (the original maker of the Harrier) proposals for a supersonic Harrier successor was by far the sexiest fighter-never-made:
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So why am I so jaded about the great British institution that is the Harrier Carrier??? Well, really it’s just a lame replacement for the Royal Navy’s real Carriers. The Royal Navy had operated a fleet of small and full size fleet carriers in the 1950s, right up to when the last one (HMS Ark Royal R09) was decommissioned in 1978. I’ve compiled a simple chronology of post- war British Carriers:
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As you can see the number of aircraft carriers in service steadily reduced from a highpoint of 12 in 1950 to just 2 today (excluding HMS Ocean). The mix also changed, with the last of the full-sized fleet carriers (HMS Ark Royal R09) decommissioned in 1978 leaving just STOVL Harrier-carriers in service.
Now Britain had planned to build two more fleet carriers to replace the WW2 generation Audacious class (HMS Eagle and HMS Ark Royal) under the CVA-01 programme. These would have been about the same tonnage as the Audacious class but significantly larger flight decks designed from the keel up as angled-flight-deck carriers. The CVA-01 programme was finally axed by a conspiracy of penny pinching politicians and jealous RAF staff officers. Sad days. A quick scale comparison of the CVA-01 with the older Ark Royal and Argentine 25 de Mayo carrier which saw service during the Falklands war:
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“But, the Harrier carriers did serve the country well in the Falklands” I hear you cry. Yes, but we’d have been better off with even one fleet carrier still in service. Even the ancient Ark Royal. Royal Navy fleet carriers ultimately carried a mix of Phantom FG1 multi-role fighters and Buccaneer S2 strike bombers. These aircraft are much longer ranged and more potent that the Harrier. And the large carriers had another massive advantage, they carried fixed-wing AEW assets in the form of Gannets. A quick gauge at the difference in combat radius of a Harrier Carrier and a fleet carrier in the context of the Falklands:
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Note that combat radius is great than typical range of combat air patrol. Also, that Buccaneer also operated as a buddy-buddy tanker thus significantly extending possible strike distances beyond that shown).

As you can see raids on the mainland would have been feasible and time over the Falklands much longer allowing 24-7 air-superiority, something the Harrier Carriers could not provide.
And the Phantom also carried a far heavier missile load of both medium ranged Sparrow and shorter ranged Sidewinders. It not too farfetched to suppose that RN Phantoms would also have the more advanced Skyflash missile by 1982 (it entered service with RAF Phantoms in 1978). This would have given the Phantom an unquestioned dominance over the Argentine Mirages.
To the Harrier’s credit though it did conclusively win air-air engagement against the Argentine aircraft including the Mirage III radar-equipped fighters which on-paper should have wiped the floor with the Sea Harrier. But the overall loss rate, including accidents and ground-fire, tells a different story:
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Statistically the highest loss rate was among the RAF Harrier GR3s(!) not any Argentine type and Sea Harrier was prone to tragic accidents. The most successful type was probably not the Sea Harrier (which gets credit for its air-air success) but the Argentine operate French built Super Etendard anti-ship fighters which not only suffered zero losses but also managed to sink two mayor ships (HMS Sheffield and MV Altantic Conveyor) with their Exocet missiles.
On the other hand, if we look at the capability map of the Phantom and Buccaneer (bottom, above) we can see that not only is the Phantom by far the most capable air combat fighter, but that the Buccaneer too has a significant advantage over the equivalent Argentine types. It’s fair to say that the Buccaneer is one of the finest low-level strike platforms ever!

Falklands Myth 1: It’s a myth that the Argentine navy could operate Super Etendards from their carrier 25 de Mayo during the war; suitable modifications were only made in 1983 after the conflict. Instead Super Etendards had to operate from shore bases.
Falkland Myth 2: HMS Invincible was not sunk by the Argentineans. That’s just ridiculous propaganda. However several other warships were sunk.
Falklands Myth 3: Atlantic conveyor was not hit by two Exocets. One was enough.

War brings out the best in technical innovation however and the Harrier did offer British planners interesting possibilities that would not have been possible with conventional take-off aircraft. With a shortage of aircraft carriers Britain explored several improvisations, taking the concepts much further than any other navy:
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Although merchant conversions proved invaluable during the Falklands war, the Arapaho system proved completely unsatisfactory for peacetime operations, even just for Helicopters. One more extensive conversion that was a success was HMS Argus. This was officially a training ship to better prepare pilots for carrier ops, but also doubled as an ASW carrier (with Seas Kings) and capable of limited Harrier VTOL ops. It was used as an assault carrier but proved inadequate for carrying large numbers of troops in peacetime comfort so a dedicated assault carrier, HMS Ocean, was commission and Argus became primarily a casualty evacuation/hospital ship. Ocean is based on the hull of the Invincible class and frees up the Invincible from assault carrier role (in Falklands the carriers had to be kept too far from the landing zone to operate effectively as both light fleet carriers and assault carriers – in effect the two roles require similar platforms but imply contradictory operational doctrines). HMS Ocean would require modest modification for sustained Harrier ops and is only used as a helicopter carrier. This may be politically motivated – in war it’s easy to imagine Ocean being modified with a ski-jump, blast resistant deck coating and weapons lifts in very quick order!


The advantages and disadvantages of STOVL
STOVL (Short Take-Off, Vertical Landing) is a mode of operation where a ‘jump jet’ takes off via a short run, typically up a ski-jump, but lands by hovering. The advantages of this mode of operations for a several:
1. Relative to ‘pure’ vertical operations the aircraft can take-off with more weight
2. No catapults or arrestor gear is required (reducing maintenance/material cost of ship)
3. Can land in worse weather than ordinary operations (as proved vital in Falklands war)
4. Several aircraft can land virtually simultaneously
5. Aircraft can be queued up for take-off and depart at a much more rapid rate than catapult launched aircraft

As a side note to the landing in bad weather point, a Falklands war pilot famously commented that it is easier to stop and then land, than to land and then stop. But, one of the harriers did drop over the side of the carrier whilst taxing.
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There are also some disadvantages to using Jump jets:

1. Generally the fighters cannot take-off with as heavy a load as a catapult launched aircraft, which reduces endurance and weapons load
2. The fighter often has to ditch ordinance before landing (depending on fuel load and what is carried etc).
3. There are relatively few makers of jump-jets so the export user tied to certain political aligencies
4. Potential role conflict between the fighter jets and other air assets
This last point is quite important. All the current operators of STOVL carriers have good political relations with UK/USA and are dependent on the Harrier family of fighters. For the future the only ‘new’ jump jet fighter becoming available is the US lead JSF (F-35B) programme. Russia did build an operational STOVL fighter called Yak-38 “Forger” which was employed in the Kiev class cruisers. Whilst the Forger was something of an underachiever, the follow-on Yak 141 ‘Freestyle’ was extremely promising and would certainly give the Harrier-II a good run for its money had it not been killed off by the collapse of the Soviet Union and financial neglect that followed.

The F-35B will massively close the gap between STOVL carriers and CTOL in quality of aircraft if not quantity, but at the same time modern fighters are becoming shorter take-off and STOBAR configurations are real challenge.




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Re: A melhor analise dos porta-aviões que já vi!

#93 Mensagem por orestespf » Dom Nov 23, 2008 8:50 am

Carioca escreveu:
Marino escreveu: Contra quem vc quer usá-lo?
Quando ele pertencia a Marinha francesa, era um elefante branco, com SUE?
O que de melhor tem um SUE em relação a um A-4M?
Compare o Alizé AEW com o S-2 AEW.
Calma com o andor que a análise tem que ser feita com equilíbrio.
Marino,
Desculpe-me a intromissão, talvez até tardia, mas o NAe SP é um estorvo para o Brasil. Serve apenas para dar a impressão de que temos uma marinha de GUERRA e satisfazer o ego de alguns almirantes gordos que desejam incluir no curriculo o comando de um NAe ou de uma FT nucleada por um NAe. Trata-se de jogar grana fora. Muita grana mesmo.
Ou o Brasil age como a India, por exemplo, ou esquece essa historinha de possuir um NAe. A antiga proposta do Minas Gerais era mais honesta (anti sub total), apesar da impossibilidade de defendê-lo eficazmente contra subs.
Se o pais pretende ter um NAe efetivo em 2060 tem que começar agora, e, digo mais, começar agora o desenvolvimento de toda a missilagem, canhonagem e aviação requerida para combater, por exemplo, a marinha inglesa (é isto mesmo, voce tem que escolher um inimigo factivel. Então que sejam os ingleses).
Do contrario, melhor construir uma enorme força de velocíssimas torpedeiras de oceano e subs.
Vixe Maria!!! Vai apanhar até dizer chega!

Caro Carioca, sugiro que apresente pelo menos um argumento sustentável, o que você fez foi apresentar críticas baseadas em suas opiniões e não baseadas em conhecimentos sobre o tema. Além do mais, da forma escrita por você, chamou todos os almirantes de gordos (este tipo de discriminação constitui crime neste País, não foi de bom tom. Opinião minha, claro).

A efetividade do SP hoje é reflexo de uma má política implementada nos últimos 10 anos, todos sabem disso, não dá para culpar a MB pelas "qualidades" (falta dela) de seu NAe. Bote grana nas mãos da MB e verá um PA decente, operacional e efetivo.

Outra coisa, começar a pensar em NAe hoje para tê-lo operacional e efetivo em 2060 é no mínimo piada de mal gosto, o que demonstra total desconhecimento sobre este vetor naval e acima de tudo da própria MB. Dizer que um país do tamanho do Brasil deveria ter "velocíssimas torpedeiras" é pensar muito pequeno, desculpe-me pela franqueza.


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Re: A melhor analise dos porta-aviões que já vi!

#94 Mensagem por Marino » Dom Nov 23, 2008 11:34 am

Carioca escreveu:
Marino escreveu: Contra quem vc quer usá-lo?
Quando ele pertencia a Marinha francesa, era um elefante branco, com SUE?
O que de melhor tem um SUE em relação a um A-4M?
Compare o Alizé AEW com o S-2 AEW.
Calma com o andor que a análise tem que ser feita com equilíbrio.
Marino,
Desculpe-me a intromissão, talvez até tardia, mas o NAe SP é um estorvo para o Brasil. Serve apenas para dar a impressão de que temos uma marinha de GUERRA e satisfazer o ego de alguns almirantes gordos que desejam incluir no curriculo o comando de um NAe ou de uma FT nucleada por um NAe. Trata-se de jogar grana fora. Muita grana mesmo.
Ou o Brasil age como a India, por exemplo, ou esquece essa historinha de possuir um NAe. A antiga proposta do Minas Gerais era mais honesta (anti sub total), apesar da impossibilidade de defendê-lo eficazmente contra subs.
Se o pais pretende ter um NAe efetivo em 2060 tem que começar agora, e, digo mais, começar agora o desenvolvimento de toda a missilagem, canhonagem e aviação requerida para combater, por exemplo, a marinha inglesa (é isto mesmo, voce tem que escolher um inimigo factivel. Então que sejam os ingleses).
Do contrario, melhor construir uma enorme força de velocíssimas torpedeiras de oceano e subs.
Antes de escrever um post destes, sugiro a leitura completa de alguns tópicos do DB, mas principalmente o que trata de Estratégia Naval, e o criado especificamente para debater Porta-Aviões.
Também sugiro que tome conhecimento do que vem ocorrendo em termos de desenvolvimento de armamentos e sistemas, como o MAN, MAR, Torpedos, SICONTA, etc.
Antes disso, dizer que o SP é um estorvo para a MB é demonstrar total desconhecimento. Digo isto sem intenção alguma de ofender, pois estamos todos aqui para aprendermos, para partilharmos conhecimento, e a maioria dos brasileiros nada sabe sobre assuntos que digam respeito ao mar e a sua Marinha.
Não se deixe influenciar pelos que postam sem conhecimento algum, que é o que ocorre na maioria das vezes com os foristas que não dominam o assunto.
Forte abraço




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Re: A melhor analise dos porta-aviões que já vi!

#95 Mensagem por Mapinguari » Dom Nov 23, 2008 2:01 pm

Carioca escreveu:
Marino escreveu: Contra quem vc quer usá-lo?
Quando ele pertencia a Marinha francesa, era um elefante branco, com SUE?
O que de melhor tem um SUE em relação a um A-4M?
Compare o Alizé AEW com o S-2 AEW.
Calma com o andor que a análise tem que ser feita com equilíbrio.
Marino,
Desculpe-me a intromissão, talvez até tardia, mas o NAe SP é um estorvo para o Brasil. Serve apenas para dar a impressão de que temos uma marinha de GUERRA e satisfazer o ego de alguns almirantes gordos que desejam incluir no curriculo o comando de um NAe ou de uma FT nucleada por um NAe. Trata-se de jogar grana fora. Muita grana mesmo.
Ou o Brasil age como a India, por exemplo, ou esquece essa historinha de possuir um NAe. A antiga proposta do Minas Gerais era mais honesta (anti sub total), apesar da impossibilidade de defendê-lo eficazmente contra subs.
Se o pais pretende ter um NAe efetivo em 2060 tem que começar agora, e, digo mais, começar agora o desenvolvimento de toda a missilagem, canhonagem e aviação requerida para combater, por exemplo, a marinha inglesa (é isto mesmo, voce tem que escolher um inimigo factivel. Então que sejam os ingleses).
Do contrario, melhor construir uma enorme força de velocíssimas torpedeiras de oceano e subs.
Carioca,

Até onde sei, a Índia tem Porta-Aviões e está construindo mais.
Construir FACs (Fast Attack Crafts) oceânicas para quê? Esses navios são para águas litorâneas. E, mesmo assim, seu uso é limitado. Lembre-se que a uma corveta Classe Inhaúma da MB sozinha acabou com as "misseleras" chilenas num exercício Bogatun.
Uma marinha de águas azuis bem balanceada necessita de NAe, de LHD, de LPD, de escoltas capazes, submarinos e outros navios, incluindo auxiliares. E é isso que a MB busca: ser um força naval balanceada. vamos aguardar o PRM.




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