Who needs tanks?

[Pomphis]

IMTU I have something between powered armor and mecha: egg-shaped vehicles (build with VE2) with arms, internal weapons and a human inside. They go from 2 cy and 6.5 tons to 6 cy and 13.5 tons.

[Anthony]

Originally Posted by copeab

In the end, it all comes down to whether or not the GM *wants* the mecha in his campaign.

If he wants them, he can make sure technology supports them. If he doesn't want them, he can make sure that technology doesn't support them.

It's not quite that simple. There's also a question of 'just how ugly do of a handwave is needed to make the technology support them'.

Most likely, if the GM wants mecha in his campaign, he's not worried about the realism problem in the first place, making the point moot.

[Joseph Paul]

Originally Posted by ectropy

All true. Which is why automated pulse laser point-defense ...to disrupt missiles.

I would rather defeat HEAT warheads with electromagnetic armors. I think that the EMA described in UT could be expanded on.

[copeab]

Originally Posted by Molokh

It's misleading because it forces one to make the intuitive assumption that a mech of the same SM is bigger. However, this is misleading because SM is exactly the number we use to refer to ease of being seen and hit on the battlefield. And that's before the fact that a mech can crouch or go prone, modifying their ease of being hit as per Basic Set for humanoids.

Ah. Sorry. I'm used to 3e vehicle design where Size Modifier is based on total volume.

[Fred Brackin]

Originally Posted by blacksmith

What about reactive armor on the battlesuit?

A relatively small factor. It might edge you up one category at most.

[Crakkerjakk]

Originally Posted by DouglasCole

Taking this down to a scale people may have actually done, the mmRHA penetration of the M16 is about 6.4mm; anyone know if the round will punch through 64mm of concrete? (2.5").

They showed us penetration capabilities of various weapons (mainly to show why sandbags are our friends.)

IIRC, a 5.56 NATO Ball went through the end and center supporting beam of about 1 cinderblock. I think that's about 2.5 inches. But having the spacing in between the layers of concrete skews the results.

[DemiBenson]

Originally Posted by Joseph Paul

I would rather defeat HEAT warheads with electromagnetic armors. I think that the EMA described in UT could be expanded on.

Well, yes. EMA plus laminate construction specifically has triple DR vs HEAT warheads, so almost all heavy battlesuits will have that.

And a small point defense turret is still a good idea.

[Joseph Paul]

Why are mechs needed for this why not say crew served weapons?

Got a crew served weapon that can make the emplacements that will protect it from the main armament of the OpFor? Remember that one of the constraints the OP laid out is that one-shot=one-kill. If that is true manipulation of the terrain becomes a viable tactic.

I did grant that there might be terrain that would make legs better than tracks. I am still not convinced that humanoid is the way to go though.

Your Mecha May Vary, but for me the ability to intuitively use the mecha is important. I think that it would be easy to get the hang of what the machine can pick up and move whereas a different planform requires a learning curve and there is no general feedback/kinesthetic feel for what legs 5 and 6 are doing or what it means when I am pitched on my side.

This is just putting the gun on an articulated arm. You could do that with non mecha, but of course in both cases it is not a gun of the power of a tank gun.

There are two different arguments here. The first is that you can’t mount the same weapon on a mech arm that you can in a tank turret. The second is that you can’t mount as effective a weapon on a mech arm as you can in a tank turret.
I would like to see the physics regarding the oft repeated claim that a mech cannot mount the same weapon as a tank. Some have provided the detail that they believe the mech would be toppled. I don’t know why. Field artillery/AT versions of large guns don’t seem to be digging their spades in excessively so the amount of recoil that is actually working on the carriage can’t be all that much.
As for the second assertion there are low recoil versions of many cannons even 120mm ones that can fire all of the rounds that the M256 does. They are mounted on light armored vehicles so it certainly is not the mass of the vehicle that is the major factor in soaking up the recoil. Also there are plenty of low recoil yet powerful weapons that can be used. Various beam weapons and kinetic kill rockets come to mind. Certainly a tank could mount them but that doesn’t change the fact that the mech can match the tank in firepower.

This is an argument for arms, not legs.

So? It was an answer to what mechs can do that tracked vehicles can’t and there were other examples of what legs can do.

Main and secondary. Nothing on an arm is going to be anything close to the power of a main gun. Torque would be a killer.

Addressed above. How robust do you think the turret ring bearing is in an MBT? Doesn't all of the felt recoil have to go through that to get to the superstructure?

Easy, have them fold up into a compartment.

And give up what? Tanks are not spacious vehicles. Many modern tanks effectively have no superstructure clear of the tracks.

A mecha is always going to be more poorly armored and with weaker weapons than a tank of equivelant mass

Addressed above.
You all have a good Thanksgiving or an enjoyable weekend if this isn’t a holiday for you. I probably will be offline til Monday.

[Johnny1A.2]

Originally Posted by blacksmith

So you only watched Patlabor and no Gundam?


The thing about a mecha is that concievably it could be a very useful general purpose machine. Sure at any given task it would be over priced and under performing, but when you want to be able to pick up a tool and use it a mecha might be superior at using a large variety of tools than a more purpose built machine.

In my gameworld's future setting, I have some groups make use of 'legged AFV units' for just that reason. They aren't humanoid by any means, though, for all the reasons already mentioned in-thread. They're more like heavily armored insects, low-built, they have the advantage of being able to move across nearly any terrain, and even to climb...somewhat. Imagine a tank-sized armoed ladybug, in most cases.

OTOH, they're a bit less efficient for each purpose than specialized combat vehicles, and much more expensive on a per-machine basis. That makes them popular for space delivery, since they are more versatile, but planet-based military forces tend to prefer the cheaper tracked and wheeled machines.

[Johnny1A.2]

Originally Posted by blacksmith

Um, the military seems unconfortable with explosives as sensetive as dynamite, why would they use AM an explosive that will explode unless it has very very specific conditions, instead of explosives that will only explode in rather specific conditions?

I'm inclined to suspect that is likely. While predicting what's likely in the future is always chancy, antimatter has the inherent problem that you can't make it failsafe in a terrene atmosphere. Any falure of whatever you're using to contain it, and BOOM. Add in the likely (as far as we can see) extreme cost, and antimatter doesn't look like a probable battle weapon (unless you're trying to just wipe out your enemy's entire country or something).

Propulsion, yeah, AM looks tempting there, if you can engineer a light enough containment system. Paradoxically, it's almost literally too dangerous to use as a weapon.