General Grav Tubes

[gchuck]

I was perusing the wiki for the planet Asura (Phlange 1414) the other day, and in the 'Infrastructure' field it mentioned 'grav tubes' for personal travel. Cool.
But the first thing in my mind was the tubes in 'Futurama'.

I was wondering if there were any other opinions on how would something like this work? Platforms? Something like a giant waterslide, with continues grav fields? Like a mass driver for people?

I'm really having a tough time comprehending this.

 

[Spinward Flow]

G-Tube

 

[Rupert]

G-Tube

That's pretty flash for TL-12, especially at only KCr45. Half the price of a grav belt for well over three times the capability.

 

[Spinward Flow]

Half the price of a grav belt for well over three times the capability.

Reduce the need for miniaturization required to fit the humanoid form factor/mass distribution and ... stuff gets cheaper.

 

[kilemall]

G-Tube

Huh never saw that before. Wrap a small stealth cover over it and you’ve got jump troops.

 

[Rupert]

Reduce the need for miniaturization required to fit the humanoid form factor/mass distribution and ... stuff gets cheaper.

My main sticking point is actually the 300 km/h speed for an upright cylinder.

 

[Spinward Flow]

My main sticking point is actually the 300 km/h speed for an upright cylinder.

CT Striker B4, p5:

GRAV VEHICLE SPEED

G​	S​
.10​	120​
.15​	180​
.20​	240​
.25​	300​
.30​	360​
.35​	420​
.40​	480​
.45​	540​
.50​	600​
.60​	720​
.70​	840​
.80​	960​
.90​	1080​
1.0​	1200​
1.2​	1400​
1.4​	1590​
1.6​	1770​
1.8​	1950​
2.0​	2120​
2.2​	2280​
2.4​	2430​
2.6​	2580​
2.8​	2720​
3.0​	2850​
3.5​	3150​
4.0​	3400​
4.5​	3640​
5.0​	3840​
6.0​	4200​
7.0​	4500​

G: Maneuver Gs.
S: Maximum speed in kph. Cruising speed is .75 times maximum speed.
NOE speed is .25 times max. speed, but not more than is allowed by avionics.

Grav vehicles (of any variety) tend to be "pretty zippy" by default.

Note that "Maneuver Gs" = (total gravitic thrust/vehicle mass)-1 ... so in order for a grav vehicle to have a 300 kph max speed, it needs a gravitic thrust that is 1.25x the mass of the vehicle ... which isn't hard to do (except at TL=8 ).
At TL=C, it's difficult to "go as slow" as 300 kph in almost any gravitic vehicle (except, perhaps, an air/raft).

 

[jec10]

Same in MegaTrav, although perhaps importantly, it further specified that 300kph was the max attainable by an unstreamlined object (like a G-tube)...

 

[Condottiere]

Wireless elevator.

 

[mike wightman]

It's a Wonkavator...

 

[Spinward Flow]

It's a Wonkavator...

 

[aramis]

I was perusing the wiki for the planet Asura (Phlange 1414) the other day, and in the 'Infrastructure' field it mentioned 'grav tubes' for personal travel. Cool.
But the first thing in my mind was the tubes in 'Futurama'.

I was wondering if there were any other opinions on how would something like this work? Platforms? Something like a giant waterslide, with continues grav fields? Like a mass driver for people?

I'm really having a tough time comprehending this.

To me, "grav tube" is just a zero-g zone on world, with "one way" arrows and parallel tubes. Assuming, of course, local TL 9+ in CT, A+ in MT/TNE/T4, or maybe as low as TL5 if there's a TL A+ within J2. Possbly working with on demand sensors...

As in, you walk the westbound tube, step in, and 2s later you're in zero G with hand rails... but only you and your next 3 seconds travel at any given point are in zero G. You get to the building,, slow down with the rails (which, I assume, for safety would be a fin with round end, rather than stairwell style rod with supports), step out, go to the vertical shaft for the needed floor, kick off an drift, and like the horizontal, it is only on when someone's inside... but unlike the horizontal, it stays on, albeit at reduced rather than zero, the entire tube, while your predicted position is kept in zero G.

No need for vehicles in it. Probably a safety system which will slow you if you exceed some posted speed.

 

[Spinward Flow]

So ... vacuum tube hyperloop for vehicles grav tube for peoples.

Sounds legit, actually.
The gravitic equivalent of a moving walkway ... so 3D instead of just 2D.

 

[Rupert]

To me, "grav tube" is just a zero-g zone on world, with "one way" arrows and parallel tubes. Assuming, of course, local TL 9+ in CT, A+ in MT/TNE/T4, or maybe as low as TL5 if there's a TL A+ within J2. Possbly working with on demand sensors...

You can have them at TL9 in TNE, by using contra-grav instead of G compensation (as C-G negates 99% of gravity within its field in TNE). You need about four times the power, 3-1/2 times the volume and 1-1/3 times the mass for the machinery, and it'll cost three times as much, but it's doable. The system won't be able to assist users in manoeuvring, which will make such a low-tech solution less than ideal for mass use.

 

[Condottiere]

1. In theory, you could install a repulsor at one end, and a tractor at the other.

2. The repulsor, depending on the technological level, accelerates the pedestrian upto nine gravities.

3. The tractor beam attracts the pedestrian, so that pedestrian doesn't drift away.

4. The initial surge is covered by an inertial compensation field.

5. Mass driver might be too slow.

6. Railgun at a couple of percentages off the speed of light, might be too fast, for inertial compensation to have much effect.

7. As the pedestrian reaches the opposing tractor beam, it reverses to repulsion, and it's inertial compensation field is switched on.

 

[aramis]

You can have them at TL9 in TNE, by using contra-grav instead of G compensation (as C-G negates 99% of gravity within its field in TNE). You need about four times the power, 3-1/2 times the volume and 1-1/3 times the mass for the machinery, and it'll cost three times as much, but it's doable. The system won't be able to assist users in manoeuvring, which will make such a low-tech solution less than ideal for mass use.

2% of gravity makes them pretty much non-equivalent. Sure, you can launch up, but for horizontal use, worse than walking.

 

[aramis]

1. In theory, you could install a repulsor at one end, and a tractor at the other.

2. The repulsor, depending on the technological level, accelerates the pedestrian upto nine gravities.

3. The tractor beam attracts the pedestrian, so that pedestrian doesn't drift away.

6. Railgun at a couple of percentages off the speed of light, might be too fast, for inertial compensation to have much effect.

Repulsors in CT are (checking Bk 5) TL A (p 24, 100 Ton Bay table)
Tractors appear first in MT, at TL G... and Repulsors remain TL A.
TNE FF&S 1 mk1 mod1 p 59 swaps the TLs... Tractors at TL A, Repulsors at TL G.
T4 FF&S2 p101 table 151 retains the TNE values.

Railguns being able to accelerate to 200+G's don't, of need, do so.

At TLF, under TNE, that's 6 G compensation at base install; 9 under double install, 10.5 under triple, 11.25 under quadruple. Under integration towards infinity, it caps at just a bit under 12G How, with that sceme, one gets to the 100+ G's needed for Gravitic Focusing? TNE's biggest tech-fail for me is the gravitic focusing being implied inconsistent to other gravitic technologies. If you can only get X G's at TL Y and install size Z, and increase is less than doubling, Euler's rule applies, and for the 50% per doubling, you can't exceed about 12G. So... TNE Gravitic tech is at least 3 different tracks, 4 if including the FF&S tweaks to to ClassicOTU. (CG, IC/AG, Gravitic Thrust, Laser Focusing).

So ... vacuum tube hyperloop for vehicles grav tube for peoples.

Sounds legit, actually.
The gravitic equivalent of a moving walkway ... so 3D instead of just 2D.

Precisely the idea. but better for groceries. At least if your bags are zipper-closed!