Por que não existem principais navios de guerra da Federação no universo de Star Trek?

When a single Borg ship can wipe out an entire Federation fleet, I would expect the Federation to come up with a Battleship or Ship-Of-The-Line capable of delivering devastating firepower

They did. The Defiant:

Development on the Defiant began around 2366 in response to the Borg threat. Although officially classified as an escort vessel, the Defiant was nothing less than Starfleet's first design of warship; intended to fight, and ultimately defeat, the Borg.
_{From: "USS Defiant (2370)", Memory Alpha}

However, it isn't mentioned in The Next Generation (aside from Riker's "tough little ship" one-liner in Primeiro Contato). It was revealed in Espaço Profundo Nove’s season 3 premiere, The Search, when it was sent on a mission to find the Dominion.

When Sisko introduces it to his senior staff, O'Brien mentions that Starfleet didn't believe in warships. Starfleet's mission is one of peace, exploration, science, and general universal love and understanding. (Why yes, the show foi conceived in California in the 1960s. Good guess!) It's harder to convince new species that you want to be friends if you show up in a ship capable of blowing up their planet.

Out-of-universe, the show's premise is an optimistic one about the future of humanity - it assumes we've developed the better aspects of our nature, and prospered as a result. It’s not about kicking the crap out of aliens.

(Except for the episodes — mainly in Deep Space Nine — featuring massive space battles where Starfleet kicks the crap out of aliens. They’re impressionante.)

In the canon Star Trek Universe, the threat to the Federation posed by the Borg and the Jem'Hadar forced them to consider for the first time, a ship whose purpose was wholly based on military capability.

Military Considerations

As a former member of the military (US Navy), it makes perfect sense to me for the Federation to avoid creating battleships, i.e. large ships designed primarily for combat. They don't make them for the same reason we don't in the Twenty-first century. The laws of diminishing returns in combat.

• While cost of production is not necessarily a factor, time to produce is. If I can make six Defiant-class ships in the same time as it takes to make one Cruiser class ship, I will always take the six ships over the one. Especially if the damage dealing capacity of that one ship is half that of the Defiant class ship. Same number of crew are required, but I have six nimble targets for the enemy to shoot at and six ships capable of attacking opponents.

• Since the weaponry of the Federation is both powerful, and easily able to fit on almost any ship (as long as it has a warp core power plant) there is no rationale for placing weapons on a single ship which might be more effective being spread out over a half dozen ships.

• The factor of size is negated if you are not able to protect that ship from attack effectively. The reason the Borg get away with such immense ships, is their resilience to damage in combat. Alpha Quadrant races depend far more on shields than they do on redundant systems or sheer mass to overcome their enemies.

• Size limits the ability to coordinate technology effectively, the larger the ship and crew, the slower the coordination; Borg ships evidently benefit from their hive mind intellect enhancing their overall combat performance. In this case, a ship is only as effective as the minds coordinating it or the technology protecting it.

Technical Analysis of the Federation

• Despite their protestations to the contrary, the average Federation starship was, despite its addition of scientific and exploratory technology, quite a capable weapon of war.
• Armed with multiple phaser arrays or banks, photon torpedoes launchers and effective defensive shielding, the average Federation cruiser was more than a match for any other single type of cruiser from most of the Alpha quadrant races. In groups or small fleets, they were more than equal to most races of the Alpha Quadrant.

This balance of power changed when the Borg arrived.

• With their Cube ships, each one was filled with redundant power systems, multiple weapons systems (torpedoes, cutting beams), layered defensive arrays and powerful tractor beams (all systems used by the Federation but with the Borg strategy of filling their ships with multiple and redundant systems).

• Each Borg Cube was strategically capable of destroying entire Federation fleets simply by being able to absorb incredible amounts of fire power and still being able to destroy one ship after another with their increased rates of fire.

• The Borg could also adapt to shield signatures, rendering a ship's shields inoperative, and with their superior firepower tear it apart in seconds. This usually only took one or two attacks unless the ship rotated their shield frequency continuously.

• Add to this their ability to adapt to a particular attack and be unaffected after a time, and you have an enemy whose ability to deal destruction was unmatched in the Alpha Quadrant. No race could have stood against them for long.

To this end, the Federation designed two experimental warships:

Defiant Class Starships: an escort sized vessel with phased cannon arrays, quantum torpedoes and defensive armor as well as enhanced mobility made it more than capable of dealing damage equivalent to that of a Galaxy-class starship. Her armaments included:

Armamento

• 4 x Class I rapid fire phaser pulse cannon
• 3 x Phased Beam Emitters, 2 forward, one aft, standard phaser array
• 6 x Pulse fire Quantum/Photon torpedo tubes + 100 torpedoes fourforward, two aft
• 1 x Probe / Photon torpedo launcher - equivalent to standard photon torpedo tube + 20 torpedoes

Defense Systems

• Auto modulated high capacity shield system, total capacity 2,376,000 TeraJoules
• Heavy Duranium/Tritanium double hull plus 20 cm Ablative armour.
• High level Structural Integrity Field

This was a warship, pure and simple, designed to deal out damage in all directions with variable phasers which could vary their frequency preventing the Borg from easily adapting to them and Quantum torpedoes who damage capacity eclipsed the photon torpedo by orders of magnitude; same box, much bigger bang.

Prometheus Class Starships: A slightly larger than cruiser-sized vehicle, the Prometheus was a warship whose full capacities were never shown fully on screen. It was equipped with armaments similar to the Defiant and could split into three separate vessels tripling their firepower and offensive capacity (multi-vector assault mode). It also had multiphasic, regenerative shielding, and ablative armor

Armament, Docked Mode

• 12 x Type XII Phaser arrays
• 2 x Pulse fire quantum torpedo tubes + 290 torpedoes

Armament, Separated Mode

Primary Hull:

• 6 x Type XII Phaser arrays
• 2 x Pulse fire quantum torpedo tubes + 115 torpedoes

Secondary Hull:

• 4 x Type XII Phaser arrays
• 3 x Pulse fire quantum torpedo tubes + 175 torpedoes

Tertiary Hull:

• 8 x Type XII Phaser arrays

Total:

• 18 x Type XII Phaser arrays
• 5 x Pulse fire quantum torpedo tubes + 290 torpedoes

This also does not invalidate the increasing of firepower on larger Cruiser and Galaxy-class ships with phase cannon arrays, quantum torpedo tubes in addition to photon torpedoes and multiphasic shield arrays. With the addition of the transphasic torpedo (claimed from a future alternative timeline by Admiral Janeway for use against the Borg) the Federation would once again be a power to be reckoned with in the Alpha Quadrant.

Battleships are typically extremely expensive, offensive vessels that take a lot of resources to build and operate. Not only do they require large amounts of personnel and equipment to run on their own, you also have to crew and supply the requisite supporting fleet of vessels (transports, frigates, destroyers etc). Since Starfleet's stated goal is the pacífico exploration of space and diplomacy, such a vessel, and fleet, would not be in line with that goal.

That is not to say that they have never built offensively oriented vessels. The most famous such example is the Defiant class ship, featured on Deep Space Nine. Originally designed to combat the Borg, the ship featured an oversized warp core, phaser cannons (in addition to phaser arrays), multiple fore and aft torpedo launchers, and as a special case with the USS Defiant, ablative armor.

But keep in mind, even though the Defiant class was arguably a war ship, it was still labeled as an escort vessel (i.e. it's primary purpose was to escolta and protect other ships). Starfleet would have had a hard time calling something as large as a battleship an escort.

With that said, there are only two on screen ships I can think of that fit the battleship classification, neither of them Starfleet:

• Jem'Hadar battleship
• Cimitarra

But all that aside, Starfleet's vessels were well suited to go one-on-one with matching classes of ships from their contemporary adversaries. Although, watching any of the shows may not make that evident as the ship would often be on the brink of destruction to build tension for the plot.

Problems with Battleships that are arguably universal to space, sci-fi/fantasy space, and 20th century, 19th, 18th, 17th, 16th etc. naval warfare that contradict typical strategy/tactics of modern and perhaps futuristic military warfare and/or the goals of Starfleet in general:

• It's a lot of eggs in one basket. You can cause a big problem in one place with a battleship. A battleship's worth of smaller craft can cause a whole lot of problems in a whole lot of different places or an almost equally big problem in one place. Smaller more mobile ships even with considerably less firepower if delivered against the same big target are going to tend to be more useful as long as their destructive/defensive capacity is good enough for a wider variety of concerns which they can most certainly achieve through mixed roles. This applies to defense and offense.

• The one thing they've generally been better at than anything else in their respective contemporary armed forces historically speaking is attacking stationary civilian targets on land from very far away. I'm not sure that translates to space battleships necessarily but as a classical weapons platform it's certainly not the sort of weapon of civilian slaughter and infrastructure destruction role Starfleet would want to emulate.

• They're not necessarily slow but they've never been the fastest in the sea and it stands to reason they would never be the fastest in space in any drive system scenario where mass or volume is a non-trivial concern. If I loosely understand the rules of warp drive properly, mass is effectively reduced, not eliminated, and power drain is still relevant. You can't cause immediate problems for something you can't catch.

• The more accurate and rapid-fire that weapons get, the less useful/versatile/cost-effective it is to have a whole lot of hugely expensive ones on one boat/starship. Damage to dollar, the US did serious damage with its PT boats while it was rebuilding replacements for its ships lost at Pearl Harbor. In a lot of ways the Defiant is similar in its focus to the PT boat although perhaps a much tougher bug to squash.

• Battleships in a lot of ways were political weapons in much the same way nukes are today. That's another model one would hope Starfleet wouldn't be a huge fan of.

• They are 100% offensive. You don't defend with a battleship. Smaller craft en masse can easily bypass and attack civilian targets through sheer force of numbers assuming relative costs are still roughly similar to what they would be now and in recent history in naval terms.

Now that said, this is sci-fi. Any one of the concerns I list could be imagined away through virtue of some circumstance or expense. If for instance one warp drive dwarfs all the other costs of building/maintaining a starship, it might make sense to have a lot more eggs in every basket. Star Trek however tends to try and find some level of analogy with modern naval forces I think and in that context we've decided there is no longer a practical use for such vessels either.

Full-Disclosure: I was a total swarmer in Homeword 2. This may inform some of my thoughts.

The main purpose of the naval battleships of the 20th Century was power projection. Basically, they were used for shore bombardment in support of amphibious landings (D-Day) and going toe to toe against opposing force battleships and cruisers (Jutland).

The analogous situation in Star Trek would be planetary bombardment in preparation for invasion - hardly what the Federation would put in its mission statement.

Even in our own time though, battleships have become obsolete because they are highly vulnerable to being swarmed with air attacks from aircraft carriers and shore based fighter bombers. Losing such an expensive item to a cheap torpedo is not sensible. Better to make many more lighter ships with more flexible combat roles for the same price.

Everyone here seems to miss one basic advantage of a battleship. Yes, they can carry an awesome array of firepower, but; since they are so heavily armored and protected (in the case of trek multiple shield generators) they have the capacity to absorb massive damage and stay in the fight longer. Sometimes this is more important than numbers particularly if you have to deploy force in more than one location. A single battleship can do this if it carries offensive fighters of it's own. Just a thought.

Also, one should never underestimate the psychological effects that a huge battleship has on an adversary. Battleships invoke fear by their sheer force of presence (granted this does not work on the Borg, but he Borg apparently have found it works on almost everyone else). Fear is a weapon. Another point is due to a battleships massive size, it could carry weapons systems that are far to large to be carried by smaller vessels. A good example of this is when Gul Dukat mounted a planetary defense cannon on the cargo vessel he was in command of in an episode of DS9. You could mount such weapons easily on a much larger battleship.

A good rule of thumb that all naval architects follow--and this extends to fictional starship architects as well--is that a ship should only be as big as its designed mission requires it to be. Battleships of the 20th C became as big as they did because that was the size it had to be in order to:

1. Effectively wield the numerous heavy artillery guns they were required to carry.
2. Fit enough power generation/propulsion systems within the hull to generate the speed they were required to achieve.
3. Carry enough armor, systems redundancy, and sub-compartmentation to withstand damage as required per design standards laid out when they were ordered.
4. Carry enough fuel, ammo, supplies, machinery, manpower and equipment to sustain continuous at-sea operations for however many months required per design standards.
5. Carry all their secondary and tertiary weapon batteries and their alternate mission equipment (i.e. adequate communications gear to serve as flagship if so deemed)

In the case of ST Fed ships, their main weapon systems were not very large in size or mass or power-hungry by standards of ST genre ships. Thus, they could easily be built into far smaller vessels than the large, exploration oriented starships of the Fed, hence the Defiant being so much smaller than other Fed ships while being easily a match or outmatch for any of them.

If the Fed were to field any weapon systems that required more power generation, larger size or heavier/sturdier hulls to absorb the recoil from fire/discharge/launch, then you would see dedicated warships of the Fed get bigger as necessary to match the new size requirements of the weapon systems they wield.

The main design point of the Dreadnoughts of the 20th Century was above all to outrange smaller vessels in order to destroy them before they could hit back, and be able to withstand the counter fire of other Dreadnoughts. This combination practically guaranteed that a fleet with Dreadnought(s) would always win against another without one if it came to battle. That's also the reason why they became quickly obsolete with the advance of aircraft carriers, as planes and rockets can target ships farther and more precisely that any naval cannon could ever hope to achieve.

In Star-Trek terms, designing a ship analogously to a Dreadnought would mean to place few (or just one) huge phaser cannon(s) on a large and well protected ship that features extremely large (or multiple) warp cores, with a primary focus on extended sensor range, decisive weapons range advantage, and such devastating hitting power that a single shot can reliably destroy anything smaller before it can fire back. Around this, a fleet of smaller vessels would make sure the behemoth cannot be overwhelmed by mass attack. Taken to extremes, that would lead to a Death Star kind of vessel: http://en.wikipedia.org/wiki/Dreadnought#Long-range_gunnery

If bigger weapons cannot achieve a decisive range superiority, for example if phaser cannon size or range is physically limited, it is indeed tactically disadvantageous to put that many eggs into one basket, and better to build more smaller ships like the Defiant that combine stealth, rapid fire, good defensive capabilities, and enough maneuverability to evade counter fire. That's why the British in the 18th century rightly preferred building more third rates compared to more 1st rate "super ships", which offered no extended weapons range, only marginally more fire power, at excessive costs: http://en.wikipedia.org/wiki/Third-rate

They do though, The Sovereign Class is effectively a battleship, especially when compared to any of the ships deployed by the major powers in the alpha quadrant.

The Sovereign is designed and used as might be expected in any setting where arms/armour development is where it's at in Star Trek, which is defensively. There's a few comments here about the cost effectiveness of battleships, but they all presume battleships are and always have been used 100% offensively which is not always the case. They can and were used as fleets in being, especially at time when armour was better than the guns. That is the Sovereign. In all her appearances she never quite has the firepower to completely overwhelm similar ships but she does have the defensive capabilities to engage them, or small fleets of smaller ships and survive.

Now ships like this have limited use, especially for a mostly peaceful and exploratory civilization/fleet like the federation. It makes sense they would only have a few of them, used primarily for "diplomacy" like "putting out diplomatic brush fires" and for internal defense. They are too expensive to have a lot of them, to valuable to afford to risk in all out combat, and too limited in there role to be of much other use.

The klingons call the enterprise a battlecruiser in ST:III.

The galaxy class is defined by starfleet as an 'explorer' or 'exploration cruiser' I would imagine that the klingons and romulans would regard it a battlecruiser, as they did the constitution class before it. The galaxy class is designed for exploration, not warfare.

The fact of the matter is that the federation design their ships to be multi-purpose. They don't just do escorts and battles, they explore, they research, they are fleets in being.

The purpose of a starship is not to fight, but to explore our universe.
To seek out new life, not seek new ways to destroy it. To that end they are equipped for defence, not offence.

From my understanding of Star Fleet and the Federation – Humanity is a little more mature than present day humanity. Protecting humanity by beating up or destroying threats isn't the Federation's MO. Granted, there are always outliers (Matthew Dougherty, Admiral Pike, etc.) that see the Federation as vulnerable and want to arm it to the teeth. As I said, though, Humanity is the beating heart of a Federation of widely diverse peoples and cultures. They are an inclusionary force in the universe, not an exclusionary one. Star Trek Enterprise had a new species or faction joining the Federation every other episode. The Federation even tried to bring in species that were overtly hostile by talking them down, e.g., the Romulans. Granted, it worked for only short periods of time, but that is the point, I think. Even though Romulus and the Federation are basically at a nonstop cold war, the Federation is always open to talking with the Romulans. They are almost always willing to take the first step and try to include someone rather than keep them at arm's length with a knife. That is the big picture painting about humanity and more over the universe. This is NOT the grim darkness of the far future where there is only war. This is a universe where bad shit happens for sure. But, more importantly, this is a universe where problems don't NEED to be solved with a fleet of Scimitar. They can more often than not be solved with a heart to heart, and some times that heart to heart is preceded by a shirtless battle on a desert world, because you have to have some action in there, right?

Simply put, the Federation is concerned primarily with exploration and unity/community with a baseline of defense as a deterrent only. It would, however, much rather invite an enemy to be an ally without firing a shot if at all possible. This version of humanity has had much more than its fair share of war, pain, suffering, and injustice thanks to World War III. ("Encounter at Farpoint" is a good example.) Your question comes from the point of 'safety through force of arms,' which is not the way the Federation mindset works.

The Borg in Star Trek are Deus ex Machina. They, by all rights, should have taken over creation by now. But given that Star Trek often misplaces technology or has single use mechanisms that cannot be reproduced, the oversight is forgivable.

The USS Vengeance on the film Into Darkness would be classed as a battleship

Because they didn't need them.

You only need them if you are at war or you envision conquest. That's not what the Federation was about.

More Cruisers take the same resources to build as one big Battleship. I'd take 2 or 3 Sovereign or Galaxy class ships over 1 Battleship any day.Besides, they can always be retro-fitted with additional weapons in the case of war.

There would be little point to have dedicated battleships, since SF ships already come with mostly 360 degrees coverage for phasers, and forward/aft torpedo launchers (which are also capable of firing seeking torpedoes) ad plethora of powerful and modular technologies.

The Defiant was described as a battleship, but this particular vessel didn't seem impressive because, it had limited firing arcs for one thing and all it managed to do was increase its phaser yield through a relatively simple 'trick' which could be adapted to other SF ships... plus it didn't deal well with speeds above Warp 9. It also came with quantum torpedoes (again, usable on other Federation ships) and ablative hull armor (which can be added to existing Federation ships).

Even the USS Lakota (an old Excelsior class ship) was upgraded to rival the USS Defiant.

When you have multi-purpose vessels like SF that are highly modular, there is very little need to have ships dedicated purely for combat as you can adjust them to the needed situation (sometimes on the fly, other times by swapping out a module like on the Nebula class ships).

Want a more powerful Galaxy class ship? Give it a more powerful warp core, shield array, rig the phasers to double the yield using the same method the Defiant has, equip it with Quantum torpedoes, and install Ablative hull armor on it.

Most of the changes the Defiant incorporated were things that crews could probably achieve on the fly. You don't necessarily need more powerful warp core to increase phaser yield... just modify their properties to make them more destructive by amplifying their forces with other methodologies. Similar principles can be applied to shields... Of course, it's a bit trickier to apply ablative hull armor on the ship's hull, but in the 24th century, it should be easily done using replicators and transporters really.

If I'm not mistaken the Sovereign Class (Enterprise-E) is considered a Battleship.

Just in case anyone is still minding this very interesting question- I think Starfleet would be considered quite incompetent if they did not have a war-ready fleet to go at any time if they were such ardent explorers. In universe they encounter many peaceful races but they also encounter extraordinarily violent ones. The Klingon ships are all weapons of war. The Romulan ships are all weapons of war. Cardassian, Breen, Borg, Dominion, etc etc were all battle ready wartime fleets. The Federation could have the "exploration" fleet that makes first contact, trades, learns new stuff, etc but they should also have a potent ever adapting and improving fleet in reserve waiting for its usage. At the moment the USA has no viable enemies on the high seas. No one can invade us or attack us with anything except nuclear missiles as no one else has the naval capacity or intercontinental bombing fleet that could penetrate NORAD defenses. We have not dismantled our fleet or mothballed our carriers and present a peaceful front to the world. The USA realized that instead of pulling a post-WWI style disarmament we realized it would be better to have an active force ready to go at any time. In universe, it would be a good idea to keep a potent force of ships that had no other usage than killing other starships to protect the Federation from future threats that might emerge. I would also like to say the idea of a larger ship wouldn't necessarily be more vulnerable as even though all starships have shield technology not all of them appear to have ablative armor. Very thick armor combined with redundant systems all built around a core structure of a moving gun would be something the rest of the galaxy does not currently appear to have and it would be exactly what could save the Federation from Borg cutting beams that easily sliced open the baddest ship the Federation had at the time. One other point- the Federation does not operate on a currency based economy. I'm not sure how they decide what to build and when but it appears they have access to unlimited resources within the Federation. If they have the industrial capacity to create starships on demand (despite the time it would take to build them) such as the Utopia Planitia Shipyards, then they would be able to keep constructing the necessary ships and it wouldn't seem to be a point of contention- building one big one vs 12 little ones as the Dominion is shown to be constantly constructing new ships and cloning new armies and pilots for those ships. During plentiful times of peace the Federation could conceivably create fleets in secured locations with certain parts removed like the warp cores to be inserted at will as the situation is required. Complex holodeck simulations can be used during brief maintenance training periods much like the Reserves we have today where civies gain the experience to act as fully trained personnel when activated. When you look at what they said the casualties were during the Dominion War alone, tens of thousands of vessels, their crews, dozens of planets conquered, pacified, and that's just on the Alliance side with another near billion Cardassian civilian casualties, and compare that to the cost of creating a reserve battle fleet with a reserve crew force then it doesn't seem to be all that expensive in a civilization that does not use money. Apenas meu 2 ¢.