Electric and Hydrogen Vehicles

[Rupert]

Which brings up a point, shouldn’t we have similar handling problems with grav in weather that we do with LTA craft?

No, because the contra-grav negates weight, but not mass, so the vehicle 'floats' but still has its full inertia. Depending on how well streamlined it is, and what aerodynamic control surfaces it has, it might experience 'weather vane' effects, and it will get pushed by the wind, but not nearly to the degree than a LTA craft does.

If the grav vehicle has some way on (i.e. it's moving under its own power) it shouldn't be concerned about most winds, except possibly when landing or taking off (like a heavier-than-air aircraft).

 

[Spinward Flow]

Which brings up a point, shouldn’t we have similar handling problems with grav in weather that we do with LTA craft?

The LBB3 Air/raft does, to some extent.

SLOW grav craft, such as the aforementioned air/raft, are subject to "fair weather flying" and wind buffeting constraints. The air/raft isn't meant to fly that fast, so it's "pushed around by wind effects" to a noticeable extent. By contrast the (6 ton, MCr1, TL=8) Speeder which can fly transonic and reach orbit in 1 hour (instead of UWP Size code in hours!) has a lot more grav power at its disposal for speed and maneuverability (rather than lift power) in addition to being a streamlined vehicle, so it has "excess grav thrust" to easily counter most wind conditions.

So the answer to the point brought up by @kilemall is a legitimate one, but it also falls into the bucket of "with enough thrust even a brick can fly" ... and not all grav vehicles are designed with "lots of horizontal thrust" built into them. The ubiquitous air/raft has good vertical thrust (vehicle plus 4 tons), but poor horizontal thrust/speed ratings ... so it's more of a "flying truck" than an all rounder type of vehicle and thus skews more towards short haul cargo lifting. By contrast the speeder is a fast passenger transport with minimal cargo capacity (driver, 1 passenger, 100kg of cargo) that can zip around at transonic speeds.

LBB3.81, p23 for details of both vehicles.

An air/raft can cruise at 100 kph (but is extremely subject to wind effects), with some capability of higher speed to about 120 kph.

A streamlined grav-powered craft intended for high speed transport between points on a world surface. Similar in principle to the air/raft and the GCarrier, the speeder is streamlined and concentrates on speed.

 

[mike wightman]

Most Traveller has air/rafts and the like using nul-grav modules (to give them their full name) which provide both lift and thrust.

If you can fly a grav vehicle in a video game today that's how hard it will be with TL8+ computer assisstance.

 

[Condottiere]

Depends on how you interpret how gravitational motors work, mine being a rejection of the local gravity field.

Which means that they float, like air/ships, so they're effected the same way by wind.

Difference, contact area.

 

[mike wightman]

So you use a house rule, canon says they produce lift and thrust. In LBB:3 it was refered to as null-gravity and as anti-gravity.

"A light anti-gravity vehicle which uses null-grav modules to counteract gravity for lift and propulsion"

"Anti-gravity is the second major breakthrough. The postulated technology produces both neutralization of weight and lateral thrust"

Contragravity which does not provide thrust was to be found in TNE, it is re-introduced in T5 as lifters, and has been creeping into MgT thanks to the SoM using T5 technology rather than sticking with Mongoose.

 

[Condottiere]

No.

I tend to view it as either one, or the other.

It's either push or repulsion.

The easiest example are spacecraft manoeuvre drives, that push against an existing gravity well.

The other possibility being a rejection of gravity, but requires a gravity field to reject.

That, would be my view of what's termed lifters.

And since vehicle gravity motors appear to levitate, I'd place them under lifters.

Now, you may think that spacecraft with manoeuvre drives can levitate as well, even with vectored thrust, I'd say no.

They're pushing against the gravity well, in order to stay in place.

 

[Condottiere]

It just occurred to me.

It might not be possible to insure a vehicle for more than forty years, hence why spacecraft are given away.

Or, twenty years.

 

[kilemall]

It just occurred to me.

It might not be possible to insure a vehicle for more than forty years, hence why spacecraft are given away.

Or, twenty years.

More likely, the insurance is rated for the actual value of the ship and not worth the payments. Better to sell it off and put down payment on the next level up ship design, especially custom.

 

[Condottiere]

If hydrogen is corrosive, you might want to replace the machinery that interacts with it, in any event.

In theory, you could use electrical components indefinitely.

 

[whartung]

Was contra grav introduced before TNE?

Its a much more formal concept in TNE, whereas before it was just "grav vehicle" and that was about it.

TNE vehicles need independent thrusters to work with the contra grav buoyant vehicle.

 

[Spinward Flow]

If hydrogen is corrosive, you might want to replace the machinery that interacts with it, in any event.

This sounds like one of those airworthiness notices hung on a Cessna that reads, "Replace ALL aft of propeller."

If hydrogen is being used as a fuel (or even just a working fluid of some variety) it's going to "interact with" ...

• Storage Tanks
• Plumbing
• Impeller Systems/Turbines/Injectors
• Evaporator/Compressor cycle system(s)
• Thermal Regulators/Heat Exchangers
• Any and all joints and sealants in the containment system(s) that need to prevent leakage

... I could go on, but I hope I've made my point clear.

 

[Condottiere]

You don't want those rubber O rings suddenly giving way.

 

[aramis]

Not necessarily. If you assume that a grav vehicle has some sort of computer assisted flight controls--common to aircraft now--then the system automatically adjusts the vehicle's grav response to neutralize weather and wind conditions to a large degree or completely. I've always made it where grav vehicles, at most, experience some minor buffeting in high winds and the like and are generally stable under most flight conditions.

Varies by edition. TNE, the gravitics do not provide any thrust, just a 98% disconnect from gravity (thus separating gravitic mass from kinetic mass) and on board artificial gravity. CT, MT, the gravitics provide thrust and artificial gravity both, but do not reduce mass for gravity purposes.
T4 does all the above. I don't know how MGT2 does it, and MGT 1 was wibbly wobbly about it.

The "OTU" is really several different universes with a common history if one uses a simulationist approach.