Starships Versus Tanks

[Ran Targas]

^ I think y'all are giving way to much credit to the starship designers and not enough to the tank designers and weaponeers. This is like trying to detect a sub with a fish finder; sure you can do it but guaranteed it's too late!

The sensor package on a Type S is presumably the best available to civilians. I would argue that these sensors are not designed to deal with terrain hugging targets nor are they designed to see thru active jamming and countermeasures. How is the scout going to lock on to his target when he can't see it thru sensor blinding aerosols, false targets? Can Type S sensors see thru hills?

This is a future battlefield we are talking about, not WWII. Any advance made in the civilian market would be several years behind the military equivalent.

I would even go as far as to say that a 3I military vessel with an experience captain could go almost unnoticed by a civilian ship if visual contact was not made.

 

[Piper]

The weapons, armor and sensor stats for ships and grav tanks are published. We're not pulling these out of the air or making judgement calls based on biases and personal preference.

The fusion gun on a Trepida can almost shoot through a Type-S. Every single hit is going to penetrate the hull. Starships are buffered by huge fuel and cargo spaces, so a number of hits will hit non-critical area. Those hits that do get home will cause major damage.
4 or 5 Trepidas could quite easily destroy a small starship, especially if it comes in high.

There will however, be a cost.

Starships aren't some kind of rusted out tramp steamer with an ancient Vickers gun strapped to a railing. The weapons they mount are enormously powerful by planetary standards. Every shot that hits a Trepida will penetrate and since tanks have less room to spare, almost every shot will hit something vital.

Starship sensors can see through hills. That's what neutrino sensors and densitomiters are for.

CT made a distinction between civilian and military sensors, but even civilian ones are capable of picking a target out thousands of miles away and against the background noise of a planet. MT eliminates this distinction in large part and virtually all sensors are available to anyone.
And starship sensor ranges are literally astronomical.

Personally, I wouldn't want to try to take a small ship against a number of grav tanks in any version of Traveller. By the same token, I wouldn't relish taking on a ship with a platoon of tanks, either.
It's like wolves on a moose. The wolves will probably win, but they'll surely pay a price.

 

[graden1]

One other little problem for the starships....

I don't have my books with me (which version? pick one.) but in most cases, IIRC, aren't starship weapons designed for a lower rate of fire than those on military vehicles? Perhaps someone on the board could check into that, while we're on the subject. What's the ROF of a shipboard laser vs. a tank's laser cannon, etc?

Many thanks,

XO

 

[Scott Martin]

Yes, starship weapons have a (significantly) lower rate of fire.

But do you want to be the "lucky" grav tank commander who eats the 250MJ laser pulse, so that your friends can blast the ship out of the air before that monster laser recycles?

Personally if I were in command of the scout ship I'd send down a forward observer or three and have them call down orbital fire from beyond the range of the Grav Tank guns. Historically Armour has had a lot of trouble dealing with Guerilla (or recon) units that have refused to engage them.

"I say we fall back and Nuke the entire site from orbit... it's the only way to be sure"

Scott Martin

 

[Fritz_Brown]

Oz has the best answer for Selunatic's conundrum, though: it should hurt, but not be quite as lopsided as some are saying. It should hurt in such a way that the players feel almost sure they aren't going to make it.

I like the rescuee utrning to rescuer bit, unless it's a PC ship - that could be an expensive plot twist.

 

[far-trader]

OK, still no mention of one little issue so here goes. As long as you keep calling them tanks I have to point out that they can't touch my ship, period.

They just don't have the elevation of the main gun to engage as long as I stay over them, and my turret can engage them from above easily.

Now you'll all be "But they are Grav tanks! They can fly!" And so you shouldn't be calling them tanks I'd say. Every depiction of Grav tanks shows them barely able to maintain a hover. Even the detailed armor versions prove that they don't engage in 3D combat or they'd have more equal armor facings.

Nope, I'll sit up here in my type-S for a month of continuous lasing. How long can your tanks take that or hide?

The threat will come from something else while the ship is in the sky, or the tanks will have to wait until the ship lands to pick up the person on the ground.

If I were the army commander and the tanks are my only resource to engage the ship, they'd be sitting quiet, dug in and invisible ready to lay down saturation fire from many angles on the landing site.

One further note. I don't for a second buy into the idea that ship weapons only fire once per space combat turn. That's an artificial game mechanic. Each combat turn represents a constant barrage of the projected target position out to a couple light seconds and accounting for it's entire possible manuvering within that cone. The one "shot" per combat turn abstraction is the odds that you'll actually hit with one of those beams or pulses.

If we engage a tank and ship they each get to trade an equal number of shots until they run out of ammo. Oh, and my ship has enough fuel and energy for 4 weeks of slagging your tanks. How many EPG rounds does your tank have for it's main gun? Oh, it's fusion powered too. Great, that makes targetting so much easier for my ship!

 

[Piper]

Ship laser rate of fire:
MegaTraveller: 30 rounds per minute
Striker: not specified, but beam lasers can engage 2 targets every phase (15 seconds) and pulse lasers 1 per phase. Hit bonus indicates a rate of fire consistent with MT.

These figures are specifically for in-atmosphere, personal and vehicle scale combat.

 

[far-trader]

So you're saying a ship laser gets 30 shots vs 8 shots from a tank laser? Hardly seems fair calling it a fight

 

[Piper]

At least one version of the Trepida in MT is armed with a rapid-pulse X fusion gun. That sucker has a ROF of 80!

Individual shots are lumped together to create an autofire bonus and number of targets engaged, just like pesonal weapons.

 

[mike wightman]

I agree with Dan - the imagery we've got for high TL "grav tanks" is a bit suspect.

According to Mercenary the TL11 grav tank has "pronounced free flight capability".
By TL12 "all grav vehicles haave sufficient free flight performance that ground combat vehicles effectively no longer exist..." the word gunship is used in place of tank.
By TL15 "gunships... are virtually indistinguishable from orbital craft."

 

[Andrew Boulton]

Most likely, whoever shoots first wins.

 

[Chuck Anumia]

I have Three Questions about Grav Tank Emissions

1) What "Sound" would you hear on the ground from a Grav tanks Engine/Anti Grav equipment?

2) What Fuel Emissions would it produce?

3) What Electronic Emissions would it produce?

Thanks

 

[Andrew Boulton]

1. a hum

2. none?

3. very little

 

[Chuck Anumia]

Originally posted by Andrew Boulton:
1. a hum

Heard about how far away do you think?
10 meters or less?
20 meters?

Originally posted by Andrew Boulton:
2. none?

Really? That would be Very helpful.

Originally posted by Andrew Boulton:
3. very little

Signature = Very Small?

Thanks!

 

[Ran Targas]

Okay, y'all will have to excuse me for being a CT purist and not a fan of all this city-fied Traveller. And since I'm obviously way off in my assumptions about starships and grav tanks, I have a few questions I need answered:

1. How much attentuation occurs in starship energy weapons (lasers) when fired in an atmosphere? with smoke, aerosols, and chaff floating in the atmosphere? with smoke, aerosols, and chaff designed to attentuate battlefield laser floating around?

2. Do grav tanks carry ablative or reflec style armor to contend with battlefield lasers (mounted or man portable) or do they just ignore this obvious threat?

3. In addition to physical countermeasures, do grav tanks carry sensor decoys and ECM packages to prevent missile and targetting sensor lock on?

4. What is the maximum elevation for a Trepida fusion cannon? Can the Trepida engage low flying air or spacecraft? What about those attempting to use the terrain to mask their approach to a downed crewman?

5. What is the maximum agility attributed to a Type S or A1 in a standard, Terra norm, atmosphere? Can a Trepida engage such a high performance aircraft? With only civilian grade sensors to defeat military grade targetting sensors?

6. If a shipboard laser is basically a horizon to horizon weapon, what is the max range of a Trepida's main gun? What is the damage at maximum range? Is it enough to punch a fist sized hole in a Type S, burn thru to the cockpit, and flash fry the pilot? What about the 10th time it's hit?

7. How big a target does a hull down Trepida present? Is it detectable from orbit or during an extremely high speed pass on the way to save a stranded crewman? Is it possible the wide-eyed gunner, looking for more obvious targets, may not even detect a hull down Trepida?

8. Is the Trepida ever escorted by anti-aircraft artillery or missile launchers? Nah ...

If I were the GM, now would be the time I look at you and say, "Roll two six siders ... please"

 

[parmasson]

y'all will have to excuse me for being a CT purist and not a fan of all this city-fied Traveller.

Damn right, damn kids and their fancy Traveller.

1. How much attentuation occurs in starship energy weapons (lasers) when fired in an atmosphere? with smoke, aerosols, and chaff floating in the atmosphere? with smoke, aerosols, and chaff designed to attentuate battlefield laser floating around?

Gravitic Focusing = not much (at least not enough to count)

My starship has a big ole fusion plant how about yours.

Ran You forgot a couple

Do grav tanks carry meson screens?

How about that P.A. for three hits and +2 to hit.

 

[Scott Martin]

Some Comments of note:

1) The type S scout is not a "civilian" design, and carries fairly high-end sensors for survey work, which just happen to be usable as military sensors.

2) A Grav Tank carries a multi-megawatt powerplant. This is going to need to radiate a mother of a lot of waste heat, even if the plant itself is 100% efficient.

3) Big nuclear plant = easy neutrino detection

4) The 3I has fairly effective gravitic anomaly detectors, which should be able to localize a high performance grav tank fairly easily.

5) Most Grav tanks are probably not designed to directly engage space targets (Plasma weapons are *crappy* space weapons, and have *very* short ranges. That said, if a scout gets within the engagement envelope of a grav tank it will know it's been in a fight.

Note that 3 and 4 are "see through hills" kind of detection, If you know what kind of thermal output you're looking for, you can probably use thermal to spot "hull down" tanks.

If it were me I'd comm the (probably mercenary) commander of any high tech forces in the area and tell them that any units in grid square "XXX" will be subject to orbital bombardment for the next 48 hours: clear out or suffer the consequences. This is *very* Traveller IMHO, and it would certainly be in a merc commanders best interests to not throw away his units for no gain.

Of course if he can figure out *why* you want that grid clear, then he will have a nice handle to bargain with you for orbital fire support...

Scott Martin

 

[parmasson]

5. What is the maximum agility attributed to a Type S or A1 in a standard, Terra norm, atmosphere? Can a Trepida engage such a high performance aircraft? With only civilian grade sensors to defeat military grade targetting sensors?

Atmospheres are very thin compared to the vastness of space. Why would a spaceship fight in that thin 10 mile deep danger zone when it can fire at an altitude of say 50,000 miles in space and have little chance of being hit?
2 gees does not sound like very much in Traveller terms but that is damn fast. You can reach orbital altitudes really fast, 60-70 seconds IIRC

Of course all of this relies on the tanks working ALONE. Something I would think they would never do on purpose. Characters on the other hand quite frequently work alone.

 

[mike wightman]

As I posted yesterday, in CT LBB4 the "grav tank" ceases to exist at TL11. By TL12 they are referred to as gunships.
The TL15 Trepida in CT terms should be a gunship - not a grav tank

1. How much attentuation occurs in starship energy weapons (lasers) when fired in an atmosphere? with smoke, aerosols, and chaff floating in the atmosphere? with smoke, aerosols, and chaff designed to attentuate battlefield laser floating around?

There's an interesting graph in FF&S that shows atmospheric absorbtion of light of different wavelengths, and you can find similar by googling. Visible has the greatest penetration, but would be too easily defeated by smoke etc, so IR or microwave frequencies would be better.

2. Do grav tanks carry ablative or reflec style armor to contend with battlefield lasers (mounted or man portable) or do they just ignore this obvious threat?

TL11 grav tanks, or TL12+ gunships?

They could do, but I would imagine that they have neither, it's too easily scrubbed off using a machine gun or high explosive round before the lasers start flying about.
They would instead rely on their armour thickness for protection, plus their sand/anti laser aerosol dispensers.

Besides, ships don't appear to make use of ablat or reflec armour in CT

Note that an anti laser aerosol isn't going to be much use to a maneuvering grav tank/gunship, unless you hold it next to the hull with an EM or gravitic field - or there's always plasma armour

3. In addition to physical countermeasures, do grav tanks carry sensor decoys and ECM packages to prevent missile and targetting sensor lock on?

ECM, definitely I would say. And point defence.
CT doesn't really handle EW, decoys etc. very well. Where are they in ship combat?

4. What is the maximum elevation for a Trepida fusion cannon? Can the Trepida engage low flying air or spacecraft? What about those attempting to use the terrain to mask their approach to a downed crewman?

This is where the OTU and the CT rules diverge, just for a change. The Trepida should be a gunship. It shouldn't even look like a tank IMHO - but anyway.
The Trepida is a fully 3d maneuverable gravcraft. Its fusion gun could be a fixed mount and it could be brought to bear at any taget just by maneuvering itself.
Think of the angles of attack demonstrated by vectored thrust experimental fighters today.

5. What is the maximum agility attributed to a Type S or A1 in a standard, Terra norm, atmosphere? Can a Trepida engage such a high performance aircraft? With only civilian grade sensors to defeat military grade targetting sensors?

The Trepida is itself such a high performance aircraft - in MT it has ~ 2.5g rating on an Earth sized world. Its sensors etc. are military grade but tuned to fighting on a planetary scale, rather than the light second scale of ship combat.

6. If a shipboard laser is basically a horizon to horizon weapon, what is the max range of a Trepida's main gun? What is the damage at maximum range? Is it enough to punch a fist sized hole in a Type S, burn thru to the cockpit, and flash fry the pilot? What about the 10th time it's hit?

You have to look to Striker, MT, TNE etc. for the answer to this one - since CT doesn't have a vehicle combat system. In all of those the fusion gun can get through the scout's hull and kill the pilot - after ten such hits there wouldn't be much of a scout ship left

Since I have MT closest to hand - the range of the Trepida's main gun is up to 500km.

7. How big a target does a hull down Trepida present? Is it detectable from orbit or during an extremely high speed pass on the way to save a stranded crewman? Is it possible the wide-eyed gunner, looking for more obvious targets, may not even detect a hull down Trepida?

If it has its power plant turned down, its grav drive idling, if it is partially burried then I would make it difficult to detect. If the sensor operator is rushed then it may even be a very difficult task - depending on how well the Trepida crew did on their "digging in" task

8. Is the Trepida ever escorted by anti-aircraft artillery or missile launchers? Nah

Not needed.
It will be escorted by nuclear damper sleds, and will itself be escorting meson artillery.

Now if you really want to spoil the scout or merchant's day, target them with a battlefield meson gun

 

[jappel]

Looks like it boils down to a) what version of rules you're using, and b) how far do you want reality to intrude?

And paramount of course is c), what will make for the most fun for you & yours?

Don't get hung up in the "Can so!" "Can not!" "Can so!" stuff. The game system, in all it's flavors, departs from real science at some point (the points vary depending on the iteration). This has been true since 1977.

If grav tanks as small craft work for you, then go for it! Sounds like a clean and elegant way to deal with the issue and keep the game going.

- John