Big Guns made Realistic

[mbrinkhues]

Actually a howitzer and a canon are quite different today:

Canons have higher muzzle velocities optimised for LOS firing with as little drop as possible and as little wind affect as doabel. This in turn needs a thicker shell resulting in less explosives per weight.

Howitzers have lower muzzle velocities and are optimised for high angel firing. The shells are thinner-walled and can carry more explosives per weight. The most extrem is the mortar, a short-range, high angel weapon with a very good weight:explosives ratio.

The same was true in WWII, compare the german 105mm field howitzer and the 105mm AA-gun (a KwK or "tank" version was produced for the E50/E75 series prototype in late 44) in muzzle velocity and explosive content. Or the 75L24 from the early Panzer IV (rated as a howitzer by the germans) to the later 75L48.

Modern times (late WWII and past that) give howitzers some direct-fire AT capacity since HEAT shells don't depend on velocity for their armor penetration. Again a 120mm rifle (most howitzers are) will be out-perform by a 120mm smoothbore when both are firing HEAT (HEAT and rotation don't match) (1)

Field guns (like the french 75mm of WWI) and their WWII relatives the AT-guns and tank canons are a lot closer, maybe even the same. But most field guns can't fire high angel and that makes them less useful against well dug-in enemies since they can't use "plunging" fire.

For modeling armor I would add a rule that models the difference between frontal and side/rear armor at least. That way you can "kill a Kingtiger with a Ronson" without relying on luck

(1) That the (complex) britisch 120mm HEAT with spin-decoupler and the german 120mm "HEAT" for the Rh120 do about equal damage is due to the fact that the Rheinmetall's "HEAT" is actually a HEDP (Dual Purpose) that can be used as a HE or a HEAT while the Brits have a HEAT and a HE (and a HESH, good for urban renewal)

 

[CosmicGamer]

Good info here, but I think it is fairly outdated to talk about WWII weaponry. Yes, there are lessons to be learned from the past, but I think things have changed a lot in just the last 200 years. I'm sure they will change a lot more in the future.

Found it. An old post of mine.
http://www.travellerrpg.com/CotI/Discuss/showpost.php?p=268769&postcount=27

I believe tanks should be more capable than a small group of infantry. They have the capacity for more armor and more weaponry. The disadvantages possibly being stealth and maneuverability.

I believe tanks are also becoming obsolete in 'war', easily taken out by aircraft. They are going the direction of troops, used more often now for police actions and checkpoints.

 

[Klaus]

Actually a howitzer and a canon are quite different today:

Well indeed. I was going from the wiki entry actually.
http://en.wikipedia.org/wiki/Howitzer#20th_Century (go to the last para of that section)

I have no experience with weaponry whatsoever, though I try to read widely on the topic to help my games.

However, how much detail can an rpg handle before it becomes over fussy or unbalancing? I don't need a wargame to run an rpg campaign, and, given that this is in the MGT section, there's only so many categories to have.

 

[Whipsnade]

However, how much detail can an rpg handle before it becomes over fussy or unbalancing? I don't need a wargame to run an rpg campaign, and, given that this is in the MGT section, there's only so many categories to have.

Klaus,

In good game designs, either RPGs or wargames, such attention to detail occurs "off stage". The designers are fully aware to the many important, yet fiddly, details and take pains to ensure that the actions and consequences of such details in the design itself.

This means the details' "meanings" are "blended" into the rules, rather than the details themselves becoming rules.


Regards,
Bill

 

[Klaus]

Klaus,

In good game designs, either RPGs or wargames, such attention to detail occurs "off stage". The designers are fully aware to the many important, yet fiddly, details and take pains to ensure that the actions and consequences of such details in the design itself.

This means the details' "meanings" are "blended" into the rules, rather than the details themselves becoming rules.


Regards,
Bill

Well that's what I'm talking about, really.

 

[mbrinkhues]

Well indeed. I was going from the wiki entry actually.
http://en.wikipedia.org/wiki/Howitzer#20th_Century (go to the last para of that section)

I have no experience with weaponry whatsoever, though I try to read widely on the topic to help my games.

However, how much detail can an rpg handle before it becomes over fussy or unbalancing? I don't need a wargame to run an rpg campaign, and, given that this is in the MGT section, there's only so many categories to have.

Thanks for the link. The key word in the last para is "Artillery". Yes, for artillery this is true, differences between canon and howitzer there are basically gone. Except for guns in third/second world countries(1) the only remaining true "field canons" are the Russian "Rapira" and Sprut series of heavy towed AT guns and some superheavy guns dereived from naval artillery

If you ever get the chance to visit a current generation Self-Propelled howitzer (PzH2000, M109A6 Paladine, AS90 Braveheart etc) doing "self defence/AT work" do so. It's quite impressive what some guns can do to the poor old M48A2

=====================

As for the level of detail I agree with Bill, a lot of that should be "in the rules". Some possibilities:

a) Have one type of gun only but use different mountings. So "Gun, 105mm, low angel mount" is the tank/AT gun, "Gun, 105mm, high angel mount" is the Artillery and "Tank, 105mm, universal mount" is the modern system. One gun but three mounting options with different prices.

b) Have only two classes of weapons "Direct fire/canon" and "Indirect fire/artillery" and ignore the dual-purpose.

c) One of the above and add some ammo types. Make it easy, say Explosive(HE), Antitank (AP), Anti-Personal (Fragment/Shrapnel) and maybe (post TL5) HEAT (AP)


Unless you go GURPS/Vehicles 2e or FFS you won't get a system that will find the applause of the wargamers. And those can be too complex. So drop any "specialist" or "rare" stuff (Direct fire/AT capabilities in howitzers are "self defence/we are so screwed" capabilities anyway) Do "just enough" details.


(1) In the Yugoslavian breakup "wars" you could see a lot of the WWII classics going into battle one last time, mostly Sowjet stuff.

 

[tbeard1999]

Good info here, but I think it is fairly outdated to talk about WWII weaponry. Yes, there are lessons to be learned from the past, but I think things have changed a lot in just the last 200 years. I'm sure they will change a lot more in the future.

Found it. An old post of mine.
http://www.travellerrpg.com/CotI/Discuss/showpost.php?p=268769&postcount=27

I believe tanks should be more capable than a small group of infantry. They have the capacity for more armor and more weaponry. The disadvantages possibly being stealth and maneuverability.

I believe tanks are also becoming obsolete in 'war', easily taken out by aircraft. They are going the direction of troops, used more often now for police actions and checkpoints.

Folks have been confidently predicting the end of the tank since 1918. Hasn't happened yet...

 

[mbrinkhues]

Realistic (IMHO) means that (assuming same TL)

+ Rifle vs. tank => You have just angered the tanker by scratching his paint job. He engages his co-axial Maschine gun and cuts you in half

+ GIMP vs. tank => More scratches. As above but after that he drives over your foxhole and squished your corps

+ RPG vs. tank => Can put a hole in the flank/top/rear and kill the tank. Might put a hole in the front

+ ATGM vs. tank => As above with longer ranges and/or more control

+ Tanks vs. tank => Might kill each other from the front. WILL kill each other from side/rear

+ Tank vs. light tank => Will kill the light one from any side. The light one might kill the heavy from the side/rear

+ Artillery vs. Charging, unarmored infantry => Lots of telegrams to the mother/wife

+ Artilley vs. Charing infantry in BD or riding lt. tanks => Some telegramms but the Artillery better starts moving otherwise it will die

+ Artillery vs. tanks => Unless using special ammo see Rifle vs. tanks

+ Artillery vs. Infantry in prepared cover => See infantry in BD/lt. tanks

+ Tank vs. BD => IF the tank can land a hit on the BD thats one dead BD.

+ lt. Tank vs. BD => The tank has better chances to land a hit but the hit may not come through




with

BD = Battledress

Tank = A first line battle tank like the Leopard II or M1A1

Rifle = Any shoulder weapon issued to the majority of ones soldiers i.e. an M16 or Mauser 98K. NOT a .50 or bigger specialist weapon

GIMP = General Purpose Maschine Gun with a rifle (s.o) caliber like the MG42. NOT a large caliber system like the Browning M2

RPG = An unguided AT-weapon using whatever to penetrate armor (IRL normale a HEAT type shaped sharge)

ATGM = A guided AT weapon

lt. tank = Anything from the M551 Sheridan to the various IFVs like Marder/Puma/Bradley

 

[mbrinkhues]

Folks have been confidently predicting the end of the tank since 1918. Hasn't happened yet...

Actually tanks are currently gaining some abilities against airborne threads. Besides the classical ones like bringing gun/missile armed AA tanks (Gepard, Roland, ZSU23-4, Tsunguska etc) that can fire on the move.

Hard- and Softkill Anti-missile systems are either in Service (Arena/Shtora) or will enter service with the next generation of vehicles (i.e the Puma IFV). Since a missile/rocket/RPG is the most common tank-killer for planes and infantry that reduces the danger

ERA and other anti-HEAT armors (with some capabilities against KE) are either in service (Kontact-5) or ready but not introduced (NATO forces). Again HEAT is the prime armor killer for planes and infantry

Modern tanks actually can engage helicopters with a decend rate of success (Leopard II and therefor the M1 also) and the new Canon-Launched Missile for the 105mm and 120mm NATO tubes introduced by Israel (as well as the older systems in Russian service) enhance that ability

Some modern AT-missiles (i.e Spike/Eurospike) have a secondary AA capability. EuroSpike is currently entering service

And on top of that you can always protect your tanks with your Airforce. Works resonably well Mo-Thu, 09:00-17:00 (Fr only 09:00 to 15:00) in resonable weather and low enemy AA thread

 

[tbeard1999]

Actually tanks are currently gaining some abilities against airborne threads.

In my opinion, the great error made by every generation of theorists who predict the end of tanks is that they do not factor in the fact that tanks are part of a Combined Arms force. Only rarely do tanks operate alone against enemy infantry, and those rare instances are when tanks usually get hammered. Which then leads to confident predictions of the tank's demise. Examples would include some early WWII tank operations (even the Germans had too little infantry in their early Panzer divisions), some theoretical writings of mobility theorists like Fuller in the 1930s, early Israeli operations in the 1973 Yom Kippur War.

In almost every war, tanks that were employed sensibly, as part of combined arms forces, were not highly vulnerable to anything except other tanks.

 

[tbeard1999]

Realistic (IMHO) means that (assuming same TL)

+ Rifle vs. tank => You have just angered the tanker by scratching his paint job. He engages his co-axial Maschine gun and cuts you in half

+ GIMP vs. tank => More scratches. As above but after that he drives over your foxhole and squished your corps

Agreed.

+ RPG vs. tank => Can put a hole in the flank/top/rear and kill the tank. Might put a hole in the front

RPGs will typically be ineffective against the front armor of any tank of the current or previous tech level. Very late TL X RPGs might penetrate the front armor of very early TL (X-1) MBTs.

+ ATGM vs. tank => As above with longer ranges and/or more control

In the 1960s and 1970s (i.e., TL6) heavy AT missiles could defeat the front armor of MBTs. But with the advent of TL7-8 composites and ERA, most MBTs are invulnerable to heavy AT missiles.

Top attack AT missiles have restored the balance somewhat. In the future, I expect missiles to be increasingly vulnerable to active point defense systems.

+ Tanks vs. tank => Might kill each other from the front. WILL kill each other from side/rear

I'd say that in general, MBTs will kill each other at effective range. In an intense arms race or extended war, tanks of the early TL might not be able to penetrate the front armor of mid-late TL tanks at anything other than close range (~50% of effective range).

+ Tank vs. light tank => Will kill the light one from any side. The light one might kill the heavy from the side/rear

Agreed. Some light tanks may mount MBT class armament (but not armor).

+ Artillery vs. Charging, unarmored infantry => Lots of telegrams to the mother/wife

+ Artilley vs. Charing infantry in BD or riding lt. tanks => Some telegramms but the Artillery better starts moving otherwise it will die

Agreed on first one. I'd expect artillery to be lethal against most unarmored infantry. Infantry in battledress probably can't realistically threaten artillery, which may be dozens of klicks away.

+ Artillery vs. tanks => Unless using special ammo see Rifle vs. tanks

Really huge HE rounds -- 200mm+ -- can kill crews from concussion without penetrating the armor.

 

[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...

 

[samuelvss]

Realistic (IMHO) means that (assuming same TL)
+ Rifle vs. tank => You have just angered the tanker by scratching his paint job. He engages his co-axial Maschine gun and cuts you in half
+ GIMP vs. tank => More scratches. As above but after that he drives over your foxhole and squished your corps
+ RPG vs. tank => Can put a hole in the flank/top/rear and kill the tank. Might put a hole in the front
+ ATGM vs. tank => As above with longer ranges and/or more control
+ Tanks vs. tank => Might kill each other from the front. WILL kill each other from side/rear
+ Tank vs. light tank => Will kill the light one from any side. The light one might kill the heavy from the side/rear
+ Artillery vs. Charging, unarmored infantry => Lots of telegrams to the mother/wife
+ Artilley vs. Charing infantry in BD or riding lt. tanks => Some telegramms but the Artillery better starts moving otherwise it will die
+ Artillery vs. tanks => Unless using special ammo see Rifle vs. tanks
+ Artillery vs. Infantry in prepared cover => See infantry in BD/lt. tanks
+ Tank vs. BD => IF the tank can land a hit on the BD thats one dead BD.
+ lt. Tank vs. BD => The tank has better chances to land a hit but the hit may not come through

The most useful yet for the original questions posted.

What can characters (in BD or less)can survive against an MBT is like asking whether a soldier in BD can survive being hit by a semi going 140 kmh. The character's task is to get out of the way. A lot of this is not so much about ballistics (21st century fire control & ballistics = if you can see it you can hit it) (MBT ballistics = character dead), but geometry and terrain. If we assume a "frictionless plane," then there is no matchup.

The character who can get to one tank, from above the elevation limits of the main gun (& coax), while it is isolated or screened from its wingman, or its wingman is similarly distracted, can punch through its top deck with an RPG. The M-21 mine used in a command-detonated mode (jury-rigged: there was no aux. fuze well; Demo-0 required) can be set up by a single infantryman, or grandpa in flip-flops, for that matter: it will take out any tank in the world if you get the shot right. Getting the shot right depends on access to terrain and intelligence, canalizing and slowing down traffic, while keeping eyes on the target area without being seen.

Now this is why a solo tank in a city is a vulnerable thing; this is why we have dismounted infantry in the world of armor and mechanized forces.
Combined arms is a bit like rock-paper-scissors, but you get to have more than one. The Soviets first battle of Grozny forgot that; they forgot to have dismounts out, beating the bushes, in this case fanning out and "beating" the very complex urban terrain.

Can a good plot line involve local commanders being ignorant, drunk, or stupid? Can the tank crew get sloppy, on a "frolic and detour?" Can the character be part of a complex military op? All fodder for the GM, but mbrinkhues's rules are probably most useful to start.

Artillery, likewise, can be a world-ender for characters who don't "get it" in time. Arty can also be very difficult to use in urban situations, where 95% of the developed world lives. They need to be saavy; anyone with Tactics-1 will know the basics. As a GM, I use Tactics to give characters some hints in tactical situations. It takes a lot to blow down an apartment block; tunnels still work in the 53rd (++?) century.

$20 of explosive (well-placed) can still rape $4.3 million dollar tank.. How to know where to place it, and get access, therein lies the drama.

Modern and future weapons systems will have incredible capabilites; characters ignore these at their peril. Weapon systems all have limitations and vulnerabilities. Tactically savvy characters will know these and use them. GM's must therefore understand them.

That being said, though grav tanks designs tend to have more up front, the belly and deck tend not to be nearly as thin (in relative terms) as in current MBT's.

 

[CosmicGamer]

Folks have been confidently predicting the end of the tank since 1918. Hasn't happened yet...

:rofl: that was good for a laugh.

 

[tbeard1999]

That being said, though grav tanks designs tend to have more up front, the belly and deck tend not to be nearly as thin (in relative terms) as in current MBT's.

I believe that tanks will always have to scrimp on armor protection on the flanks. The reason is that on a typical MBT, the surface area of each flank and the top or bottom will be 2-3 times what it is for the front.

This means that 1 cm of armor on both flanks will weigh 4-6 times what 1 cm of frontal armor weighs. 1 cm of top armor will weigh 2-3 what 1 cm of frontal armor weighs.

 

[saundby]

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.

When I sit down to play, I play the game that's in front of me. Afterward, I try to reserve comments to the GM to what's welcome. I might express some surprise during the game if things don't work out the way I'd expect them to based on my experience, but out of good manners I try to keep it well below the level of pissing and moaning.

When I was gaming regularly with a set of engineers we used to regularly rework whatever ruleset was at hand to try to make it "realistic." We came from a broad selection of disciplines, ages ranged from the young prodigies to guys who had worked on the Panama Canal. All of us had defense sector in our C.V. We'd no sooner get one section of the rules worked out than somebody would show up and mention that their current line of work undermined our entire reasoning behind the new rules. :rofl:

While many real world systems don't play out in the field as well as hoped, it's also true that many real world systems perform better and in more roles than their designers ever imagined. Every end user of one of my systems that I've had a chance to talk to has taught me something invaluable. So I try to talk to them as much as I can.

The engineer's gaming group I mentioned eventually gravitated to "rules light" type gaming. We had more fun blowing up each other's minis (in-game, not in actuality) than in wrangling over rules. Then after the game bragged about how much better our units would have been if they'd been made according to our design rules.

We were in the process of putting our excess engineering hormones into the sport of building model ships for combat with BB guns after we found out about a group that did this in Texas, but an upheaval in our industry came along and about 3/4 of us ended up moving away to various other places before we could get our boats out to a lake and start using physics to do some of our die-rolls for us.

 

[veltyen]

I believe that tanks will always have to scrimp on armor protection on the flanks. The reason is that on a typical MBT, the surface area of each flank and the top or bottom will be 2-3 times what it is for the front.

This means that 1 cm of armor on both flanks will weigh 4-6 times what 1 cm of frontal armor weighs. 1 cm of top armor will weigh 2-3 what 1 cm of frontal armor weighs.

That would be a current limitation based on shape. The tradeoff is between carry and maneveur space and protection and the needs of the drive system. Hence the small front and flat (ish) sides.

With Grav tanks potentially that goes away. Diamond shaped tanks that keep the pointy end directly towards the biggest threat. At a pinch more the shape of a standard scoutship (an elongate cone) though that leaves an obvious flat rear target.

 

[Icosahedron]

Yeah, I've often figured grav tanks would be a radically different shape from current designs, especially considering (unless it's a ground-hugger) one of the greatest threat angles would be from below.

 

[Whipsnade]

Yeah, I've often figured grav tanks would be a radically different shape from current designs, especially considering (unless it's a ground-hugger) one of the greatest threat angles would be from below.

Icosahedron,

The greatest threat angle is from below even now.

Do you see grav tanks regularly "flying" during combat? That is, do you see them moving at an "altitude" greater than that at which current tanks do?

I see grav tanks "flying" during landing operations and during strategic/operational movement but, once they enter a combat zone or potential combat zone, I don't see them moving about at a greater "altitude" than current tanks except in very rare circumstances.


Regards,
Bill

 

[mbrinkhues]

While not the best books in the world the two "Renegade Legion" novels "Damned if we do..." and "Frost Dead" give a lot of nice ideas what to do with Grav-tanks and how they operate in a rather modern battlefield.