MGT Only: Planetary invasion ships

[mike wightman]

The important questions in my earlier post IMHO :

why are wars between the Imperium and the Zhodani and Solomani so civilized?

what was the difference between the civil war and the rebellion?

what did the Jullians do that brought the 3I to the treaty table?

My contention is that the major polities have long since agreed unwritten rules of civilised warfare - the Zhodani do not scrub worlds during the frontier wars. They could, but they don't.
The Imperium could have sterilized Terra, but they didn't.

The Jullians realised the only way to beat the 3I was call the bluff - you threaten our world we will srub yours, you will scrub ours - let's just call it quits.

Until the rebellion era mass destruction of planets has been frowned upon for almost a millennia, but during the rebellion the various power blocks decided reducing their opponent's capacity to wage war required a destruction of their population and industrial base - quite when this line is crossed is a matter for debate.

The civil war era was fleet vs fleet, winner takes the Imperium - a very civilized version of conflict. The rebellion - and the Jullian threat - is total war. The civil war did not result in 'Hard Times', if anything the Imperium underwent a renewal and progression. The rebellion destroyed the Imperium.

 

[Condottiere]

Since Terra is the birth place of the human race, you could have a massive backlash from Solomani humans who are within or serving the Imperium.

 

[kilemall]

I can think of other reasons to not go scrubbing.

The Imperium's reason to be is trade.

Take out entire planets and you aren't hurting just the rebellious planets, you are hurting the long term economics of the entire region- and a good deal of the reason for allegiance and why worlds willingly support the Imperium.

This is warfare for the Age of Reason, or say intramural feudal squabbling of the sort practiced in Europe, China and Japan. The warriors and kings fight each other, but none look to engage use or destroy the underlying peasant/serf/merchant economic structure.

Then, there was total war, regional cleansing, best historically exemplified by the Mongols. To be able to destroy is to control- that which cannot be controlled must be destroyed, as eliminating a future threat AND serving examples for other potential rebels.

An entire system that can build hostile starships in your midst can be a bigger regional threat in terms of both flipping systems as naval force is available to protect them and mercantile shipping raids.

So both approaches would still have use in the OTU environment, on realpolitik reasons alone.

 

[Kaeto]

In MTU in a total war situation I have 1,000 tonne displacement landers to land the Combat Units of the Dinochrome Brigade.

 

[McPerth]

You manoeuvre assault carriers close enough to launch helicopters over the horizon, and schedule air transports to land as airfields are captured and the surrounding areas are cleared.

And what is close enough for the 10 G fighters and 6 G landers?

Nowdays helicoptes have relatively short ranges, so the assault carriers have to close the coast for them to launch the helicopters, while protected by their escorts and any air assets available.

For those planetary assaults, standard operation is quite different:

1. when they arrive at the system, they refuel and move to the target planet.
2. combat fleet fights orbital defenses (and hopefuly achieves supremacy). Transports and Lander ships stay with their escorts at standoff distance
3. once orbilal supremacy is obtained, combat ships begin deploying reccon and GPS satellites and begin softening ground defenses if needed. If defensive positions are known (rebel planet) so the better, otherwise, as intelligence is gained.
4. though the intelligence gained by the satellites, they choose the landing spot/area (ideally far enough form main points to be relatively safe, though close enough to reach them ASAP). The landers are loaded with the troops in the transports and begin to move to the planet, while the fighters move for straffing runs and support. Ships in orbit asume overwatch stance (though some are kept as ortillery)
5. the landers deploy the first troops (the assault troops from the transports) to establish the "skyhead", supported by fighters and ortillery. If grav tanks may also land by their own means, they do so to support them
6. once "skyhead" is established, the troops in ground enlarge it, hopefuly before enemy troops may reach it, again supported by fighters, in interdiction and straffing missions, and ortillery. Overwatch ships react against any SDBs emerging or static defenses revealing themselves.
7. follow up troops and supplies are landed in the "skyhead", either by the remaining landers or by other ships, as needed.

Of course, things must adapt to the specific needs, be them known (atmosphere type, gravity, etc) or unexpected (reinforcements appearing in the system, etc...), but that occurs in any military action.

 

[McPerth]

Until the rebellion era mass destruction of planets has been frowned upon for almost a millennia, but during the rebellion the various power blocks decided reducing their opponent's capacity to wage war required a destruction of their population and industrial base - quite when this line is crossed is a matter for debate.

Even then not all factions engage in Black War. While Lucan fully engages it and Dulinor responds in kind, Margaret outright refuses to, while Vland keeps it a mínimum and Strephont does not engage it, but it's not clear if due to lack of will or ressurces. Nothing is said on Daibei, but it seems not to engage on it according the map in page 17 of MT:HT, and in the Solomani front it seems not to be engaged.

Basically, it is limited to the Lucan/Dulinor front, with some srikes elsewhere.

 

[Carlobrand]

Lucan was a few bricks shy of a full load, sanity-wise.

 

[whartung]

Seems to me once you have orbital superiority, air superiority is not far away. There's always ground defenses, but anything that flies is likely easy pickings for orbital laser systems.

The next phase is locating the anti-air defenses so you can support the troops coming in.

 

[jec10]

Seems to me once you have orbital superiority, air superiority is not far away. There's always ground defenses, but anything that flies is likely easy pickings for orbital laser systems.

The next phase is locating the anti-air defenses so you can support the troops coming in.

Except that grav technology allows things to fly that are far more heavily armoured than aircraft. So a defender could have a go with grav gunships that are both fast/agile and heavily armoured.

Unfortunately, most Traveller editions don't handle this phase very well if at all so it is hard to say how it would turn out.

Megatrav at least made an attempt. Under the MT rules it is actually not a trivial exercise to hit and destroy an evading grav vehicle from an orbiting starship. Is this realistic? I don't know but them's the rules.

 

[McPerth]

Except that grav technology allows things to fly that are far more heavily armoured than aircraft. So a defender could have a go with grav gunships that are both fast/agile and heavily armoured.

Unfortunately, most Traveller editions don't handle this phase very well if at all so it is hard to say how it would turn out.

Megatrav at least made an attempt. Under the MT rules it is actually not a trivial exercise to hit and destroy an evading grav vehicle from an orbiting starship. Is this realistic? I don't know but them's the rules.

In MgT rules, see that just the fact that the ortillery (or fighters') weapons use scale combat, while any tanks will use personnel/vehicular ones (so, a factor of 50 separates them) will make the tanks at a high disadvantage, as any hit to a tank will be quite damaging, while return fire quite ineffectual (more so against the factor 15 armor of the fighters and landers).

----------------

But, though this is a MgT only thread, let's study it from MT POV as, as you say, is the system that attempted to integrate all in the same rules:

That would depend on how do you read the rules.

What rules would apply?

Indirect fire (you cannot see the target)?

Direct fire by crewed weapon (it's direct fire, after all)?

Space combat rules (is sensor directed fire, and, after all, it's what you'd do if the tank was a fighter, that can be even smaller than the tank, though time scale is quite different)?

Let's imagine an overwatch ship, orbiting at 10000 km from the world, tries to destroy a grav tank.

If you use indirect fire rules, as you say, it's a difficult task (11+), modified by the FO skill. If it fails, it's quite likely to hit within the danger space (45 m), so damaging the tank...

If you use direct fire rules, range is planetary, so out charts for fire controled table in page 72, though well inside the weapon range...

If you use space combat tables, you'd need a difficult task, but the computer and weapon modifiers would make it nearly a sure hit.

In any case, a hit is likely to be quite damaging for the tank, as, in standard atmosphere, the penetration value would be halved (so 51), doing half damage to any tank armored up to 50, and 10% to more heavily armored ones. As the Damage value is 900, it will rarely make a difference (PM, page 80)...

And now imagine one of the told fighters tries to fire at a tank from very distant range (5-50 km). Using crewed weapons fire, that would be (at TL15) a difficult task, with any hit being likely devastating (pen 40, damage 800).

As for the return fire, here we face a lack of consistency (again). Assuming the tank is TL 15 and equiped with Fusion Y rapid pulse gun, according PM page 80, range is regional (so up to 500 km), while in RM (page 87) the range is Vdist (21), so 21 km. In any case, pen is 71/5 (so 35 at this range) and damge 30.

if able to fire, (in range), again it would be difficult task, and any hit would face a 125 AF fighter (the maximum for a spacecraft at TL 15) .

I'm not familiar enough for using COACC air combat rules, but I guess they could also apply (and probably the fighter, with 10 Gs, will be quite more agile and maneuverable there).

 

[AnotherDilbert]

is there any reason for a troop transport to be j3? (using the spinward marches as a guide) there are very few systems which cannot be reached by j2.

From Depot/Deneb to Jewell is 24 J-2 or 13 J-3 (according to TravellerMap). If you want your invasion fleet to actually show up during the war low jump is impractical.


The major trade routes are j-3 or j-4 because that is the most economical way to transport stuff long distances. Hence large civilian transports are likely j-3 or j-4.

 

[mike wightman]

The 3I would be pretty stupid not to move everything strategically by jump 6 tender.

Canonically Imperial core worlds use drop tank merchants and liners, and moves were afoot to upgrade the x-boat system to jump 6 using drop tanks in 1105+

The IN has had over a hundred years to re-equip its strategic transport network with jump 6 tenders.

 

[Reban]

The 3I would be pretty stupid not to move everything strategically by jump 6 tender.

Now thats an interesting idea. Does it give rise to a sort of fire brigade reserve that can be moved anywhere quickly?

What are the strategic or doctrinal implication of fast transport for Imperial troops?

 

[Condottiere]

If you look at population sizes, you can have elite troops stationed in every subsector.

The only difference is a question of loyalty, not quantity or quality.

 

[AnotherDilbert]

The 3I would be pretty stupid not to move everything strategically by jump 6 tender.

I doubt they have many. A J-6 tender (w/o jump fuel) that can lift a 200 kT battleship costs about GCr 145, or slightly more than the battleship (HG'80).

I guess the Admiralty prefers to have two battleships, rather than a battleship and a tender. The second battleship will get there slower, but the first battleship will likely already be in the vicinity.

 

[mike wightman]

The Imperium can afford it.

 

[aramis]

The Imperium can afford it.

The payload of J6 is (using High Guard)

-67% J6 Drive and fuel
-12% P6 drive and fuel
-2% bridge
-1% M1
-0.56% =(14%*0.02*2) Engr crew SR DO
-0.6% Maint Crew SR DO
-1% other fixed costs as a rough round.

around 15.8% unarmored unarmed

We can knock off another 1% for turrets for defense - lasers and sand.

A J4, at about 2/3 the cost, and 2.5x the payload.
-45% J4 D/F
-8% PP D/F
-2% bridge
-1% M1
-0.36% =(9%*0.02*2) Engr crew SR DO
-0.6% Maint Crew SR DO
-1% other fixed costs as a rough round.

for around 42%, same caveats. You can afford to throw some armor.

 

[McPerth]

From Depot/Deneb to Jewell is 24 J-2 or 13 J-3 (according to TravellerMap). If you want your invasion fleet to actually show up during the war low jump is impractical.


The major trade routes are j-3 or j-4 because that is the most economical way to transport stuff long distances. Hence large civilian transports are likely j-3 or j-4.

Remember that I already said that I used j-3 because it was the standard Brandon C was using in the "setting" from which I took the idea for those ships.

The 3I would be pretty stupid not to move everything strategically by jump 6 tender.

Canonically Imperial core worlds use drop tank merchants and liners, and moves were afoot to upgrade the x-boat system to jump 6 using drop tanks in 1105+

The IN has had over a hundred years to re-equip its strategic transport network with jump 6 tenders.

According the "setting" Brandon C designed, it's a small ship universe (up to 6000 dtons). In such a universe, and due to the low payload a J-6 ship could have there (as Aramis so well points us), I doubt there are many battleships or transports with J-6, most of them being very specialized ones (courriers, very fast special cargo transports, maybe some raiders and scouts), but little else.

 

[aramis]

Remember that I already said that I used j-3 because it was the standard Brandon C was using in the "setting" from which I took the idea for those ships.



According the "setting" Brandon C designed, it's a small ship universe (up to 6000 dtons). In such a universe, and due to the low payload a J-6 ship could have there (as Aramis so well points us), I doubt there are many battleships or transports with J-6, most of them being very specialized ones (courriers, very fast special cargo transports, maybe some raiders and scouts), but little else.

Note that numbers are worse in Bk2 and MGT 1 & 2 ... 2.5% per Jn instead of (1+Jn)%...

So if you're building a setting on the MGT drive paradigms, it will be worse.

 

[AnotherDilbert]

The Imperium can afford it.

If you want to postulate infinite resources, riders with J-6 tenders makes more sense.

By canon strategic reserves is supposed to be riders.