High Guarding again

[whartung]

That implies that agility works by moving the targeted hull (or specific parts of it) out of the weapon's area of effect.

It also implies that there's not enough power on larger ships.

Simply, the reason smaller craft are "more agile" is that the power/weight ratio is higher than a larger ship.

But consider, something like a Saturn V, which by all accounts is pretty large, accelerates faster than most ground cars. What it lacks in nimbleness is more a factor of that it doesn't have any wings to make it turn (in atmosphere) like, say, a missile does.

But give it suitable vanes (and the structural integrity, I'm going to bet as is, the V doesn't really turn well), the V will turn quite quickly.

Put a 6G 500K ton dreadnought in a race with a 6G 50 ton cutter, and guess who wins the race?

The singular problem with larger ships is that they have more surface area they need to "get out of the way" compared to a small fighter or a missile. (Which is where size modifiers come in to play.)

The other issue is simply that we don't have much information on how ships use M-Drives to turn, rather than just accelerate. They don't have rudders, they need more like bow thrusters to make turns, or maybe REALLY BIG gyroscopes. And the power of THOSE will actually have more influence to the "agility" than the M-drive alone.

A 6G ship with paltry .1G thrusters aren't doing any turns very quickly. Like the Suzuki Samurai, "it really goes straight!".

 

[Rupert]

Just adding to this thread (which, perhaps inevitably, has headed into the contested terrain of "what is agility" that we traversed in an (in)famous TML thread many years ago) Joe Fugate's thoughts in TD #14:
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Which was dumb then, and has remained dumb ever since. Bigger targets being easier it hit is already addressed by the modifiers to the 'to hit' roll. With 20 minute turns it's never been about how fast you can roll your ship, but how hard to can thrust to evade. Funny how no rule set since stayed with MT's interpretation.

 

[Rupert]

The other issue is simply that we don't have much information on how ships use M-Drives to turn, rather than just accelerate. They don't have rudders, they need more like bow thrusters to make turns, or maybe REALLY BIG gyroscopes. And the power of THOSE will actually have more influence to the "agility" than the M-drive alone.

A 6G ship with paltry .1G thrusters aren't doing any turns very quickly. Like the Suzuki Samurai, "it really goes straight!".

Or possibly the thrusters are vectorable, either by having them on gimbals or because they can do something like a phased array does for radio signals. A combination of this and manoeuvring thrusters seems reasonable to me. And of course they don't use this to 'make turns'. They use this to face in a new direction and then they apply their main thrusters to changing their course.

If the combat turns were much shorter it would make sense for a more massive ship (especially one with the mass greatly dispersed, and thus having great rotational inertia) to be less agile, because it wouldn't be able to change orientation as quickly. But with 1000 second or more turns and mutli-G thrusters speed of attitude adjustment doesn't much come into it.

 

[mike wightman]

It was utter rubbish then and it remains utter rubbish now.

The folks at DGP didn't have a clue how ships worked - they failed to notice the CT rules had changed, they didn't understand agility, and as to his continual reference to weight when he actually means mass then the question has to be asked why the mass of the ship isn't used for maneuver drive rating.

Acceleration compensation fields, inertia compensators, make all this rotational moment moot - the people on the ship are compensated but the hull structure isn't... handwavium has to be at the very least consistent.

 

[AnotherDilbert]

Just adding to this thread (which, perhaps inevitably, has headed into the contested terrain of "what is agility" that we traversed in an (in)famous TML thread many years ago) Joe Fugate's thoughts in TD #14:

It's just a simplification, with a silly technobabble excuse, found already in the MT RM.

It's much simpler to dimension the M-drive by volume (fixed) than by mass that changes with every system added to the ship, so by volume it is, ditching Newton...
Then they wanted to use mass for something as the design system produced it, so Agility was chosen.


They demonstrated with grav vehicles (in the same design system) that they believed in Newton and used it...

MT RM, p86:
For grav vehicles, begin by computing the vehicle's maneuver thrust:
(Total thrust / vehicle's loaded weight) - 1.
The result must be greater than zero. If it is not, the design is flawed and more thrust must be provided.

i.e. Newton's Second Law of Motion (F=ma) => a = F/m - 1, where 1 is the standard gravity as thrust is by default downward, so the grav vehicle can fly like a helicopter.

Note that is the same grav drive that is used on spacecraft before TL11.

 

[Ulsyus]

Agility is acceleration. M-drives need power in order to produce thrust. If you provide less than full power to the M-drive, you get less than full thrust. Currently available acceleration, depending on how much power is routed to the M-drive, is called Agility in HG'80.

So Agility is the actual thrust that is produced by an engine fed by the power plant, while the M-drive rating is the potential?

If you ignore weapons and other power consumers, and send full power to the M-drive, you get Emergency Agility = M-drive rating (reduced by battle damage):

....which seems to be just another way of saying "the thrust of a vessel is the power actually going to the M-drive, expressed as Agility, rather than the raw rating of the M-drive itself". If there another interpretation?

 

[AnotherDilbert]

So Agility is the actual thrust that is produced by an engine fed by the power plant, while the M-drive rating is the potential?

Yes. Agility is current throttle and M-drive rating is full throttle.

....which seems to be just another way of saying "the thrust of a vessel is the power actually going to the M-drive, expressed as Agility, rather than the raw rating of the M-drive itself". If there another interpretation?

It's the same thing, you just send max power to the M-drive, kind of like turn off the aircon and give it full throttle.

 

[kilemall]

Just adding to this thread (which, perhaps inevitably, has headed into the contested terrain of "what is agility" that we traversed in an (in)famous TML thread many years ago) Joe Fugate's thoughts in TD #14:
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That is disappointing to read.

If nothing else you still boil it down to vee/mass and end up with an effective G rating.

 

[kilemall]

Yes. Agility is current throttle and M-drive rating is full throttle.


It's the same thing, you just send max power to the M-drive, kind of like turn off the aircon and give it full throttle.

The way I roll its total mdrive rating determined by how much power assigned and split between agility for erratic maneuver evade and vee for accel/decel. But again I’m coming at it from actual CT maneuver.

 

[Rupert]

The way I roll its total mdrive rating determined by how much power assigned and split between agility for erratic maneuver evade and vee for accel/decel. But again I’m coming at it from actual CT maneuver.

That's how TNE, Brilliant Lances, and Battle Rider do it as well.

 

[Ulsyus]

Yes. Agility is current throttle and M-drive rating is full throttle.


It's the same thing, you just send max power to the M-drive, kind of like turn off the aircon and give it full throttle.

Rgr, so it can be a waste of capacity on a vessel to put in M-drives that require more power than the PP can deliver, while firing weapons, unless you are planning on drive redundancy to keep you moving in a battle or you want to be able to do a flat-out run if breaking off needs to happen. Sound about right?

That is disappointing to read.

If nothing else you still boil it down to vee/mass and end up with an effective G rating.

That's not really a calculation done in CT HG though is it? It's more of a MT and TNE thing.

 

[McPerth]

Rgr, so it can be a waste of capacity on a vessel to put in M-drives that require more power than the PP can deliver, while firing weapons, unless you are planning on drive redundancy to keep you moving in a battle or you want to be able to do a flat-out run if breaking off needs to happen.

I guess not always, as you will reach places quickly, maybe allowing you to keep with the fleet (M-drives are also used out of the battle)...

And, of course, it will allow you to use higher emergency agility

 

[AnotherDilbert]

Rgr, so it can be a waste of capacity on a vessel to put in M-drives that require more power than the PP can deliver, while firing weapons, unless you are planning on drive redundancy to keep you moving in a battle or you want to be able to do a flat-out run if breaking off needs to happen. Sound about right?

For a warship, yes.

Traders probably have M-1 or M-2 with a similar PP. Then weapons are a choice between shooting or going.

 

[AnotherDilbert]

That's how TNE, Brilliant Lances, and Battle Rider do it as well.

In TNE the power for the M-drive is required at all times, but reaction fuel is limited.

You can spend M-drive rating acceleration every turn, divided between changing velocity vector and evasion, as long as reaction fuel lasts.

Power for the M-drive (HEPlaR) is baked into the minimum power requirement, as are weapons. There is no choice of routing power to drives or weapons, unlike CT.

 

[McPerth]

For a warship, yes.

As posted above, I disagree.

You may have a warship with M-drive 6 and Agility 4 and, while in combat it may seem a waste to have M6, it may not be to reach the combat area.

So to say, outside combat, ships are using emergency agility, moving at their full M-drives G, and only in combat, when powering their weapons, standard Agility takes importance. This acceleration difference may make a difference on strategic moves, and so, it's not a waste.

 

[McPerth]

Traders probably have M-1 or M-2 with a similar PP.

True for interstellar traders, that jump close to their destination and only use the M-drive to go to/from jump point to plaet (be it surface or orbital terminals).

But never forget space (in system) trade also exist, and they are merchants too. In those cases, I guess high G is also desirable, as shortens the time of transit

 

[mike wightman]

Depends on transit time... if you are moving stuff that will take you a week at 6g yu are better off with a jump 1 drive
a 6g drive is 17% (plus a pp 6 which depending on TL could be very large and costly), jump 1 + 1g is 14% (note you also save on pp and pp fuel)

 

[AnotherDilbert]

But never forget space (in system) trade also exist, and they are merchants too. In those cases, I guess high G is also desirable, as shortens the time of transit

Same thing, just at higher acceleration. A trader isn't going to waste space (=revenue capacity) and money on an oversized power plant they might use once a year.

If you intend to fight more than very occasionally, it's basically a warzone and something like light warships are required, and the freight rates will have to be correspondingly much higher.

Depends on transit time... if you are moving stuff that will take you a week at 6g yu are better off with a jump 1 drive
a 6g drive is 17% (plus a pp 6 which depending on TL could be very large and costly), jump 1 + 1g is 14% (note you also save on pp and pp fuel)

Depending on how you treat jump shadows, it can be much more. Liveable words, hence trade tends to be close to stars that occlude jumps, hence high G traders can be faster and the cheaper option, even if it might take more than a week.

 

[McPerth]

Depends on transit time... if you are moving stuff that will take you a week at 6g yu are better off with a jump 1 drive

But there are situations where this is not practica. I've read in this very board about systems where the 100 diamaeters limit from the sun is quite farther than the mainworld, just to give you an example. In those systems, bery quick (6G) shuttles would be appreciated to move from the space station in the 100 diameter limit to the main planet (and vice versa, of course).

Also, in some cases where time may be similar with a in-system jump and maneuver, the latter may be safer, I guess, along well traveleld lines.

And in some cases, in-system traffic can be quicker with 6G or jump depending on relative positions of the planets...

Same thing, just at higher acceleration. A trader isn't going to waste space (=revenue capacity) and money on an oversized power plant they might use once a year.

Fully agreed. A 6 G intrasystem tradeship will not have any PP over 6, for cost/revenue reasons.

 

[Spinward Flow]

But never forget space (in system) trade also exist, and they are merchants too. In those cases, I guess high G is also desirable, as shortens the time of transit

Reference: Interplanetary Distance by Time and Acceleration

7 days @ ...

• 1G = 6.112 AU
• 2G = 12.225 AU
• 3G = 18.338 AU
• 4G = 24.450 AU
• 5G = 30.563 AU
• 6G = 36.676 AU

Depends on transit time... if you are moving stuff that will take you a week at 6g yu are better off with a jump 1 drive
a 6g drive is 17% (plus a pp 6 which depending on TL could be very large and costly), jump 1 + 1g is 14% (note you also save on pp and pp fuel)

If there are no Jump Shadows interposed between your point of origin and destination, sure.

The star (Sol) of the Solomani homeworld (Terra) has a Jump Shadow of 0.94 AU ... with Terra orbiting the star @ 1 AU ... so the Solomani homeworld lies just barely outside the Jump Shadow of the local star.

Since planets move in their orbits (who knew, right? ) this means that depending on planetary ephemera (where they are in their orbits at any given time), a craft launching from Orbit 3 (1 AU) to any other planet in the Sol system has an almost ~55% chance of the line of sight path to that other planet being blocked by the Jump Shadow of Sol.

Sure, Venus might be 0.3-1.7 AU distant from Terra ... but you're not going to be using your jump drive to get there!

Sure, Neptune orbits at 29.9 AU distant from Sol ... but if Neptune is "behind the Jump Shadow of Sol" when you launch from Terra, you may need to do "a fair bit more accelerating in normal space" before you can reach a jump point that will reach Neptune unimpeded by a Jump Shadow.

Depending on how you treat jump shadows, it can be much more. Liveable words, hence trade tends to be close to stars that occlude jumps, hence high G traders can be faster and the cheaper option, even if it might take more than a week.

THIS.

And then there's the whole "thrust/acceleration minus gravity" requirement/argument to be able to lift off from a surface in the first place.
If surface gravity exceeds the thrust/acceleration rating of your maneuver drive and you're "parked" on the ground ... You Are Not Going To Space Today™.

So while 1G maneuver acceleration may be "all you need" once you're orbiting in space ... the "minimum requirements" shift a bit for any craft expected to (VTOL) touch down and take off from planetary surfaces before/after unloading & loading of passengers and cargoes. 2G maneuver should be sufficient for "any inhabited terrestrial mainworld" generated with a Traveller UWP code.

Vland/Vland is classified as a Big World.

The world has a standard gravity between 1G and 1.3G.
Vessels with only 1G of thrust should avoid landing on this world.

According to Travellermap, Vland has a surface gravity of 1.12G.

Since the J1/1G Free Trader is undeniably a design of Vilani origin, this would mean that the class was NEVER INTENDED to land on the Vilani homeworld while in service (well, never land more than once ... ... since Lithobraking IS A THING™). Therefore, ALL J1/1G Free Traders were designed to interface with highport facilities in orbit around Vland, with no intention (or capability) of descending to downport(s) for the unloading/loading of passengers & cargo on the planetary surface. This made the J1/1G Free Trader a "purely off-world" transport craft that could ORBIT Vland, but never attempt to land there (more than once ).

You'd need a 2G maneuver drive in order to VTOL on Vland.