Big Guns made Realistic

[atpollard]

I'm very unhappy if weapons I want to use are described with unrealistic characteristics (eg ranges), because I'm not at liberty to ignore that, I'd have to redesign all the tables, and I don't want to buy a dog and bark myself.

If I'm paying a software developer to design a program, I expect it to be right. If I'm paying a game developer to design a game, I expect it to be right too. I'm paying you to do your homework so I don't have to. Good science fiction should add to, but never contradict, science fact.

If the latest versions have corrected these errors, fine; if not, they should.

A modern Main Battle Tank typically mounts a gun of about 120mm firing a variety of shells. I admit to only a limited knowledge of such weapons, but my basic understanding is that such a weapon has a range extending beyond the horizon. The anti-armor warheads will punch through any remotely plausible tank armor. The HE warheads have a devastating blast radius (like an entire building or a small city block). Please feel free to correct any errors in my limited understanding.

It seems safe to assume that future MBTs (including “the Far Future”) will equal or exceed these capabilities. So my question is how can such weapons (realistically rendered) be included in a Traveller game? Surely even Battle Dress cannot be better than a Main Battle Tank’s Armor, so the weapon is a one shot – multiple kill weapon. How can one play a RPG under such conditions?

I’ve heard lots of general criticism which seems valid on one level (big guns shoot VERY far) but I cannot reconcile that with the obvious play effect of “the enemy reports your position and an artillery shell explodes over your position. The squad is instantly killed. Time to roll new characters.” (Not much fun, IMHO).

So what ideas do those who want/use such weapons in their Traveller games have for balancing Reality and Playability?
What am I overlooking?
What could Mongoose do differently?

 

[mbrinkhues]

Okay:

+ The Effective range (effective = can reliably hit and damage a target) depends on the type of gun. The British rifled L11 and L30 (Challenger, Chieftain) outshoot the smoothbore Rh120 (Leopard, Abrahams) range wise

+ Explosive damage from HE shells isn't all that great. The shells have to be resonably sturdy to survive firing. The HE from a 107 or 120mm Mortar was considered more powerful than the rounds from the 105mm L7/Rh105 tank guns (Late Centurions, some M48, M60). And further reduced since tank guns are "line of sight" (firing "parallel" to the ground) reducing effects against targets behind cover

+ Blow through can occur against lightly armored targets but the round get's unstable. For the fin-stabilised rounds that quickly terminates the flight

+ Damage for KE (solid) rounds drop with range travelled/velocity on target, Damage for HE/HEAT/HESH type explosive is less effected if at all (HEAT isn't, HESH needs a minimum speed)

+ Fragmentation damage (That's what a "blast radius IRL often refers to) is easily countered. Look up the M113 APC and it's rather limited armor. Even today we have vests/helmets that give some protection against fragment. Blast damage (Actually Overpressure) is normally even less of a problem unless the weapon system is designed to make use of it (Nebelwerfer, Katjusha, some modern MLRS, the Fuel-Air / Thermobaric weapons)

+ Artillery is totally different from a tank gun. Artillery is indirect fire, non line of sight. Otoh it's an area effect weapon relying on fragmentation and that can (even today) be countered (see M113 above, Foxholes with overhead cover work also). There are guided / self guided shells (Copperhead, Stryx, Merlin) but those are rare and don't work all that great against targets on the move.

+ Rifles have performance as good as and often better than fragments

So:

Unarmored infantry doing a "Urrräääääh" charge will die if the artillery is ready for them. Otoh the same is true if they charge regular trenches

Infantry in APC and/or wearing armor will suffer losses but you'd better have a GPMG ready (The Rheinmetall MG42 comes highly recommended)

Infantry in well-build combat positions is quite difficult to dig out. Covered 2 man positions are standard in most western armies

 

[veltyen]

Okay:

+ The Effective range (effective = can reliably hit and damage a target) depends on the type of gun. The British rifled L11 and L30 (Challenger, Chieftain) outshoot the smoothbore Rh120 (Leopard, Abrahams) range wise

The real world numbers tossed around tend to be:

Effective range 120mm smoothbore (Such as the L44) with a fin stabilised round is approximately 4km.

With a guided rocket assisted munition (Russian technology) the range can get as far as 6km direct fire effective range. The caveat being that that round has less bang for greater complexity and cost.

With guided munitions (next gen warfare technology, call it the next TL or maybe the one after) then the effective range on a tank gun reaches into the 30km range. Something like the proposed 152 mm smoothbore artillery and/or direct fire weapon on the Black Eagle tank. All this with the option of tactical nuclear shells.

 

[far-trader]

Seems like a chart for horizons by world size would be helpful in determining maximum direct fire range for a (theoretical) flat terrain/seas. Just so you know when you're talking direct fire (line of sight*) vs artillery (over the horizon). Let folks fudge their own (drastically reduced or possibly significantly increased) direct/los ranges for hilly and other terrains.

* something in the neighbourhood of 5km for earth iirc, from a 5' view point

I think I've seen some guided munitions on the order of cruise missile smart and capable either proposed and/or in development. So I'd figure next TL for initial introduction and usage, common usage the TL after that. Talking tank/field artillery pieces. Maybe another TL or two beyond that for man-portable (possible BD required) versions of a recoilless rifle/bazooka size/type. Just guessing.

 

[Almuric]

A modern Main Battle Tank typically mounts a gun of about 120mm firing a variety of shells. I admit to only a limited knowledge of such weapons, but my basic understanding is that such a weapon has a range extending beyond the horizon. The anti-armor warheads will punch through any remotely plausible tank armor. [/B]

Modern tank armor has kept up with tank guns. While the side armor is easily penetrated, the front turret and hull armor on a main battle tank is equal or better to the penetration of the best main gun ammunition. In general, if you get a good shot you can hit a weak area, knock out the gun, etc. But there's a very good chance that a 120mm tank gun's APFSDSDU round with a penetration of about 600-700mm of steel equivalent will bounce off the front armor of a latest-generation LEO 2 or Abrams which has an equivalent resistance of 600-700mm (and often 900-1100mm vs. HEAT). Of course, the race is close: tanks are continuously upgraded with better variations of the armor and better models of penetrating rounds.

Traveller assumes continued development of advanced armor types e.g., crystaliron, superdense, bonded superdense, etc. keeping pace with advances in energy weapons (plasma gun/fusion gun). As such, it's reasonable to assume this will continue: a tank's frontal armor will be a match for standard tank weapons, while the side armor will be vulnerable. This is good news for PCs, who can sneak up in their chameleon combat suits and try to ambush a tank by firing a shoulder-fired rocket or whatever from a few dozen meters away...

HE shells (and even 155mm artillery) will destroy a building if they hit. Against troops in the open who have no armor or the kind of partial body armor we have now, they, or the more effective cluster munitions (ICM) are quite dangerous. Against troops taking cover, they are less dangerous.

Against Traveller troops with bull-body sealed combat armor (or battledress), however, HE or ICM rounds are not very dangerous at all. The rigid sealed armor will stop the fragments and blast, so you have to hit within a few meters to take out a soldier, and of course an infantry formation will disperse over several dozen meters when under bombardment. Battledress and combat armor make future tube artillery less dangerous (I imagine that's why they switch to things like rapid pulse plasma guns and meson weapons).

 

[tbeard1999]

A modern Main Battle Tank typically mounts a gun of about 120mm firing a variety of shells. I admit to only a limited knowledge of such weapons, but my basic understanding is that such a weapon has a range extending beyond the horizon. The anti-armor warheads will punch through any remotely plausible tank armor. The HE warheads have a devastating blast radius (like an entire building or a small city block). Please feel free to correct any errors in my limited understanding.

Effective range for modern (i.e. TL 8) MBTs with 120mm guns will be about 2.4-2.7km, when firing kinetic energy rounds (i.e., armor piercing fin stabilized discarding sabot [APFSDS]; basically a tungsten or depleted uranium dart), with laser rangefinder and digital ballistic computer. At that range, a 50% hit probability is reasonable. At 3.6-4 km, the hit chance drops off. Hits outside of 4km are extremely unlikely (though there are occasional reports of hits at that range). A modern MBT would be unlikely to engage at greater ranges due to the virtual impossibility of a hit and ammo limits. While the projectile can probably fly a lot further, this is the maximum effective range at TL 8.

Don't have HE blast radius handy, but it's lower than your estimate. A typical 120mm round is 22.3 kg; 7.1 kg is the high explosive part of the warhead (about 4kg is warhead casing).

We're already reaching a plateau IMHO on direct fire unguided ranges. At extremely long ranges, even the most minute factors (like wind along the projectile's path) can cause a miss. Also, as a practical matter, few battlefields will offer many opportunities for line-of-sight engagements at 4km+.

A new generation of guided projectiles are coming into service (maybe if funding survives) that will extend engagement ranges to 8-13km. These are essentially gun fired guided missiles. They are slower and are "non line of sight" (NLOS) systems, which makes them vulnerable to active defenses. They are also *very* expensive compared to normal tank shells.

IMHO, TL9+ armored combat will be largely a battle between long range NLOS weapons and point defense systems, followed by a shorter ranged battle between LOS weapons and tank armor.

Mass Drivers should allow tanks to carry far more ammo, especially if the power requirements are more modest. Railgun ammo is also not prone to exploding when the tank is hit.

It seems safe to assume that future MBTs (including “the Far Future”) will equal or exceed these capabilities. So my question is how can such weapons (realistically rendered) be included in a Traveller game?

Absolutely. Search the CT forum for CT rules to use MBTs through TL15. If CT can handle it, MGT certainly should be able to.

Surely even Battle Dress cannot be better than a Main Battle Tank’s Armor, so the weapon is a one shot – multiple kill weapon. How can one play a RPG under such conditions?

Infantry armor will *never* exceed the front armor of MBTs; the physics simply aren't there (too much surface area on a human being compared with an MBT; it's why also why mecha will never be able to defeat tanks).

However, infantry armor should be geared to defend against infantry weapons, not tank weapons. Tank armor is geared to defend against tanks.

I’ve heard lots of general criticism which seems valid on one level (big guns shoot VERY far) but I cannot reconcile that with the obvious play effect of “the enemy reports your position and an artillery shell explodes over your position. The squad is instantly killed. Time to roll new characters.” (Not much fun, IMHO).

The answer is that you have to rig the game so that it's fun, and only passably realistic. I'm doing this with the first planned supplement to my Fistful of TOWs 3 rules. FFT:2030 covers armored combat in the mid-21st century. In reality, I think that armored combat will be very boring -- track it, kill it, move to next target. I also doubt that combat hovercraft will be viable. BUT...I want a fun game and I want to use the cool hovercraft models dammit, so I will put my finger on the scales.

So what ideas do those who want/use such weapons in their Traveller games have for balancing Reality and Playability?
What am I overlooking?
What could Mongoose do differently?

Ask the CT grognards how to run military campaigns.

In addition, make sure that the military tech in MGT is plausible and reasonable.

 

[tbeard1999]

The real world numbers tossed around tend to be:

Effective range 120mm smoothbore (Such as the L44) with a fin stabilised round is approximately 4km.

According to our research for FFT3, this is more like the maximum engagement range (and the hit chance is pretty low). 2.4-2.8km is more like effective range (~50% hit chance).

With a guided rocket assisted munition (Russian technology) the range can get as far as 6km direct fire effective range. The caveat being that that round has less bang for greater complexity and cost.

The Russian 125mm AT rounds are also incapable of penetrating the front armor of modern Western MBTs (claims to the contrary notwithstanding).

Warhead diameter is the most important indicator of penetration for High Explosive Armor Piercing rounds, with liner material being second. Western 155mm missiles cannot penetrate the front armor of the M1A2HA or the Leopard 2A6, so smaller Russian missiles surely can't do it.

With guided munitions (next gen warfare technology, call it the next TL or maybe the one after) then the effective range on a tank gun reaches into the 30km range. Something like the proposed 152 mm smoothbore artillery and/or direct fire weapon on the Black Eagle tank. All this with the option of tactical nuclear shells.

152mm rounds will be extremely heavy, especially if they are hyper velocity rounds. Autoloaders will be required, which have generally not been optimum. They are slower than human loaders and mechanically cranky. They do allow smaller profile (thus heavier armored) turrets, but this brings a host of habitability issues.

Note that the US M551 Sheridan and M60A2 had a 152mm gun/missile launcher. The rounds were (barely) capable of being man-handled because they were low velocity rounds and therefore much lighter than hyper velocity rounds of the same size. These tanks are generally considered failures for familiar reasons - expensive ammo, maintenance issues, low rate of fire.

As noted in a previous post, the theoretical range of projectiles is FAR higher than their effective range. And I am unconvinced that guided missiles will rule the future battlefield, due to cost, lengthy engagement time and vulnerability to countermeasures. Plus, they're boring

At the end of the day, I expect that evenly matched opponents will wind up slugging it out in line of sight engagements. And as noted, most terrain will present few opportunities for engagements at 4km range.

The Cold War Soviets planned for the majority of tank battles to be fought at 1km range or less. I seriously doubt the accuracy of this assumption, but I've studied Western Europe's terrain a lot in my decades as a modern wargamer. In Germany, there would have been relatively few shots at greater than 2km.

 

[far-trader]

On the los horizon issue, if anyone is interested, I was sure I had done up a table or found one ages ago. After looking (briefly) I couldn't find it. But it's pretty easy to recreate (just naturally lazy looking first to avoid some basic math ).

So, for a typical human height observer the distance to the horizon (not factoring a mess of things like actual slopes and atmospheric lensing and such, i.e. good enough for a game) a basic table of standard world sizes and distance to horizon (in Km):

World   Horizon
 Size      in km

  1          1.6
  2          2.3
  3          2.9
  4          3.3
  5          3.7
  6          4.0
  7          4.4
  8          4.7
  9          4.9
  A          5.2

Mostly useful for sea engagements, limited use for open plains engagements.

If you want to figure it for different observer heights (a tank on a hill, a target on a hill, that sort of thing) the basic formula is:

H = squareroot of (D x E)

Where H is the distance to the Horizon, D is the Diameter of the world (presumes sphere and "flat" terrain), and E is the Elevation of the observer.

So for example, a tank on a 200m high hill commands line of sight to the horizon on a size 5 world out to:

H = squareroot of (8000km x 0.2km)

H = squareroot of (1600km)

H = 40km

(likewise, someone 40km out on that plain has a los to that tank on that hill :smirk: )

Works for flying (i.e. grav or hover) tanks too, just put in the flight altitude as E

 

[tbeard1999]

Modern tank armor has kept up with tank guns. While the side armor is easily penetrated, the front turret and hull armor on a main battle tank is equal or better to the penetration of the best main gun ammunition.

FWIW, our research for A Fistful of TOWs shows that the 120mm Rheinmetal smoothbore *can* defeat the front armor of any other tank at effective range -- 2.4-2.8km depending on barrel length and ammo type. This assumes the latest generation of APFSDS penetrators (tungsten or depleted uranium).

Of course, no tank has a completely homogenous armor thickness across its front arc. The mantlet, for instance, will usually be better armored than the lower hull. And the latest versions of the Abrams and Leopard II have been forced to emphasize turret armor at the expense of hull armor. So the turret may be relatively invulnerable, but the hull assuredly is not. WWII German experience was that 2/3 of hits were against the turret, so it's statistically more efficient to armor the turret. The turret also has lower surface area, so armor protection is maximized. Assuming, of course, that the German WWII data is still valid now.

In general, if you get a good shot you can hit a weak area, knock out the gun, etc. But there's a very good chance that a 120mm tank gun's APFSDSDU round with a penetration of about 600-700mm of steel equivalent will bounce off the front armor of a latest-generation LEO 2 or Abrams which has an equivalent resistance of 600-700mm (and often 900-1100mm vs. HEAT).

Our research indicates that the US M829A3 APFSDS round will penetrate 82cm-95cm of rolled homogenous steel armor at effective range (~2.6 km). To illustrate what I was talking about above, here are the estimates for the front armor of the M1A2SEP (vs KE):

Front Turret: 92.5-99.1 cm
Front Glacis/Hull: 55-62cm

So obviously, a hit from the M829A3 will go right through the glacis, but probably won't penetrate the turret.

Russian tanks tend to have a much wider range of protection. Compare the T-80U:

Front Turret: 25-60cm
Front Glacis/Hull: 49-53cm

Oh, and to show how much tank armor has improved since TL5 (WWII):

PzKpfw V Ausf. G Panther
Front Turret: ~14.5cm on average
Front Glacis/Hull: ~17.5 cm on average
(HEAT protection ~5cm less)

However, a tank can be knocked out of action by far less damage than a penetration of armor. The gun barrel can be hit. The sighting system knocked out. A track damaged. The turret jammed. Etc.

Traveller expects for tanks to generally be able to defeat contemporary tanks' armor, based on my review of Striker and Traveller literature over time.

 

[tbeard1999]

Seems like a chart for horizons by world size would be helpful in determining maximum direct fire range for a (theoretical) flat terrain/seas.

I seriously doubt that this will be used much in realistic engagements. As noted, few terrains on Terra, circa 2010 AD, will allow many shots at 4km. The horizon is far longer than that.

Also, the horizon won't be particularly relevant to non line of sight weapons.

But here's a nifty calculator if you're interested -- http://radarproblems.com/calculators/horizon.htm

 

[atpollard]

Ask the CT grognards how to run military campaigns.

I am ...

Using CT: LBB4 (Mercenary)

At TL9, my MBT mounts a Heavy Mass Driver able to launch 10 shots per combat round a range of 24 kilometers with a blast radius of 35 meters per shot. Each round hits all characters within the 70 meter diameter blast radius with 6D of damage on a roll of 7+.


A TL 14 Infantry is outfitted with the best Battle Dress and FGMP-14 and able to launch 1 shot per combat round to an extreme range of 1500 meters and inflicting 4D6 (extreme range) damage to 1 target on a roll of 5+.


I admit that I am fuzzy on the whole cavity-A and cavity-B armor for vehicles, but at a first glimpse, even a single TL 9 tank should drive SOTA TL 14 infantry from the battlefield. Artillery seems to me to utterly negate all RPG scale actions. Looking only at damage per round, the tank does 60D6 (ignoring overlapping damage from blast radius) and the FGMP does 4D6 – that alone means that 1 tank offsets 15 FGMP/Battle Dress Infantrymen. The range advantage makes it even worse.

Could someone paint me a Traveller scenario involving Players and Artillery?

 

[tbeard1999]

I am ...

Using CT: LBB4 (Mercenary)

At TL9, my MBT mounts a Heavy Mass Driver able to launch 10 shots per combat round a range of 24 kilometers with a blast radius of 35 meters per shot. Each round hits all characters within the 70 meter diameter blast radius with 6D of damage on a roll of 7+.


A TL 14 Infantry is outfitted with the best Battle Dress and FGMP-14 and able to launch 1 shot per combat round to an extreme range of 1500 meters and inflicting 4D6 (extreme range) damage to 1 target on a roll of 5+.


I admit that I am fuzzy on the whole cavity-A and cavity-B armor for vehicles, but at a first glimpse, even a single TL 9 tank should drive SOTA TL 14 infantry from the battlefield. Artillery seems to me to utterly negate all RPG scale actions. Looking only at damage per round, the tank does 60D6 (ignoring overlapping damage from blast radius) and the FGMP does 4D6 – that alone means that 1 tank offsets 15 FGMP/Battle Dress Infantrymen. The range advantage makes it even worse.

Could someone paint me a Traveller scenario involving Players and Artillery?

Let them be a forward observer team calling strikes in on enemy infantry, per typical US operations in Vietnam. Maybe the ECM environment (or EMP environment) is such that drones are unreliable. Maybe doctrine requires humans to call in artillery -- too many friendly fire incidents. Such teams are small, but heavily armed for self defense. Problems include spotting enemy columns, running into enemy patrols, etc. A really bad Fwd Obs roll might mean that you accidentally input your coordinates (actually happened in real wars). To keep them from being annihilated, maybe the battle computers caught it, but only after a few rounds were fired. Faulty high tech gear might require more primitive measures to spot artillery. They can blunder into a minefield. Maybe their extraction chopper/air raft gets shot down (or they have to fight their way to the LZ).

Ditch the idea that infantry of any tech level can carry enough armor to shrug off even a TL6 heavy tank shell. Per Striker, even TL14 battle dress can be popped open by an RPG-7.

Maybe they run into an armored column that HQ doesn't believe is really there. And the artillery available only has cluster bomb munitions -- great vs infantry, relatively ineffective vs armor.

Forget the rules; the values for tanks and such are probably defective (I don't have the Mercenary reprinted edition; but that's the intelligence I get). Allow infantry portable FGMP/PGMPs to penetrate the flanks and rear of MBTs at close range. Hit them with light tanks -- front armor roughly what the flank armor is on an MBT. Give them a few manportable AT missiles -- 1000m range, hypervelocity, jamproof, etc. But only a few, and not as many as the enemy has tanks.

Just a few random thoughts.

 

[far-trader]

Very nifty...

But here's a nifty calculator if you're interested -- http://radarproblems.com/calculators/horizon.htm

...and handy. Thanks

 

[far-trader]

...Ditch the idea that infantry of any tech level can carry enough armor to shrug off even a TL6 heavy tank shell.

I often wondered how even those who imagine their BD will protect them from the penetration and/or explosion can justify that they won't be kicked several yards(?) from the kinetics or blast force alone

Have they not seen the kick the main gun on a tank throws into the multi-ton tank? Or do they not imagine that same kick hitting a fractional-ton person in BD is going to do much much more? Not counting what happens inside that armor (barring the gel layer absorbing most of the shock of impact )*

Would you have a handy calculator handy for that tbeard? (just hoping, no need to go digging, I like my imagination version, but validating the actual physics might be worth me doing a little digging sometime).

The force of the shell acting on the mass of a human in BD with no bracing to speak of (i.e. standing) should be 'interesting'. I figure solid bracing (against a wall or whatever) would just mean an explosive splat anyway.

* a quote (if I didn't mess it) from Halo (the game) which I'm off to play a bit for some relaxing fragging

 

[Almuric]

FWIW, our research for A Fistful of TOWs shows that the 120mm Rheinmetal smoothbore *can* defeat the front armor of any other tank at effective range -- 2.4-2.8km depending on barrel length and ammo type. This assumes the latest generation of APFSDS penetrators (tungsten or depleted uranium).

Of course, no tank has a completely homogenous armor thickness across its

Our research indicates that the US M829A3 APFSDS round will penetrate 82cm-95cm of rolled homogenous steel armor at effective range (~2.6 km). To illustrate what I was talking about above, here are the estimates for the front armor of the M1A2SEP (vs KE):

Front Turret: 92.5-99.1 cm
Front Glacis/Hull: 55-62cm

So obviously, a hit from the M829A3 will go right through the glacis, but probably won't penetrate the turret.

Huh - cool. Hadn't been keeping track. The estimates I saw from 3-4 years ago were only about 700-750mm for the A3. Well, it's been in service for a while now, so I guess there's more data on it now... (checks ATK). Yep.

Still, many tanks with 120mm guns may not have refitted with the best ammunition and may still have mid-90s performances. (On the other hand, refitting with new ammo is cheaper than buying a new gun). I imagine that the Traveller equivalent would be even more variable with the wide TL diversity.

In general, I think it's fairly safe to say that it's possible in Traveller to build a tank that is survivable at either effective, long, or extreme range (though possibly not all three) against at least some frontal attacks from equivalent TL and tank size weaponry, but still likely to be vulnerable across other quarters.

 

[saundby]

I was formerly involved with a fair bit of arms development, I still do a bit here and there. So, a few comments from the perspective of someone who worked on a range of projects including both the smoothbore and rifled main batteries of the M-1 (XM-1 through late M-1A versions), ordnance for same and the GAU-8, naval gun propellants, TOW-2, Hawk, Sparrow, Patriot PAC 1-B & 2, and some exotic stuff like gelled propellant stuff, some DEW and fancy KEW, etc. etc.

Weapons systems are designed to perform specific missions. Advancement is not a matter of further, faster, stronger, more, etc. You have something specific you want to accomplish, and a set of constraints within which to work. So you design and build to do a specific job, not just to go as far, fast, etc. as you can. You make choices, and build to those.

Presently we are undergoing 2 or 3 simultaneous revolutions in how conflicts are fought. Extrapolations of what things are going to look like in the future are inevitably flawed because the next twenty years will surprise us, never mind centuries (I'd say the next 10 years, but the stuff in that time frame is already in the pipeline, anyone who follows the trade journals will pretty well know what that is now, though the public awareness runs years behind most deployment, and decades behind the decision-making that produces it all.)

So, the best a system can do is start by making a set of base assumptions about how conflict will be pursued, build some doctrine, then start fitting systems into that framework. The technique of taking publicly available stats for current and historical systems and extrapolating from there isn't effective. There's no real "line of progress" to follow. Advancements don't work like that.

Also, assuming present systems will be available in the future isn't effective. Every system has a body of logistics that comes with it, and sometimes a system that has better stats isn't going to persist because the tail adds too many costs, deployment problems, training problems, or whatever. Or the folks who made it are gone, recovering the techniques to make and operate it is too troublesome, and the tooling's long gone, never mind the processes themselves.

We can make and have made systems that outperform what's in deployment. What's deployed is based on a whole slew of factors, many of them not technical (e.g. which congressional district is it manufactured in.) It's also true that much money spent developing technically "superior" systems was wasted because the supposedly superior system didn't serve a real mission need. E.g. longer range terminally guided tank gun ordinance is only interesting in certain circumstances, and is a waste of time and money in others. It sounds like a sure winner, but that's what attracts money. Such things do not always justify that support. In fact, whizzy stuff most frequently does not. But every so often, somebody really has done their homework and the whizzy stuff pays off. At which point the "decision makers" are sure to ignore it until after 1-4 decades of being beat about the head and shoulders on the subject.

Anyway, find a system with some workable base assumptions and doctrine. Most of these will rely on history and add some "futuristic" tweaks to remind you you're not in Korea or Normandy. Then pick the equipment that fits. MGT doesn't have any such thing at present, so the equipment doesn't have any guiding principles for it's stats. A vehicle design system doesn't by itself result in useful weapons systems. Even in the real world.

The CT stuff blends nicely with MGT if you adjust damage to account for the effects part of damage in MGT. Frex, if you start with the assumptions of Striker, you can mix in and adjust workable equipment from the MGT lists. With such a base you can also start making your own tweaks, but beware of simply adding features just because they seem futuristic. E.g., adding a shopping list of technologies like blue force tracking, UAVs, DEWs, battlefield "Brilliant Pebbles" or "Sapient Sand", terminally guided small arms ordnance, and so on. Pick a few dominant assumptions, build from there. E.g. "Armor is king" or "Armor can't survive." "Air is death, stay close to the soil," or "Without air dominance, nothing else matters." "Space resources are largely invulnerable" to "satellites fall out of the sky if you look at them funny."

I'm hoping we'll see the reasonable coherence of the (dated but still usable) assumptions of Hammer's Slammers reflected in the MGT material for that setting.

 

[tbeard1999]

I often wondered how even those who imagine their BD will protect them from the penetration and/or explosion can justify that they won't be kicked several yards(?) from the kinetics or blast force alone

Update -- I consulted the FFT brain trust and got this response:

"Not a simple question at all. Depends primarily on how much momentum it transfers to the target, and what friction the target sees once it starts moving. Alternatively, it depends on how much energy it transfers to the target, and how that energy is partitioned between thermal energy, rotational kinetic energy, and translational kinetic energy, and again, on the friction it experiences in motion. If we assume a perfectly inelastic collision (no billiard ball bounce, but rather the penetrator embeds itself in the target and they move as one object), and we assume the projectile's velocity vector is aligned with the center of mass of the target (so no rotation is induced by the impact) then we get as worst case the following for the initial velocity:

6750000 J = 0.5 x (106kg) x V^2

So V = 356 m/s immediately after the impact, or slightly above Mach 1 at sea level...

How fast it slows down depends on too many variables to worry about: air resistance (which involves its shape and surface finish), friction with any surface it is in contact with (is it bouncing or sliding, does it start to tumble, etc)."

So obviously a non-penetrating hit from a 120mm KE round will have a dramatic effect on someone in battledress...

 

[tbeard1999]

Huh - cool. Hadn't been keeping track. The estimates I saw from 3-4 years ago were only about 700-750mm for the A3. Well, it's been in service for a while now, so I guess there's more data on it now... (checks ATK). Yep.

Don't feel bad. A lot of information has come out in the last few years and it's sometimes shocking just how wrong the experts were. We've revised *every* vehicle and weapon for FFT3 (which means thousands of lines of data).

Still, many tanks with 120mm guns may not have refitted with the best ammunition and may still have mid-90s performances. (On the other hand, refitting with new ammo is cheaper than buying a new gun). I imagine that the Traveller equivalent would be even more variable with the wide TL diversity.

Absolutely agree. That can have interesting ramifications in play. Maybe the enemy starts out with crappy ancient ammo that's relatively ineffective, but gets resupplied with the latest stuff.

As an example, we estimate that the original US M829 120mm penetrator had ~57cm RHA penetration at effective range. The latest M829A3 has ~88cm penetration. That's a 54% improvement in only 30 years. Of course, this won't continue indefinitely. Each gun has limits and the 120mm was new 30 years ago.

By contrast, the Russian 125mm BM-9 penetrator in the late 1960s had 25 cm penetration. The latest BM-42M has 62 cm penetration. We think that the Russian 125mm gun is approaching its limits, but you can see that it more than doubled in penetration over its life. (By the way, that's something that most wargames miss -- penetrator performance improves significantly. As far as I know, my Fistful of TOWs rules are the only rules that detail this).

Also note that locally produced rounds can be dramatically inferior. Iraq armed its T-72s in 1991 with locally produced versions of a Russian penetrator. However, instead of using Tungsten (hard to machine and expensive), they used steel. Result -- far crappier performance. (Of course, even the Russian rounds wouldn't have done much against the M1A1's front armor package). And light tanks are vulnerable period.

It's also useful to note that most tanks are still highly vulnerable to flank/rear/top shots. I recall a Fistful of TOWs game that a guy ran at a convention called "Marines vs Mexicans". He had a US Marine task force attacking a Mexican army position. The Mexicansa had WWII era tanks and armored cars while the Marines had LAVs and some M1A1s. The Marine player got a nasty surprise when the ancient WWII tanks killed his M1A1s with flank shots...

In general, I think it's fairly safe to say that it's possible in Traveller to build a tank that is survivable at either effective, long, or extreme range (though possibly not all three) against at least some frontal attacks from equivalent TL and tank size weaponry, but still likely to be vulnerable across other quarters.

Agreed. And as can be seen from the M1A2SEP armor package, the turret might be invlunerable, but the hull might be easily penetrated.

 

[Icosahedron]

A modern Main Battle Tank typically mounts a gun of about 120mm firing a variety of shells. I admit to only a limited knowledge of such weapons, but my basic understanding is that such a weapon has a range extending beyond the horizon. The anti-armor warheads will punch through any remotely plausible tank armor. The HE warheads have a devastating blast radius (like an entire building or a small city block). Please feel free to correct any errors in my limited understanding.

It seems safe to assume that future MBTs (including “the Far Future”) will equal or exceed these capabilities. So my question is how can such weapons (realistically rendered) be included in a Traveller game? Surely even Battle Dress cannot be better than a Main Battle Tank’s Armor, so the weapon is a one shot – multiple kill weapon. How can one play a RPG under such conditions?

I’ve heard lots of general criticism which seems valid on one level (big guns shoot VERY far) but I cannot reconcile that with the obvious play effect of “the enemy reports your position and an artillery shell explodes over your position. The squad is instantly killed. Time to roll new characters.” (Not much fun, IMHO).

So what ideas do those who want/use such weapons in their Traveller games have for balancing Reality and Playability?
What am I overlooking?
What could Mongoose do differently?

Er, right, exactly.

I probably know less about big guns than you do, ATP, which is precisely why I pay game developers to do it all for me.

The problem arises when they haven't done it correctly and I get one of the guys above playing in my game and compaining that the rules are crap.

I can do without that sort of hassle.

The rules should be realistic. How I use that realism is what makes my game unique.


To answer your specific question, War is deadly - especially future war. But games are cinematic - even 'non-cinematic' ones. The shell hits (and eliminates) the fire team next to the PCs, highlighting their danger.

PCs fight NPCs, not artillery. The artillery shells land around them, creating a deadly background against which they are channelled (who said railroaded?) into meeting an enemy armed similarly to themselves...

 

[Klaus]

Been fiddling with some rough guidelines for things like tanks in MGT. I've kept it wide and loose so the categories are broad.

Firstly, a house rule: small arms (though not lasers) unable to penetrate beyond AT18.

An MBT will have an average armour type of 4 times TL. Some designs might have a few extra points.

Field Guns: these will be the primary MBT armament up to TL10, but will also be equivalent to artillery pieces. Modern weapons are gun/howitzers anyway, so they'll need 2 range types, one for direct fire and one for parabolic.

Size Category      DMG   Av/Max Dmg  TL for MBT turret   Av AT

60mm               5d6      19/30         5               20
90mm               6d6      23/36         6               24
120mm              7d6      27/42         7               28
150mm              8d6      31/48         8               32
180mm              9d6      35/54         9               36
210mm             10d6      39/60        10               40

So, an MBT of any particular era will on average do 1 less point of damage than that era's armour, but a good hit, with good effect, should be able to hurt it.