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Old 10-08-2017, 07:28 AM   #81
mlangsdorf
 
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Default Re: [Ultra-Tech] What would naval warfare at TL10 look like?

Like I said, it was really quick math. I set up a table of hull sizes, armor DR, and payload weights, and then calculated the structure weight/cost and total weight/cost for a surface ship and submersible with those characteristics. Payload in this sense means weapons, power plants, crew, electronics, and all that - all the stuff that the vehicle structure is meant to deliver.

Roughly, the structure of a sub weighs 2.5x as much as a surface ship and costs 2x per pound (or 5x overall), and the sub has modestly more surface area and thus armor weight and cost, but at TL10, the cost and weight the payload dominates structural and armor costs.

I didn't really try to do any designs, so I don't know if an actual TL10 fusion powered, gauss cannon and missile toting battleship becomes substantially more expensive when you build it as submarine.
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Old 10-09-2017, 11:43 AM   #82
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Default Re: [Ultra-Tech] What would naval warfare at TL10 look like?

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Originally Posted by Fred Brackin View Post
With fusion air-rams you can have that indefinite dwell time but you probably want AI "pilots" to take advantage of it.
I think NVAI was given as a possibility in the setting anyway. But even without it, AFAIK, modern-day military pilots already fly long endurance missions, so I don't see this being an impediment.

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Sending back to the other side of the world for replacements due to combat or operational losses is going to be extremely inconvenient
At the speed of the HTV-2 (13,000mph or Mach 17), it's a 50min commute from London to Sydney. Or the TL10 aerospace fighter in Spaceships 4, with a more modest Mach 4.5, would cover 3000 miles in the same time. I'm not sure what time-to-target range modern-day carrier operations expect, but it wouldn't be much different than that.

Ok, if one is shot down, they'd probably need recovery assets more locally available, but that wouldn't be the deciding factor for a mission profile.
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"Seven league boots" missions are alright for planned strikes against immobile targets and they can even work somewhat for armed reconnaissance missions ("Here is a bomb. Go find something to drop it on."). However when the groundpounders radio for back-up it works a lot better if it's physically close.
I'm picturing the strike vehicles quickly commuting in from a distant ground base, settling into a holding pattern near the theatre of operation, and being immediately available for called-in airstrikes.

But that's also not necessarily a persistent paradigm. Wouldn't brilliant cruise missiles launched from an off-shore battlecruiser be more likely?

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Originally Posted by Crystalline_Entity View Post
That was my original instinct, I just imagined naval warfare would be like it is now but with ultra-tech weaponry, with no major paradigm shifts in tactics or technology.
I think a paradigm shift happens every 30-50 years, at least.

One article I came across while browsing the topic suggested that carriers may already soon be obsolete, due to their vulnerability to anti-ship cruise missiles being developed by China and Russia. In that case, we might only see carriers in use in asymmetric conflicts.

On the other hand, hypersonic missiles might indeed fall under treaty ban, due to their outright effectiveness despite being classed as conventional weapons. This would put carrier fleets back on the table.

My final thought, concerning the orbital theatre-
Wouldn't orbital weapons platforms be even more sitting ducks than surface-based assets? And wouldn't any orbital combat quickly bring on the Kessler Syndrome, a cascading chain reaction of debris, therefore denying orbital positions? It's very possible then that TL10 warfare surprisingly doesn't have much LEO activity.
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Old 10-09-2017, 12:13 PM   #83
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Default Re: [Ultra-Tech] What would naval warfare at TL10 look like?

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Originally Posted by Daigoro View Post
My final thought, concerning the orbital theatre-
Wouldn't orbital weapons platforms be even more sitting ducks than surface-based assets? And wouldn't any orbital combat quickly bring on the Kessler Syndrome, a cascading chain reaction of debris, therefore denying orbital positions? It's very possible then that TL10 warfare surprisingly doesn't have much LEO activity.
LEO pays more for each pound of armor, and has more valid angles of attack than a ground based installation. Its only slightly more maneuverable. Additionally, top tier powers will have a LOT of effort invested in shooting down things in low earth orbit. Its quite possible that people won't achieve orbital supremacy, and possibly only parity, at least until the ground forces start moving.

This doesn't apply to all orbital levels though. Farther orbits may be quite a bit safer. Geosynchronous in particular shows promise. I don't know how hard it will be to get things into GEO once the shooting starts though.
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Old 10-09-2017, 05:36 PM   #84
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Default Re: [Ultra-Tech] What would naval warfare at TL10 look like?

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. . . Get a solid head-on impact during reentry, and you stand a good chance of blowing the entire head off that rod. .
.
Probably not even necessary.

Even a good sized dent in a Rod from God would create asymmetric aerodynamic forces. At Mach 4+ that should be enough to make the Rod tumble and then break apart (going from head-on to sideways at Mach 4 would probably cause the breakup of even a tungsten-alloy Rod.) Or at least would cause it to veer, make it uncontrollable and therefore miss.

So a "canister" round of multiple small projectiles that will scatter should work. One or more of these little pellets would be very likely to hit and dent the Rod and so cause a mission failure, if not a break-up.
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Old 10-12-2017, 01:04 PM   #85
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Default Re: [Ultra-Tech] What would naval warfare at TL10 look like?

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Sorry, I'm not sure how this is relevant. I'm postulating fighters with enough long range to reach over the horizon to half way round the globe. Any particular naval group would be under their umbrella. If you need them nearby for immediate defense, then they'd have a long enough dwell time to remain with the group on patrol for a shift before returning to their distant ground base, with another patrol arriving to relieve them, thus not requiring a local carrier.
I've been poking around at this idea for a bit, and I don't think that hypersonic aircraft operating from home base is cost-effective enough to definitely rule out carriers.

Take a F-35: moderately stealthy, 9 ton combat load, maneuverable strike fighter and build it in Vehicles at TL8. (I used a hull size of 700 cf, two wings at 52.5 cf, and a 21K-lbs vectored-thrust afterburning turbofan weighing in at 69000 lbs, for reference, with Very Good streamlining).

Update that plane to TL10 and optimize it slightly: 14000 lbf fusion air ram, Excellent streamlining, 18000 lbs internal weapons bay. Costs ~$5.5M and flies at ~2076 mph. Call that the Fusion-35.

Take the TL10 plane and make it hypersonic. Airspeed is dependent on the square root of engine power, you want to go 5x as fast, so you end up with 220,000 lbf fusion air ram (saved some thrust by moving to radical streamlining). Chassis size increases to 975cf to fit the engine. Total cost is ~$18M. Call that the Sonic-35.

Modern aircraft carriers costs ~125-150x the cost of the aircraft they carry. 72 Sonic-35s cost ~$1.3B, more or less, 72 Fusion-35's with a $825M carrier cost $1.2B.

Advantages to the Fusion-35s:
* Slightly cheaper, but operating costs of the carrier may overwhelm those savings
* They are where the naval task force is and don't need to route around unfriendly airspaces.
* Slightly more maneuverable and stable if things go to a dog-fight.
* Damaged planes can recover on the aircraft carrier.

Advantages to the Sonic-35s
* Vertol capability.
* Ridiculous amounts of excess lift if you don't need hypersonic capability and can put weapons external on the wings.
* Don't lose all your planes if a vulnerable carrier is destroyed.

I don't think it's a wash, but I think the correct answer is going to depend on the situation. Sonic-35s are probably better if you expect to mostly operate within 5000 miles or so of home, and you can guarantee overflight rights to anywhere else you want to go. Fusion-35s and a carrier edge out if you expect to operating far away from bases and you expect non-friendly air defenses between your bases and where you need to operate.
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Old 10-13-2017, 10:11 AM   #86
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Default Re: [Ultra-Tech] What would naval warfare at TL10 look like?

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Originally Posted by mlangsdorf View Post
I've been poking around at this idea for a bit, and I don't think that hypersonic aircraft operating from home base is cost-effective enough to definitely rule out carriers.

Take a F-35: moderately stealthy, 9 ton combat load, maneuverable strike fighter and build it in Vehicles at TL8. (I used a hull size of 700 cf, two wings at 52.5 cf, and a 21K-lbs vectored-thrust afterburning turbofan weighing in at 69000 lbs, for reference, with Very Good streamlining).

Update that plane to TL10 and optimize it slightly: 14000 lbf fusion air ram, Excellent streamlining, 18000 lbs internal weapons bay. Costs ~$5.5M and flies at ~2076 mph. Call that the Fusion-35.

Take the TL10 plane and make it hypersonic. Airspeed is dependent on the square root of engine power, you want to go 5x as fast, so you end up with 220,000 lbf fusion air ram (saved some thrust by moving to radical streamlining). Chassis size increases to 975cf to fit the engine. Total cost is ~$18M. Call that the Sonic-35.

Modern aircraft carriers costs ~125-150x the cost of the aircraft they carry. 72 Sonic-35s cost ~$1.3B, more or less, 72 Fusion-35's with a $825M carrier cost $1.2B.

Advantages to the Fusion-35s:
* Slightly cheaper, but operating costs of the carrier may overwhelm those savings
* They are where the naval task force is and don't need to route around unfriendly airspaces.
* Slightly more maneuverable and stable if things go to a dog-fight.
* Damaged planes can recover on the aircraft carrier.

Advantages to the Sonic-35s
* Vertol capability.
* Ridiculous amounts of excess lift if you don't need hypersonic capability and can put weapons external on the wings.
* Don't lose all your planes if a vulnerable carrier is destroyed.

I don't think it's a wash, but I think the correct answer is going to depend on the situation. Sonic-35s are probably better if you expect to mostly operate within 5000 miles or so of home, and you can guarantee overflight rights to anywhere else you want to go. Fusion-35s and a carrier edge out if you expect to operating far away from bases and you expect non-friendly air defenses between your bases and where you need to operate.
That's an interesting comparison, for just over three times as much you get five times the speed. I'd not really realised that the cost of an aircraft carrier would depend on the aircraft you flew from it, I'd somewhat naively assumed that hangar space and all the other systems (fuel tanks etc) wouldn't change - despite the larger size of the craft.

Is there any benefit to hypersonic flight in evading missiles? Missiles seem to travel at a comparable speed now at TL8, and they're presumably much more agile than a fighter, so I'd guess not.
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Old 10-13-2017, 10:29 AM   #87
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Default Re: [Ultra-Tech] What would naval warfare at TL10 look like?

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Originally Posted by mlangsdorf View Post
I don't think it's a wash, but I think the correct answer is going to depend on the situation. Sonic-35s are probably better if you expect to mostly operate within 5000 miles or so of home, and you can guarantee overflight rights to anywhere else you want to go. Fusion-35s and a carrier edge out if you expect to operating far away from bases and you expect non-friendly air defenses between your bases and where you need to operate.
That's a useful analysis. A fuller calculation would probably need a hefty amount of armour, which might bring speeds down a bit.

But anyway, 5000 miles is pretty long range. That would have, for example, sorties for North Korea flying out of a base in Scotland. Bases in UK, Japan, USA and Australia would almost stitch up the whole globe, ignoring overflight issues.

And if you're worried about air defenses that can target your Mach 13/10,000mph fighter, wouldn't they be just as much a problem for a carrier?
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Old 10-13-2017, 10:38 AM   #88
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Default Re: [Ultra-Tech] What would naval warfare at TL10 look like?

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Originally Posted by Crystalline_Entity View Post
I'd not really realised that the cost of an aircraft carrier would depend on the aircraft you flew from it, I'd somewhat naively assumed that hangar space and all the other systems (fuel tanks etc) wouldn't change - despite the larger size of the craft.
Well, it might be a coincidence, or an artefact of defence procurements.

But - for example, the faster an aircraft goes, generally the higher its stall speed, which is why carriers kept getting bigger through the 1940s-1980s. There are lots of small things like that which point in the general direction of a correlation.
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Old 10-13-2017, 11:38 AM   #89
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Default Re: [Ultra-Tech] What would naval warfare at TL10 look like?

I'm not saying that there's any particular reason for carriers to cost roughly 150x as much as the strike plane, I'm saying that a Nimitz class carrier costs about as much as 150 F-14s and a Gerald Ford class carrier costs about as much as 125 F-35s. It's a rule of thumb to take a guess at how much a carrier would cost without having to build the carrier.

It makes a certain amount of intuitive sense to me: the more bells and whistles you throw on your planes, the more bells and whistles you're going to throw on your carrier. And larger planes obviously need larger carriers. But the exact relationship is pretty vague and depends on technology: an Essex class carrier cost as much as 1000 F6Fs, or something like that.
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Old 10-13-2017, 12:08 PM   #90
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Default Re: [Ultra-Tech] What would naval warfare at TL10 look like?

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And if you're worried about air defenses that can target your Mach 13/10,000mph fighter, wouldn't they be just as much a problem for a carrier?
Carriers can be put to sea weeks before the tension starts, and loiter until trouble happens. Really fast fighter aircraft don't have that kind of endurance.

Also, sea lanes and overflight routes are different things. If you're the New Norway Empire, not allied with all of Europe, Russia, Oceania, and the Americas, then when you want to intervene in the Korean Civil War, you're basically going to have to fly around South America. Yes, the ships have to cruise the same route, but the point remains, hypersonic flight becomes less attractive as the number of non-friendly countries increase.

I'm using non-friendly here very specifically. In a multi-polar world, there may be countries that don't object to your war with another country but still don't want you to overfly their territory at Mach 15.

Playing with the map some more, I suspect that overall, hypersonic is better than carrier, but it's not decisively enough better that no one will use carriers. Landing forces may still want their landing ships, but maybe not - a Sonic-35 variant that carries 32 cramped passengers isn't that much larger than a Sonic-35 (1175 cf versus 975 cf). I think I'd put this on my list of open questions for TL10 warfare.

Also, the entire distant hypersonic solution depends on fission/fusion air rams, and fission/fusion air rams that can be miniaturized under ~10 tons. Which is GURPS standard at TL10, but if some of the TL9 restriction on nuclear engines persist and they weigh 30+ tons minimum, then hypersonic becomes a lot less attractive. It might be possible to build a fuel burning turbo-ramjet aircraft that can travel 10,000 miles, maybe, but it isn't possible to build one that can go that far and come back.
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