Quote from: The Traveller;557423Well what I was looking for really were environments where all else being equal mechaform machines from WH40k dreadnought size and up would offer advantages over tanks, flying or otherwise, and as far as I can tell jungle or forest in steeply sloped mountainous areas with lots of fast flowing rivers would seem to be it, plus that practically requires you to bolt a giant circular saw/chainsword/grappler arm on there somewhere.

Urban pacification might be another area where they would be useful, to a small size.

So, something like the AFL-98 Lhada from the anime movie Patlabor 2 would be about the right size. It was a walking/wheeled command unit used by the UN in jungle terrain against insurgant units.



The team that was being commanded by this unit were AL-97B-var Hannibals, a heavy walker unit.

Yes, those are good, the spiderform one especially. Insofar as one can estimate the value of a fictional war machine, mecha wouldn't do so well in most traditional theatres of conflict. They wouldn't be much use outside mountainous jungles or somewhere like Afghanistan perhaps, real raw untamed wilderness areas where you either walk or fly, and flying in the jungle isn't an option.

Following on from that, these kind of illuminate the ideas emerging...





















Maybe a bit more jerry-rigged, baggage strapped to the sides, camo netting also.

Quote from: The Traveller;557126Note how its only just been invented and, for example, it took about a century odd to move from puttering metal tins to sleek fully electric cars.

I'll coin a new law here; the more heavy handedly someone swings into a conversation citing "science" and "engineering", the more likely it is that they have no clue what they're talking about.

The anti-mecha brigade isn't looking so well thought out to be honest. And I'm not particularly a mecha fan.

I know this has been buried for a while, but I think I have something to contribute to muscle usage in mechs and its usefulness in its competing alternatives IE. single transmission drive trains, that Premier didn't cover.

Let M be the sum of energy needed to move a leg or arm around.

And let L be the sum of energy needed to drive a single transmission drive train.

Moving an arm or a leg around will always be, by virtue of its complicated design, be more inefficient than using a single drive train like something that uses wheels. The reason for this is because arms and legs require multiple drive trains- multiple ones at each joint, and not all of them are focused on that one motion that moves the arm or leg forward. Some of them whether powered by hydraulics, wires, or mini actuators will inevitably be used to move the rest of the limb into position, thus not contributing to that forward motion thing. The raising of the leg in the movement of walking for example, is an extremely wasteful use of energy compared to the efficiency of the single motion of turning a wheel or a set of wheels. No matter what power source you use, it is the design principles behind legs and arms that makes M inefficient compared to L, not the tech. If you can think of a design where an arm or leg design would be more efficient, not only would your setting and story likely be very good, but you might also be the owner of an extremely lucrative patent .

So even if we use artificial muscles that are effiecient enough to move a leg like a human (this is assuming that the leg's weight in question would be far out of proportion scale wise compared to its size), and even assuming that larger more complex muscles don't have higher efficiencies as it scales up, it would still be much more efficient putting these muscles inside of a single drive transmission like that of IFVs or tanks. Transforming horizontal motion into lateral motion is the basic tenet of how an engine piston works . Think of it as a muscled powered engine.

Quote from: The Traveller;557423Well what I was looking for really were environments where all else being equal mechaform machines from WH40k dreadnought size and up would offer advantages over tanks, flying or otherwise, and as far as I can tell jungle or forest in steeply sloped mountainous areas with lots of fast flowing rivers would seem to be it, plus that practically requires you to bolt a giant circular saw/chainsword/grappler arm on there somewhere.

I have some reservations about those locales.

In the jungle, if your mech has enough power to wretch its arms and legs out of the many assortment of entanglements and obstacles in the jungle, it's likely that a tank with its wide tracks (and thus extremely great grip of the ground) will do so as well. Ground pressure in such soft ground will also be a problem as will surface roots will be for the feet.

That is not to say that obstacles will be your main enemy in the jungle. It is the problem of a single opposing combatant laying in the mud, covered with a thick blanket of foliage with an anti-armor weapon. If the enemy is skilled and experienced, and in war you pretty much have to assume they will be, they will have some rudimentary knowledge of your sensors, IR, nightvision, or otherwise. There are ways to avoid these, like how at the end of the Iraq invasion the Iraq soldiers managed to figure out that wearing thick blankets could conceal themselves from the infrared vision American armor had, but I'm getting off topic...

In the forest, being tall isn't usually an advantage, unless the forest itself has undisturbed thousand year old trees with hundred meter high canopies in vast areas, though in most forests, it's usually bloody thick. I think it's safe to assume that in the thickets that vegetation will likely reach several metres high if it gets particularly bad. This might produce problems for a tank, but again, if your mech can walk through this with a more inefficient drive train system than a tank, it's likely the tank can power its way through the thickets with the same engine.

For photogenic type forests we see on park/hiking trails and media, tanks usually don't have trouble with them. The only reason it's not a preferred locale when plains are available is because it limits your sight range, and thus the tremendous killing range and firepower of the tanks is neutralize. If tanks need to get through forests, they don't tend to have much trouble, they just tend to crush everything in their way aside from the huge thousand year old trees and those don't tend to grow close enough to each other to warrant the super tight turns a mech might be able to do in any case.

Another problem that the mech will have to confront is the soft ground that is often found in forests and jungles. If its ground pressure per square inch is too high, it's likely to sink into grass fields like it's a swamp on a rainy day. Most tanks nowadays try not to exert much more PSI than double that of a person. The abrams has a psi of 15. The average male has a psi of 8. The abrams is near the end of the heaviest main battle tanks in the world.

For steep mountainous areas, most modern tanks as far as I know should be able to go up more than 45 degrees incline. The M1A1 can go up an insane 60 degrees. At that sort of incline, a normal human being would be crawling up that to maximize their contact with the incline to increase their friction. The difference is again due to the huge tracks that a tank has. The amount of friction that those threads produce is staggering when you look at the math.

For the mech, it would likely have to be crawling as well. What I'm not so sure about this motion being effective compared agains a human is the fact that most of the weight is being concentrated in the fragile fingers of the mech. In extreme circumstances, the fingers will likely have to bear the entire weight of the mech. And though climbing may not be a problem at our human size proportions, when you scale up the human body, and composed the body mostly of metal making the weight significantly heavier than its size scale ratio, the material that makes up the fingers, hand, and wrist would have to be unbelievably strong. And this is considering that the fingers would have to do delicate things like hold plasma swords and sabre fences and such!

For environment so far as I know, no combat realm, not even in space, does the need for mechs arise. There's really nothing about the human shape that does it any favors efficiency wise (compared to what we can build, other animals can go suck on a ploin). The environment will have to be tailored to neutralize the competing-vehicular-alternatives to mechs. For example, a society with such an absurd sense of paranoia about tanks, IFVs, and air power they build their country in such a way that any of these would have trouble navigating for anything more than 200 meters without running into an obstacle or being blown up.

QuoteUrban pacification might be another area where they would be useful, to a small size.

Yes! Heck, bigger mechs are useful here because protesters almost never have any anti-armor weapons on hand. Unlike military personnel either, they are not trained to confront things with violence, have much morale, nor do they have any sort of organized attack plan most of the time. A mech (as expensive as it is) would probably pose as a good source of authority on the streets if it has the tools to neutralize and confront force and backed up by police officers.

The pressure problem would also be solved since it's going to be walking around on flat, paved ground.

Welcome to theRPGSite Swadius! Most welcome.

Quote from: Swadius;562866Let M be the sum of energy needed to move a leg or arm around.

And let L be the sum of energy needed to drive a single transmission drive train.

Moving an arm or a leg around will always be, by virtue of its complicated design, be more inefficient than using a single drive train like something that uses wheels. The reason for this is because arms and legs require multiple drive trains- multiple ones at each joint, and not all of them are focused on that one motion that moves the arm or leg forward. Some of them whether powered by hydraulics, wires, or mini actuators will inevitably be used to move the rest of the limb into position, thus not contributing to that forward motion thing. The raising of the leg in the movement of walking for example, is an extremely wasteful use of energy compared to the efficiency of the single motion of turning a wheel or a set of wheels. No matter what power source you use, it is the design principles behind legs and arms that makes M inefficient compared to L, not the tech. If you can think of a design where an arm or leg design would be more efficient, not only would your setting and story likely be very good, but you might also be the owner of an extremely lucrative patent .

So even if we use artificial muscles that are effiecient enough to move a leg like a human (this is assuming that the leg's weight in question would be far out of proportion scale wise compared to its size), and even assuming that larger more complex muscles don't have higher efficiencies as it scales up, it would still be much more efficient putting these muscles inside of a single drive transmission like that of IFVs or tanks. Transforming horizontal motion into lateral motion is the basic tenet of how an engine piston works . Think of it as a muscled powered engine.

I think there are a few concepts you might be mixing up here. Efficiency has many different uses for example. If you want to go fast in a straight line on a level surface, a tracked or wheeled design is the best. If you want to lift something from the ground to the top of a building, you need a crane which bears quite a lot of similarity to an arm. Cornering rapidly, sharp turns, these are things a mecha would do better - tanks can't shuffle sideways.

There's no particular reason why tank engines couldn't be put in a mecha, although from the looks of that link to metal muscle you might not need it, as it seems to be far more efficient (more power delivered per joule of energy put in) than hydraulics or any of those).

Quote from: Swadius;562866I have some reservations about those locales.

In the jungle, if your mech has enough power to wretch its arms and legs out of the many assortment of entanglements and obstacles in the jungle, it's likely that a tank with its wide tracks (and thus extremely great grip of the ground) will do so as well. Ground pressure in such soft ground will also be a problem as will surface roots will be for the feet.

In the forest, being tall isn't usually an advantage, unless the forest itself has undisturbed thousand year old trees with hundred meter high canopies in vast areas, though in most forests, it's usually bloody thick. I think it's safe to assume that in the thickets that vegetation will likely reach several metres high if it gets particularly bad. This might produce problems for a tank, but again, if your mech can walk through this with a more inefficient drive train system than a tank, it's likely the tank can power its way through the thickets with the same engine.

The main points I was touching on were that a) there are obstacles neither a tank nor a mecha can bull past, such as large trees where you don't have a good run at them, and b) there are often steep gradients which make tanks worthless jungle or not, which a mecha could ascend.

The thing you're missing here is that tanks aren't usually very flexible. A mecha on the other hand can turn sideways, crouch down, bend, crawl, and even do a standing jump to get past obstacles.

Actually just watch this video, which says it all:

http://www.youtube.com/watch?v=CD2V8GFqk_Y

Looks like John Deere had the same idea!

Quote from: Swadius;562866That is not to say that obstacles will be your main enemy in the jungle. It is the problem of a single opposing combatant laying in the mud, covered with a thick blanket of foliage with an anti-armor weapon. If the enemy is skilled and experienced, and in war you pretty much have to assume they will be, they will have some rudimentary knowledge of your sensors, IR, nightvision, or otherwise. There are ways to avoid these, like how at the end of the Iraq invasion the Iraq soldiers managed to figure out that wearing thick blankets could conceal themselves from the infrared vision American armor had, but I'm getting off topic...

This is just as much of a problem for tanks though. Typically tanks deal with it by having lots of infantry around them in support, but if you wanted serious firepower on the spot you're out of luck in the jungle, unless you have a mecha there.

Quote from: Swadius;562866If tanks need to get through forests, they don't tend to have much trouble, they just tend to crush everything in their way

Eh no, this is just factually wrong.

Quote from: Swadius;562866Another problem that the mech will have to confront is the soft ground that is often found in forests and jungles. If its ground pressure per square inch is too high, it's likely to sink into grass fields like it's a swamp on a rainy day. Most tanks nowadays try not to exert much more PSI than double that of a person. The abrams has a psi of 15. The average male has a psi of 8. The abrams is near the end of the heaviest main battle tanks in the world.

See the video above for that one.

Quote from: Swadius;562866For steep mountainous areas, most modern tanks as far as I know should be able to go up more than 45 degrees incline. The M1A1 can go up an insane 60 degrees. At that sort of incline, a normal human being would be crawling up that to maximize their contact with the incline to increase their friction. The difference is again due to the huge tracks that a tank has. The amount of friction that those threads produce is staggering when you look at the math.

There's a big difference between gunning up a ramp or a nice even hillock and driving up rugged and uneven terrain. Tanks can't even go over level rocky rugged terrain.

Quote from: Swadius;562866the material that makes up the fingers, hand, and wrist would have to be unbelievably strong. And this is considering that the fingers would have to do delicate things like hold plasma swords and sabre fences and such!

Look on youtube for some videos of diggers lifting themselves into trucks using only their arms. Nothing magical there.

Quote from: The Traveller;562875I think there are a few concepts you might be mixing up here. Efficiency has many different uses for example. If you want to go fast in a straight line on a level surface, a tracked or wheeled design is the best. If you want to lift something from the ground to the top of a building, you need a crane which bears quite a lot of similarity to an arm. Cornering rapidly, sharp turns, these are things a mecha would do better - tanks can't shuffle sideways.

As far as I know, you raised those muscles for one of two reasons. You either wanted to show that movement with muscle like actuators is possible with these muscles, or/and wanted to show a type of engine that a tank can't utilize.

For one, you can already do everything these muscles do with hydraulics, wire, or mini actuators. Secondly, for them to move a mech more efficiently than any of the traditional methods, the muscles would have to put out more power than said methods. At which point you'd simply put them into a single drive train and give your tanks more power.

On shuffling sideways I would think it's a novelty, tanks and IFVs can't, but they can turn in place by moving one set of wheel on one side forward and the other backwards. Not very good for the transmission but very possible and fast, not to mention the transmission is quick to replace on MBTs.

QuoteThere's no particular reason why tank engines couldn't be put in a mecha, although from the looks of that link to metal muscle you might not need it, as it seems to be far more efficient (more power delivered per joule of energy put in) than hydraulics or any of those).

You can certainly put tank engines in mecha, but the drive train would become supremely complicated. A tank or IFV is more or less a box. Engines become more efficient the bigger you make them, and a box gives you the most amount of space for that compared to something human shaped or has to have the power routed through legs. You could have one big engine on the mech, but it still doesn't sold the design problem that legs issue.

QuoteThe main points I was touching on were that a) there are obstacles neither a tank nor a mecha can bull past, such as large trees where you don't have a good run at them, and b) there are often steep gradients which make tanks worthless jungle or not, which a mecha could ascend.

A tank doesn't really need to go very fast to push down a tree.

http://www.youtube.com/watch?v=MKnB5XabdxI

We're talking about 60 tons of metal moving at 5 mph. The amount of force even at that speeds is huge.

Besides, unless your forest or jungle is filled with meter thick, hundred feet tall trees, it's not going to be a problem. I mean, even by WW2, german tanks were steam rolling through the Ardennes forest. It might slow down a tank, but it's not that big of a deal on the issue of its mobility.

QuoteThe thing you're missing here is that tanks aren't usually very flexible. A mecha on the other hand can turn sideways, crouch down, bend, crawl, and even do a standing jump to get past obstacles.

Holy cow no on the jumping thing. Even if it weighs half as much as a MBT, it's way too heavy to jump and not incur any damage. The square inverse law would effectively shatter the mech at 30 tons if it dropped 2 meters. The amount of force a 30 ton object dropping from that height, or even half that height is immense.
The amount of power the legs need to generate is also absurdly high for that to happen. Even at 5 tons, the energy required to clear the ground to a point where we can't just raise the tank treads is absurd. Whatever you're generating that power with, you're going to have tanks zooming around like Ferraris.

Flexibility on the battle field isn't always a good thing either. For something ever so slightly bigger than power armor and is meant to fight infantry in building this might be a good thing, but flexibility often means  more points of weakness that you'll have to armor. For a mech to crawl, bend, crouch, or kneel, the amount of joints you need to cover up with armor increases exponentially putting more pressure on your engines and taking out your speed.

Besides which we already have vehicles that can kneel, or raise itself from its wheels. Modern day buses can kneel in order to accommodate handicapped persons. Tank destroyers and IFVs tend to have this ability as well.

QuoteActually just watch this video, which says it all:

http://www.youtube.com/watch?v=CD2V8GFqk_Y

Looks like John Deere had the same idea!

Did I seriously hear that guy say challenging terrain on an otherwise flat ground?

Have you seen logging shows? I've caught one where the logging cats had  the ability to lean too, and come with the advantage that during spring, they won't sink into the mud as the ice melts (and even given the huge surface area of these things they still get them stuck, let alone a mech and its feet).

QuoteThis is just as much of a problem for tanks though. Typically tanks deal with it by having lots of infantry around them in support, but if you wanted serious firepower on the spot you're out of luck in the jungle, unless you have a mecha there.

If we're talking about power armor, sure. But anything that can fight off an IFV and we're clearly talking about disproportionate technology application. The amount of power needed to move a mech comparable to how fast a single drive train vehicle can go, let alone how fast infantry can advance in the jungle and you're decades ahead of current technology. Whatever power source you're using for the mech, you can easily fit in with the tank with far better results. A better propulsion system for a tank and the more armor and weight you can fit on it as well as wider tracks. Vegetation's not going to be a problem in the jungle at that point.

The biggest danger in an area where it's not sure of its footing would be falling over. At over 10 tonnes, with something that complicated falling from an upright position, you're going to generate a huge amount of force falling over. It's like the difference between dropping a mouse off the roof and dropping an elephant off the roof. The mouse will be fine, and on the other hand you're going to hit the neighbors with elephant bits.
 

Quote

QuoteIf tanks need to get through forests, they don't tend to have much trouble, they just tend to crush everything in their way

Eh no, this is just factually wrong.

How so?

Quote

QuoteOriginally Posted by Swadius  
Another problem that the mech will have to confront is the soft ground that is often found in forests and jungles. If its ground pressure per square inch is too high, it's likely to sink into grass fields like it's a swamp on a rainy day. Most tanks nowadays try not to exert much more PSI than double that of a person. The abrams has a psi of 15. The average male has a psi of 8. The abrams is near the end of the heaviest main battle tanks in the world.

See the video above for that one.

How fast do you think a vehicle that needs to move SIX legs in order to complete one round of movement goes? What that guy has traded is psi advantage for a huge detriment to the speed at which the vehicle can go.

QuoteThere's a big difference between gunning up a ramp or a nice even hillock and driving up rugged and uneven terrain. Tanks can't even go over level rocky rugged terrain.

Can you show me what you mean by rocky terrain? As far as I know, this problem can be easily solved by sending in a wheeled IFV. A tank might not be able to go full speed up a maximum incline, but the suspension system is capable of letting obstacles slip under the fly wheels if you know what I mean.

QuoteLook on youtube for some videos of diggers lifting themselves into trucks using only their arms. Nothing magical there.

And look at how slow they do it. If your tanks are finding themselves having to go over things higher than themselves you simply need to make the treads higher. Kinda like the first world war tanks. This to to say nothing of simply moving the tank body higher than the treads. What this would do is raise the profile, though it would still provide a stable firing platform, carry a bigger weapon, be more armored, and be faster.

Quote from: Swadius;562889As far as I know, you raised those muscles for one of two reasons. You either wanted to show that movement with muscle like actuators is possible with these muscles, or/and wanted to show a type of engine that a tank can't utilize.

Actually I brought them up because another poster said they were physically impossible, when I knew they already existed.

Quote from: Swadius;562889For one, you can already do everything these muscles do with hydraulics, wire, or mini actuators.

Poorly and inefficiently, apparently. Have a read over that article.

Quote from: Swadius;562889Secondly, for them to move a mech more efficiently than any of the traditional methods, the muscles would have to put out more power than said methods. At which point you'd simply put them into a single drive train and give your tanks more power.

You can certainly put tank engines in mecha, but the drive train would become supremely complicated. A tank or IFV is more or less a box. Engines become more efficient the bigger you make them, and a box gives you the most amount of space for that compared to something human shaped or has to have the power routed through legs. You could have one big engine on the mech, but it still doesn't sold the design problem that legs issue.

To be honest these things are already being designed, so opinions on the matter of whether or not they can be built are moot. That scary looking robot mule isn't being built for the novelty value, its being built because tracks and wheels don't work in quite a lot of places.

Quote from: Swadius;562889A tank doesn't really need to go very fast to push down a tree.

http://www.youtube.com/watch?v=MKnB5XabdxI

We're talking about 60 tons of metal moving at 5 mph. The amount of force even at that speeds is huge.

Besides, unless your forest or jungle is filled with meter thick, hundred feet tall trees, it's not going to be a problem. I mean, even by WW2, german tanks were steam rolling through the Ardennes forest. It might slow down a tank, but it's not that big of a deal on the issue of its mobility.

Hahah, that's not a tree, that's a tall shrub. You seriously don't know what you're talking about here. Temperate European forest is quite capable of blocking tanks. Here's a bit more information:

QuoteIt must be realized that, in the jungle, tank movements are largely confined to roads or trails.

In the frontal attack, in thick jungle, it is unlikely that the tanks will be able to leave roads or trails

In thick jungle, tanks can do little or nothing to hold up the enemy

Quote from: Swadius;562889Holy cow no on the jumping thing. Even if it weighs half as much as a MBT, it's way too heavy to jump and not incur any damage. The square inverse law would effectively shatter the mech at 30 tons if it dropped 2 meters. The amount of force a 30 ton object dropping from that height, or even half that height is immense.
The amount of power the legs need to generate is also absurdly high for that to happen. Even at 5 tons, the energy required to clear the ground to a point where we can't just raise the tank treads is absurd. Whatever you're generating that power with, you're going to have tanks zooming around like Ferraris.

Its not a question that tanks will always be faster in more open terrain. That's not the point. As for dropping, again you're thinking in terms of a tank. Flexible joints will quite easily absorb enormous amounts of impact energy. You have a hugely better chance of surviving falling out of a plane onto a pile of straw than onto concrete for the same reason.

Quote from: Swadius;562889Flexibility on the battle field isn't always a good thing either. For something ever so slightly bigger than power armor and is meant to fight infantry in building this might be a good thing, but flexibility often means  more points of weakness that you'll have to armor. For a mech to crawl, bend, crouch, or kneel, the amount of joints you need to cover up with armor increases exponentially putting more pressure on your engines and taking out your speed.

So a bit like the treads and wheel sides of tanks then?

Quote from: Swadius;562889Besides which we already have vehicles that can kneel, or raise itself from its wheels. Modern day buses can kneel in order to accommodate handicapped persons. Tank destroyers and IFVs tend to have this ability as well.

Are you really trying to compare a bus tilting itself at a 15 degree angle to mecha-like agility?

Quote from: Swadius;562889Did I seriously hear that guy say challenging terrain on an otherwise flat ground?

Have you seen logging shows? I've caught one where the logging cats had  the ability to lean too, and come with the advantage that during spring, they won't sink into the mud as the ice melts (and even given the huge surface area of these things they still get them stuck, let alone a mech and its feet).

If we're talking about power armor, sure. But anything that can fight off an IFV and we're clearly talking about disproportionate technology application. The amount of power needed to move a mech comparable to how fast a single drive train vehicle can go, let alone how fast infantry can advance in the jungle and you're decades ahead of current technology. Whatever power source you're using for the mech, you can easily fit in with the tank with far better results. A better propulsion system for a tank and the more armor and weight you can fit on it as well as wider tracks. Vegetation's not going to be a problem in the jungle at that point.

The biggest danger in an area where it's not sure of its footing would be falling over. At over 10 tonnes, with something that complicated falling from an upright position, you're going to generate a huge amount of force falling over. It's like the difference between dropping a mouse off the roof and dropping an elephant off the roof. The mouse will be fine, and on the other hand you're going to hit the neighbors with elephant bits.

Can you show me what you mean by rocky terrain? As far as I know, this problem can be easily solved by sending in a wheeled IFV. A tank might not be able to go full speed up a maximum incline, but the suspension system is capable of letting obstacles slip under the fly wheels if you know what I mean.

And look at how slow they do it. If your tanks are finding themselves having to go over things higher than themselves you simply need to make the treads higher. Kinda like the first world war tanks. This to to say nothing of simply moving the tank body higher than the treads. What this would do is raise the profile, though it would still provide a stable firing platform, carry a bigger weapon, be more armored, and be faster

How so?

Lets just get this out of the way. You're saying tanks can go anywhere. I'm telling you that they can't, particularly not through jungle, and I have supplied links and facts in this post and throughout the thread to support this. Argue with them if you like.

Quote from: Swadius;562889How fast do you think a vehicle that needs to move SIX legs in order to complete one round of movement goes?

A lot faster than a tank that can't move at all. And thats assuming the JD machine is the final word on the subject, it really obviously isn't. The fact that its being produced at all means there is a recognition of the limitations of tracks and wheels.

Mecha don't need justification. Ever.

Quote from: The Traveller;562897Actually I brought them up because another poster said they were physically impossible, when I knew they already existed.

Ah, okay.

QuotePoorly and inefficiently, apparently. Have a read over that article.

"Nature's choice is to provide chemical power for natural actuators like muscles. Human engineers have typically taken another route, relying on converting electrical energy into mechanical energy using motors, hydraulic systems, or piezoelectric actuators."

The article states that hydraulics and electric actuators are inefficient because they need to convert electrical energy into mechanical energy. This is true for actuators, but not for hydraulics for which it seems the word he is looking for is inconvenient rather than inefficient when you look at how hydraulics work and how much power they can put out.
Another reason I think this is the case for hydraulics is because this method doesn't necessarily involve the conversion of electric power to mechanical power. There are gasoline and diesel powered hydraulic systems. Rather than converting electrical energy into mechanical energy, these engines do convert chemical energy into mechanical energy as well.

But we go back to the issue of design. A leg will inevitably require much more power to make it move, when it weighs much more than its scale in size, as a human. Any form of locomotion you give this mech, that can accomplish this incredibly feat will turn single drive vehicles into absolute beasts to deal with. The inefficiency of the design is such that you could probably get more if you put your mech on a bicycle (or mountain bike if we're talking about going through forests) as with a human being.

The costs of developing a vehicle from the ground up to soley fight in one terrain is a waste, considering all you need to do is to modify existing tracked or multi-wheeled vehicles to accommodate. It might make these single transmission vehicles severely disadvantage in other terrain, but they

QuoteTo be honest these things are already being designed, so opinions on the matter of whether or not they can be built are moot. That scary looking robot mule isn't being built for the novelty value, its being built because tracks and wheels don't work in quite a lot of places.

I've never questioned whether mechs can or cannot be built. Neither did premier as far as I remember. This argument is a strawman as our main argument is that all the mech's competing alternatives like tanks, IFVs, and weasel type vehicles pretty much have the upper hand in pretty much all the factors that matter the most.

QuoteHahah, that's not a tree, that's a tall shrub. You seriously don't know what you're talking about here. Temperate European forest is quite capable of blocking tanks. Here's a bit more information:

I've never argued that jungles and forests were the best places for tanks to be, but they can roll through most of them without much trouble. Trees thick and tall enough to stop a tank need a lot of jungle flooring to survive, and as such, if a mech can side step it, a tank can easily drive around it.

That being said I will have to comment on the fact that the articles you're brought up are from WWII. The tanks you're talking about are not MBTs. Aside from the tiger, no other tank weighed as much as today's tanks.

But even then, for the more powerful tanks of that era: http://www.youtube.com/watch?v=8T2hfpi3KLs&feature=player_detailpage#t=16s

Again the issue that would stop a mech is the ground pressure that it exerts. Most of the types of grounds tanks can go through small modern day cars simply can't due to the lack of traction.

QuoteIts not a question that tanks will always be faster in more open terrain. That's not the point. As for dropping, again you're thinking in terms of a tank. Flexible joints will quite easily absorb enormous amounts of impact energy. You have a hugely better chance of surviving falling out of a plane onto a pile of straw than onto concrete for the same reason.

Dropping into straw is true, but the mass of a mech is simply too big for the amount of  ground contact that they have. The best possible configuration for surviving a landing of even 2 meters with legs would be 1 very resilient leg. The issue again would be that the force of the impact travels upwards, the weakest link in the delicate machinery that makes a leg work would be broken even if there are parts in the foot that can absorb the impact.

Additionally, notice that when a person falls into your haystack, they shouldn't do it legs first. Professional stunt people fall on their backs to maximize the contact area with the straw. As such a tank would have an advantage over the mech due to it's incredibly ground contact area and the wide suspension systems. A tank's treads are not rigid, they flex upon impact. If you put a boulder in the path of a tank's treads, the individual fly wheels would go over it like the wheels of a cross country vehicle.

And again the issue of equivalency of tech is also at the forefront, I find it a little hard to imagine under what circumstances where you can fit in the required suspension system and shock absorbers into something as complicated as a mechanical leg, and yet not be able to put these onto already existing systems of locomotion and find more room for the suspension in said systems.

QuoteAre you really trying to compare a bus tilting itself at a 15 degree angle to mecha-like agility?

Read my comment again carefully. Compare? Other than that they can both do it? Yes. State that this is the best that we can do? No. I did raise the best that we could do or that which is practical: Tank destroyers.

On top of this, I don't think you've quite understood how slow mechs move with today's technology. Suppose you do, with the advent of new technology, make mechs as fast as you imagine. There's really no reason given the advance in technology that these technologies cannot be mounted onto a tracked vehicle and be made ever the more powerful than the mech due to its inefficient form of locomotion.

If you want your vehicle to jump left and right for some purpose I've questioned (and you've yet to defend), then simple put them on a tank. Raise the body of the tank as high as the challenger, make the treads higher, and put the jumping muscles into the treads. You'll not only have much more room to work with, but the amount of friction that treads will afford to you will be something that a mech won't get unless it too is tracked.

QuoteLets just get this out of the way. You're saying tanks can go anywhere.

No not really. I've never said they were totally submersible (though you can conceivably make them to be this way), they can't go into space (though you could make them that way), they can't move through the equivalent of the mined stockpile of a quarry (though you can make them that way), they have trouble going through forests and jungles (though there are things that you can do to maximize their ability to transverse these locations). The costs of modifying them to do such things however are going to be incredibly expensive just so you can have a vehicle that can operate in one type of setting efficiently and suffer massively in the others. Then you have to take into account of the cost of building a competing walking vehicle from the ground up.
 

QuoteI'm telling you that they can't, particularly not through jungle, and I have supplied links and facts in this post and throughout the thread to support this. Argue with them if you like.

The tanks that the British used in Burma were out of date shermans and lees. Both scraps left over from the lend lease agreement, and a lack of political will to defend India with adequate resources when Britain was threatened at home. The thing that won the theatre for the British was the commanders exploiting the speed at which their tanks and armored vehicles can move through the bush when the Japanese was falling back. The armored cars in particular were used to great effect as their much greater speed allowed them to maneuver far better, and I think this highlights a bit of an issue with the discussion of terrain we're having. Tanks might not be the best vehicle you want in a bush, but a mech doesn't not top the alternatives to the vehicles you could be using otherwise.

Tanks can more through jungle terrain:

http://blog.usni.org/wp-content/uploads/2009/10/marine_tank.jpg

It's not because of the trees, as you can see in the back ground jungle trees, other than on rare occasions get very thick. The tank in that picture is hounded by the biggest issue of jungle fighting with vehicles: Mud. As a sherman though, it's tiny tracks compared to an modern day MBT is more susceptible to this problem. How something that shuns the use of treads and uses a type of locomotion where you're basically chopping the treads into little shoes solves this problem is an issue is an issue I've not solved.

Spoiler

They will have trouble, but tanks are not necessarily confined to the trails other than in the worst places where even I suspect the more real anime mechs will have trouble transversing.

QuoteA lot faster than a tank that can't move at all. And thats assuming the JD machine is the final word on the subject, it really obviously isn't. The fact that its being produced at all means there is a recognition of the limitations of tracks and wheels.

JD machines is a gun company :/. Could you elaborate on this?

It might seem that everything that was ever invented might be of good use due to us not having any memory of failed inventions, but for every single successful design many other failed ones lie in its shadow.
For example: http://www.toptenz.net/top-10-failed-military-inventions.php

Many of those things were being researched and some were being produced and built, but none of them came out as well as expected.

Quote from: Phantom MechMecha don't need justification. Ever.

Some mechs don't. Tengen toppa gurren lagann doesn't, as do many super robot anime. There are however some mech series that seem to strive for a more close bound interpretation to our reality though. The gundam series was a series that tried to be more realistic than the dominating super robot types of shows at the time. The mechs needed other fighting vehicles like carriers and supporting fighting vehicles, and they needed maintenance and supplies. In short, if you point out a flaw in their design the creators would probably agree with you on that. It's no different than pointing out a plot hole.

Traveller, you obviously really, really want mecha to work.

You can have that in your games - you need no other justification beyond "mecha exist because AWESOME".

In real life, however, the laws of physics hate you and want you to die in a fire.  There's really no getting around that.

Quote from: daniel_ream;563135Traveller, you obviously really, really want mecha to work.

You can have that in your games - you need no other justification beyond "mecha exist because AWESOME".

In real life, however, the laws of physics hate you and want you to die in a fire.  There's really no getting around that.

His argument isn't rule of awesome though, he's just offering some reasons on why he thinks they might work. I want them to work too, and he might have a reason that might convince me of that, maybe he just hasn't gotten to it yet.

Quote from: Swadius;563107Any form of locomotion you give this mech, that can accomplish this incredibly feat will turn single drive vehicles into absolute beasts to deal with. The inefficiency of the design is such that you could probably get more if you put your mech on a bicycle (or mountain bike if we're talking about going through forests) as with a human being.

And yet John Deere seem to have mastered it, among others. As I said, I'm not disputing that tanks have a clear advantage in open level terrain. But there are lots of terrain types where they simply don't work.

Quote from: Swadius;563107The costs of developing a vehicle from the ground up to soley fight in one terrain is a waste, considering all you need to do is to modify existing tracked or multi-wheeled vehicles to accommodate.

No amount of modifications will make tanks work in jungles, unless you attach a twenty meter deep laser sword to the front and bring an engineering crew along, and then you may as well just bring a bulldozer and build roads instead. Combat wise it just wouldn't work.

Quote from: Swadius;563107I've never argued that jungles and forests were the best places for tanks to be, but they can roll through most of them without much trouble. Trees thick and tall enough to stop a tank need a lot of jungle flooring to survive, and as such, if a mech can side step it, a tank can easily drive around it.

That being said I will have to comment on the fact that the articles you're brought up are from WWII. The tanks you're talking about are not MBTs. Aside from the tiger, no other tank weighed as much as today's tanks.

But even then, for the more powerful tanks of that era: http://www.youtube.com/watch?v=8T2hfpi3KLs&feature=player_detailpage#t=16s

Again the issue that would stop a mech is the ground pressure that it exerts. Most of the types of grounds tanks can go through small modern day cars simply can't due to the lack of traction.

The tanks that the British used in Burma were out of date shermans and lees. Both scraps left over from the lend lease agreement, and a lack of political will to defend India with adequate resources when Britain was threatened at home. The thing that won the theatre for the British was the commanders exploiting the speed at which their tanks and armored vehicles can move through the bush when the Japanese was falling back. The armored cars in particular were used to great effect as their much greater speed allowed them to maneuver far better, and I think this highlights a bit of an issue with the discussion of terrain we're having. Tanks might not be the best vehicle you want in a bush, but a mech doesn't not top the alternatives to the vehicles you could be using otherwise.

Tanks can more through jungle terrain:

http://blog.usni.org/wp-content/uploads/2009/10/marine_tank.jpg

It's not because of the trees, as you can see in the back ground jungle trees, other than on rare occasions get very thick. The tank in that picture is hounded by the biggest issue of jungle fighting with vehicles: Mud. As a sherman though, it's tiny tracks compared to an modern day MBT is more susceptible to this problem. How something that shuns the use of treads and uses a type of locomotion where you're basically chopping the treads into little shoes solves this problem is an issue is an issue I've not solved.

Spoiler

They will have trouble, but tanks are not necessarily confined to the trails other than in the worst places where even I suspect the more real anime mechs will have trouble transversing.

No not really. I've never said they were totally submersible (though you can conceivably make them to be this way), they can't go into space (though you could make them that way), they can't move through the equivalent of the mined stockpile of a quarry (though you can make them that way), they have trouble going through forests and jungles (though there are things that you can do to maximize their ability to transverse these locations).

Pictures of tanks rolling along trails and in clearings mean very little. Here:
http://www.military-sf.com/infantry.htm

QuoteTraditionally, infantry units have fought where other units couldn't go. Mountains, jungles, and other types of rugged 'impassable' terrain are considered infantry terrain and infantry are the easiest kind of troops to produce. Tanks have a difficult time in the woods, most jungles render a tank useless and mountainous terrain is no friend of the tank either.

http://www.tanks.net/vietnam-war-tanks/index.html

QuoteAlthough a plethora of deadly weapons and new tactics for killing people were employed throughout the Vietnam War, only a handful of different tanks were used - this may be because of the terrain, which was often jungle interwoven with many rivers and swamps.

During the Vietnam war, about half the county was completely impassable to tanks, and that was during the dry season. Getting swamped by mud was far more of an issue in the paddy fields. Tanks did see use in the Vietnam war, mainly attacking urban areas and moving along trails and roads however, which was not in the jungle.

Quote from: Swadius;563107Dropping into straw is true, but the mass of a mech is simply too big for the amount of  ground contact that they have. The best possible configuration for surviving a landing of even 2 meters with legs would be 1 very resilient leg. The issue again would be that the force of the impact travels upwards, the weakest link in the delicate machinery that makes a leg work would be broken even if there are parts in the foot that can absorb the impact.

Again you seem to be conflating "precision" with "delicacy". A digger operator can part someone's hair, and nobody can say a digger is fragile.
http://www.youtube.com/watch?v=cuWSxFWv3Fo

Quote from: Swadius;563107Additionally, notice that when a person falls into your haystack, they shouldn't do it legs first. Professional stunt people fall on their backs to maximize the contact area with the straw. As such a tank would have an advantage over the mech due to it's incredibly ground contact area and the wide suspension systems. A tank's treads are not rigid, they flex upon impact. If you put a boulder in the path of a tank's treads, the individual fly wheels would go over it like the wheels of a cross country vehicle.

And again the issue of equivalency of tech is also at the forefront, I find it a little hard to imagine under what circumstances where you can fit in the required suspension system and shock absorbers into something as complicated as a mechanical leg, and yet not be able to put these onto already existing systems of locomotion and find more room for the suspension in said systems.

You aren't getting the physics here. The full weight of the machine doesn't come down all at once on small areas, but is spread out and distributed by the flexing as contact is made.

A better example would be recoil absorbers in guns, which work just fine without anyone get dislocated shoulders.

Quote from: Swadius;563107Tank destroyers.

Tanks have no advantages over mechs in this regard.

Quote from: Swadius;563107On top of this, I don't think you've quite understood how slow mechs move with today's technology. Suppose you do, with the advent of new technology, make mechs as fast as you imagine. There's really no reason given the advance in technology that these technologies cannot be mounted onto a tracked vehicle and be made ever the more powerful than the mech due to its inefficient form of locomotion.

And yet again we return to the fact that it doesn't matter how fast you can go if you aren't able to move. An F-16 is a hell of a lot faster than a submarine but it's not going anywhere underwater.

Quote from: Swadius;563107If you want your vehicle to jump left and right for some purpose I've questioned (and you've yet to defend)

I didn't think it needed defending, but if you like then evading incoming fire is a good reason.

Quote from: Swadius;563107The costs of modifying them to do such things however are going to be incredibly expensive just so you can have a vehicle that can operate in one type of setting efficiently and suffer massively in the others.

Then you have to take into account of the cost of building a competing walking vehicle from the ground up.

So given that the objection is now the cost, I take it you accept that mecha do have the upper hand over tanks in rugged mountainous terrain?

Quote from: daniel_ream;563135Traveller, you obviously really, really want mecha to work.

You can have that in your games - you need no other justification beyond "mecha exist because AWESOME".

In real life, however, the laws of physics hate you and want you to die in a fire.  There's really no getting around that.

Which laws of physics would those be?

I'm not particularly gone on the idea of mechs myself, but when in fact mechalike machines are being developed to replace mules for difficult terrain at this moment, I find the objections entertaining.

http://www.youtube.com/watch?v=y3W8dm5JxFc

None of cost, the laws of physics, maintenance issues, or any lack of AWESOME appear to be dissuading that horrible looking thing.

Quote from: The Traveller;563253I'm not particularly gone on the idea of mechs myself, but when in fact mechalike machines are being developed to replace mules for difficult terrain at this moment, I find the objections entertaining.

None of cost, the laws of physics, maintenance issues, or any lack of AWESOME appear to be dissuading that horrible looking thing.

It is possible to build just about any damn fool thing.  Whether that thing can do its job effectively, efficiently, or (for the purposes of this thread) better than the obvious and simpler alternative is the crux of the matter.

There are robotics hobbyists in Japan that have built a walking, armed mech.  That doesn't mean that walking, armed mechs are a good idea, or that they're ever going to be an effective combat vehicle.

Nobody here is saying that mechs aren't possible.  They're saying that mechs aren't feasible.

Quote from: daniel_ream;563348It is possible to build just about any damn fool thing.  Whether that thing can do its job effectively, efficiently, or (for the purposes of this thread) better than the obvious and simpler alternative is the crux of the matter.

There are robotics hobbyists in Japan that have built a walking, armed mech.  That doesn't mean that walking, armed mechs are a good idea, or that they're ever going to be an effective combat vehicle.

Nobody here is saying that mechs aren't possible.  They're saying that mechs aren't feasible.

Good thing the guys in DARPA aren't hobbyists then, isn't it, as they seem to think that robot mule is both feasible and neccessary. Otherwise surely a tracked or wheeled vehicle, or even an actual mule, would do the same job far better?

Quote from: The Traveller;563518Good thing the guys in DARPA aren't hobbyists then, isn't it, as they seem to think that robot mule is both feasible and neccessary.

... to carry a couple of backpacks or a wounded person across easy terrain. Note how they're not designing it to carry a big cannon and engage other heavily armoured targets while traversing genuinely heavy terrain, climbing trees etc..

Indeed, it's a good thing the guys in DARPA aren't hobbyists.

QuoteOtherwise surely a tracked or wheeled vehicle, or even an actual mule, would do the same job far better?

Nobody's arguing that a wheeled or tracked vehicle would do this particular job better. What people are trying to tell you is that they would do a tank's job better.

Quote from: Premier;563531... to carry a couple of backpacks or a wounded person across easy terrain. Note how they're not designing it to carry a big cannon and engage other heavily armoured targets while traversing genuinely heavy terrain, climbing trees etc..

Indeed, it's a good thing the guys in DARPA aren't hobbyists.

And I still remember when drones were unarmed. Missiles are already armed drones they said, enemy fighters can easily destroy remotely piloted drones they said. All true, but for a quite particular set of circumstances, drones are a good fit. But this is different, right?