1g Ships and Size:7 worlds...

[Grav_Moped]

So, thrust vectoring?

It doesn't say directly, so we have to look for secondary hints, e.g. manoeuvrability or the lack of it.

A normal 1.1 G air/raft would be able to use 1 G lift (down) and 0.1 G propulsion (rearwards).
In 0.5 G gravity it would be able to use 0.5 G lift (down) and 0.6 G propulsion (rearwards).
That seems to suggest that it can change the trust vector quite a lot?

Except that the LBB3 Air/raft does not do that. If it could, it would be significantly faster than it's stated performance when empty, and it's not.

 

[Grav_Moped]

Then why both, select one or the other?

Because antigravity (as implemented in LBB3 grav vehicles) is of limited utility.

Edit 2: ... away from a planet. Its effect is not thrust, it's something like buoyancy. Straight up or down, while anything at an angle to that is very limited. And it's range-limited to an undefined extent, beyond "it's not for interplanetary use".

 

[AnotherDilbert]

Except that the LBB3 Air/raft does not do that. If it could, it would be significantly faster than it's stated performance when empty, and it's not.

Doesn't it?

No grav vehicle is discussed in that much detail, e.g. Striker, B3, p29:

Not even Striker discuss different performance at different loads or local gravities, but apparently relies on the rules for that.

Why would the Air/raft be any different?

 

[mike wightman]

I think Jame is probably the closest with how it works in the Third Imperium.

The grav plates, acceleration compensation and null-grav components are beneath the resolution of LBB2/5 ship design. The Striker derived numbers for the null-grav modules that AnotherDilbert calculated (1.5dt and 100 MW per 100dt of ship) could be handwaved as included in the 20t bridge displacement.

 

[AnotherDilbert]

Because antigravity (as implemented in LBB3 grav vehicles) is of limited utility.

Edit 2: ... away from a planet. Its effect is not thrust, it's something like buoyancy. Straight up or down, while anything at an angle to that is very limited. And it's range-limited to an undefined extent, beyond "it's not for interplanetary use".

I think you are thinking of T4 Contragrav, CT/MT anti-grav does not work that way as far as I know.

LBB3'81, p23:
Air/Raft (8) Cr600,000, 4 tons. A light anti-gravity vehicle which uses null-grav modules to counteract gravity for lift and propulsion. 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. An air/raft can reach orbit in several hours (number of hours equal to planetary size digit in the UPP); ...

Striker, B3, p5:
Anti-gravity is the second major breakthrough. The postulated technology produces both neutralization of weight and lateral thrust.

CT/MT anti-grav tech can be used for thrust, up to and including hypersonic velocities.

 

[Condottiere]

Contra would be against, anti would be opposite.

 

[AnotherDilbert]

The grav plates, acceleration compensation and null-grav components are beneath the resolution of LBB2/5 ship design. The Striker derived numbers for the null-grav modules that AnotherDilbert calculated (1.5dt and 100 MW per 100dt of ship) could be handwaved as included in the 20t bridge displacement.

Sweeping it into the bridge tonnage might work for a 100 Dt ship, but hardly for a 1000 Dt ship; that would be the entire bridge.

You can of course hand-wave anything you want, and disregard the rules that states that ship does not behave that way. Just use T5 lifters?

But the OTU might find that a bit more difficult.

 

[Jame]

I think Jame is probably the closest with how it works in the Third Imperium.

The grav plates, acceleration compensation and null-grav components are beneath the resolution of LBB2/5 ship design. The Striker derived numbers for the null-grav modules that AnotherDilbert calculated (1.5dt and 100 MW per 100dt of ship) could be handwaved as included in the 20t bridge displacement.

My assumption, and YMMV, is that these things are factored into the cost and displacemenr of the various parts, such as the bridge and the M-drives.
Part of why I subsume it into the M-drive is to explain why they cost and displace what they do, and be proportional to the tonnage of a given vessel.

 

[Grav_Moped]

Doesn't it?

No grav vehicle is discussed in that much detail, e.g. Striker, B3, p29:
View attachment 3534
Not even Striker discuss different performance at different loads or local gravities, but apparently relies on the rules for that.

Why would the Air/raft be any different?

The laden and unladen weight of the APC aren't that different.

Also, Striker isn't LBB3.

 

[Grav_Moped]

Sweeping it into the bridge tonnage might work for a 100 Dt ship, but hardly for a 1000 Dt ship; that would be the entire bridge.

You can of course hand-wave anything you want, and disregard the rules that states that ship does not behave that way. Just use T5 lifters?

But the OTU might find that a bit more difficult.

There's already plenty of things "wrong" with LBB2 ships at about the 1000Td point (powerplant fuel, crew size if LBB5 is assumed to be the new baseline). What's one more?

And, having an extra 0.25G "thrust" (or less, if it's proportional to local gravity rather than being a flat 0.25G) that pretty much only can be applied directly away from the nearest planet, doesn't affect LBB2 significantly.

 

[Grav_Moped]

I think you are thinking of T4 Contragrav, CT/MT anti-grav does not work that way as far as I know.



CT/MT anti-grav tech can be used for thrust, up to and including hypersonic velocities.

Striker and MT anti-grav tech. Not quite the same as LBB3. I'll grant LBB3 handwaved a lot and occasionally lacked internal consistency, but it is also rules.

 

[AnotherDilbert]

Striker and MT anti-grav tech. Not quite the same as LBB3.

LBB3 anti-grav is lift and considerable propulsion, just like Striker and MT:

LBB3:
Speeder (8) Cr1,000,000, 6 tons. A streamlined grav-poweredcraft intended for high speed transport between points on a world surface. Similar in principle to the airlraft andtheGCarrier,thespeeder isstreamlinedandconcentratesonspeed. Itis capable of 1000 kph cruise speed (maximum speed is 1200 kph), ...

I'll grant LBB3 handwaved a lot and occasionally lacked internal consistency, but it is also rules.

Agreed, it's just Gygaxed, but it's not at all detailed. It just doesn't say what you seem to want it so say.

 

[AnotherDilbert]

There's already plenty of things "wrong" with LBB2 ships at about the 1000Td point (powerplant fuel, crew size if LBB5 is assumed to be the new baseline). What's one more?

If you want to house rule it, just do it, no excuses needed.

And, having an extra 0.25G "thrust" (or less, if it's proportional to local gravity rather than being a flat 0.25G) that pretty much only can be applied directly away from the nearest planet, doesn't affect LBB2 significantly.

OK, not much, but gravity effects in combat more or less disappears.

But why add T4 contragrav and not CT anti-grav?

 

[AnotherDilbert]

The laden and unladen weight of the APC aren't that different.

No, but we were discussing the effect of local gravity and thrust vectoring.

Also, Striker isn't LBB3.

No, obviously, but Striker is the vehicle design system for CT. It describes how grav vehicles work in more detail.

 

[mike wightman]

The laden and unladen weight of the APC aren't that different.

Also, Striker isn't LBB3.

African or European?

The Striker numbers are close to LBB3/A12 - but using Striker an empty air/raft should be much faster, unless it is limited by avionics and computer control.

 

[mike wightman]

No, but we were discussing the effect of local gravity and thrust vectoring.


No, obviously, but Striker is the vehicle design system for CT. It describes how grav vehicles work in more detail.

But doesn't duplicate the numbers exactly...

 

[AnotherDilbert]

But doesn't duplicate the numbers exactly...

Of course not, but it presumably describes the same technology.

Corollary: Only LBB5 describes internal gravity fields onboard ships, yet we generally assume that extends to LBB2 ships. Two different books, describing the same reality, from two different views.

Can we conclude from the lack of discussion in LBB2 that LBB2 ships don't have internal gravity?

 

[Grav_Moped]

Of course not, but it presumably describes the same technology.

Corollary: Only LBB5 describes internal gravity fields onboard ships, yet we generally assume that extends to LBB2 ships. Two different books, describing the same reality, from two different views.

Can we conclude from the lack of discussion in LBB2 that LBB2 ships don't have internal gravity?

You could.

Remember the "typical travel times" table from '77 that only described times for 1G trips?

 

[mike wightman]

Forget LBB5 exists. Forget S5, S7 or any of the ship based adventures exist.
77 edition - what fuel is used? The word hydrogen is used exactly 0 times in LBB2.
Is there artificial gravity on ships? It doesn't mention any.
Is there acceleration compensation? It doesn't mention any.
Do we assume the fuel is animatter and that StarTrek/Star Wars physics apply?

HG79 provides us with the details that

Tech level requirements for maneuver drives are imposed to cover the grav-plates integral to most ship decks which allow high-G maneuvers while the interior G-fields remain normal...
Fuel used for ships is light elemental gases, especially hydrogen.

And of course the m-drive is the equivalent of an energy weapon with a factor equal to the g rating.

Where are the numbers for the grav plates or acceleration compensators?

We then get HG80 - still no design numbers for gravitics - so do we conclude that they are subsumed within some other system, the bridge and the m-drive?

LBB2 81 - hydrogen fuel is now mentioned, still no mention of gravitcs and no numbers.

Then we get Striker - note that LBB4 and Striker were Frank Chadwick's - MWM doesn't even get a credit in Striker.
No internal grav fields or acceleration compensation as design elements.
Do we also conclude that 7g grav vehicles kill their crew when they execute a high g turn since they lack artificial gravity and acceleration compensation and can thus achieve dozens if not hundreds of gs of centripetal/centrifugal force (reference frame dependent) during maneuvers? Or do we assume that these null-grav units have an internal field that ignores the maneuvering gs?
Which would imply that these null grav units can be used to generate the acceleration compensation and artificial gravity fields within a ship, and have the side benefit of making the ship gravitationally buoyant.

I think I need sleep.

 

[AnotherDilbert]

You could.

When was the last time someone actually insisted LBB2 ships didn't have internal gravity?

Remember the "typical travel times" table from '77 that only described times for 1G trips?

This one with a formula for all accelerations?