16 replies to this topic

[Leonardo Monteiro]

Probably something been discussed before, but I am curious:

How would a 60 ton M1A2 Abrahams versus a 60 Ton mech (you get to choose, but no clantech) fare?
Especially considering that the tank I use as example if one of the best in the world, and probably has better "stats" than most mechs that we accostumed too


http://en.wikipedia.org/wiki/M1a2

Edited by Leonardo Monteiro, 17 November 2011 - 05:22 AM.

[Gawain Emrys]

A better comparison might be to a Bulldog Medium Tank, also a 60 tonner but in the Battletech Universe. Making that comparison the Bulldog is more heavily armed and faster, but with no data for comparison we don't really know how the modern Chobham armour compares with that in use in the 31st century.
As a rule it is assumed (and I think the games have supported this assumption) that a 'Mech will beat a tank on most occasions so if the Bulldog could take an M1A2 then a 'Mech would have little trouble with it. Based on mass the Abrams main gun is an AC/2 at best, however the numbers in Battletech are based on game balance not realism so no accurate comparison can be made. Personally I'd place the Abrams as having an AC/5 or AC/10.
This is, however, the guesstimate of a man with no real experience of any of the vehicles of weapons mentioned here.

[AcesHigh]

assuming each has"equal" tech, terrain will determine the advantage. on wide-open flat stretches of land the tank would have the advantage due to it's lower frame, smaller target silhouette, and bigger armor/weight ratio.

given much terrain variation(such as a dune or rolling hills), a mech such as the crossbow has the edge; with it's 20 km/hr higher top speed, heavier weapons loadout, and better terrain navigation.




Also, As far as i can tell, a 105mm or 120mm shell = 10-12CM shell, = AC10 or AC12

Edited by AcesHigh, 17 November 2011 - 05:58 AM.

[Metalbourne]

It really depends on how really lethal the Mechs weapons are in real life. I think an AC-10 is technically around 100mm so depending on the rounds used the M1A2 could probably withstand some hits to the front. The other thing is range. The Abrams could fire on the move and hit targets 2+ miles away while the mechs seem to have very close range weapons. The M1's are actually 70 tons battle ready and are being equipped with some very cool anti-missle technology so LRM's could also lack hits. The M1's 120mm with Depleated Rounds I think could cause serious issues to any mechs joints IMHO. Of course this is all fact vs fiction and could really never know the true outcome.

[Firefly]

'Mechs do not compare with today's firepower. The future of the 1980s BattleTech is not the future of today. I mean, really... if a hex is 30 metres, and prior to upgraded rules and retcons and reconfigures and whatnot, an LRM shot 21 hexes, that's 630 metres.

... I don't know about anyone else, but I could bullseye a target with my M249 SAW at 800 metres, and that was a pathetic little 5.56 round.

So yeah. Btech weapons != real life weapons. Sorry. This argument does not compute.

[MogCarns]

Too many apples and oranges here to be sure, but it really comes down to what you accept as the rationale for BattleTech's ruleset.

The ruleset has the very short ranges because very few people have tables large enough to support maps with modern gun ranges, much less missiles. The first rationale was that the depleted technology of 3025 has left targeting computers unable to be accurate over range... that the servos controlling the weapons were no longer precise enough for accuracy... and it was never a question if lasers could hit a target... it was always if a target was damaged.

The second rationale, that came out after the SL tech, was that armor technology had finally defeated the warhead in the age old arms race. As such, the armor could no longer be penetrated... it was now required that weapons hit with enough "shock force" to knock away the armor plates, or melt away the supports.



If you still subscribe to the first rationale, then the battle is decided by whom fires first. The 120mm is going to hit at a much longer range, esspecially considering the huge vertical size, and the rounds will penetrate the armor, unless the Boron Carbide can stop it. If the gun can penetrate, the Mech is going to be engineless long before the Mech has even the most remote chance to fire back. If the Mech were to be able to sneak up on the tank, then missiles and autocannon have a pretty low chance of victory, but I doubt Chobham does all that much against PPCs and Laserfire.

If you hold to the second rationale, then the Mech has all the cards... the 120mm is going to be doing one or two points of armor damage, and then only at much closer ranges. As such, even the Locust and Wasp stand a reasonable chance of defeating it; if it can remain on its feet.

[Arctic Fox]

I think as far as BattleTech weapons go, the Abrams' gun is a Medium or Heavy Rifle at most (These weapons are specifically stated to be the ones used on tanks in the 20th century and afterwards, and yes, I know they're not actually rifles), and the armor protection is probably significantly lower than even Age of War tanks, let alone modern 'Mechs. I don't think a 20th/21st century tank has much chance against 31st century 'Mechs.

The range is probably the only major advantage if you use the real world one for the Abrams compared to the ranges in BattleTech, which are explicitly lower than they would be in real life in order to make for a more interesting game.

[Firefly]

MogCarns, on 17 November 2011 - 06:32 AM, said:

Too many apples and oranges here to be sure, but it really comes down to what you accept as the rationale for BattleTech's ruleset.

I'm interpreting it literally, based upon the title and the OP. So I'm taking a real-life Abrams with its real-life stats and dropping it right into the BattleTech universe.

[ice trey]

In Battletech history, way back in the 25th century, the first Battlemech, the Mackie, was invented by the Terran Hegemony, and it was unleashed against a large number of tanks. It absolutely decimated them, in spite of being extremely primitive even compared to 3025 standards.

Why was this? Well, Battletech tends to use the following handwavium to describe things.

Ferro-Ceramic armor: Layered armor of ceramic, steel, and diamond weave breaks off in chunks rather than absorbing the blow, but this allows it to absorb any kind of round of the time period with great efficiency. It won't be many years yet until an armor piercing round that can defeat 'mech armor is developed. As such, one of the most common weapons systems of the time, the "Mech Rifle" (What we'd know as the main gun on a tank) was grossly ineffective against 'mech armor (in battletech terms, it was the damage of the rifle, less three. In order for it to do it's full damage, it had to be fired against a target with something like BAR-8 or less armor)

Armor Defeating rounds: Battletech weapons were made to have much greater punch, able to tear through even the strongest tank armor like butter. Since real tank armor tends to work on a "It breaks through/Doesn't" principle, they used a new kind of armor - "Barrier armor". This kind of armor acts similarly to standard armor, but once you pass the threshold of the armor (So, for BAR 8 Armor, it would be any weapon that does 9 or greater damage in a single cluster), the shots automatically penetrate. It was said that for the time period, even the strongest tanks didn't have BAR ratings any greater than 8) Since the Prototype Mackie sported an AC10 and PPC (Backed up by two medium lasers), it would have been more than enough to defeat even the hardest tank armor of the time.

With the mackie having an array of weapons that could break clear through an assault tank, and armor that could shrug of the most powerful of attacks, the fight was a a foregone conclusion. The tank forces were decimated, and each other nation of the early inner sphere started racing to develop their own 'mech once the plans were stolen from the Terran Hegemony. All the gear on the Mackie changed the battlefields of the inner sphere forever.

So if that was a tank from the 25th century, according to Battletech's "Sci-fi of the 80s", I think that any modern equivalent would still be chewed up and spat out by any Battlemech it faced, even in spite of technological advantages we've acquired in the past 25 years. The 'mech could have a Vic 20 for a targeting computer and still win the fight, with the gear it was packing (And considering it was from the 80s, I'm sure a Vic 20 wouldn't be that far off).

Of course, this is all hypothetical. Most Pro-tank arguments would argue that the Handwavium didn't work like handwavium. Of course, if Battletech weren't rife with Handwavium, there would be very little reason or capacity to have giant robots, or most any other technology illustrated therein. For one, interstellar travel would be pretty hard without Battletech's rewriting physics for jumpships.

[Damocles]

I'd take anything that has just a small laser over an Abrams.

Because real world and battletech are not the same.

[Nebfer]

Are we assuming that a battlemech is working as it should be, or are we just using real life rule through out.

If we are using real life rules, then the real life tank, as partly the mech dose not exist, and if it did would not be as effective as it ought to be (less armor per area of mass, more moving and complicated parts to go wrong...)...

If we assuming both are working as they should be, then it's a bit more mixed, and partly runs on how you view the battletech universe.

Battletech armor seems to require more along the lines of raw energy than simply penetrating the armor, as such the M829A3 rounds that is the current round the US army uses for the Abrams may be found not to be all that good on a battlemechs armor, even though it can penetrate at lest 800mm of RHA. On the other hand B-tech rounds may not be able to directly penetrate the Abrams armor but they might not have to due to their shear mass and velocity. And theirs the fact that an Abrams or any other real world vehicle dose not have to worry about getting hit by a Laser cannon that makes the real world "battlefield" laser prototypes (like the Airborne laser) look like wet firecrakers.

In battletech the only known caliber for a heavy rifle is 150m with a shell weight of 68kg (most real world 150mm rounds are 45kg), velocity is not stated but lets assume a high end WW2 era velocity of about 1,150m/s
150mm with a 68kg shell with a assumed velocity of 1,150m/s Kenetic energy = 45 megajoules, this deals six damage
A 120mm shell with a mass of 7kg with a velocity of 1,555m/s (M829A3) has a Ke of 8.5 megajoules. B-tech damage unknown (but based from the above numbers one or two damage would not be unreasonable)

Then theirs Gauss Rifles, both the Heavy and regular Gauss Rifles are quite often stated to be hypersonic (above 1,700m/s to about 3,400m/s or so).
So a 250kg slug at say 1,750m/s = 383 megajoules = 25 damage or 15.3 Mj per damage point
Based off the Hvy Gauss the Regular Gauss would produce 230 megajoules of Ke and have a velocity of ~1,920m/s
Comparison
A 16 inch gun at 760m/s firing a 1,225kg AP round would produce 353 megajoules (Iowa Class battleship)
A 14 inch gun firing a 680kg shell at 820m/s is 228 megajoules (New Mexico class).

With this I would think it would be safe to say that a 120mm tank gun would do at best a single point of damage. Also note a real life MBT would not be-able to survive a Ke impact with the Ke of a battleships gun, such an impact would turn the MBT into scrap.

Laser Cannons are just as powerful, to fully melt 62.5kg of B-tech armor requires some 190 megajoules of energy assuming 30kg each of Steel and CBN (rest being non armor materials). And B-tech armor is often described as having large amounts of it being melted per hit. but 190 Megajoules is a bit high, and dose not factor in any armor being simply thrown off via vaporization effects, so lets drop this to say 50 megajoules to remove one point of armor... The real life ABL is a megawatt class weapon requiring 3 to 5 seconds...

Autocannons are a lot harder do get useable info from, but their calibers very considerably, an AC-5 for instance ranges from 40mm to 120mm (50 to 80mm are the most common for AC-5s). Their rating is based of their ROF and over all damage capability. Their are a few that mention their projectile velocity is in the hypervelocity range, a bit odd if some Gauss rifle fluff is to believed... Though we do know that a B-tech autocannon has a higher MV than the obsolescent "Rifle cannon" series.
AC-2s are commonly 30mm, but range from 20 to 50m
AC-5s are commonly 40 to 80mm, but range from 40 to 120mm (50mm is most common)
AC-10s are commonly 80mm, but range from 75 to 100mm
AC-20s are commonly 120mm, but range from 100 to 300mm (one source mentions that an AC-20 could range from one that's firing a single 300mm shell, or one that's much smaller firing dozens of shells).
------------------------------------------------------------------

Well I think thats enough for armor...
Speed, most real world MBTs are governed to speeds of about 50 to 60kph on roads which would equal a 4/6 vehicle in B-tech terms, but off road is always slower than road speeds (in fact a Abrams off road speed is ~48kph which would be 3/5, add a extra MP for road travel rule and it's got it's road speed). So most real world MBTs would likely end up having a governed speed in B-tech terms of around 3/5. though they can go faster than this...

Interestingly enough so can B-tech vehicles, Tactical ops allows units to "sprint" with the basic effect of having free MASC (which it also stacks with) and it also allows units to gain an extra MP if it has access to a navigation satellite. and further more a RPG pilot ability allows a unit while sprinting to gain an extra two MP (then theirs the supercharger in tack ops which is fluffed to partly be a engine governor...).

So a 3/5 battlemech (or vehicle) can with out any chassis mods can move at speeds of up to 97kph (or 108kph for vehicles on roads).
Likewise a 5/8 battlemech can reach a top speed of 140kph using the same rules and configuration.
---------------------------

As for range well Total warfare mentions that the range in game is partly due to the fact that if it was realistic one would require vastly larger playing areas (like the size of entire rooms) or larger hexes with or with out a time scale change, which would have odd results either way (why can my mechs autocannon only attack once per minute, or why can only one mech fit into a 250m hex, or how did a mech hit another in melee when their some 250m apart...)... And theirs a number of oddity's and rules that indicate their real combat ranges are not as it my seem... Though the Novels seem to have largely ran with the games ranges (but infantry can kill each others at ranges much farther than mechs supposedly can...)... A few of these oddity's/rules are
Tactical ops Line of sight ranges, if the weapon apply it can fire out to the units max line of sight regardless of how big the playing area is (their are optional rules that bring that to a more manageable number). Anti aircraft shooting ground units can hit aircraft at 2,000 meters, which is some four times the range of the weapons capable of doing that (requirement is 16 hexes or longer) Also elevations is not tracked in game, so it's perfectly legal to engage a target on a 100 elevation hex with a machinegun, thats 600m above it by the way (a single elevation is 6m by the way). The RPGs infantry weapons allows for infantry support lasers to engage targets out to 2.5km away, LRMs can reach 2.1km and so on. Strategic ops allows ground units to be used in space (hint they suck) but they can engage targets in their own hex which can be some 9 to 18km away depending on where they are in that hex...

In short the Abrams and most other real life MBTs in rough B-tech terms is a ~40 to 65 ton tank that moves roughly 3/5 and armed with at best an AC-2, with at most 8 points of armor low grade armor (sub BAR 8) on it's turret and front armor, side & rear armor being substantially weaker, with their likely having basic fire control as well.

[Alizabeth Aijou]

Pretty one-sided, afaik.
Even a 20-ton Light 'Mech would make short work of the Abrams.
Because really, what is a Light Rifle (Cannon) going to do against battlemech-grade armour?

Looking at a 60-ton, tracked Tech Rating B medium support vehicle.
That's 18 tons for the chassis' interal structure (excluding turret).
Lets say that it moves 3/5, ICE engine.
We're looking at an engine weight of: 30.50 tons.(only 11.5 tons left now)
1 ton fuel (gives us a range of 325km). (10.5 tons left)
A crew of four requires 0.5 tons of seating (10 tons left), can throw in a fifth crew member (officer) for no additional weight.
Two guns, a Light Rifle (Cannon) and a Machine Gun (3 tons and ½ tons), plus ammo for both (1 tons and ½ ton), with both in a turret (0.5 ton). That's 4½ tons remaining.
Lets say that the remaining tonnage goes to Tech Rating C BAR6 armour (giving at least reasonable # of points - 93 to be precise) (Tech Rating C since I'm feeling generous.)
Initially I wanted to give it TechB BAR4 armor (90 points), which would mean that even a simple Medium Laser would score a crit whenever it hits.

In short, a veritable joke to any battlemech - even primitive ones.
Tech Rating B is roughly 1950, while Tech Rating C is roughly 22nd century.

Hm... FLE-4 Flea.
For a BattleMech, rather thin-ish armour (only 2 tons), less than half of what is possible for its tonnage (which is 4½). Still more than adequate protection against the Abrams (light rifle (cannon) simply cannot penetrate it), while the MG is simply too short-ranged.
The Flea also outmanoeuvres the Abrams by far at nearly twice the speed.
The Flea can easily damage the Abrams with the Large Laser penetrating the armour with every shot, scoring plenty of criticals, while the twin small lasers strip away the armour.

And that for a 'Mech costing only 1½ million C-Bills.

Edited by Alizabeth Aijou, 17 November 2011 - 04:09 PM.

[jojobear]

I think you are all discounting the Abram's biggest main advantage.

Accuracy.

An M1 Abrams tank has a highly classified targeting computer that will produce a direct hit 95% of the time at 2.5km. It even automatically leads the crosshairs.

And it can do this while moving down a paved road at 72 kmph

I'd imagine an Abram's could be used to tactically take out slower mechs in the heavy and assault class by aiming for the cockpit and gyros. They could easily stay out of radar and weapon range by staying on a paved road and outpacing the mech, all while pelting shells at the cockpit and leg joints.

It's not ideal. They are definitely outgunned and out-armored, but it's not impossible.



Now something really interesting would be tactical missile strikes with stealth drones. Fly in, drop a couple hellfire missiles directly on top of the mech, and get out. Mosquitoes from hell I tell ya.

[Iseinolf]

There was an article many, many years ago in one of the now defunct fanzines that played out this scenario with "Earth" being discovered by one of the Houses. As they were dropping in(over cold war Germany) they began taking critical system damage from the defenders. What was happening was that the Warsaw Pact and NATO tanks were pelting them with SABOT rounds which were penetrating their armor and hitting the sensitive systems underneath. The House had deployed nukes as a prep bombardment. The end of the invasion came about when precision muntions were deployed in the form of LGBs and artillery fire. The author attributed the win by the Earth people was brought about because the Mech armor was subject to spalling due to its designed intention to slough off under duress.

[Nebfer]

jojobear, on 17 November 2011 - 04:22 PM, said:

I think you are all discounting the Abram's biggest main advantage.

Accuracy.

An M1 Abrams tank has a highly classified targeting computer that will produce a direct hit 95% of the time at 2.5km. It even automatically leads the crosshairs.

And it can do this while moving down a paved road at 72 kmph

I'd imagine an Abram's could be used to tactically take out slower mechs in the heavy and assault class by aiming for the cockpit and gyros. They could easily stay out of radar and weapon range by staying on a paved road and outpacing the mech, all while pelting shells at the cockpit and leg joints.

It's not ideal. They are definitely outgunned and out-armored, but it's not impossible.



Now something really interesting would be tactical missile strikes with stealth drones. Fly in, drop a couple hellfire missiles directly on top of the mech, and get out. Mosquitoes from hell I tell ya.

This is a possibility but not entirely likely.
A battlemech is a quite mobile target, and likely faster most of the time than the Abrams it self (depending on the speed of the mech).
Also due to the high probability of the Abrams it self existing in B-tech past in some form (the Sea Wolf Class sub dose, and B-tech made more of them than we did).
If we assume it's in real life then we can easily say it has the range it has, in B-tech universe and a strict rules view, then it's not going to be any different than a B-tech weapon, a less strict view can retain it's range but also likely has to face B-tech weapons at the same ranges.
And also how likely is it going to find a long stretch of smooth road for it to use that allows it to travel at 72kph? From what I heard accuracy drops off at speeds above what it's governed for (and not to mention above 30kph off road).
As mention a mech is quite mobile, its assumed to be consistently in motion, even when not moving into other hexes (and when assumed not to it's easier to hit), and can easily accelerate much faster than even an Abrams can, in the range of zero to max speed in about five seconds.

An interesting thing to note that it's possible that an Abrams would be classed as having a basic fire control, to note it would likely find part of it's fire control gear rendered less effective due to interference of B-tech jamming.

A battlemech like the CN9-D Centurion has an effective all Terran movement of 97kph (combat capable) with a maximum (unmodified & non combat capable) speed of up to 162kph (the max the rules allow it to go with out bringing in a "engine mod"). Compared to an Abrams 67kph road speed and 48kph off road speed (governed), with the road speed ungoverned being possible on smooth surfaces of around 110 - 120kph.

The CN9-D5 can reach combat speeds of 130kph for shot amounts of time (and non combat speeds of up to 194kph).
In any case it is possible for an Abrams weapons to hit accurately at long range but that weapon may find it self to be all but useless. Though theirs one question, how will the Abrams crew know where to aim for the cockpit or even to aim their? Considering theirs a wide range of battlemechs with a wide array of cockpit locations and configurations....

As for Drones well the OP was only dealing with a MBT vs a Mech. But you probably do not want to face the Drake Medium Stealth Fighter (eat your heart out F-22)... Though the hellfires the drones are likely using are probably at best not going to be much better than ATM HE rounds...
B-tech fighters will eat current day fighters alive, their faster (all capable of at lest Mach 3 sustained), have better acceleration ability's (the slowest have 4Gs of acceleration vs 1.5Gs for the best real world fighters), have longer endurance (some can fly all the way around the world with out refueling), just as agile (Most of them are VSTOL capable), they can fly higher (many are SSTO capable, and thoughs that are not can reach 36km real world tops out at around 20km) and their armored like tanks.

[Alizabeth Aijou]

Iseinolf, on 17 November 2011 - 05:29 PM, said:

There was an article many, many years ago in one of the now defunct fanzines that played out this scenario with "Earth" being discovered by one of the Houses. As they were dropping in(over cold war Germany) they began taking critical system damage from the defenders. What was happening was that the Warsaw Pact and NATO tanks were pelting them with SABOT rounds which were penetrating their armor and hitting the sensitive systems underneath. The House had deployed nukes as a prep bombardment. The end of the invasion came about when precision muntions were deployed in the form of LGBs and artillery fire. The author attributed the win by the Earth people was brought about because the Mech armor was subject to spalling due to its designed intention to slough off under duress.

Which would be fairly inaccurate, given the Tech Ratings.
Even the Merkava Mk. VI's that fought the first Mackie are vastly superior to what we currently got.
AC/5, LRM-10, SRM-4, twin MGs, 4½ tons of BAR7 armour, with the Merkava Mk. VI being only 15 tons heavier. The Mk. VI was introduced in 2384.

[Brenden]

The only thing I'd have to say the Abrams tank has over the Battlemech is Accuracy and Range. I mean, that thing can hit at like, 2 miles an hour with still pretty good accuracy. Battlemech weapons, for some reason, have somewhat poor accuracy (though in MWO that's not really the case).

When it comes to weapons, though, the Battlemech has a pretty well advantage in that it has Energy Weaponry. Though I'm inclined to include it, a Clan Plasma Cannon, which mostly sends off heat, might be perfect against the Abrams. Have a mech hold it down with it's foot and fire away; cook the crew from the inside.

Then there's the PPC, which probably could melt the thing from one side through to the other. The lasers, though they are not that wide, could certainly be used to cut that barrel off. And the mechs like the No-Dachi and that outrageous sword could impale that thing, hoist it up and toss it across the battlefield. When it's on it's side it could blast it away with MRMs.

Then again, we have no idea how these would work out in the real world. The lasers and PPC might not work; The sword might break or the Abrams could be specially insulated to protect against heat.