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Blaze
In a run a couple of weeks ago I ended up throwing in a wheels-man I'd been working on as an NPC. To cut a long story short, he ended up giving one of the characters a lift through Vegas at speed- in a customised Saab Dynamit. By 'customised' I mean Drive-by-Wire, two levels of engine customisation and a NOX tank. I told the character they got fast enough to make him scream and needed a drag chute to stop, but didn't actually work out how fast they'd got until after the game.
The car had a speed rating of 250, plus 30 from one of the customisations and multiplied by 2.5 by the NOX for a burst-speed of 700 metres per combat turn, or 840kph/525mph. Now, it's a while since I did physics but I work that out somewhere around Mach 0.68, or waaay-too-fraggin'-fast. And if I remember correctly, that's just using the average top speed- imagine if the driver had used his ten dice of Car skill (gotta love vehicle adepts) to push the envelope further.
My question- even given the character's magically-enhanced skills and the sterling performance of a DbW Dynamit, is it physically possible for a road vehicle to be capable of performance like this, and what would be the effects on the car, passengers, road surface and surrounding buildings?

-JH.
Tarantula
Its quite easily to make a custom vehicle hit mach1, if not something around mach5 or more. And screw adept drivers, imagine the rigger putting his entire control pool into it.

IRL no, this could never happen, by the SR book rules, yes, it can.
grendel
QUOTE (Blaze)
My question- even given the character's magically-enhanced skills and the sterling performance of a DbW Dynamit, is it physically possible for a road vehicle to be capable of performance like this, and what would be the effects on the car, passengers, road surface and surrounding buildings?

Yes, it is. Here's a useful page on breaking the sound barrier on land. As you can see, though, the designs and materials required are exotic, and not something to be found on an everyday vehicle.

But setting aside the practical physics of accelerating a vehicle to supersonic velocities for a moment, the passage through the sound barrier is going to be a traumatic event for a vehicle. First, the heating of the vehicle's skin due to friction with the air is going to enough to damage any plastic body panels, as well as blister and peel the paint. The shockwave and pressure interactions as the vehicle passes through the sonic barrier are going to be even more damaging, to the point that as the shock cone flattens over the nose of the vehicle it will craze and shatter the windscreen and side windows, possibly even the headlights, as well as tearing off any exposed fairings: sideview mirrors, radio antennae, etc. Due to the airfoil shape of most vehicle's engine cowlings, the high speed will probably cause the latch mechanism to fail, tearing off the hood. Shockwaves will also form on other sharp points on the car: wheel fairings and spoiler if mounted. Interactions between those shockwaves and the vehicle's body will be damaging as well: stress fractures and warping in the body panels. Additionally, the shock cone will stretch beneath the vehicle as well, reflecting off the street surface and damaging the softer portions of the chassis: brakes, oil pan, and exhaust system. Beyond that, at trans and supersonic speeds, friction heating of the tires are going to cause them to explode.

Shockwave interaction with the roadway, as described in the article above, will cause significant damage to even reinforced concrete surfaces. Building windows within 20 to 30m from the vehicle will crack, possibly shatter. People in that range will suffer skin bruising from overpressure as well as shattered eardrums and momentary loss of hearing.

Effects on the passengers inside the car are going to be a little milder, but still noticeable. Insulated from damaging shockwave effects, the passengers will still be heavily bruised during the supersonic drive as each bump in the road is transformed to a bone-jarring shock at supersonic speeds. Also, the force required to turn a car on normal streets is going to apply a significant angular force to the passengers as well.
BitBasher
But all that is irrelevant because most roads, even highways are not smooth enough to do that. Downforce is a touchy thing and the physicas of the way a car handles changes dramatically even at speeds around 200.

Even if there are almost no cars on the road cars that are there are going so slow compared to you they are like immobile obstacles. at 200 ccars going 80mph the same direction are coming at you at 120 miles per hour. I'd say anything over 200 on a real road is unrealistic, and that's pushing it. At 200 your margin for error is about squat and god forbid the toad has turns, becuase even shallow ones aren't shallow at that speed.

Even in the Nevada open road race where they shut down a highway and let people be jackasses people are hard pressed, even in custom cars built for this race, to break 200. Even at speeds lower than that deaths are not rare at higher speeds.

All those land speed records are done on salt flats or dry lake beds.
Zeel De Mort
This is true. But remember that in the 2060s major roads are build with very high speed drones in mind, for shipping things long distances in minimal time. So you've got to assume major cross-country highways are at least very smooth, if not pretty damn straight as well.

Obviously drones can react much faster than humans, but then a good rigger with VCR3 can react much faster than even a superb racing driver nowadays. So driving at higher speeds on public roads is a little more viable in the future.

Breaking the sound barrier still sounds physically unlikely under those conditions though!
BitBasher
QUOTE
This is true. But remember that in the 2060s major roads are build with very high speed drones in mind, for shipping things long distances in minimal time. So you've got to assume major cross-country highways are at least very smooth, if not pretty damn straight as well.
Where do you get this information from? AFAIK there's not a single long distance cargo carrying road drone. There's land trains and semi's, all of which are still piloted, with I think only one coming with a rigger adaptation. Honestly, just like 60 years ago, we're still using the same roads we were then for the most part.

QUOTE
Obviously drones can react much faster than humans, but then a good rigger with VCR3 can react much faster than even a superb racing driver nowadays. So driving at higher speeds on public roads is a little more viable in the future.
Actually drones react about the same as people uness we talk about very expensive drones, and it's unlikely that riggers will replace conventional cargo haulers just because of the logistics of it. None of the normal vehicles come with a rigger adaptation without some decent modifications.
Kremlin KOA
There are references in many of the older books to road train drones hauling cargo around
Zeel De Mort
I get the information about drone vehicles from older books, as Kremlin KOA points out. Alas I don't own any 2nd ed books, so I couldn't tell you where exactly. I just assumed that since such high speed drone vehicles exist, there must be at least some roads that are designed for them to drive safely at high speed. Although I think they have their own lanes if I remember correctly.

Also, I'm fairly sure the speed limits (for metahumans (in cars)) on major highways are higher in SR times than they are now (in the US), which would lead me to believe that either the roads are safer, smoother, and straighter, or that cars are safer and easier to handle, or both. Again I'm afraid I can't tell you exactly where I got all this, but pretty sure it's around one one book or other from 2nd ed days.

I'm certainly not saying that riggers will replace regular long haul drivers or anything, you're quite right they wouldn't. I just mean for any insane Mach 1 land monsters, a rigger would be better equipped to try it than a regular guy from current days. Goes without saying I suppose.
Rev
The maps and history in shadowrun give no indication of major road building efforts since today. Basically thier highways are all the exact same highways we drive on today that were designed to be reasonably safe at about 60mph.

That doesn't mean I don't think it is fine to say truckers in 2063 drive 90, they just kill lots of people doing it despite the computer assisted driving. smile.gif
Tarantula
Is everyone forgetting drive-by-wires, as well as improved suspension, better tires, lighter metals, better materials overall throughout the vehicle?
BitBasher
QUOTE (Tarantula)
Is everyone forgetting drive-by-wires, as well as improved suspension, better tires, lighter metals, better materials overall throughout the vehicle?

None of that means anything when it's the same idiots driveing 99.99% of all the cars.
Modesitt
Your cheese-fu is weak.

I link this regulairly, because it comes up often.

Note #1 The car was written on the previous errata(The one before the errata that was mostly a list of availability changes on every single drone in the book) and I'm not sure how the car's design would be altered by that. I don't think it would. Note #2 is that I forgot in that thread that there IS a negative modifier in the book for high speeds, however it only applies to crash tests. See page 147-148 for details.

Other than that, grendel has it. Cray'll eventually show up and correct any fine points about what kind of damage you'll do to the surrounding environment when you go super sonic.
D.Generate
Never mind all that, if hte car isn't built for it all kinds of bad things happen. From it lifting off the ground and flipping over to over heating the surface and melting plastics and rubber. not to mention that if hte road isn't perfectly smooth, flat and straight you're pretty much fragged anyways. It don't matter how good your reflexes are you can't control the laws of Physics. Street cars are just not made to go that fast.

This is the reason I basically homebrewed my own rules for vehicles in the game, too many of my players liked having cars and bikes that even in the more advanced future would still cause them to be spots on walls. I like to keep my games a little more towards the real side but hey thats just me.

The New Big D
mmu1
There's no way you can get anything to Mach 1 that relies on an engine turning wheels, and on friction between the wheels and the road to get the car moving forward. It's too inefficient, and I don't think it's physically possible to make tires (or roads) that wouldn't turn to molten slag as a result of something like this. There's a reason the really high speed cars use jet engines and don't transfer the power to the wheels.
hobgoblin
theoreticaly you can propell anything to any speed. yes, current wheel and engine tech is to ineffective to get anything up to, let alone past, mach 1. but you never know what may come in the future. allso remeber that to make a car perform like that in sr you have to design it from the ground up. if not then its a heavy engine job (with the risk of permanent stress) for you. any after market mod is limited to the stuff in the customization section, the design section is totaly off limits...

allso, if this game would have to take every small detail of physics into account then the number of rolls and so on for just doing a normal turn would number the double digits or more...
mmu1
QUOTE (hobgoblin)
theoreticaly you can propell anything to any speed. yes, current wheel and engine tech is to ineffective to get anything up to, let alone past, mach 1. but you never know what may come in the future. allso remeber that to make a car perform like that in sr you have to design it from the ground up. if not then its a heavy engine job (with the risk of permanent stress) for you. any after market mod is limited to the stuff in the customization section, the design section is totaly off limits...

allso, if this game would have to take every small detail of physics into account then the number of rolls and so on for just doing a normal turn would number the double digits or more...

Current "ground tech" is also not up to the task... wink.gif You can do whatever you want with the wheels and engine, but you also need a road surface that'll support that sort of vehicle.
draco aardvark
QUOTE (BitBasher)
But all that is irrelevant because most roads, even highways are not smooth enough to do that. Downforce is a touchy thing and the physicas of the way a car handles changes dramatically even at speeds around 200.

Even if there are almost no cars on the road cars that are there are going so slow compared to you they are like immobile obstacles. at 200 ccars going 80mph the same direction are coming at you at 120 miles per hour. I'd say anything over 200 on a real road is unrealistic, and that's pushing it. At 200 your margin for error is about squat and god forbid the toad has turns, becuase even shallow ones aren't shallow at that speed.

Even in the Nevada open road race where they shut down a highway and let people be jackasses people are hard pressed, even in custom cars built for this race, to break 200. Even at speeds lower than that deaths are not rare at higher speeds.

All those land speed records are done on salt flats or dry lake beds.

Actually there's a company in Europe which (heavily) modifies sports cars to be Auto-Bond toys, I think they top out at about 214 MPH. At that point the car is shaking and they're struggling to make the nice wide turns.

It was rather funny watching the guy drive that thing and go back to the right lane after passing someone doing 90MPH above what they were doing. He can outrun police helicopters with it, and there's not a chance someone's going to pass him, but hey - the law's the law.

Remember boys and girls, DRIVE RIGHT! The left lanes are for passing, cruising along at 120MPH in the left lane is just as illegal as 20MPH. You never know who will be behind you.
Edward
I assumed that the drone road trains used the same trailers and modified (or purpose built but otherwise similar) prime movers to the ones the truckies drive, they would still be constrained by the same speed limits. There advantage is you don’t have to pay a driver, the pilot program never gets tired takes drugs, loses concentration, doesn’t speed thus doesn’t get fined or loos its licence and doesn’t quit because somebody offered it better pay. And at the same time it can drive without stoping for as long as it has fuel.

It dose not however actually drive any faster.

As a side note, if your car is travelling at ½ mach 1 the top of your weals is travelling at mach 1, what is that going to do to things?

Edward
Fortune
QUOTE (draco aardvark)
Remember boys and girls, DRIVE RIGHT! The left lanes are for passing, cruising along at 120MPH in the left lane is just as illegal as 20MPH. You never know who will be behind you.

Try and remember that this is an international forum. For those drivers in Japan, England, New Zealand, Australia, and various other nations, the opposite is true. biggrin.gif
Arethusa
I sure hope he wasn't implying that someone driving along at 214 on clean road should stay right of the passing lane just to stick to the law. What that driver did was goddamn stupid.
hyzmarca
QUOTE (hobgoblin @ Dec 18 2004, 10:11 AM)
theoreticaly you can propell anything to any speed.
Not past 299,792,458 meters per second. But, that's so far beyond the speed of sound that I doubt even an SR car can reach it. Moving at that speed would likely destroy a large chunk of the earth when it crashes, anyway.

QUOTE ("Edward")
I assumed that the drone road trains used the same trailers and modified (or purpose built but otherwise similar) prime movers to the ones the truckies drive, they would still be constrained by the same speed limits. There advantage is you don�t have to pay a driver, the pilot program never gets tired takes drugs, loses concentration, doesn�t speed thus doesn�t get fined or loos its licence and doesn�t quit because somebody offered it better pay. And at the same time it can drive without stoping for as long as it has fuel.

It dose not however actually drive any faster.


Actualy, they do. They don't violate the speed limit, but they can navigate at much higher speeds than a human can in similar conditions, meaning that they don't have to slow down nearly as much. They can also drive close together at very high speeds, which is one of the real advantages of the fleets of autopilot equiped trucks that they've been planning to release for nearly a decade now. From what I understand, the technology is viable right but still far from implimentation.
Fortune
Brings up the question of speed limits. There are numerous references to 'speeding' or 'barreling' road trains in Shadowrun.

There are also a few places in RL that have no posted (or enforced) speed limits, like the German Autobahn or Oz's Northern Territory's non-urban roads.

Personally, I think there are much less restrictions placed on speed in the Sixth World.
hobgoblin
QUOTE (hyzmarca)
QUOTE (hobgoblin @ Dec 18 2004, 10:11 AM)
theoreticaly you can propell anything to any speed.
Not past 299,792,458 meters per second. But, that's so far beyond the speed of sound that I doubt even an SR car can reach ir moving at that speed would likely destroy a large chunk of the earth when it crashes, anyway.t.

currently physics says so, but one can allso argue that its the fastest speed that we are able to observe given current tech...
Edward
Interesting thought,

Network all your trucks install radar detectors in them and have them inform each other of speed traps also include a sensor system good enough to recognise a cop car, standing orders to all vehicles. When in vicinity of speed trap or cop car obey speed limit, else drive as fast as you can safely.

Edward
Thistledown
better than that, just find the radio transponder frequency the police are using, use that to triangulate their position, link it to your gps, and know when to slow down from a few miles away.
Kagetenshi
QUOTE (hobgoblin)
QUOTE (hyzmarca @ Dec 19 2004, 09:58 AM)
QUOTE (hobgoblin @ Dec 18 2004, 10:11 AM)
theoreticaly you can propell anything to any speed.
Not past 299,792,458 meters per second. But, that's so far beyond the speed of sound that I doubt even an SR car can reach ir moving at that speed would likely destroy a large chunk of the earth when it crashes, anyway.t.

currently physics says so, but one can allso argue that its the fastest speed that we are able to observe given current tech...

Not really, no. At least no more than one can argue that we're all tiny pink bunnies in bio-engineered suits, but that no one has seen the bunnies because there's a massive coverup conspiracy.

~J
Arethusa
Well, we just can't observe the pink bunnies given current tech...

ARGUMENT FROM IGNORANCE JUST KICKED IN, YO!
hobgoblin
they are allready working on theorys for above-lightspeed particles, they just dont have the tech to test it yet. and i belive i have read reports about a lab test where they slowed down light. so it seems that the speed of light may not be as stable as einstein belived it to be.

yes currently the ultimate speed-limit is set at the lightspeed as this is the highest observed speed known to man.

history have shown that ignorance can hit both ways. theorys belived compleatly silly have later been proved correct. until man is able to send a craft so fast that it matches the speed of light we will not know if its possible to go faster. just remember why the soundbarrier got its name.

only time will tell (in more ways then one) but we will probably never live to see it happen...
Kanada Ten
The "police" don't do most traffic monitoring, the street signs and stop lights (ect) do.
iPad
I pritty much agree with the 'crater' side of this debate.
RATHart
Actually, the speed of light is not a speed limit, it is an acceleration limit. An object cannot be accelerated up to the speed of light.

The sound barrier is a completely different problem, by the way. While the acceleration limit of light is a physical law, the sound barrier was an engineering problem. It was a matter of designing an airplane, and a power plant to power that airplane, capable of not only surviving the stress of supersonic flight (which occurs at a speed known as the Critical Mach number, which is always less than the speed of sound) but also designing a jet engine which could operate at high speeds, and a body capable of sustaining lift in such conditions.

A supersonic land vehicle is a reality, although a supersonic street car is probably in the realm of unrealistic.

By the way, a supersonic helicopter is an impossible device... if you were to design such an improbably device it would likely be so different from what we have now as to make it an entirely different vehicle.
Kremlin KOA
Sorry to disappoint man but it was hypotheissed early last century that no vehicle could ever be accelerated up to or beyond the speed of sound.

Those who suggested otherwise were the "crackpot fringe" that nobody believed until the war efforts made theorizing the impossible profitable
RATHart
I'm not saying that people didn't view the sound barrier as an impossibility, just that they viewed it as an engineering impossibility. There was no way to get an airplane to fly level, accelerate, and maintain Mach 1.0 without breaking apart. The problem was solvable though... there was little argument that something could accelerate past the speed of sound. It was a problem of technology, not of theory.

Accelerating to the speed of light is like breaking a basic law of physics... unless our basic understanding of physics is wrong, there's absolutely no way. Even if we had some sort of super technology, that over cam basic problems of energy, our mass would still be affect at relativistic speeds, eventually skewing towards infinity.

Kagetenshi
QUOTE (RATHart @ Dec 19 2004, 10:25 PM)
By the way, a supersonic helicopter is an impossible device... if you were to design such an improbably device it would likely be so different from what we have now as to make it an entirely different vehicle.

Yes, it is. The theoretical maximum speed of a helicopter in relation to the surrounding air is about 250 miles per hour.

QUOTE
Sorry to disappoint man but it was hypotheissed early last century that no vehicle could ever be accelerated up to or beyond the speed of sound.


Sorry to disappoint man but previously erroneous hypotheses do not invalidate current ones.

QUOTE
they are allready working on theorys for above-lightspeed particles, they just dont have the tech to test it yet. and i belive i have read reports about a lab test where they slowed down light. so it seems that the speed of light may not be as stable as einstein belived it to be.


There are two errors here. First off, above-lightspeed particles are theorized, but massless particles only. For anything with mass, the theoretical speed/acceleration limit currently holds.

The second I made myself a few years back. The speed of light isn't a constant, but the speed of light in a vacuum is. There's actually a type of radiation (Cherenkov radiation) emitted when an object moves faster than the speed of light in the medium it is moving in. The speed of light in a vacuum, however, is thus far as stable as thought.

But my basic point is much like RATHart's. If the speed of light is breakable by a massive particle, that requires everything we know to be wrong. It is, therefore, just as reasonable to believe in the above pink-bunny proposal as to believe in FTL massed particles.

~J
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