Pacific Rim- how to do it more efficiently?

[Rogue 9]

That's a fairly good point: Only the 'final boss' Kaiju, their largest type seen in what, like 10 years, was able to survive an underwater nuke. The others died.

So that means the most cost effective thing is to break out those old nuclear torpedos, and have attack subs pretty much annihilate them prior to landfall.

I've said this very thing in prior threads on the matter and been laughed out.

[Gaidin]

How maneuverable are attack subs compared to them? Or do they just kind of sit there aimed at them like an "underwater nuclear sniper"?

[Rogue 9]

Modern attack subs couldn't just sit in the Mariana Trench waiting anyway. You'd need a detection network and to dispatch packs of submarines (or surface task forces, for that matter) to intercept once one emerged.

[Gaidin]

Well, I mean, my main worry is, their survivability when trying to attack one of these things. Not exactly like they've been known to be unable to find things. Or hide. Or deceive.

[Rogue 9]

You don't hide from active sonar in the open ocean, particularly not when you're that big. In fact, that leads me to wonder how one would react to being sonar-lashed. It probably wouldn't work for long, but the results on the first couple could potentially be hilarious.

[Q99]

How maneuverable are attack subs compared to them?

Not very.

The Kaiju in the movie were rapidly circling enough the jaeger had some trouble tracking them. Maneuverability edge makes sense, the Kaiju can flex their whole body to turn after all and have tails and sometimes their whole body shape as huge maneuver surfaces, unlike a submarine that is reliant on small rudders.

[Simon_Jester]

Honestly, everything I've heard suggests that kaiju are vastly more maneuverable, speedy, and deep-diving than human submarines, and for that matter human torpedoes. You'd be better off with mines- the problem being that nuclear mines cause fratricide when they initiate, so you couldn't really create a multi-layered shell of mines around the rift.

[Q99]

Honestly, everything I've heard suggests that kaiju are vastly more maneuverable, speedy, and deep-diving than human submarines, and for that matter human torpedoes. You'd be better off with mines- the problem being that nuclear mines cause fratricide when they initiate, so you couldn't really create a multi-layered shell of mines around the rift.

And fratricide is a major issue when a single nuke isn't a guaranteed kill depending on yield/kaiju/distance and multi-events can mean they come out after the nukes are cleared.

[Borgholio]

Honestly, everything I've heard suggests that kaiju are vastly more maneuverable, speedy, and deep-diving than human submarines, and for that matter human torpedoes. You'd be better off with mines- the problem being that nuclear mines cause fratricide when they initiate, so you couldn't really create a multi-layered shell of mines around the rift.

And fratricide is a major issue when a single nuke isn't a guaranteed kill depending on yield/kaiju/distance and multi-events can mean they come out after the nukes are cleared.

But a single nuke hit isn't going to simply bounce off, it would still hurt like hell. So you could probably send the nukes in far enough apart to avoid fratricide and still kill the things.

[Q99]

But a single nuke hit isn't going to simply bounce off, it would still hurt like hell. So you could probably send the nukes in far enough apart to avoid fratricide and still kill the things.

The shockwave will travel kilometers (unless you lower the yield, in which case, kill odds reduced), so I don't see how. The fratricide range should punch a gigantic hole in any nuke mine 'net' which a kaiju can easily swim through.

[Borgholio]

I'm referring to the nuclear torpedo idea. Send down a torp, confirm a hit, send down another if the thing is still moving.

If you want to go the mine route, put a single MASSIVE mine on a tether hovering directly over the rift. Kaiju comes thru, immediately gets a 25 megaton bomb to the face. If you get two kaiju in a row, then hit the second one with torpedoes.

[Q99]

I'm referring to the nuclear torpedo idea. Send down a torp, confirm a hit, send down another if the thing is still moving.

Again, kaiju are faster and more maneuverable than subs or torpedoes, and the only torpedoes we have that can go near their speed are sonar blind so they can't even adjust aim or work off promixity.

So if your torpedo has to travel, say, 2km, then the kaiju in that time can travel 2km+, in any direction (North, South, East, West, and changing in depth), and actively maneuver and chance course, in the same time frame.

If you want to go the mine route, put a single MASSIVE mine on a tether hovering directly over the rift. Kaiju comes thru, immediately gets a 25 megaton bomb to the face. If you get two kaiju in a row, then hit the second one with torpedoes.

You don't want it too close to the rift- because one good smack and you no longer have a nuclear explosion, you have a dirty bomb at best, which may possibly mildly annoy the kaiju. Though sufficiently big you can manage somewhat further out, granted.

But to do the torpedo after, now the distance you have to fire from is outside the radius of a *25* MT blast. You're now firing from no-where near the breach, the Kaiju has completely open water in three dimensions to work with.


The biggest the bomb, the less redundancy you can do near the breach.

[Borgholio]

Again, kaiju are faster and more maneuverable than subs or torpedoes, and the only torpedoes we have that can go near their speed are sonar blind so they can't even adjust aim or work off promixity.

Has it been established how fast they really are? We see short bursts of speed and high maneuverability during the final battle, but a high sprint speed means nothing if a torpedo can outrun it over a chase distance of 20 or 30 miles.

You don't want it too close to the rift- because one good smack and you no longer have a nuclear explosion

Well yeah but it doesn't HAVE to be close to the rift. A 25 megaton bomb is almost hard to comprehend in terms of how powerful a shockwave it can make underwater. With that said however, even a bomb of that size won't harm second-layer defenses 10 miles away or so.

[Q99]

Has it been established how fast they really are? We see short bursts of speed and high maneuverability during the final battle, but a high sprint speed means nothing if a torpedo can outrun it over a chase distance of 20 or 30 miles.

Right in the opening Alaska scene Knifehead travels miles while the fishboat crew was talking when it wasn't in combat. During the final missions, even when they're just circling the Jaegers at a distance they're too fast to keep up with. The time-frame of them emerging from the breach to hitting shore isn't too long either, their long range speed has to be good.

Supercavitation torpedoes don't have that long of range, btw... and as mentioned before can't operate at the depths Kaiju can go, and they're sonar blind so targeting is going to be an issue.

Plus with the maneuverability differences, a kaiju doesn't only have the option of outpacing a torpedo, it can just take tight turns and make the torpedo have a really hard time trying to even stay on target.

Hitting something with something else that's at or below it's speed (possibly well below with a normal long range torp) and not as good at turning is really really hard.

Well yeah but it doesn't HAVE to be close to the rift. A 25 megaton bomb is almost hard to comprehend in terms of how powerful a shockwave it can make underwater. With that said however, even a bomb of that size won't harm second-layer defenses 10 miles away or so.

Daaang, a net of bombs 10 miles away? That'd be a hemisphere with a 20 mile diameter.... I figured you'd want bombs at *least* every quarter mile (otherwise the kaiju can swim through the gaps and a detonation would have to be fairly far away. Slattern survived a 1.2 megaton at under a hundred meters), or if they're farther apart have them be, again, really really huge ones... that is a whole lot of bombs in your second sphere!


Triple events are a thing. So, one backup sphere won't even do once you get to that point.

[Borgholio]

Right in the opening Alaska scene Knifehead travels miles while the fishboat crew was talking when it wasn't in combat. During the final missions, even when they're just circling the Jaegers at a distance they're too fast to keep up with. The time-frame of them emerging from the breach to hitting shore isn't too long either, their long range speed has to be good.

Their long range speed has to be literally supersonic to go from the breach to Hong Kong in the time frame that they did in the movie. There are so many things wrong with that number that we might as well assume that physics doesn't work in the PR-verse the way it does here. With that being said, maybe a torpedo CAN keep up. But I'm just pulling stuff out of my ass here. If we assume that Kaiju can easily move at supersonic speeds underwater, then even a nuke might not be effective if they can outrun the shockwave.

Daaang, a net of bombs 10 miles away?

No, torpedoes. Say the bomb fails and the Kaiju is heading towards land, it has to pass over the ring of torpedo defenses where they can get off some shots as it moves by.

[Q99]

Their long range speed has to be literally supersonic to go from the breach to Hong Kong in the time frame that they did in the movie. There are so many things wrong with that number that we might as well assume that physics doesn't work in the PR-verse the way it does here. With that being said, maybe a torpedo CAN keep up. But I'm just pulling stuff out of my ass here. If we assume that Kaiju can easily move at supersonic speeds underwater, then even a nuke might not be effective if they can outrun the shockwave.

The on-screen speed was *near* sonic, at least- that is, air-sonic. Water sonic is 4.3x as fast, shockwaves still work without any doubt.

Also as noted, supercavication likely can't be accomplished at that water depth, since it works by pushing water out of the way. So that pretty much zeros our fastest torpedo until a kaiju rises to the upper levels of the ocean.

No, torpedoes. Say the bomb fails and the Kaiju is heading towards land, it has to pass over the ring of torpedo defenses where they can get off some shots as it moves by.

Hemisphere, you want a hemisphere, not a ring, whatever your defense, otherwise the answer is 'swim upwards.'

[Borgholio]

Also as noted, supercavication likely can't be accomplished at that water depth, since it works by pushing water out of the way. So that pretty much zeros our fastest torpedo until a kaiju rises to the upper levels of the ocean.

Not necessarily. Remember that physics doesn't appear to apply to stuff in the water in the film. Kaiju can move at nearly supersonic speeds without any noticeable effort, and Jaegers can somehow survive the incredibly crushing pressure of the Challenger Deep.

Hemisphere, you want a hemisphere, not a ring, whatever your defense, otherwise the answer is 'swim upwards.'

Not necessary to have a full hemisphere. Modern torpedoes have a range of 20 - 30 miles. That's plenty for a ring to work.

[Q99]

Not necessarily. Remember that physics doesn't appear to apply to stuff in the water in the film. Kaiju can move at nearly supersonic speeds without any noticeable effort, and Jaegers can somehow survive the incredibly crushing pressure of the Challenger Deep.

I wouldn't say it's without effort... but note, those are shown to be super strong and super tough above water too, so it's hard to blame it on the water alone- especially as the Jaegers seemed noticeably slower underwater.

Not necessary to have a full hemisphere. Modern torpedoes have a range of 20 - 30 miles. That's plenty for a ring to work.

Then they swim up and you don't get any hits or anything close enough for a proxy hit ^^;; A tail-on chase won't work, so if you can only fire from a rear arc- and in this case even a 'has to make a direction change to stay on the trail at all'- you're not likely to get close enough to do much of anything.

Especially with conventional torpedoes that are about 1/10th the speed- another limitation of supercavitating torpedoes, aside from not being able to handle the depth, is they have shorter range.

[Gaidin]

So we're in a world capable of designing these outrageously huge robots. Would this world be capable of designing torpedoes and/or submarines with new capabilities whether based on material or fuel or whatever? What about the same principle for air forces or ground army in and around likely target cities?

I mean, canonically, the military as is modern day loses. In fact gets curbstomped. What would theoretically happen if *that* were upgraded with the kind of technology, armor, and such that we could derive as being capable thanks to the Jaegers. Instead of talking about normal technology over and over...

[Caiaphas]

I'm by no means an expert on hydrodynamics and I'm only an engineering student, but from what I can gather there are several factors to this situation that severely limit any countermeasures that can be designed.

Factor 1: the majority of the time, the enemy operates in the water. From my understanding, the shapes of objects designed to move through water and other such fluid mediums are more or less optimized as they are; any material advances made in the creation of the Jaegers is obviously not going to improve that, since it's a function of how the shape of the object interacts with the medium. Therefore, to my thinking, it's likely that you'll see variations on existing submarines and torpedoes, and neither is going to really see a massive increase in speed and maneuverability. Perhaps you could simply brute-force a solution and create a weapon that physically powers its way through the water, drag be damned; I can't speak to the feasibility of that, and I'm not even going to try to speculate on their potential range, homing capabilities, or payload.

Factor 2: the point is to stop the damn kaiju before they hit the shore, since they a. plow through buildings as though they're made of wet bread and so can do a lot of damage in a very short time, b. are significantly faster and more maneuverable (well, most of them. I doubt Raiju would be) and therefore more difficult to stop when they emerge from the water, thanks to the physical fact that air is easier to push aside than water, and c. presumably you want to minimize property damage and lives lost without evacuating everyone to the interior of large landmasses. If you don't want giant mecha linebackers, then obviously you need to hammer them with overwhelming firepower the instant they rear their heads. The tracking bit can probably be easily done with a modern CIWS (hell, given how big the things are you could probably nail them on radar with a WWII-era system); it's the overwhelming firepower that's the difficult bit, especially since we can't leave out the possibility of kaiju showing up with armor plating.

Factor 3: How do you deal with the stupid amounts of overwhelming force that will inevitably pour through the breach? If you can address factor 2 sufficiently, then I think that you can probably work out part of a solution to this, but I don't know.

This is basically all I can think of for now.

[Q99]

b. are significantly faster and more maneuverable (well, most of them. I doubt Raiju would be) and therefore more difficult to stop when they emerge from the water, thanks to the physical fact that air is easier to push aside than water,

I think a lot of the kaiju are at least moderately water optimized, and much of their body is pushing surface in most cases. Tails are common, and they can mostly flex their whole bodies to boot.

Jaeger, on the flip side... well, aren't water optimized. Their best water trick is 'get sealed up and walk.'

It seems to me that while Kaiju might have an absolute higher speed on land, the relative capabilities advantaged Kaiju more in water.

This is basically all I can think of for now.

Good breakdown

Though, flipside- let's say your the Kaiju Makers. What's your gameplan from their end? Since there's obviously a fair amount of flexibility in the general shape and size of kaiju, you've got options.

[Caiaphas]

b. are significantly faster and more maneuverable (well, most of them. I doubt Raiju would be) and therefore more difficult to stop when they emerge from the water, thanks to the physical fact that air is easier to push aside than water,

I think a lot of the kaiju are at least moderately water optimized, and much of their body is pushing surface in most cases. Tails are common, and they can mostly flex their whole bodies to boot.

Jaeger, on the flip side... well, aren't water optimized. Their best water trick is 'get sealed up and walk.'

It seems to me that while Kaiju might have an absolute higher speed on land, the relative capabilities advantaged Kaiju more in water.

This is basically all I can think of for now.

Good breakdown

Though, flipside- let's say your the Kaiju Makers. What's your gameplan from their end? Since there's obviously a fair amount of flexibility in the general shape and size of kaiju, you've got options.

Er, I was really thinking more along the lines of while you think the kaiju are bad in the water, they're, from a basic speed-strength-durability breakdown, worse in the open air. I mean, you're certainly going to have a lot more offensive options once they leave the water, but that was outside the scope of what I was talking about.

And if I were the makers, put everything into speed for the first few at least. The kaiju are big enough that even a small one will be difficult to kill with conventional forces at first (I mean, come on, how deep are its vitals going to be?), and I'm going for maximum disruption and havoc.

[Q99]

And if I were the makers, put everything into speed for the first few at least. The kaiju are big enough that even a small one will be difficult to kill with conventional forces at first (I mean, come on, how deep are its vitals going to be?), and I'm going for maximum disruption and havoc.

Yea, small and fast seems like a good bet.

If aquatic defenses are used a lot, making them more fish and eel like could work. Even with ones like Raiju, it's still amphibious, one could really max out the water speed if one was willing to sacrifice land capability more.

[Sky Captain]

Given that in Pacific Rim humans have much better power sources why it is assumed a non supercavitating torpedo can't be made fast enough. If Kaiju can swim at several hundred km/h I see no reason why torpedo or submarine couldn't do the same given enough power. Both move in water and same physics apply to both. In real life there are fish that can reach 100 - 130 km/h even with power to weight limitations of animal muscle. Right now there are electric motors available with power to weight ratio of 10 kw/kg. With good enough batteries or ultracapacitors a torpedo with propulsive power in megawatt range are not out of the question.

[Q99]

Given that in Pacific Rim humans have much better power sources why it is assumed a non supercavitating torpedo can't be made fast enough.

Because the big problems with torpedoes and speed aren't simply power. Drag, and translating the power into motive force are the issue. Simply making a propeller that's the same size go faster and faster has diminishing returns.

The super power sources on jaeger are, like, huge and heavy. Most of them are literally nuclear reactors. Kaiju are neutrally buoyant, jaegers sink. So I don't think they could make a jaeger swim like a kaiju (using the method of using most of a huge body as a pushing surface) even if they tried.


Or to put it another way- rather than assuming they can't, the problem is none of the observed technologies show such a method, so you'd have to assume they can.