Hunting Leviathans

[beachhead1985]

If you were building a large warship for the express purposes of engaging and destroying a single Leviathan or a pair of Leviathans of any sub-type, how would you do it?

Would it need to be more or less mobile?

What kind of weapons would be best? A lot of BT warships feature these huge, diverse armaments, but I personally favour more unitary weapons loadouts; throwing your faith behind a main armament built mainly on one type of weapons system. But does that matter at all, or is it more important to just have X-Tons devoted to weapons?

Really interested to hear what people think.

Asking for a friend...yeah; that's it.

[Tyler Jorgensson]

To fight a Lev of any flavor you need to take one of three approaches.

First: Death by a Thousand Cuts. Take large swarms of fighters or Dropships from Carriers that stay in the back. A Super Carrier with massive armor and huge bays to spit out fighters and Dropships like confetti. Weapons are long range AA brackets and PD Anti Warship lasers and missiles. Custom or Castrum level Dropships, and Custom or Assault level fighters. Preferred fighters with some nukes just in case. Swarm Small Craft too if you can fit them with boat loads of Marines. Fill the space with targets.... or corpses.


Second: A similar sized behemoth. Armor of a Mjolnir or a Lev (I can't remember which is higher), with a huge SI, and enough fighters and Dropships for PD work. Weapons bays like the Texas or McKenna or similar SL era ships: Large, murderous, and many of them. Put enough smaller weapons (smaller naval AC's or missile banks) and PD weapons to defend on against the Levs fighter swarms or Dropships. Slug it out. Very risky.


Third: Why Risk Anything? Drone it up: build a faster smaller Caspar that basically is a Ramship. Build them cheap with a couple NLs as distractions and then use a Jump Core to "Ancestral Home" the thing. I mean you could do the previous two with Drones as well except it's more expensive than the boondoggle Enterprise. .... or you could make a volunteer crew Ramship ... but I'd hesitate to tell your Commanding Officer of that plan unless it's Plan Z.


Oh and FWIW: I've never played any BT with Aerospace in it but it's my two cents anyways. Good luck and I hope the Ghost Bears smash your fleet! ;)

[Tai Dai Cultist]

A Lev's simply got too much armor for anything other than another Lev or a series of crits from nat 12s on to-hit rolls to plausibly harm them.  I'd go for the swarm*... go for as many to-hit rolls as you can and hope probability doesn't betray you.

*= a swarm being over and above what you bring to counter the Lev's escorts and organic fighter/dropship support, of course.

[glitterboy2098]

Nuclear Itano Circus.. cram as many White Shark launchers onto the ship as you can, loaded with Santa Anna warhead missiles. spam them as you close.

even better, also give it lots of fighter bays (and/or dropship collars for carrier dropships), and load them up with fighters able to lob Alamo's.

Leviathans, in all forms, may be massively armored.. but while they might shrug off one or two nukes, they won't fare well vs a dozen plus per turn..

[SCC]

Arrange for a mis-Jump to Taurus, it's the closest thing you're going to get to the Black Hole of Cantauri.

[Jellico]

If I was to build a single large WarShip as suggested I would look to NAC30s. They are notably more efficient than NL55s.

3/5 thrust to get the SI to mount 6000 plus armour.

Tactically I would bull my way to 24 hexes where the benefits of bracketing are minimised and rely on the greater firepower generated by the more potent Macs.

Leviathan are generalists combining Battlespace armament with AT2 armour. It is not hard to use the mass more efficiently to target specific roles.

[beachhead1985]

If I was to build a single large WarShip as suggested I would look to NAC30s. They are notably more efficient than NL55s.

3/5 thrust to get the SI to mount 6000 plus armour.

Tactically I would bull my way to 24 hexes where the benefits of bracketing are minimised and rely on the greater firepower generated by the more potent Macs.

Leviathan are generalists combining Battlespace armament with AT2 armour. It is not hard to use the mass more efficiently to target specific roles.

What are your thoughts regarding Naval Gauss, HNPPCs, Kraken-T and Mass Drivers?

[I am Belch II]

Ships with a lot of firepower like a Black Lion or a Aegis is what you need. Need to do damage to the beast, but you are going to lose a bunch of ships to do it.

[beachhead1985]

The situation I'm looking at is the Dracs rebuilding the Yamato and Ryu mobile factories as a Super-Heavy Battleship and Battle-Carrier, respectively for the express purpose of providing a deterrent to a revitalized GBD fleet mainly consisting of several Leviathans. There are supporting ships, but principally the job of these two is to break warships from the Leviathan family.

[RunandFindOut]

Sunshine, lots and lots of highly concentrated Sunshine!
In fact if you can dig up an old Quixote missile ship there you go.  Pack it full of nukes and fire away.  Sure it has lots of armor, just keep spamming nukes at it in mass quantities till it starts failing rolls.  Don't even need a Quixote for it, you could do the same with a group of carrier dropships and massed Alamo strikes.  Oppenheimer's Light shines past all obstructions.

[Tai Dai Cultist]

The situation I'm looking at is the Dracs rebuilding the Yamato and Ryu mobile factories as a Super-Heavy Battleship and Battle-Carrier, respectively for the express purpose of providing a deterrent to a revitalized GBD fleet mainly consisting of several Leviathans. There are supporting ships, but principally the job of these two is to break warships from the Leviathan family.

If it's solely deterrence, another option might be spamming BattleSats over important worlds on the border. 

Of course my go-to option to kill a Lev would be to send a boarding party onto the ship during a firefight.  Rather than fighting room-to-room to capture the vessel, just set off a nuke from inside the hull once you successfully board.

[Jellico]

What are your thoughts regarding Naval Gauss, HNPPCs, Kraken-T and Mass Drivers?

They are weapons that exist in the game. All are very heavy per point of damage compared to NACs.
HNPPCs are useful and they reach out to extreme range with a useful level of bracketing. They use less fire control than NL55s but lack an AA mode. Swings and roundabout.

Krakens offer no real advantages over conventional cap missiles at WarShip scales.

The rest are largely flavour pieces that I wouldn't touch on a min maxed design.

Finally it is highly likely that the Yamoto is smaller than a Leviathan because of the original IS technological limitations.

[Hellraiser]

If I was to build a single large WarShip as suggested I would look to NAC30s. They are notably more efficient than NL55s.

3/5 thrust to get the SI to mount 6000 plus armour.

Tactically I would bull my way to 24 hexes where the benefits of bracketing are minimised and rely on the greater firepower generated by the more potent Macs.

Jell hit it on the head.

In universe look for an old McKenna hull somewhere in the TH boarders that C* or WoB never fixed up.
Gut the weapons, cargo, & armor for Maxed Lamellor FC & dozens of NAC30's.
Then pray, because after all, it is still a LEV & on any given Sunday.........

[marauder648]

As folks have said, hunting a Leviathan is a HUGE challenge.

Lets say that she's alone but with her dropships and fighters onboard.

Thats a Galaxy's worth of ASF, 300 of them in total.  And eight dropships, and knowing the Dominion (or anyone with common sense) you'd take a full group of 8 Vanir assault droppers to extend the AA bubble and engage assault droppers with its sub cap missiles.  That alone is a HUGE wall to overcome.

Bringing enough fighters means probably stripping your Clan or House of a good chunk of its fighters, as you're probably going to need at least 5 - 600 to get through that lot with anything resembling an intact strike package.

the Leviathan III is a different beast but one even worse to face, she lacks the raw number of ASF but can carry 20 dropships, so expect many Vanir class Carriers with 30 ASF per dropper. And the Lev 3 has an even heavier AMS and anti-fighter battery.

To take on a Leviathan realistically you need numbers, be it fighters or warships and a willingness to take heavy casualties.  In the current period the only ones who can do it with Warships are the Falcons or Ravens, and it would probably be at the cost of most of those Warships as there's no battleships in the setting that can overmatch a Levi's armour save if you do a head on closing approach with some heavy naval autocannons. 
There's also very few Warships that can take a Levi's undevided attention for very long that are still around.  An Aegis would probably be destroyed in short order, and they are well protected cruisers.  Any action against a Leviathan would gut a current TL's fleet or destroy them if it was a House force. 

As i've said in other threads, the Leviathan is a Super Star Destroyer analogue, massive, hugely well built and well protected with more guns than is really necessary.  And taking one down is either going to be

A.  Very painful and costly.
B.  Praying for a lucky crit.

Failing that, then the other option is breaking out nukes and pelting her with them. If its a Leviathan 3 though, good luck breaking through her AMS battery.

I made an article about the Leviathan III here - http://bg.battletech.com/forums/index.php?topic=52210.msg1204535#msg1204535

[Jellico]

3 x Aegis have the gun power / armour balance to kill a Leviathan. You can tweak the daughter craft as needed.

[marauder648]

I dunno, the Leviathan has the thrust advantage, and the range/firepower advantage.  The Aegis would stand a chance if you managed to get in really close to bring the numbers up for their NAC's and threw all three at her same flank, but its getting there to do it.  300 odd fighters and 8 assault droppers in your way are not going to be fun to punch through.

In a raw gun fight sure, but its a case of surviving long enough to get into accurate firing range as the Aegis can't really bracket fire to improve her hit numbers whilst its what the Lev was built to do.

[Jellico]

First up I don't agree that a 3/5 can hold a 2/3 ship at range. Especially if it has to turn to expose a broadside. In the case of a Leviathan it is especially vulnerable in a stern chase because of weapon placement.

Secondly 3 x Aegis = 12 x Docking Collars. In round numbers you are looking at 60 (give or take a shuttle bay) native fighters and what ever the docking collars might carry. 4 Vengeances is an immediate thought making it 180 ASF. Beyond that you are into all sorts of creativity. Given the nature of the target 12 Vengeance isn't unreasonable, but then we are asking how the target to change and it all gets messy. So... I am happy to give you the 300 fighters. Just understand that time/damage space means that there is always a window of opportunity of a capital weapon armed craft to achieve victory before the slow tsunami of ASF firepower takes effect.*

This leaves a stand up battle. The primary armament of the Aegis isn't its NAC35s. It is the 12 NAC20s in each broadside. These bracket quite acceptably at 40 hexes. A Leviathan will be bracketing at a similar level at the same range.

At 40 hexes an Aegis is doing approximately 260.
At 24 hexes an Aegis is doing approximately 470.

A Leviathan does a consistent 500. For all intents and purposes the ability to bracket is equal and mostly depends upon luck with ECCM. Or maybe no. I assume both sides would be using Active probes.

586 points of armour vs 6000.

Using very basic modelling a Leviathan will defeat 4 Aegis at 40 hexes with about 2300 points of armour intact. 5 Aegis is a rout with 2 cruisers surviving.

I am happy to revise my estimate so that at 25 hexes 4 Aegis would still be needed with 2 cruisers surviving based on the modelling. Not a bad effort for the Leviathan given it is about 70,000 tons lighter. 4 Aegis also gives the kind of docking collars needed to match the 300 ASF.

Perhaps more interestingly, this gives you a window on the kinds of ships you would need for the job. For example a Black Lion or Luxor is basically an Aegis that can fire at full strength to 40 hexes.

A Mjolnir will definitely close the range do 24 hexes and 2 will do the job and survive. ASF will be an issue, but the battle cruisers survive so well I can't see ASF being effective in time.

3 Avalons come disturbingly close to a victory. Mind you they have to stop at McDonalds for drive thru their cargo load is so poor. The 18 collars would make the ASF mix very interesting and probably vital to the outcome here.

Mjolnirs, Avalons, and Leviathans have the typical AT2 low cargo %s so it is not surprising that similar tonnages of ships are similar in capability. Perhaps that is the thing for the DCN to take away from this. They don't need a super ship. They just need 2.4 million tons and a way to keep the ASF at bay.



*For the uninitiated ASF do low damage but have high armour. Capital ships (and DropShips) do high damage but have low armour. So it is quite possible for the capital ship to get in, complete its mission objectives, and escape before the ASF can be effective. Note the ASF will barely be scratched in the process.
The longer the battle goes the more effect the ASF will have and the sheer inability to kill them will ultimately prove fatal at relatively low cost to the ASF.
I have had a lot of fun using Taihous to exploit this dynamic. This doesn't necessarily mean carrier killing. They might be nowhere nearby. But it is well worth a capital ship playing by smash and run.     

[snewsom2997]

What about the Boondoggle Enterprise? Lots and lots of fighters, though I'd expect you would end up putting a large fraction any House's or Clan's ASF in one big giant basket.

[marauder648]

What about the Boondoggle Enterprise? Lots and lots of fighters, though I'd expect you would end up putting a large fraction any House's or Clan's ASF in one big giant basket.

Could work, the ship would be obliterated very quickly but that many fighters would do it.  Sure in a campaign you'd then possibly loose all those fighters if you engaged the Leviathan in deep space and the fighters, with limited supplies, air and fuel would probably run out before they could reach safety :p

[beachhead1985]

3 Avalons come disturbingly close to a victory. Mind you they have to stop at McDonalds for drive thru their cargo load is so poor.

An aside; I have always wondered about the humongous cargo loads some warships carry and what they use it for. Given; my designs usually have much larger fuel bunkers, magazines and larders than some canon designs and 1% spare parts.

[marauder648]

An aside; I have always wondered about the humongous cargo loads some warships carry and what they use it for. Given; my designs usually have much larger fuel bunkers, magazines and larders than some canon designs and 1% spare parts.

In a Sov Soy's cargo you could loose a mega sized passenger ship, like one of the largest there is now.  Over 200,000 of cargo. 

[Kit deSummersville]

I'd build a super-opulent SpaceYacht and regularly take out members of the steering committee out on it. Be sure to keep refilling Bay #2 with cash and expensive artwork. When it comes time for the next budget for the Leviathan watch it go down to 458 C-bills. See how long they keep operating it with that sort of support.

[Iron Mongoose]

I won't try to contradict the tactical analysis of my more aerospace savvy peers, but it's worth thinking strategically about the Leviathan as well.  As noted, it's very short legged, and yet very hungry.  The best strategy would simply be, as in baseball, him 'em where they ain't.  If the Leviathan defends a world, attack another.  If you're feeling cheeky, hit a nearby world, let the big monster scramble out to meet you, then run.  If you're feeling really cheeky and have access to a few LFB ships that pose a medium sized threat, jump in, let them scramble their fighters and light up their engines, and then jump away before it can crush you.  Do that for a week or two, run the monster out of food and gas, and pretty soon it will have to either go home, or resupply on the road, in which case you could potentially use that as a moment to strike.

Honestly, only above the small number of targets that simply must be defended does one really need to think about fighting the thing.  Sure you can't run from a place like Luthien or Terra or Hesperus or New Avalon or some place like that, and you can bet it won't retreat from Alshain or Rasalhague (and there it will have access to supplies).  If you're in that situation, then you use what you've got, which is more likely to be vast swarms of fighters (no need to special infrastructure, and once the mission is over they can be dispersed into ten or twenty groups) unless you're the Ravens or FWL before the Jihad or one or two other groups.  But, if you've got several ships to fight the one Leviathan, may as well just attack several other targets, and tie it up, and make it either sit over a place you're not going to attack anyway, or else chase you around aimlessly.

[Thunder]

So after reading the link to the Levi III article, people seem to think that its point defense systems are great.  While I'll grant they're capable of knocking out any stray missile that comes close, Small Bays of missiles would get through without much deterrence from my understanding of the rules.  For example, a Bay of 4 white shark missiles would lose 2 missiles, and forces the third missile to miss unless the margin of success for the hit roll is 2 or greater.  The Fourth missile would hit like normal, which is all you need for the critical hit roll you're really after. (Assuming 2 firing arcs worth of Point Defense engage.)  So am I missing something?

Edit:
The voices finally remembered PDS only engages out 1 hex, so 2 Arcs worth of PDS vs 1 missile bay is extremely unlikely.  Still the point remains.

[Jellico]

I'd build a super-opulent SpaceYacht and regularly take out members of the steering committee out on it. Be sure to keep refilling Bay #2 with cash and expensive artwork. When it comes time for the next budget for the Leviathan watch it go down to 458 C-bills. See how long they keep operating it with that sort of support.

I am imagining Scrooge McDuck in an ocean sized money bin.

[sadlerbw]

How do you kill a Leviathan? Give it a Jade Falcon pilot   ;D

Seriously though, I still feel like the best way to deal with any warship is lots and lots of nukes. It worked for thinning out the fleets in the succession wars, and it worked in the jihad. No reason you can’t get it to work on a single ship. Sneak one into a shipment of spare parts headed for the big Lev, and you don’t even need any warships or fighters.

In general sabotage is pretty effective. Once you get a spy on the engineering crew, there are all sorts of nasty things you can do. Hell, you don’t even need to kill it completely. Just get the jump core to crack and it becomes the universes biggest system monitor.

Now, assuming you don’t want to use such shenanigans, and you want to legitimately blow it up on a hex map with a minimum of advanced rules, I’d go for a fighter and small craft swarm of massive proportions. Get as many big fighters and small craft with stuff like improved heavy large lasers, UAC20s, and heavy Gauss rifles as I can. The Huscarl C isn’t a bad choice, or the Xerxes 3, or Sabutai A should work. If you are ok with dark age stuff, the Scytha F and Jenghiz F would be pretty nice, or the TIG-40 gunboat. The idea would be to throw so many squadrons at the thing that it literally doesn’t have enough mech-scale weapons bays to kill them all before they bore through the armor and supporting craft. Basically, make as much of that capital-scale weaponry useless as possible. It would be an almost unmanageably large battle to play out physically, and would probably be boring, but it should work.

[vidar]

Another idea is lighter warships with extreme range weapon and high thrust.  Dance at range and hope to wear down the armor and SI  before you losses are to bad. 
The converion of a yard ship to a warship is very short sighted.  Big Bad BB are scary on paper but the ability to repair and rearm on the strategic level is a real game breaker.  I would never convert them to fight BB's. Fighting Leviathan's is not the way to win.   

[truetanker]

I'd take the following: 2x Hunter and 3x Odyssey LF jumpers.

Gives me 14 dropships, 10 Titan C's, 2 Titan Monitors and 2 Outpost 3070 Refits.

Allowing me 320 ASF, 4 Killer Whales, 10 mechs ( mostly the space variants ), 20 Sealed Tanks, 20 Points of BA- space adaptive and 4 Points of Protomechs- space adaptive.

It would also be a joint adventure by clan Hells Horses and the Raven Alliance.

Finally I can " beam " useless HPG traffic into the area from both Monitors and Hunters to " fog up " the response times, kinda like the old Imperial Interdictor-class cruisers with their Gravity well generators.

TT

[beachhead1985]

Finally I can " beam " useless HPG traffic into the area from both Monitors and Hunters to " fog up " the response times, kinda like the old Imperial Interdictor-class cruisers with their Gravity well generators.

TT

Are you saying that this works to mess with naval senors?

Using HPGs to spam the incoming jump alarms?

[RunandFindOut]

No I think he means using an HPG to transmit garbage to prevent the Leviathan from calling out for help.