Grav Floater question on page 103 in PDF rules.

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GJD
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Postby GJD » Thu Feb 03, 2011 3:52 pm

simonh wrote:
far-trader wrote: Personally I've always thought the idea that an Air/Raft or the like could achieve orbit is ludicrous.
Given the technology, why wouldn't it be able to reach orbital altitudes?

Simon Hibbs
That it CAN doesn't mean that it will - there are many cars that have limiters on the engines these days, because the performance outstrips the average persons ability to control them. Grav Vehicles qould equally be limited to certain altitudes by planetary ordinances. Lazy players not bothering to check the NOTSPAM (Notice To Spacemen) as they jump into a new system may find that dropping from orbit in their Air Raft earns them a fine and attendance on a mandatory Good Piloting course.

G.
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Postby DFW » Thu Feb 03, 2011 5:18 pm

GJD wrote: That it CAN doesn't mean that it will - there are many cars that have limiters on the engines these days, because the performance outstrips the average persons ability to control them. Grav Vehicles qould equally be limited to certain altitudes by planetary ordinances. Lazy players not bothering to check the NOTSPAM (Notice To Spacemen) as they jump into a new system may find that dropping from orbit in their Air Raft earns them a fine and attendance on a mandatory Good Piloting course.

G.
Yes. I think all of the above were covered in GT. I remember a specific mention of an altitude governor so that stupid civilian drivers using grav cars without pressurization, didn't fly too high and pass out.
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Postby GJD » Thu Feb 03, 2011 5:22 pm

DFW wrote:
GJD wrote: That it CAN doesn't mean that it will - there are many cars that have limiters on the engines these days, because the performance outstrips the average persons ability to control them. Grav Vehicles qould equally be limited to certain altitudes by planetary ordinances. Lazy players not bothering to check the NOTSPAM (Notice To Spacemen) as they jump into a new system may find that dropping from orbit in their Air Raft earns them a fine and attendance on a mandatory Good Piloting course.

G.
Yes. I think all of the above were covered in GT. I remember a specific mention of an altitude governor so that stupid civilian drivers using grav cars without pressurization, didn't fly too high and pass out.
Yarp. I was actualy reminded by an episode of Voyager I saw where Lieutenant Attitude was given piloting lessons after driving like a jerk in the highport, with HILLARIOUS consequences.

G.
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Postby Bense » Thu Feb 03, 2011 5:27 pm

BP wrote:However, 'achieving orbit' (assuming one is referring to 'orbiting' rather than an escape or ballistic trajectory) requires a velocity at an altitude. Here, the speed limits make this virtually impossible for a planet.
What speed limits? Once you're out of the atmosphere I don't see any reason your grav vehicle can't just keep accelerating to an orbital velocity (other than, obviously, fuel and time restrictions).
Is your Tactics (internet forum) skill better than mine?
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Postby BP » Thu Feb 03, 2011 7:19 pm

Bense wrote:What speed limits? Once you're out of the atmosphere I don't see any reason your grav vehicle can't just keep accelerating to an orbital velocity (other than, obviously, fuel and time restrictions).
The post was in reference to why prior posts could both be valid. Core pg 103, under Speed, 400 kph for Air/Raft and 40 kph for Grav Floater. ;)

Nothing in the rules states the speeds have a direct relation to being in atmo (they should be different for different atmo's then - as it is IMTU ).

As to 'reasoning' that the speed should be unlimited out of atmo... nothing prevents that - though, unlike M-Drives, unlimited acceleration is not a given for all gravitic devices (Though it could be in YTU).

IMTU, smaller gravitic devices lack the ability of M-Drive sized ones to tap into a background, universe permeating 'gravtic field' (reasoning that M-Drives can still function far from any large masses) - thus they experience diminishing acceleration as they get farther from a large mass (like a planet or moon) and have very slow acceleration in stations and starships. But, that is MTU - not the OTU.
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Postby vitalis6969 » Thu Feb 03, 2011 7:48 pm

DFW wrote:
UBIQUITOUS

: existing or being everywhere at the same time
commonplace, everyday, common,

Umm, it's just a 'bigger' word for common.

So, you did find the reference for them being common.
No, YOU stated in a previous post that they were common on high tech worlds, I have found no such thing in the rules that says that.

The rules state that they are ubiquitous. Not that every man has a floaty car in the garage. So when comparing all terrain explorer vehicles at that price level, I'm sure they are the most common way to go since they have all kinds of advantages.

As I have said over and over, industrial equipment is ubiquitous, but it doesn't mean the common man can buy one. Freetraders are ubiquitous, but not every man can afford them.

Ubiquitous has nothing to do with the common man owning them and you know it.

The Nimitz class aircraft carrier is the ubiquitous sign of the US Navy's air arm, and we have ten, most countries can't even afford ONE.

This is nothing but another example of you looking for every nitpick fault you can in this game. Nothing more, nothing less. And that is a shame because you do have such wonderful things to add at times.

-V
Last edited by vitalis6969 on Thu Feb 03, 2011 8:54 pm, edited 1 time in total.
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Postby hdan » Thu Feb 03, 2011 8:52 pm

I always imagined an Air/Raft as being more like, well, a hover-raft than an "air car". Sure, plenty of people can afford a boat (or the "grav floater" equivalent kayak), but they're not parked in everyone's driveways. Though they might be a common sight in a shopping center or office complex parking area.

Why? Well, for one thing, driving is easier than piloting. Advances in electronics and such would make operating a grav vehicle way easier than a modern air vehicle or hovercraft, but with wind and the lack of any real friction surface to operate against, it's still going to be trickier to get an air/raft to go exactly where you want it to.

IMTU, Air/Rafts propel themselves by way of a sort of "gravity caterpillar drive", which can provide both lift and directed propulsion force at right angles to the lift vector. The lift is not "thrust" in the usual sense; it's more of a cancellation and reflection of gravity. This cancellation doesn't "block" gravity (so the passengers still feel their own weight) so the Air/Raft's lifting power is not unlimited.

That is, they don't work like helicopters, they work more like a hypothetical variable-altitude hovercraft with both forward/reverse and left/right fans. Speeders add some sort of jet engine for primary propulsion (at TL12+ the best ones use a variant of thruster plate technology) and aerodynamic controls for better handling at high speeds.

(Side note: there ARE pitch/roll override controls, but the "civilian" models are limited to 45 degrees or less, and use the trim controls to land on uneven surfaces. This is usually done by an automated system - you "press the land button" and the air/raft conforms to the ground below and disengages the gravity drive.)

Now if you have a "Star Wars" or "5th Element" flavored view of grav vehicles as "3d cars" which can turn on a dime and which are used on 3d "highway systems" then you're probably not going to agree with my assessment.

Back on topic:
You could allow that one player to go to the top, though the rest will have to slog up the old fashioned way. I'd still make the floater guy roll for altitude sickness.
/hdan
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Postby DFW » Thu Feb 03, 2011 11:56 pm

vitalis6969 wrote:No, YOU stated in a previous post that they were common on high tech worlds, I have found no such thing in the rules that says that.

The rules state that they are ubiquitous. -V
Now, THAT is funny.
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Postby vitalis6969 » Fri Feb 04, 2011 12:47 am

Yeah, it is since you seem to think ubiquitous means every joe shmo has one.

The words "common on high tech worlds" does not appear.

But as usual you ignore the post, pick the parts you want, and add nothing.
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Postby simonh » Fri Feb 04, 2011 1:16 am

GJD wrote:
Given the technology, why wouldn't it be able to reach orbital altitudes?

Simon Hibbs
That it CAN doesn't mean that it will - there are many cars that have limiters on the engines these days, because the performance outstrips the average persons ability to control them. Grav Vehicles qould equally be limited to certain altitudes by planetary ordinances. Lazy players not bothering to check the NOTSPAM (Notice To Spacemen) as they jump into a new system may find that dropping from orbit in their Air Raft earns them a fine and attendance on a mandatory Good Piloting course.

G.
Prohibited != Ludicrous

Simon Hibbs
Last edited by simonh on Fri Feb 04, 2011 2:00 am, edited 1 time in total.
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Postby simonh » Fri Feb 04, 2011 2:00 am

Get a grip everyone. Ubiquitous does legitimately mean commonplace and everyday. Omnipresent. Present or appearing everywhere.

Let's consider some technology and see whether or not they're ubiquitous.

Cars - ubiquitous.
Cell phones - Ubiquitous.

Helicopers? Aircraft Carriers? These are not omnipresent, I don't come across them everywhere. They are not ubiquitous.

That doesn't mean everyone must own an air raft, but they must come across them all the time. In London taxi cabs are ubiquitous without everyone owning one, so maybe that's a model except that the book doesn't qualify by saying they're ubiquitous in urban areas. Anyway taxis are really just cars.

Transit vans are ubiquitous but not everyone owns one. I'd say articulated lorries are borderline. They're pretty commonplace I suppose, but not everywhere - there are plenty of places you never, or hardly ever see an artic so I hold that they don't quite fit the definition although it's a close call.

So I'd say it's possible for air rafts to be ubiquitous without everyone having one in their garage, but you're still going to see them all over the place. That's what ubiquitous means. For that kind of availability I'd expect a lower base price. Maybe the listed model is a long endurance, ruggedises adventurer model though. The TMB only gives a few sparse data points on these things. I'd expect it's quite possible to buy most equipment with varying features, performance and build quality for anything from 50% to 200% of the example prices given.

Simon Hibbs
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Postby BP » Fri Feb 04, 2011 3:49 am

simonh wrote:...Maybe the listed model is a long endurance, ruggedises adventurer model though. ...
:D PC Prices!

(The air/raft dealers can see them coming half a plot away!)
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Postby rust » Fri Feb 04, 2011 9:22 am

BP wrote: (The air/raft dealers can see them coming half a plot away!)
Well, the guys in de-militarized battle dress with grav platforms on their
backs are not that difficult to spot ... :wink:
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Postby simonh » Fri Feb 04, 2011 10:29 am

rust wrote:
BP wrote: (The air/raft dealers can see them coming half a plot away!)
Well, the guys in de-militarized battle dress with grav platforms on their
backs are not that difficult to spot ... :wink:
Just try hitting one of those suckers with a stealth modifier and prepare for some serious whinging though. :roll:

Simon Hibbs
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Postby GJD » Fri Feb 04, 2011 12:20 pm

simonh wrote:
GJD wrote:
Given the technology, why wouldn't it be able to reach orbital altitudes?

Simon Hibbs
That it CAN doesn't mean that it will - there are many cars that have limiters on the engines these days, because the performance outstrips the average persons ability to control them. Grav Vehicles qould equally be limited to certain altitudes by planetary ordinances. Lazy players not bothering to check the NOTSPAM (Notice To Spacemen) as they jump into a new system may find that dropping from orbit in their Air Raft earns them a fine and attendance on a mandatory Good Piloting course.

G.
Prohibited != Ludicrous

Simon Hibbs
Excuse me? Care to expand on that?

G.
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Postby Jame Rowe » Fri Feb 04, 2011 6:30 pm

I thought that the floaters were TL 10?

And if so there should be a TL 11 version - smaller, faster and a bit more expensive.
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Postby simonh » Mon Feb 07, 2011 9:48 am

GJD wrote:
simonh wrote: Prohibited != Ludicrous

Simon Hibbs
Excuse me? Care to expand on that?

G.
It's my contention that it's not at all ludicrous that air rafts can reach orbit given how grav technology is described as working in Traveller.

Even if some, many or even most grav vehicles have limiters or overrides that arbitrarily prevent them from doing so in practice, that doesn't make it ludicrous that a grav vehicle such as an air raft is capable of it.

The contention I was responding to wasn't that flying air rafts to orbit was prohibited, but that it's ludicrous that they are described as being capable of doing so.

At least that's what I understood the point being made to mean.

Simon Hibbs
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Postby DFW » Mon Feb 07, 2011 2:55 pm

BP wrote: :D PC Prices!

(The air/raft dealers can see them coming half a plot away!)
:lol:

Too funny!
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Postby far-trader » Mon Feb 07, 2011 6:09 pm

simonh wrote:
GJD wrote:
simonh wrote: Prohibited != Ludicrous

Simon Hibbs
Excuse me? Care to expand on that?

G.
It's my contention that it's not at all ludicrous that air rafts can reach orbit given how grav technology is described as working in Traveller.
I've tried to answer this a few times since you asked, being it was me who posted the "ludicrous" comment. Every time I've tried I find my inability to clearly express the problem having me delete the post before finishing.

It's difficult to explain.

A big part of the problem is in your own comment, the "given how grav technology is described as working in Traveller" bit. Partly because it really isn't well described at all, and where it is, is often contradictory to other bits.

Another part is the simple physics of the problem and what the definition of "orbit" is taken to mean.

And as noted by GJD(?) above there's the language issue of "reach orbit" to interpret as well.

Let's take it that the original technology (CT) totally negates gravity (it really doesn't say) from the equation, and you have 100kph max speed (not acceleration, none is noted). Why would it take you hours to reach orbit even at that pedestrian speed? Taking Earth (size 8 ) as an example, we need 8 hours to "reach orbit". Let's take that as LEO, between 200km and 2000km. That should take 2-10 hours at 100kph (the CT Air/Raft top speed).

And kudos if you're asking "Wait a minute, orbit is a function of gravity, if the tech eliminates gravity, orbit is meaningless."

Now let's throw in MgT's updated Air/Raft with 4x the max speed. Hmm, where in MgT does it say how long to reach orbit? Is it still the same old (hours x size) rule from CT? And shouldn't it be quicker with 4x the speed? And a little slower than that for the Grav Belt (top speed 300kph), and much much slower for the Floater (top speed 40kph). Is that just a logic fail, or an editing error. Or does it mean the tech functions in some new and different (and again unexplained) way?

OK, how about we look at when anti-grav finally got a number put to it in further describing how it worked. MT (iirc) put the effect at a cancellation of 99% of the local gravity. We can work with that, and I did ages ago to correct or confirm my early suspicions those 30 some years ago. If we presume "reach orbit" means the body's natural LEO, and using Earth (size 8 ) as an example again, then all we need to do (if I did the math right at the time) is attain something like 200kph (instead of about 20,000kph). And recall at the time the Air/Raft only had 100kph as a top speed.

That looked like a confirmation of my ludicrous statement earlier. Closer to possible certainly, so maybe less ludicrous. And one could make an argument of being able to coax 200kph out of the Air/Raft if nearly empty (a sole operator, stripped down to frame) for plot purposes.

Again though, it's a messed up idea from the get go. Poorly thought out and described imo. Intended I suspect merely as a plot device with no more thought than that given to it. And probably (I can almost recall the story) ripped whole cloth out of some Golden Age sci-fi. One that wasn't originally well thought out I expect, or if it was that info was neglected in dropping it into Traveller.

I'm sure I'm still not getting my point across clearly enough but it's the best I'm likely to do, and you deserved the attempt. If I try to clear it up by editing or further explanation it's just get worse and I'll trash the whole thing without posting it, again. Best I hit the submit button quickly.

Can you offer your points to why you think the whole "reach orbit" thing is a reasonable statement?
Dan "far-trader" Burns

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Postby GJD » Mon Feb 07, 2011 9:14 pm

simonh wrote:
GJD wrote:
simonh wrote: Prohibited != Ludicrous

Simon Hibbs
Excuse me? Care to expand on that?

G.
It's my contention that it's not at all ludicrous that air rafts can reach orbit given how grav technology is described as working in Traveller.

Even if some, many or even most grav vehicles have limiters or overrides that arbitrarily prevent them from doing so in practice, that doesn't make it ludicrous that a grav vehicle such as an air raft is capable of it.

The contention I was responding to wasn't that flying air rafts to orbit was prohibited, but that it's ludicrous that they are described as being capable of doing so.

At least that's what I understood the point being made to mean.

Simon Hibbs
My point was simply that just because a device is capable (according to the letter of the rules) of doing something, there is no reason at all to let that intrude into the reality of your universe, without having to break the cannonicity. If, according to the rules, an Air Raft can reach "orbit" in X hours, but that is incompatible with YTU, well, that's why there's a Y in YTU.

G.

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