Updated Vehicle Handbook in the works

[MasterGwydion]

air density isn't a constant - unless you want to make it a constant variable. Atmosphere lower to sea level is denser than atmosphere higher. If you are de-orbiting and landing on a planet you can enter the upper atmosphere at very high speed (shuttle would de-orbit at about 17,500mph) at early re-entry, but it had to slow down because it would rip itself apart and/or melt if it tried to do that all the way down as air density increased, drag increased and heat/structural stress increased. It would enter over the Pacific and do a few corkscrews to bleed off speed and get down to lower mach as it descended towards Florida.

As it descended it continued to slow, by design and because of drag/increasing air density. Objects flying at high speeds at low altitudes have to be designed very carefully, and even then there are still limitations to things. And all are very aerodynamic or else they couldn't do it. Small objects, like say a railgun projectile, are smaller and usually dense enough to do things that a manned starship could not due to the increased size and increases across the board in drag/resistance and power requirements.

Air density in Traveller is constant. Nowhere in the rules does it state that air density varies with altitude. That would be realistic, but that is not how the game is written so your point is moot.

 

[MasterGwydion]

Wait till the last moment, and then overclock the manoeuvre drive.

Not sure what kind of acceleration forces that would impart on the hull.

Though, going by the current rules, inertial compensation should also spike to cancel that out for the passengers.

Except by the current rules, the "inertial compensators" are limited to the G-rating of the engine, so overclock and the compensators can't keep up.

 

[Condottiere]

It's ambiguous.

Ships are typically equipped with enough gravitic compensation to counter whatever Thrust score the ship has.

If inertial compensation mirrors thrust caps, you could also overcompensate.

 

[MasterGwydion]

It's ambiguous.

Ships are typically equipped with enough gravitic compensation to counter whatever Thrust score the ship has.

If inertial compensation mirrors thrust caps, you could also overcompensate.

True, but this would mean that I can "overclock" one without "overclocking" the other. This could have implications during boarding actions.

 

[Condottiere]

Parts being greater than the whole.

Manoeuvre drive(s) are a black box, so pretty much pure speculation as to what you can do with it outside of movement, or what's inside.

 

[MasterGwydion]

Parts being greater than the whole.

Manoeuvre drive(s) are a black box, so pretty much pure speculation as to what you can do with it outside of movement, or what's inside.

They are not a black box since We know that they use gravity to function and We know for a fact that M-Drives include inertial compensators. We know how much power they use, what they cost, how much it costs to maintain them, and they can be repaired by skilled technicians instead of just having to be replaced entirely.

Now here is something that will really bake your brain. Is the force from the M-Drive asserted on the M-Drive itself, meaning if the bolts holding down the M-Drive break it propels itself forward until the connections with the power supply are broken, or it creates a field that pulls the ship along, in which case, an M-Drive not attached to a ship could be used for many other things as well were having a gravity field which generates thrust could be very useful.

 

[Sigtrygg]

And we know they output more energy than is put in, unless the MgT EP is going to be redefined as GW.

I'm so glad I don't use the MgT m-drive paradigm in any game I run.

 

[MasterGwydion]

And we know they output more energy than is put in, unless the MgT EP is going to be redefined as GW.

I'm so glad I don't use the MgT m-drive paradigm in any game I run.

How do We know that they put out more energy than is put into them? As far as I am aware, Mongoose has not defined how much energy a PP is. Did I miss this in one of the books?

 

[AndrewW]

Air density in Traveller is constant. Nowhere in the rules does it state that air density varies with altitude. That would be realistic, but that is not how the game is written so your point is moot.

Actually there is mention of this. There is at least one planet description that mentions people living at different altitudes due to this and needing a breather mask or some such when traveling to a different altitude. Don't ask me for an exact reference though don't recall where that is.

 

[Condottiere]

1. One power point is ten tonnes of thrust, default, one tenth of a tonne, one fifth of a megastarbux.

2. So it would depend on how many watts one power point represents.

3. I don't think that the default manoeuvre drive has generates a general field, except for inertial compensation.

4. If there is a field for propulsion, it expresses itself narrowly through the engine nozzles, creating thrust.

5. Apparently, you can vector that nozzle jet.

6. And apart from what's above, we don't know what's happening within the manoeuvre drive.

 

[MasterGwydion]

Actually there is mention of this. There is at least one planet description that mentions people living at different altitudes due to this and needing a breather mask or some such when traveling to a different altitude. Don't ask me for an exact reference though don't recall where that is.

I have seen this on Atmosphere F planets as well, but We have no rules for how that changes things for ships or vehicles. We barely have rules for flying spaceships in an atmosphere as it is. Although, I only make My players roll for stuff that has dramatic impact or is high enough above their skill level that they have a better than 50/50 chance of failure. So, this may affect Me and My games less than others.

 

[MasterGwydion]

1. One power point is ten tonnes of thrust, default, one tenth of a tonne, one fifth of a megastarbux.

For all mass that fits within that volume. Based on that alone, you cannot assign a value for how much energy is required in real world units, since all real world units to do that conversion would require us to use Mass, not Volume.

2. So it would depend on how many watts one power point represents.

See above. Plus, since the writers didn't do the math from a real world units standpoint, none of the different systems will have the same power usages in real world units. If you look at them in isolation and calculate the power point to watt conversion for each system individually, none of the numbers will match.

3. I don't think that the default manoeuvre drive has generates a general field, except for inertial compensation.

It provides something like 10% of its thrust forward, 25% to the sides, and 100% to the rear, so I doubt there are "nozzles", but the way it has been described to date in Mongoose materials is woefully lacking. Mainly because the writers (and a lot of players and referees) don't think ships look right if they don't have big engines sticking out the back and providing thrust. My belief is that if you are using "gravity" for your thrust, then your engines should be omnidirectional and not have any engines sticking out of the ship. Therefore, put the M-Drive in the middle of the ship, have no "external engines" and fly backwards if you feel like it. It makes no difference to the people on the ship. Ship orientation only matters when in combat or when docking and such. Big advantage being able to fly backwards and shoot the spinal mount at the ships chasing you while still accelerating along an escape vector.

As I said though, most people want big engines sticking out the back.

4. If there is a field for propulsion, it expresses itself narrowly through the engine nozzles, creating thrust.

See above.

5. Apparently, you can vector that nozzle jet.

See above.

6. And apart from what's above, we don't know what's happening within the manoeuvre drive.

 

[Condottiere]

Whichever direction the nozzle is pointing, you have ionization.

Does ionization cause cancer?

Or raise ambient temperature?

 

[MasterGwydion]

Whichever direction the nozzle is pointing, you have ionization.

Does ionization cause cancer?

Or raise ambient temperature?

Why does manipulating a gravity field cause ionization localized to a "nozzle"?

Do inertial compensators cause ionization also? How about artificial gravity on a ship? Does it cause ionization? What about lifters?

This is one of the many reasons I never use published deckplans. lol. They always have big-ass engines in the back.

 

[Condottiere]

When in operation, thruster plates build up an ionisation field that glows blue.

 

[Arkathan]

Actually there is mention of this. There is at least one planet description that mentions people living at different altitudes due to this and needing a breather mask or some such when traveling to a different altitude. Don't ask me for an exact reference though don't recall where that is.

Victoria in Lanth Subsector is one

 

[Sigtrygg]

How do We know that they put out more energy than is put into them? As far as I am aware, Mongoose has not defined how much energy a PP is. Did I miss this in one of the books?

It is a trivial thing to calculate the increase in kinetic energy the maneuver drive imparts on the ship. The energy you feed into the m-drive is measured in EPs as are the EPs going into ship systems etc.
The kinetic energy imparted by the m-drive has to be of the order of 1GW per EP, so that means you are using ridiculous amounts of energy in your environmental systems, weapon systems, sensor systems etc.

 

[Sigtrygg]

For all mass that fits within that volume. Based on that alone, you cannot assign a value for how much energy is required in real world units, since all real world units to do that conversion would require us to use Mass, not Volume.

You have to accept the space magic then and just ignore science, or approximate the mass. The fact remains that a ship gains kinetic energy as it accelerates, that acceleration comes form the m-drive, the power for the m-drive comes from the power plant. it is possible to estimate the masss of the ship hence get a ballpark figure for kinetic energy, which gives you an idea of what 1EP has to be.

See above. Plus, since the writers didn't do the math from a real world units standpoint, none of the different systems will have the same power usages in real world units. If you look at them in isolation and calculate the power point to watt conversion for each system individually, none of the numbers will match.

Correct, which is why the whole system needs to be scaled.

It provides something like 10% of its thrust forward, 25% to the sides, and 100% to the rear, so I doubt there are "nozzles", but the way it has been described to date in Mongoose materials is woefully lacking. Mainly because the writers (and a lot of players and referees) don't think ships look right if they don't have big engines sticking out the back and providing thrust. My belief is that if you are using "gravity" for your thrust, then your engines should be omnidirectional and not have any engines sticking out of the ship. Therefore, put the M-Drive in the middle of the ship, have no "external engines" and fly backwards if you feel like it. It makes no difference to the people on the ship. Ship orientation only matters when in combat or when docking and such. Big advantage being able to fly backwards and shoot the spinal mount at the ships chasing you while still accelerating along an escape vector.

As I said though, most people want big engines sticking out the back.

See above.

See above.

Most of the artwork shows a noticeable drive plume.

 

[Sigtrygg]

When in operation, thruster plates build up an ionisation field that glows blue.

What is ionising? The plate itself? That means the plate degrades over time and will need replacing as it ablates.

 

[MasterGwydion]

When in operation, thruster plates build up an ionisation field that glows blue.

Is the thruster plate the M-Drive? If so, how do you get thrust in other direction as stated in MgT2 books? I have never seen "thruster plates" on the front or sides of any ship in any of the materials.