Rule for grav vehicles?

[sideranautae]

Mongoose and all the other editions kept it simple

No. MGT HAS vehicle sized deep space Grav powered vehicles. HENCE, one reason why I am looking at the rules angle of this and why I started the thread...

 

[Reynard]

I ask again, what is the source so I can verify and understand why there is contradiction. I'm answering from what I have found so far both in Mongoose and older canon editions. I either missed the reference in a sourcebook I have or have yet to buy the particular book you cite.

 

[sideranautae]

I ask again, what is the source so I can verify and understand why there is contradiction.

The TL 14 Long Range thruster pack for space suits. It has a Grav drive & fusion PP. See CRB equipment list.

 

[CosmicGamer]

First, if a star has enough gravity to hold planets (orbit - for those keying in on that word) would not it's gravity be enough to operate some grav vehicle that needs such?

Second, vehicles (the non ship type) typically have a very short range so going between planets would likely be impossible. Could this be a possible source of a general statement about being limited to planetary orbit?

 

[phavoc]

CRB, pg 97:

Thruster Pack (TL 9): A simple thruster pack gives the user the ability to manoeuvre in zero-gravity. A Zero-G check is required to use a thruster pack accurately. Thruster packs can only be used in microgravity environments and are only practical for journeys between spacecraft (or other objects) at Adjacent range (see page 146). Cr. 2,000.

At TL 12 the long-range thruster pack gives 0.1g acceleration for up to 48 hours, using standard starship fuel. This increases its practical range on the spacecraft scale to Short but gives it a weight of 10 kg. Cr. 14,000. The TL 14 version of the long-range pack is much smaller as it uses grav-thruster plates instead, but has the same performance profile as the TL 12 version. Cr. 20,000.

There is no mention of fusion power capabilities. TL14 is "much smaller", so I suppose through inference one could say it only masses 5 kg.

The term "thruster" is used in a number of different ways, and possibly not very precisely. For example, A standard-confi guration ship can also enter a planet’s atmosphere, but is reliant on its thrusters to keep it aloft at all times and is extremely ungainly. Pilot checks are required for all movement and suffer a –2 DM.. That seems a bit silly to me. It's not thrusters that are keeping a massive starship aloft, it's the contragravity that keeps it up. Thruster plates make it go forward.

As an interesting aside, I don't think thrusters plates allow you to "reverse" a starship, since they are push-only. I'd think you'd have to rotate 180 degrees to have the main engines push you in the right direction. This is where another concept of thrusters comes along that would be located near the front and rear of the ship and fire small bursts to turn, much like the shuttle's thrusters allow it to spin in any plane while maintaining it's course.

For vehicles I've always seen them equipped with a different form an anti-grav that required a grav well to work in. This means you can do ground-to-orbit in your air raft, but no jaunts to the moon from the planet in it. It also would mean you could alter the characteristics of grav vehicles and give them the ability to turn and move backwards because they are playing against the grav field, unlike ships which always 'push'.

 

[CosmicGamer]

The TL 14 Long Range thruster pack for space suits. It has a Grav drive & fusion PP. See CRB equipment list.

I think the CRB has equipment that could be used in a variety of settings and may very well not be valid in all settings. Fun stuff, but perhaps not necessarily proof for or against any actual rules.

 

[CosmicGamer]

For vehicles I've always seen them equipped with a different form an anti-grav that required a grav well to work in. This means you can do ground-to-orbit in your air raft, but no jaunts to the moon

This is where my science knowledge of "grav wells" fails. I'd think that if the moon is in orbit, held by a planets gravity, it would be in the "grav well", no?

Even if not, is there any actual rule that says specifically says anything about "grav wells" being needed for any type of drive to operate? Do they say "gravity field"? Something else?

 

[sideranautae]

There is no mention of fusion power capabilities.

Starship fuel is L-hyd. The only way to use it in that context is by fusing. In the volume given there isn't room for O2 enough to "burn" with the L-hyd to give 12 hours of thrust at .1 G. That's inescapable chemistry.

The term "thruster" is used in a number of different ways

The COMPLETE term used in the CRB is "grav-thruster plates". It is a GRAV drive being used in deep space. It is NOT another kind of drive. So, we either need errata getting rid of Deep space, vehicle scale grav drives or, we go with the RAW and have vehicle scale deep space vehicles in MGT.

 

[sideranautae]

I think the CRB has equipment that could be used in a variety of settings and may very well not be valid in all settings. Fun stuff, but perhaps not necessarily proof for or against any actual rules.

It is proof of a rule in MGT. That is de facto. Setting wise is up to the GM's
The CRB default char gen rules are for the 3I. So, the assumed setting is the 3I...

 

[sideranautae]

This is where my science knowledge of "grav wells" fails. I'd think that if the moon is in orbit, held by a planets gravity, it would be in the "grav well", no?

You are correct. And, no human has ever left Earth orbit, technically.

Even if not, is there any actual rule that says specifically says anything about "grav wells" being needed for any type of drive to operate? Do they say "gravity field"? Something else?

In MGT there is no mention of needing a grav well to operate. That's why I ruled that MGT Grav Space drives create their own grav well of sorts.

 

[phavoc]

For vehicles I've always seen them equipped with a different form an anti-grav that required a grav well to work in. This means you can do ground-to-orbit in your air raft, but no jaunts to the moon

This is where my science knowledge of "grav wells" fails. I'd think that if the moon is in orbit, held by a planets gravity, it would be in the "grav well", no?

Even if not, is there any actual rule that says specifically says anything about "grav wells" being needed for any type of drive to operate? Do they say "gravity field"? Something else?

If you were to look at a depiction of a grav well, it looks like a funnel, with the gravity being stronger the closer it gets to the source. So as the strength of the gravity gets smaller as you get further from the surface, so does the efficiency of your contra-gravity. At a certain distance it's not strong enough to repel and therefore you can't use it for locomotion. This explanation fits within the canon.

There is no mention of fusion power capabilities.

Starship fuel is L-hyd. The only way to use it in that context is by fusing. In the volume given there isn't room for O2 enough to "burn" with the L-hyd to give 12 hours of thrust at .1 G. That's inescapable chemistry.

So you are saying you can get a micro-fusion reactor, with fuel, shielding and associated widgets within a much smaller than 10kg package?

The term "thruster" is used in a number of different ways

The COMPLETE term used in the CRB is "grav-thruster plates". It is a GRAV drive being used in deep space. It is NOT another kind of drive. So, we either need errata getting rid of Deep space, vehicle scale grav drives or, we go with the RAW and have vehicle scale deep space vehicles in MGT.

Not everywhere is the term thruster preceded by grav. Using the handy search function of Adobe:

Pg4 - thruster plates, no grav.
pg54 - overcharging a thruster plate, no grav
pg59 - using thruster packs, no grav
pg 96 - upgrades like thruster packs or grav floaters, no grav(on thruster)
pg97 - uses grav thruster plates instead, magical grav!
pg136 - damaged thrusters, no grav
pg 137- reliant on its thrusters, no grav
pg 149 - attackers must use thruster packs, no grav
pg 149 - boarding parties using thruster packs, no grav
pg 188 - thruster pack, no grav.

Like I said, the term thruster is used in a number of different ways. I dunno why you jumped on "COMPLETE" because I'm quoting word for word outa the book. How was my quote in any ways incomplete? If we use your train of logic then only TL14 thruster packs have grav thruster plates. Everything else just uses thrusters.

 

[sideranautae]

So you are saying you can get a micro-fusion reactor, with fuel, shielding and associated widgets within a much smaller than 10kg package?

No. MGT CRB is. I already gave you the reference. Why do you think that I wrote that item in CRB?

The term "thruster" is used in a number of different ways

The COMPLETE term used in the CRB is "grav-thruster plates". It is a GRAV drive being used in deep space. It is NOT another kind of drive. So, we either need errata getting rid of Deep space, vehicle scale grav drives or, we go with the RAW and have vehicle scale deep space vehicles in MGT.

Not everywhere is the term thruster preceded by grav.

In the description of the item in question it is. Which is the item under discussion. We are not discusing EVERYWHERE that the term is used in Traveller. So, all else is meaningless within this context. Thruster can also be proceeded by "water" when talking about certain flush toilets manufactured in Japan circa 1980. But, we are talking about MGT TL 14 Long Range Thruster packs for space suits...

 

[Reynard]

And the TL 14 thruster pack is preceded by the rest of the information pertaining to all the thruster packs. They all are only good in micro-gravity environments and are very short duration. They cannot be used to achieve planetary orbit and I doubt I want to try reentry.

The vehicle grav units are more powerful but still no where near the power of a ship system. They can make orbit, probably Low Orbit proportional to the planet, but can't make escape velocity. I would say a grav vehicle could operate somewhat like a thruster pack in a micro-gravity environment and transfer between ships but they are not built for space operations. Again, drones used in space are either crawlers, thrusters or actual ships and these are the closest thing to space worthy vehicles. It's purely scale efficiency.

 

[sideranautae]

And the TL 14 thruster pack is preceded by the rest of the information pertaining to all the thruster packs. They all are only good in micro-gravity environments and are very short duration.

Right. Because they only built the grav module to rate 1/10 G. If you take a vehicle grav module rated at 1G for a 2 ton vehicle an put it on a 20 ton vehicle you get about 1/10 G rating.

So, what is your point? Vehicle sized grav modules WORK in deep space. Increase the size relative to the vehicle to change G rating. Just like any other drive.

Did you know that once in orbit, if you can create ANY "thrust" you can reach ANY speed? And thus leave orbit. Did you know that?

Any other questions?

 

[Reynard]

You make a lousy engineer. Planetary vehicles are not thruster packs and thruster packs can only operate in space and are not even listed under Vehicles. Space based Drones are the next size up and one type is just a remote spaceship while the others use thrusters and therefore can't operate outside micro-gravity. They are not grav vehicles nor listed under Vehicles. Vehicles have a Speed rating not an Acceleration rating. They have a max speed and even then they normally move at a lesser speed. They do not continually accelerate as to spacecraft. That is the big difference in engines and power supply so don't scale their engines up and down as if they were the same thing. That's like scaling nuclear power plants and the drive system on an aircraft carrier to a car's I.C.E engine. This is why spaceplanes today need to cheat with rockets to just achieve orbit. Traveller vehicles just can't produce enough energy to do any better than orbit.

To top it yet *again*, Traveller says vehicles don't leave planetary orbit on their own. They are functionally planet bound.

 

[sideranautae]

You make a lousy engineer. <snipped rest of whatever>.

Actually, I was a fairly good engineer but preferred the executive suite as the pay was MUCH better. :lol: A grav belt sized item is considered vehicle scale. The rest of your "writing" is incomprehensible though and has nothing to do with the MGT item that is part of RAW.

N.B. since you had to resort to ad hom as opposed to intelligence and facts, you lose the argument by default.

 

[CosmicGamer]

To top it yet *again*, Traveller says vehicles don't leave planetary orbit on their own. They are functionally planet bound.

Where does it say this? Did a search on "planetary orbit" and could not find it.

 

[Reynard]

The descriptor in every edition says the air/raft can only achieve orbit. Of all the grav vehicles it is the vehicle of choice as a carried vehicle on spacecraft and starships and frequently mentioned having the duty to ferry between ground and ship. If the air/raft is unable to produce escape velocity with its capabilities other grav vehicles most certainly are no better. And how many examples over the decades have there been showing planetary grav vehicles leaving orbit and flying in deep space? Personally I can't. How many in the Vehicle Book are labeled deep space capable?

 

[CosmicGamer]

The descriptor in every edition says the air/raft can only achieve orbit.

Can't speak for other versions, but in Mongoose it is "Air/rafts can even reach orbit".

Kind of like saying "my car can even do 100mph". Still don't know what else it can do.

If the air/raft is unable to produce escape velocity with its capabilities other grav vehicles most certainly are no better.

The air/raft is designed as a open vehicle without life support. I'm not sure if I'd use it as the end all in determining what the full space capabilities are for a vehicle.

In general, grav vehicles are predominantly for on planets and this is what is detailed. I'd expect this functionality to be what is most described. To me, the lack of specifically saying the grav vehicle can operate in deep space is no more an indicator of lack of capability than the lack in any vehicle at all saying it can operate in reverse (from a search of key words "backward" and "reverse" - did not look at every vehicle).

I'm not saying you are wrong for having your interpretation, many things in the books can be interpreted different ways by different people. Just wondering if there is something specific in the rules, and not personal interpretation, that says grav vehicles can not operate in open space, or something like an asteroid belt.

 

[Jeraa]

I'm not saying you are wrong for having your interpretation, many things in the books can be interpreted different ways by different people. Just wondering if there is something specific in the rules, and not personal interpretation, that says grav vehicles can not operate in open space, or something like an asteroid belt.

Well, the adventure Beltstrike does have the prospecting buggy.

This 4-ton vehicle is a pressurised air/raft variant styled and equipped for non-atmospheric prospecting. The vehicle can be operated with the Flyer (Grav) specialisation in atmospheres, and Pilot (Small Craft) specialisation in zero-g. The buggy is equipped with a ‘mule unit’; a reinforced rig with a heavy-duty winch, laser drill platform, work-bench (large enough to house an Ore Sampler) and toolkit. It is configurable to carry four people with no cargo; two people with two tons of cargo or a single occupant with three tons of cargo. Changing the internal configuration takes 10 minutes per stage (meaning that changing from four persons to two takes 10 minutes, and two to one a further 10 – or vice versa).

Doesn't mention speeds (I would assume it is the same as a standard air/raft), but it is usable in an atmosphere and in a vacuum. Since the rest of Beltstike is dealing with prospecting in a asteroid/planetoid belt, I would assume the buggy is perfectly capable of operating in open space. Or at least not in orbit of a planet.