The Problem with Giant Robots

[dragonfett]

I was reading a Cracked article about problems one would have with giant robots. Half the article deals with the issue of a lone person owning/operating a one off giant robot which would not be the case on Rifts Earth. But the other half of the list talks about physical/environmental limitations of having giant robots in the world. The article can be seen here:

http://www.cracked.com/blog/6-problems-you-are-going-to-run-into-with-your-giant-robot/

But I will summarize the points here:

Size
Nesting Birds
Teenagers
Distance from fellow man
Government
Combat Effectiveness

The two red ones I don't see as being a huge problem in Rifts Earth while the blue one might be an issue that commanders would want to look into, but that is beyond the scope of this post.

The three points that I wanted to mention were size, birds, and combat effectiveness.

The problem with size is that the volume (and therefore weight) of an object increases faster than its surface area would (also known as the sqare/cube law), which would cause problems with trying to walk on any ground that is not reinforced.

The problem with birds is that they like to make their nests where it's warm and cozy, but also in a small place (such as an exposed nook of a robot) and will defend what they perceive as a threat during mating seasons.

The problem with combat effectiveness is it's sight profile (what's easier to hit from a distance? The 30' tall robot vehicle with six legs, or the 8' literal tank)

Are there any other potential problems that giant robot could cause?

[Shark_Force]

you mean apart from the fact that legs are an incredibly inefficient way to move things around, even if the ground can actually support you?

anyways, i doubt nesting birds are likely to be a problem for rifts robots. last i recall, by default they're sealed to the point where you can walk around in them underwater. if water can't get in, neither can a bird (unless it comes equipped with a shaped charge or equivalent - though that isn't entirely improbable in rifts, to be fair)

[Blue_Lion]

I was reading a Cracked article about problems one would have with giant robots. Half the article deals with the issue of a lone person owning/operating a one off giant robot which would not be the case on Rifts Earth. But the other half of the list talks about physical/environmental limitations of having giant robots in the world. The article can be seen here:

http://www.cracked.com/blog/6-problems-you-are-going-to-run-into-with-your-giant-robot/

But I will summarize the points here:

Size
Nesting Birds
Teenagers
Distance from fellow man
Government
Combat Effectiveness

The two red ones I don't see as being a huge problem in Rifts Earth while the blue one might be an issue that commanders would want to look into, but that is beyond the scope of this post.

The three points that I wanted to mention were size, birds, and combat effectiveness.

The problem with size is that the volume (and therefore weight) of an object increases faster than its surface area would (also known as the sqare/cube law), which would cause problems with trying to walk on any ground that is not reinforced.

The problem with birds is that they like to make their nests where it's warm and cozy, but also in a small place (such as an exposed nook of a robot) and will defend what they perceive as a threat during mating seasons.

The problem with combat effectiveness is it's sight profile (what's easier to hit from a distance? The 30' tall robot vehicle with six legs, or the 8' literal tank)

Are there any other potential problems that giant robot could cause?

Size, and mass while moving would be big ones.
Birds nesting would be minimal, more of an pest issue. Once you move the robot the nest would be dislodged.
Humanoid shapes and tall objects are not optimized for combat and not the best choice. In addition high impacts on giant robots would have a greater affect on the center of balance and increase knock down risk. Being tall you can see better but you also can be detected easier. The hands on most robots are not really needed for combat its not like they typically care hand held weapons. (Some one will probably bring up they are useful for picking up and moving things but that is not why people buy combat robots there are non combat options that can do the same thing.)


The rise and fall as it moves along would be another issue for bipeds. Think about it when some runs or walks typically there is a little rise and fall as the legs pas under the main body it is pushed up when the leg moves away the body falls. This would be further enhanced during running. imagine getting pushed up and dropped 6 inches 120-180 times a minute. not going to be the most comfortable ride and because the scale is larger than normal might create some issues. Would robot pilots be prone to getting shaken baby syndrome?

[Alrik Vas]

Problems with giant Robots.

People with no sense of fun.

[Proseksword]

In addition to having an exceedingly high target profile, a bipedal war machine is also incredibly unstable, which makes it significantly more likely to be knocked over by weapons fire than a tank. Even an attack that wouldn't penetrate the armor may produce enough kinetic force to throw it on its back and injure/kill the pilot.

[kaid]

The biggest issues are high profile target and mobility on anything but very firm ground for a bipedal robot design.

Giant robot designs that would be reasonable are things like the NG scorpion robot vehicle. The main body is low to the ground and can basically lay flat if it needs to with only its tail exposed to shoot. The multiple legs fixes a lot of the issues with a bipedal design in that you gain both redundancy of losing a leg is not a total mobility kill and spreads the surface area of the weight out enough to be less prone to just sinking into the ground.

[Alrik Vas]

Look, everything should be tanks and APC/AFV's, realistically, we get it.

I think the real issue with giant robots is their stats. They done messed up big time and made them too vulnerable and most of them don't deal the damage needed to make up for it.

[Nightmask]

Look, everything should be tanks and APC/AFV's, realistically, we get it.

I think the real issue with giant robots is their stats. They done messed up big time and made them too vulnerable and most of them don't deal the damage needed to make up for it.

That's pretty much it, the bigger the vehicle the more durable it should get in general and with larger weapons should deal more damage it shouldn't deal equal to or less than someone in a smaller vehicle (i.e. power armor). About the only robot vehicle I've seen that really scaled up was the Battle Ram from Phase world, 70' tall with 2250 MDC and could launch ship-scale missiles and even it didn't scale up as much as it probably should have damage-dealing wise.

[Alrik Vas]

The BattleRam is indeed a serious piece of hardware. The Devastator Mk2 comes in as a middling range 2nd place there, just from the crazy amount of LRMs and the dual Boom Guns.

I think the Skull Smasher is a good medium class Robot. It's rather squat with wide feet at least. And the MRMs it mounts can dominate opponents. Though if it gets focused on without support even the 900+ MDC it has won't last that long.

[J_cobbers]

Bah, everything I know about Giant Bipedal Robots comes from Movies, Anime, Battletech, Rifts and video games, and they all tell me that super science and or magic fixes the weight to strength and mobility issues! Real life physics be dammned!

We need to be up high to be able to get a better angle of attack on those pesky tanks hiding behind their fortified position!

We need arms and legs to climb over steep and mountainous terrain or through woods where tracked vehicles can't go. Roads? Where we're going we don't need roads!

Seriously though, hexipedial locomotion or quadrupedal at the very least would probably be a lot better than bipedal. I see the original Spider Skull walker and it's CWC successors as somewhat more 'realistic' as potential armed weapons platforms that could handle a lot of adverse terrain, and by extension the Triax Bug and Land Crab robot vehicles as well.

[kaid]

Look, everything should be tanks and APC/AFV's, realistically, we get it.

I think the real issue with giant robots is their stats. They done messed up big time and made them too vulnerable and most of them don't deal the damage needed to make up for it.

Actually no. I would argue tanks/apc/afv in the rifts environment would be hugely vulnerable. One of the biggest dangers to tanks is infantry and always has been. Now add in infantry that is nearly as tough as the tank itself is AND is as fast or faster than the tank so the tank has no real hope of maintaining separation for firing = a really nasty environment to be a tanker.

Mechs advantage there is they are capable of hand to hand combat so if it turns into a scrum they have some way to defend themselves. For tanks if something like a power armor or a demon gets on top of them you are at best able to bring secondary weapons to shoot at them and may have troubles even using those at targets on the hull.

As awkward as bipedal robots would be in a land where giant creatures that are capable of quickly/instantly closing distance on you then their ability to actually fight competently in hand to hand combat is probably a valid reason to attempt that design. Something like the scorpion layout makes a lot more sense still able to fight things off in hand to hand low to the ground wider base to distribute weight.

[Blue_Lion]

Look, everything should be tanks and APC/AFV's, realistically, we get it.

I think the real issue with giant robots is their stats. They done messed up big time and made them too vulnerable and most of them don't deal the damage needed to make up for it.

Actually no. I would argue tanks/apc/afv in the rifts environment would be hugely vulnerable. One of the biggest dangers to tanks is infantry and always has been. Now add in infantry that is nearly as tough as the tank itself is AND is as fast or faster than the tank so the tank has no real hope of maintaining separation for firing = a really nasty environment to be a tanker.

Mechs advantage there is they are capable of hand to hand combat so if it turns into a scrum they have some way to defend themselves. For tanks if something like a power armor or a demon gets on top of them you are at best able to bring secondary weapons to shoot at them and may have troubles even using those at targets on the hull.

As awkward as bipedal robots would be in a land where giant creatures that are capable of quickly/instantly closing distance on you then their ability to actually fight competently in hand to hand combat is probably a valid reason to attempt that design. Something like the scorpion layout makes a lot more sense still able to fight things off in hand to hand low to the ground wider base to distribute weight.

There are ways to defend yourself from hand to hand that do not require clunky biped robots.
Without trying I can think of 3 ways to deal with them that are more practical.
Insolating the armor and running a nero-mace like charge through it.
Shaped charges to push them off the hard to shoot places so you can shoot and shoot them.
Laser network that can be turned on the hard to shoot spots.

not that most giant creatures are climbing on things to punch them.
In addition why does the tank not have support troops to help deal with boarders it is not like they can not keep up.

[kaid]

The problem with most of those is vs supernatural and power armor equipped infantry.

Neuro-mace stuff is not going to have any effect on borgs/demons/devils/power armor/eba equipped infantry
shaped charges help but those tend to be limited payload and combined that with how tough some of the infantry is unlikely to be sufficient to protect a tank from destruction.
As for a laser network we have seen no indication of anything like this implemented. It is a possible defense but your tank would have to darn near be a porcupine to cover all angles well enough.

If something like a hatchling dragon decides to teleport on top of your tank your tanker option currently are really limited. Some tanks do have AOE denial grenades/shaped charges but none that I have seen would do any more than annoy a hatchling before they are out of ammo. Depending where the hatchling lands there may literally be no weapons you can bring to bear other than potentially a hatch gun and that could be problematic if you don't want to get your head bitten off by a dragon.

A lot of demons are also pretty good teleporters and can do similar tactics.

Power armor and borgs are both tough enough to simply wade through a tanks defensive fire to get into range and are fast enough the tanks have no hopes of outrunning them typically. Once they get onto the hull of the tank you pretty much can't bring any primary weapons to bear vs them.

There are some potential ways to minimize there is a limit on what you can do with a tank when all your main weapons get negated. This is why tankers dreaded city fights if infantry can get up close to the tank it is really hard to use their big guns to bare. On rifts earth this would be hundreds of times worse due to how much tougher the infantry is and how much stronger their capabilities.

[kaid]

With support tanks can be useful but for small units a bipedal robot is capable of defending itself even vs these types of tactics where as a tank in a lot of cases simply is not. Overall rifts is a deadly environment for tanks and robot vehicles do have some usability there that does not exist in the modern world currently.

[Blue_Lion]

The problem with most of those is vs supernatural and power armor equipped infantry.

Neuro-mace stuff is not going to have any effect on borgs/demons/devils/power armor/eba equipped infantry
shaped charges help but those tend to be limited payload and combined that with how tough some of the infantry is unlikely to be sufficient to protect a tank from destruction.
As for a laser network we have seen no indication of anything like this implemented. It is a possible defense but your tank would have to darn near be a porcupine to cover all angles well enough.

If something like a hatchling dragon decides to teleport on top of your tank your tanker option currently are really limited. Some tanks do have AOE denial grenades/shaped charges but none that I have seen would do any more than annoy a hatchling before they are out of ammo. Depending where the hatchling lands there may literally be no weapons you can bring to bear other than potentially a hatch gun and that could be problematic if you don't want to get your head bitten off by a dragon.

A lot of demons are also pretty good teleporters and can do similar tactics.

Power armor and borgs are both tough enough to simply wade through a tanks defensive fire to get into range and are fast enough the tanks have no hopes of outrunning them typically. Once they get onto the hull of the tank you pretty much can't bring any primary weapons to bear vs them.

There are some potential ways to minimize there is a limit on what you can do with a tank when all your main weapons get negated. This is why tankers dreaded city fights if infantry can get up close to the tank it is really hard to use their big guns to bare. On rifts earth this would be hundreds of times worse due to how much tougher the infantry is and how much stronger their capabilities.

Where does it say that nero mace does not work on demons?
It was a way to deal with giant monsters closing to do melee.
Typically driving could deal with attempts of EBA to climb on. PA is usally better to shoot their guns than punch through. If they are climbing on you the driver can take actions to try and shake them off hard to punch something while clinging on for dear life.

Several rifts tanks have a coopla mini turret that could shoot the dragon hatchling siting on the main turrat.
The shaped charges where about nocking a clinger off so you can get positon to move and shoot them not about killing them. (you could use wide angle plasma ejectors tied to your power plant in as the charges. they need to be set up to hit people climbing up or on top the turrets blind spot.

Deepening on the tank it could be hard to take the fire of its weapons and get in melee. Specially considering unlike PA and borgs the tank can shoot and move with no penalty. So the tank can move a way from the PA and borg while gunning it down. It poses a risk only when they swarm you with numbers but in that case they could kill you quicker by shooting you than punching.

the laser net could be done based off an existing rifts weapon without turning your tank into a porcupine. Place a few modified Wilks laser Grenades in key positions and you can create a network that covers all the blind spots. Depending on the number of grenades and placement damage could very.

Risk of getting into hand to hand is a poor reason to justify use robots. Effort would be better spent exploring ways to make it hard for the demons to get in hand to hand.

the realistic problem with the bipedal robots is the ground would be unlikely to hold up to their movement resulting in them having poor ability to move in unreinforced land terrains. Not that it is used in rifts. An average 180 pound foot soldiers heal can strike the ground with 550 pounds of force.(state from a military class on mines.) What would be the impact force of 18 ton UAR-1? If the math was the same a 55 ton hammer every time it takes a step. Most terrain would break under such an on slot. Not that is impact force not sustain bearing force.
This sight shows similar math. http://hypertextbook.com/facts/1999/SaraBirnbaum.shtml
Several studies have shown similar numbers (looks like a one has a listed midstride ratio increase to speed.)


looking at the load bearing per square foot(from a table on footing for a house) of the ground, clay, sandy and silt soils have a load bearing of 2000 pounds per square foot, crystal line bedrock 12000 pounds per square foot. Source: Table 401.4.1; CABO One- and Two- Family Dwelling Code; 1995.

So we are loosing at a impact force 10 times stronger than the load bearing capacity of the crystalline bedrock bedrock in conscruction that seams like it would be sufficient force to break up most surface and cause footing issues.


Edit I found an equastion for cacualting the on the foot while traveling.

With a numerical approximation of the impulse of running in hand, we can now model the shape of the VGRF curve of a single step of a run. We initially assume that the VGRF curve is a parabola given by FR(t) = −at2 + bt + c, where 0 ≤ t ≤ T and T is the amount of time that the foot is in contact with the ground. The initial point of contact occurs at t = 0 while the last point of contact occurs at t = T. Notice that the first term of FR(t) is negative; this sign occurs because the VGRF curve is shaped like a parabola opening downward. Given FR(t), the impulse is given by I = −aT3 3 + bT2 2 + cT. There are numerous ways to determine the constants a, b, and c. Two logical boundary conditions are FR(0) = 0 and FR(T) = 0. These boundary conditions reduce the original equation to FR(t) = −a(t2 −Tt) = −at(t−T) with only one unknown parameter a. Now we can use FR(t) to calculate the impulse, I =RT 0 FR(t)dt = aT3 6 . Therefore, the size of the impulse depends on the size of the yet unknown parameter a. Visually, the most straightforward final assumption to find the final unknown parameter, a, is that the maximum value occurs approximately at the midpoint of the VGRF curve, i.e. F0 R(T 2 ) = 0. Interestingly, this condition is automatically satisfied due to the choice of a parabola to model the VGRF curve and the boundary conditions that have already been used. Since the maximum occurring at the midpoint is automatically satisfied, we can examine other possibilities to determine the final unknown, a. Assume the impulse, say I∗, is given
5
or calculated from the experimental data. Then, we can determine the quadratic curve for VGRF in running as F(1) R (t) = −6I∗ T3 t(t−T), where I∗ is the known impulse. We have called this approximation F(1) R (t) to differentiate it from the following approximation. Another possiblity is to assume that the maximum VGRF value, M, is given, i.e. FR(T/2) = M. Then, F(2) R (t) = −4M T2 t(t−T) with an impulse given by
I =2MT /3
. (1)
The size of the impulse depends on what happens to the value of MT, where M is the maximum value of the VGRF and T is the amount of time that the runner’s foot is in contact with the ground. Notice that the mathematics completely agrees with the definition in the Introduction. We can now use (1) to calculate the impulse of F(2) R (t) from Figure 2. With T = 0.2237 seconds and M = 2158.8 N, the impulse is I = 321.964 N·s, which is larger than the numerical value of 309 N·s. This discrepancy, along with the poor visual match of the quadratic approximation with the experimental data, motivates the following section where we introduce additional biomechanical concepts.

http://mathaware.org/mam/2010/essays/To ... unWalk.pdf

Some of the equation may have been damaged in cut in passed. Such as I= 2mt over(divided by) 3
I am sure some math buff could use that to estimate the force of a giant robots foot steps.

[ShadowLogan]

Look, everything should be tanks and APC/AFV's, realistically, we get it.

I think the real issue with giant robots is their stats. They done messed up big time and made them too vulnerable and most of them don't deal the damage needed to make up for it.

Giant Robots aren't any more messed up in their game stats than your tanks/APC/AFV (and other vehicles) though. Not looking at specific cases, their total MDC to mass ratios range in the 0.## (and big heavies like capital ships have even smaller value), where Power Armor/EBA/Borgs are 1.0>=. Typical weapons in either zone aren't classed much different in terms of damage and though range tends to favor the larger platforms.

Seriously though, hexipedial locomotion or quadrupedal at the very least would probably be a lot better than bipedal. I see the original Spider Skull walker and it's CWC successors as somewhat more 'realistic' as potential armed weapons platforms that could handle a lot of adverse terrain, and by extension the Triax Bug and Land Crab robot vehicles as well.

I agree, though I'd probably also add in the hybrids that have an upper body humanoid with a vehicular lower body like Fury Iron Juggernaut (SoT#1 pg86-7 TW I know but its the concept), or Holocaust Cyborg Shocktrooper, WoR pg126-8, yes I know its a borg but its the concept), or Mindwerk's T-1000/1200 (SB3 pg27-30, both are drones its the concept though) would be a good compromise.

Mechs advantage there is they are capable of hand to hand combat so if it turns into a scrum they have some way to defend themselves. For tanks if something like a power armor or a demon gets on top of them you are at best able to bring secondary weapons to shoot at them and may have troubles even using those at targets on the hull.

As Blue_Lion said there are ways to address this in some form that don't require giving them legs. You could give an armored vehicle limbs (arm/tentacle/tail type) for HTH engagements.

Neuro-mace stuff is not going to have any effect on borgs/demons/devils/power armor/eba equipped infantry

Maybe if we read to closely to the "neuro-mace like" to being the CS Neuro-mace for hand-held use, but heavier versions we find similar weapons do exist that can hurt (as in doing Mega Damage!) which is what I think Blue_Lion was thinking of more or less:
-H-02 Stunner (on the IAR-4 Hellraiser, CWC pg142) could be seen as "neuro-mace like"
-Electro Mace (X-2500 & X-2700 Giant Robots in WB5) could be seen as "neuro-mace like"

Then you have field effects like the Solar Combat Armor (SA2 pg64-6) or the Sun Chariot (Naruni Wave 2 pg57-60) or the personal harness in Spyn Market (pg163-4) that mimics Burster-style flame auras that one can find in a few other places (various SA1 & SA2 mutants, Psycape RCCs, probably others). Not to mention Kittani Plasma melee weapons or their more conventional energy counterparts (they surround the weapon's blade with an energy field, same principle). And I'm avoiding the magical stuff that can do the same thing.

Or adapt aerial denial systems based on Wilk's Blinder grenades (mentioned), or a couple of South America 2 systems ("Death Mirrors" on the Mastodon 'Bot, and the SLAS on the Puma Medium Battle Tank), Naruni's Blinding Flash Photon Flash Generator (Naruni Wave 2, NE-1A Tech Warrior PA), chemical sprays, could prove inspirational.

[Blue_Lion]

Look, everything should be tanks and APC/AFV's, realistically, we get it.

I think the real issue with giant robots is their stats. They done messed up big time and made them too vulnerable and most of them don't deal the damage needed to make up for it.

Giant Robots aren't any more messed up in their game stats than your tanks/APC/AFV (and other vehicles) though. Not looking at specific cases, their total MDC to mass ratios range in the 0.## (and big heavies like capital ships have even smaller value), where Power Armor/EBA/Borgs are 1.0>=. Typical weapons in either zone aren't classed much different in terms of damage and though range tends to favor the larger platforms.

Seriously though, hexipedial locomotion or quadrupedal at the very least would probably be a lot better than bipedal. I see the original Spider Skull walker and it's CWC successors as somewhat more 'realistic' as potential armed weapons platforms that could handle a lot of adverse terrain, and by extension the Triax Bug and Land Crab robot vehicles as well.

I agree, though I'd probably also add in the hybrids that have an upper body humanoid with a vehicular lower body like Fury Iron Juggernaut (SoT#1 pg86-7 TW I know but its the concept), or Holocaust Cyborg Shocktrooper, WoR pg126-8, yes I know its a borg but its the concept), or Mindwerk's T-1000/1200 (SB3 pg27-30, both are drones its the concept though) would be a good compromise.

Mechs advantage there is they are capable of hand to hand combat so if it turns into a scrum they have some way to defend themselves. For tanks if something like a power armor or a demon gets on top of them you are at best able to bring secondary weapons to shoot at them and may have troubles even using those at targets on the hull.

As Blue_Lion said there are ways to address this in some form that don't require giving them legs. You could give an armored vehicle limbs (arm/tentacle/tail type) for HTH engagements.

Neuro-mace stuff is not going to have any effect on borgs/demons/devils/power armor/eba equipped infantry

Maybe if we read to closely to the "neuro-mace like" to being the CS Neuro-mace for hand-held use, but heavier versions we find similar weapons do exist that can hurt (as in doing Mega Damage!) which is what I think Blue_Lion was thinking of more or less:
-H-02 Stunner (on the IAR-4 Hellraiser, CWC pg142) could be seen as "neuro-mace like"
-Electro Mace (X-2500 & X-2700 Giant Robots in WB5) could be seen as "neuro-mace like"

Then you have field effects like the Solar Combat Armor (SA2 pg64-6) or the Sun Chariot (Naruni Wave 2 pg57-60) or the personal harness in Spyn Market (pg163-4) that mimics Burster-style flame auras that one can find in a few other places (various SA1 & SA2 mutants, Psycape RCCs, probably others). Not to mention Kittani Plasma melee weapons or their more conventional energy counterparts (they surround the weapon's blade with an energy field, same principle). And I'm avoiding the magical stuff that can do the same thing.

Or adapt aerial denial systems based on Wilk's Blinder grenades (mentioned), or a couple of South America 2 systems ("Death Mirrors" on the Mastodon 'Bot, and the SLAS on the Puma Medium Battle Tank), Naruni's Blinding Flash Photon Flash Generator (Naruni Wave 2, NE-1A Tech Warrior PA), chemical sprays, could prove inspirational.

I was thinking the damage laser grenade not the blinder, but blinding weapons work as well.

[guardiandashi]

one counter argument to the "enormous impact/groundpressure" issue for giant robots is that it can be mitigated pretty easily.

the enormous impact can be mitigated by having shock systems in the legs and feet, instead of the foot placement being considered an "instantaneous" full loading, it uses springs in a manner akin to a recoil suppressing mount, and goes from no loading to full loading over a period of time (typically 1-3 seconds) this of course also limits the movement speed of said vehicle as it limits the stride rate.

as far as ground pressure considerations if the feet are proportionally comparable in size (or bigger) than a humans foot it is quite possible that the ground pressure "footprint" can be significantly mitigated and or reduced. example you have a 25 ton giant robot if each foot (2) is 250 square inches (only 25 inches by 10 inches pretty small actually) the ground pressure when standing on both feet would be 100psi, and on 1 foot 200psi if you doubled the are of the feet (25 inches by 20 inches) it would be 50/100 psi the typical ground pressure for a human foot is ~16psi to reach that loading would require 2 ~40in X 40in feet

[eliakon]

Don't forget. Rifts robots are made of some sort of advanced aerogel metal or something... As huge multi-story robots only weigh twenty or thirty tons.
Combined with the size of the foot of those robots they are not in danger of sinking into the ground in most cases.

[Blue_Lion]

one counter argument to the "enormous impact/groundpressure" issue for giant robots is that it can be mitigated pretty easily.

the enormous impact can be mitigated by having shock systems in the legs and feet, instead of the foot placement being considered an "instantaneous" full loading, it uses springs in a manner akin to a recoil suppressing mount, and goes from no loading to full loading over a period of time (typically 1-3 seconds) this of course also limits the movement speed of said vehicle as it limits the stride rate.

as far as ground pressure considerations if the feet are proportionally comparable in size (or bigger) than a humans foot it is quite possible that the ground pressure "footprint" can be significantly mitigated and or reduced. example you have a 25 ton giant robot if each foot (2) is 250 square inches (only 25 inches by 10 inches pretty small actually) the ground pressure when standing on both feet would be 100psi, and on 1 foot 200psi if you doubled the are of the feet (25 inches by 20 inches) it would be 50/100 psi the typical ground pressure for a human foot is ~16psi to reach that loading would require 2 ~40in X 40in feet

Yea basically means your doing a slow walk with your suppression mount system.
Military walking cadence for walking is about 120 steps per minute you just cut it down to 20-60, the thing would be really slow and not effective.

The issue becomes the increase in force of impact and push off needed for high speed. Movement requires applying force greater than the standing weight typically at an area less than the full foot size. The highest amount happens at the point you push the foot off the ground. (meaning shock abosrbers will not get rid of the high point as at the push off point.) At human speeds the force is 3-7 times the body wight but the faster you to the more force you create. Shock abosrbors typically will be required to try and reduce shaken pilot syndrome.

It the ground can bear 2000-12000 pounds per square foot, and you have a foot with 200 psi X144 that is 28800 per square foot well over over what the soil is rated to support. So it is going to have significant amount of sinking in the ground in the ground. Much higher at key points of movement such as heel strike and push off while running.

[Alrik Vas]

Isn't that why you see tread heels in some mecha anime? So the giant can move more easily and mitigate some of the problems of it's high profile by being evasive?

That might make the high vantage point more than worth it. Though this is the sort of thing that RPG designers don't consider all the time, and when they do it's generally because the art looked cool.

[Blue_Lion]

I think the biggest problem I have with giant robots and tanks is they are over priced for their survival ability.
In RUE the Titan combat robot is complete garbage. 370 MD main body for 24 million credits only thing it has on cheaper power armor is its MRM. For the cost of one titan combat robot you can buy 24 Samson PA. Or 15 PA and load some mountaineer ATV with LRM.

[ShadowLogan]

I was thinking the damage laser grenade not the blinder, but blinding weapons work as well.

Sorry I think of the Beehive and Blinder as beeing in the same sub-category so lumped them together.

I think the biggest problem I have with giant robots and tanks is they are over priced for their survival ability.
In RUE the Titan combat robot is complete garbage. 370 MD main body for 24 million credits only thing it has on cheaper power armor is its MRM. For the cost of one titan combat robot you can buy 24 Samson PA. Or 15 PA and load some mountaineer ATV with LRM.

The problem though stems from the Palladium System's inability to handle scale well and we see it in a variety of places, this being one of them. The system needs a plug-in to handle scale mis-matches such as this.

Don't forget. Rifts robots are made of some sort of advanced aerogel metal or something... As huge multi-story robots only weigh twenty or thirty tons.
Combined with the size of the foot of those robots they are not in danger of sinking into the ground in most cases.

Really? Lets take a look...

I pulled Mercenaries SB, Merc Ops SB, CWC WB, SA1 WB and Rifts Main Book off my shelf (I could add more books in, but for various reasons I won't) and calculated a rough PSI they exert by using their fully loaded weight (when expressed) and their width and length for armored vehicles (non-hovercraft) and giant bi-pedal robots (or at least most of them in both cases). I converted the tons into lbs, and the width and length into area expressed in inches. Then divided them out. Yes I know in both cases I'm giving them area they won't actually get so the values would be higher in both cases, but lets assume they can distribute their entire weight on their idealized available area and posted the PSI results below.

We should also keep in mind that the armored vehicles will keep a pretty even amount while in motion (barring any stunt driving), but the walking giant robots will see their values x2 each time they raise a foot as they have now lost contact area. In the sample I'm posting we can see that the armored vehicles out perform all but 1 giant bot (maybe another, but both have distorted lengths so I'm not considering them)) as the highest/worst armored score was ~2.1psi vs the 'bot's lowest/best of ~1.9psi which doubles to ~3.8psi when walking which gives the tanks some comfortable margin.

The Giant Robots (all Bipedal), using IDEALIZED Surface Areas:
EX-5 Behemoth: ~13.2psi (RMB weight, if one uses the revised weight in WB33 mentioned elsewhere it works out to ~0.2psi, its length distorts things though in either case)
IAR-4: ~8.1psi
IAR-3: ~5.7psi
IAR-5: ~4.9psi
Naruni Nomad Scout: ~4.8psi
Titan Recon: ~4.4psi
IAR-2: ~4.2psi
GA-9 Jaguar: ~3.2psi
Licator: ~3.1psi
Titan Explo & Light Combat: ~3.1psi
CS UAR-1: ~2.8psi
Naruni Death Knight: ~2.5psi
Titan Combat: ~2.2psi
Heavy Titan Combat Robot: ~2.1psi
G-18 Aguirre: ~1.9psi
Dragon Death PA: ~1.9psi (while technically a PA, its size is that of a giant robot)
Kittani T-Rex: ~0.6psi (while bipedal, it's length distorts things)

Tanks & Armored Vehicles using IDEALIZED surface areas:
Iron Hammer: ~2.1psi
Iron Bolt: ~1.7psi
Iron Fist: ~1.5psi
CS Grinning Tank: ~1.4psi
Stinger Light Tank: ~1.3psi
GAW-M1A3: ~1.3psi (an M1A1 at 63tons would be ~2.0psi)
GAW-M113: ~1.2psi
Iron Maiden Tank: ~1.1psi
Lancero: ~0.8
CS M9 EPC: ~0.6psi

EDIT: I added in applicable Merc Ops vehicles and giant robots. I also tried to be clear that the surface areas used are idealized

[Alrik Vas]

Iron Hammer is 2.1psi...lol

M1A1 is 15psi.

2psi is recommended for soft ground like marshland. though i suppose depending on the way your traverse it, that might have an impact on how well you do.

Was looking at a wikipedia article on Ground Pressure.

[dragonfett]

Iron Hammer is 2.1psi...lol

M1A1 is 15psi.

2psi is recommended for soft ground like marshland. though i suppose depending on the way your traverse it, that might have an impact on how well you do.

Was looking at a wikipedia article on Ground Pressure.

The Iron Hammer is also 20' tall vs. the M1A1's 8' tall.

It's also 35' long and 12' wide, but I doubt that the weight would be on the full width. I would say that the effective load bearing width would be about 4' total.

[Blue_Lion]

Iron Hammer is 2.1psi...lol

M1A1 is 15psi.

2psi is recommended for soft ground like marshland. though i suppose depending on the way your traverse it, that might have an impact on how well you do.

Was looking at a wikipedia article on Ground Pressure.

The Iron Hammer is also 20' tall vs. the M1A1's 8' tall.

It's also 35' long and 12' wide, but I doubt that the weight would be on the full width. I would say that the effective load bearing width would be about 4' total.

It is quit tall for a tank. Perhaps because of the double turret.

I highly doubt most robots have feet any where close to width X length. His formula used the max area because we are not giving a size for the feet tires, or tracks.

[ShadowLogan]

Iron Hammer is 2.1psi...lol

M1A1 is 15psi.

2psi is recommended for soft ground like marshland. though i suppose depending on the way your traverse it, that might have an impact on how well you do.

Was looking at a wikipedia article on Ground Pressure.

To be clear:

All the PSI values I calculated used an idealized surface area since there is no easy way to determine the size of the tracks on the armored vehicle or the foot of the giant robot. To be fully comparable both used the idealized surface areas available to them, not their actual surface areas from the wheel/tread/foot that we have no way to easily determine.

Using the idealized surface area, the GAW-M1A3 in Merc Ops (basically an upgraded M1A1, but about 23tons lighter) has ~1.3psi (~2.0 at the 63tons of the M1A1) and the GAW-M113 is ~1.1psi. The Titan Heavy Combat Robot (only robot in the book, though several power armor) comes in at ~2.1psi.

[Alrik Vas]

I'm confused. What is the "idealized" surface area?

[Blue_Lion]

I'm confused. What is the "idealized" surface area?

Length X width.

[ShadowLogan]

I'm confused. What is the "idealized" surface area?

As Blue_Lion has said.

Its basic geometry of a rectangular object.

Listed Length x Listed Width = total possible surface area. Everything was put into inches from the listed feet (and weight was put into pounds).

Maybe I missed it, but where in the Rifts books I cited does it describe the length and width of the tracks on those armored vehicles or even the size of the giant robot's foot? Without those numbers we do not have the ability to calculate the actual surface area. All we can do from the information in those books is to generate an idealized best case scenario based on their stated dimensions.

[Alrik Vas]

And that's totally fair, honestly. Fortunate they actually give us length and width of even robots. Most games aren't generally so precise (even if inaccurate to reality ).

In any case I think it might be fair to run treads 85% of the tank's length and between the two of them, give them together about 1/4 of it's width. That's just ballpark without even looking at pictures. Robots for the most part would be less of a percentage of their area. Except when the feet are obviously huge (like with a Glitter Boy, specifically).

I get that you're going best case, but we know it's not accurate.

[eliakon]

Don't forget. Rifts robots are made of some sort of advanced aerogel metal or something... As huge multi-story robots only weigh twenty or thirty tons.
Combined with the size of the foot of those robots they are not in danger of sinking into the ground in most cases.

Really? Lets take a look...

I pulled Mercenaries SB, Merc Ops SB, CWC WB, SA1 WB and Rifts Main Book off my shelf (I could add more books in, but for various reasons I won't) and calculated a rough PSI they exert by using their fully loaded weight (when expressed) and their width and length for armored vehicles (non-hovercraft) and giant bi-pedal robots (or at least most of them in both cases). I converted the tons into lbs, and the width and length into area expressed in inches. Then divided them out. Yes I know in both cases I'm giving them area they won't actually get so the values would be higher in both cases, but lets assume they can distribute their entire weight on their idealized available area and posted the PSI results below.

We should also keep in mind that the armored vehicles will keep a pretty even amount while in motion (barring any stunt driving), but the walking giant robots will see their values x2 each time they raise a foot as they have now lost contact area. In the sample I'm posting we can see that the armored vehicles out perform all but 1 giant bot (maybe another, but both have distorted lengths so I'm not considering them)) as the highest/worst armored score was ~2.1psi vs the 'bot's lowest/best of ~1.9psi which doubles to ~3.8psi when walking which gives the tanks some comfortable margin.

The Giant Robots (all Bipedal), using IDEALIZED Surface Areas:
EX-5 Behemoth: ~13.2psi (RMB weight, if one uses the revised weight in WB33 mentioned elsewhere it works out to ~0.2psi, its length distorts things though in either case)
IAR-4: ~8.1psi
IAR-3: ~5.7psi
IAR-5: ~4.9psi
Naruni Nomad Scout: ~4.8psi
Titan Recon: ~4.4psi
IAR-2: ~4.2psi
GA-9 Jaguar: ~3.2psi
Licator: ~3.1psi
Titan Explo & Light Combat: ~3.1psi
CS UAR-1: ~2.8psi
Naruni Death Knight: ~2.5psi
Titan Combat: ~2.2psi
Heavy Titan Combat Robot: ~2.1psi
G-18 Aguirre: ~1.9psi
Dragon Death PA: ~1.9psi (while technically a PA, its size is that of a giant robot)
Kittani T-Rex: ~0.6psi (while bipedal, it's length distorts things)

Tanks & Armored Vehicles using IDEALIZED surface areas:
Iron Hammer: ~2.1psi
Iron Bolt: ~1.7psi
Iron Fist: ~1.5psi
CS Grinning Tank: ~1.4psi
Stinger Light Tank: ~1.3psi
GAW-M1A3: ~1.3psi (an M1A1 at 63tons would be ~2.0psi)
GAW-M113: ~1.2psi
Iron Maiden Tank: ~1.1psi
Lancero: ~0.8
CS M9 EPC: ~0.6psi

EDIT: I added in applicable Merc Ops vehicles and giant robots. I also tried to be clear that the surface areas used are idealized

Um yeah...
Those numbers look impressive until you compare them to real world comparisons.

Hovercraft: 0.7 kPa (0.1 psi)
Human on Snowshoes: 3.5 kPa (0.5 psi)
Rubber-tracked ATV: 5.165 kPa (0.75 psi)
Diedrich D-50 - T2 Drilling rig: 26.2 kPa (3.8 psi)
Human male (1.8 meter tall, medium build): 55 kPa (8 psi)
M1 Abrams tank: 103 kPa (15 psi)
1993 Toyota 4Runner / Hilux Surf: 170 kPa (25 psi)
Adult horse (550 kg, 1250 lb): 170 kPa (25 psi)
Bagger 288 Excavation machine: 170 kPa (25 psi)
Passenger car: 205 kPa (30 psi)
Wheeled ATV: 13.8 kPa (2 psi)
Adult elephant: 240 kPa (35 psi)
Mountain bicycle: 245 kPa (40 psi)
Road racing bicycle: 620 kPa (90 psi)
Stiletto heel: 3,250 kPa (471 psi)

(From the Wikipedia)

[ShadowLogan]

I get that you're going best case, but we know it's not accurate.

And I never say they are going to be accurate, just idealized so if someone tries to claim they are accurate didn't read close enough.

But even there, we can see that GRs are going to exert more ground pressure than a conventional armored vehicle.

Um yeah...
Those numbers look impressive until you compare them to real world comparisons.

The point though isn't to be impressed by the actual numbers, the point is to show that giant robots have more ground pressure than conventional armored vehicles. And last I checked:
-we don't have any actual giant bi-pedal robots on that list
-Rifts platforms do not allow knowing the actual areas (unless you can point to the text in the books that give us this)
-if we attempt to extrapolate from the artwork, we run into the issue of is art cannon, perspective distortion, and doing case-by-case
-if we attempt to apply a standard % for either case to get a more accurate surface area
--how do we determine that standard %
--and is it going to be contested (granted idealized can be contested)
--what about special cases that exist with the data set (wheels vs treads, or non-human foot, which is in the dataset).

I also make no attempt to portray these as the actual ground pressure exerted, only the idealized ground pressure because that is all we can calculate with the Rifts platforms to any degree of actual certainty. I'm done debating the idealized nature of the data.

[Blue_Lion]

well we do have gaint robots https://www.kickstarter.com/projects/me ... escription
and a upcoming epic battle.

[ShadowLogan]

well we do have gaint robots https://www.kickstarter.com/projects/me ... escription
and a upcoming epic battle.

I know people are trying to make them, but none are included on the list eliakon posted.

It is also noticeable that the kickstarter project you link to doesn't have bipedal designs show cased either, but a tread system (and its competitor has wheels). Yes they have a video of bipedal walking, but the robot they plan to use in the competition doesn't have it.

[Blue_Lion]

well we do have gaint robots https://www.kickstarter.com/projects/me ... escription
and a upcoming epic battle.

I know people are trying to make them, but none are included on the list eliakon posted.

It is also noticeable that the kickstarter project you link to doesn't have bipedal designs show cased either, but a tread system (and its competitor has wheels). Yes they have a video of bipedal walking, but the robot they plan to use in the competition doesn't have it.

Neither are bipedal do to problems with that type of movement on the scale they are built on. But you can not say we have no giant robots.

[eliakon]

I get that you're going best case, but we know it's not accurate.

And I never say they are going to be accurate, just idealized so if someone tries to claim they are accurate didn't read close enough.

But even there, we can see that GRs are going to exert more ground pressure than a conventional armored vehicle.

Um yeah...
Those numbers look impressive until you compare them to real world comparisons.

The point though isn't to be impressed by the actual numbers, the point is to show that giant robots have more ground pressure than conventional armored vehicles.

My point is that if the "idealized" ground pressure is, for example the 2.8 PSI of the UAR-1 then it will have to be more than 1/30th of idealized to have a PSI greater than a mountain bike. Unless some is going to argue that mountain bikes fall through the earth all the time then the "PSI is to high" argument seems to have a minor problem.

[Jefffar]

This has been discussed in the past

viewtopic.php?f=9&t=62858

viewtopic.php?f=8&t=93008

viewtopic.php?f=9&t=40678

[Blue_Lion]

Seams unlike the other rifts thread you posted this is more about the realistic capabilities.

[ShadowLogan]

Neither are bipedal do to problems with that type of movement on the scale they are built on. But you can not say we have no giant robots.

except I didn't say "we don't have any giant robots" I said: "we don't have any actual giant bi-pedal robots on that list" (emphasis mine)

There is a bit of a difference there, one is generic catch all term and one is a specific sub-category. If one is looking to showcase a giant bipedal robot's ground pressure in comparison to other known items (as I did), then it makes sense to put applicable examples on the list (which I did, but eliakon's provided list did not).

My point is that if the "idealized" ground pressure is, for example the 2.8 PSI of the UAR-1 then it will have to be more than 1/30th of idealized to have a PSI greater than a mountain bike. Unless some is going to argue that mountain bikes fall through the earth all the time then the "PSI is to high" argument seems to have a minor problem.

Yes there is a difference between the "idealized" and "actual" ground pressure. I do not dispute that, nor do I hide that, nor do present it as anything that what it is. However with the available information on the units in the books we can not know the "actual" ground pressure which requires us to either "idealize" it or "guesstimate". Comparing my list using "idealized" ground pressure versus wikipedia's "actual" ground pressure is like comparing apples and oranges.

You are free to recalculate the ground pressure of the Rifts Books examples cited to be closer to actual if you don't like the "idealized" approach.

[eliakon]

Neither are bipedal do to problems with that type of movement on the scale they are built on. But you can not say we have no giant robots.

except I didn't say "we don't have any giant robots" I said: "we don't have any actual giant bi-pedal robots on that list" (emphasis mine)

There is a bit of a difference there, one is generic catch all term and one is a specific sub-category. If one is looking to showcase a giant bipedal robot's ground pressure in comparison to other known items (as I did), then it makes sense to put applicable examples on the list (which I did, but eliakon's provided list did not).

My point is that if the "idealized" ground pressure is, for example the 2.8 PSI of the UAR-1 then it will have to be more than 1/30th of idealized to have a PSI greater than a mountain bike. Unless some is going to argue that mountain bikes fall through the earth all the time then the "PSI is to high" argument seems to have a minor problem.

Yes there is a difference between the "idealized" and "actual" ground pressure. I do not dispute that, nor do I hide that, nor do present it as anything that what it is. However with the available information on the units in the books we can not know the "actual" ground pressure which requires us to either "idealize" it or "guesstimate". Comparing my list using "idealized" ground pressure versus wikipedia's "actual" ground pressure is like comparing apples and oranges.

You are free to recalculate the ground pressure of the Rifts Books examples cited to be closer to actual if you don't like the "idealized" approach.

The point is that if the claim is that the Giant Robot will not work because of ground pressure, but when calculated the ground pressures don't get higher than things which we know don't have ground pressure issues, then I am going to have to call BS. The foot size of the robot to get a PSI higher than 30 let alone 50 is small enough that I am HIGHLY skeptical that any robot can be honestly argued to have them.

<Edit>
It was pointed out to me that the Spider Skull Walker has absurdly tiny feet. But barring the few things like that I am unconvinced.

[rem1093]

I have a question about the robots walking and ground pressure, how does it compares to a 10 tom Giganotosaurus, or even other Giant races?

[say652]

While i don't completely understand the math, i believe the calculating is based on the GR having a foot size equivalent to its height.

[glitterboy2098]

I have a question about the robots walking and ground pressure, how does it compares to a 10 tom Giganotosaurus, or even other Giant races?

giganotosaurus has too little palentological record discovered so far to tell, but the Tyrannosaurus rex weighed (current estimate) 7 tons (14000lbs), and had a footprint area of around 4ft long and 3ft wide on the few footprint's we've found. Trex footprint

which means 4-6 PSI depending on how much surface area you lose to the triple toe shape.

[ShadowLogan]

The point is that if the claim is that the Giant Robot will not work because of ground pressure, but when calculated the ground pressures don't get higher than things which we know don't have ground pressure issues, then I am going to have to call BS. The foot size of the robot to get a PSI higher than 30 let alone 50 is small enough that I am HIGHLY skeptical that any robot can be honestly argued to have them.

Except that isn't the point of the list I generated. The point of the list I generated was to show that Giant Bipedal Robots will generate more ground pressure than armored vehicles in Rifts, not to show that they can't work because of ground pressure.

The amount of Ground Pressure that the ground can sustain before the object starts to sink will be determined by well the type of ground. Snow/mud/marsh for example aren't going to sustain as much weight as a concrete road. Which will determine when and where such units can be deployed. By the Wikipedia article you mentioned ground pressure is a measurement of potential mobility, so if a GR has more GP than an AV, then the AV is has a higher potential mobility than the GR.

The closest analogy on your list is the Elephant (35psi, I'll assume that's standing) vs M1A1 tank (15psi). However there are several advantages the elphant has that the giant bipedal robots of Rifts doesn't have:
1. It has 4 feet to distribute the load, not 2, which gives it much more surface area to use. Rifts bots don't go around with oversized clown-esque feet as a rule, not to mention height wise most giant robots IINM are going to be in the height range of an elephant standing on its 2 rear legs (so that 35psi would be 70psi if it was standing bipedally). Now Rifts does have a small selection of multi-legged bots, but their feet are typically small
2. when walking the ground pressure will increase when a foot is raised off the ground (which can cause it to sink), if our elephant is walking on its hind legs that 35psi becomes 140psi as it walks bipedally (though as a quadroped its more like an extra 8-9psi IINM)
3. the typically elephant weighs under 10tons, and 10tons is the lightest robot on the list I used and a GR lighter than 10tons is fairly rare in Rifts (of 89 manned robot vehicles I know of, 14 weigh less, though I don't have all the Rifts books and this is ignoring borderline PA/bot and TW/magical and drones, of those 14 six IINM are more massive than a typical african elephant and 9 out of 14 are more massive than the lighter typical asian elephant).

So we can extrapolate out from the elephant to giant robots, the giant robots will be generating more ground pressure than armored vehicles. Which means they won't be able to go to the same places said armored vehicle can go because they will have a higher chance of the ground not being able to support them.

And we do have the Mastodon Robot in SA2, which follows the elephant form. Now the Mastodon is approx 4x taller and x2 as long as a typical Asian elephant (I couldn't find a stated width, but in images it looks to be approx 1/2 the height), but it weighs 160tons fully loaded vs 4tons (US) for the Asian elephant, that's 40x more weight in a space that is not as proportional. The African elephant is larger and more massive (~6.5tons IINM) than the Asian, but not enough to be a factor as the heaviest African elephant on record weighed ~10tons (the Mastodon is x16 more massive). That means the Mastodon Robot in SA2 isn't generating 35psi, but many times more. Which means the Mastodon can't go to the same places that their conventional Puma-class Medium Battle Tank can (if we assume the Puma is proportional to the M1A1 in surface area).

[Shark_Force]

if a quadruped lifting a foot increases ground pressure (which it should probably do by 33% rather than 25% since if you have 3/4 the number of legs on the ground each leg needs to hold 4/3 of the weight) that really isn't good news for bipeds...

but anyways, it serves to explain one of the reasons why we don't have giant robots irl (other reasons are that legs are much more complicated to move on, probably slower in most cases, don't offer a significant advantage in mobility on the giant robot scale the way they do in the human scale, and are more expensive to build, and harder to balance than wheels, tracks, etc).

surely we must all know that the reason we have giant robots in an imaginary world is that they're cool, i would hope. if we were to hold rifts to proper science, giant robots are only one of many problems...

[Blue_Lion]

if a quadruped lifting a foot increases ground pressure (which it should probably do by 33% rather than 25% since if you have 3/4 the number of legs on the ground each leg needs to hold 4/3 of the weight) that really isn't good news for bipeds...

but anyways, it serves to explain one of the reasons why we don't have giant robots irl (other reasons are that legs are much more complicated to move on, probably slower in most cases, don't offer a significant advantage in mobility on the giant robot scale the way they do in the human scale, and are more expensive to build, and harder to balance than wheels, tracks, etc).

surely we must all know that the reason we have giant robots in an imaginary world is that they're cool, i would hope. if we were to hold rifts to proper science, giant robots are only one of many problems...

Typically normal movement half the legs of a quadruped are in movement while traveling. So when a quadruped moves the increase would likely be similar to bipeds.

Note you math is off. four legs on the ground means each leg holds 4/4 of the weight, three legs on the ground each leg holds 3/3 of the weight, two legs on the ground each leg holds 2/2 of the weight one leg on the ground each leg holds 1/1.

(You like intended 4/3 of normal wight but you never specified that and just said 4/3 of the weight that represents an increasing the base weight.)

[Blue_Lion]

Neither are bipedal do to problems with that type of movement on the scale they are built on. But you can not say we have no giant robots.

except I didn't say "we don't have any giant robots" I said: "we don't have any actual giant bi-pedal robots on that list" (emphasis mine)

There is a bit of a difference there, one is generic catch all term and one is a specific sub-category. If one is looking to showcase a giant bipedal robot's ground pressure in comparison to other known items (as I did), then it makes sense to put applicable examples on the list (which I did, but eliakon's provided list did not).

My point is that if the "idealized" ground pressure is, for example the 2.8 PSI of the UAR-1 then it will have to be more than 1/30th of idealized to have a PSI greater than a mountain bike. Unless some is going to argue that mountain bikes fall through the earth all the time then the "PSI is to high" argument seems to have a minor problem.

Yes there is a difference between the "idealized" and "actual" ground pressure. I do not dispute that, nor do I hide that, nor do present it as anything that what it is. However with the available information on the units in the books we can not know the "actual" ground pressure which requires us to either "idealize" it or "guesstimate". Comparing my list using "idealized" ground pressure versus wikipedia's "actual" ground pressure is like comparing apples and oranges.

You are free to recalculate the ground pressure of the Rifts Books examples cited to be closer to actual if you don't like the "idealized" approach.

The point is that if the claim is that the Giant Robot will not work because of ground pressure, but when calculated the ground pressures don't get higher than things which we know don't have ground pressure issues, then I am going to have to call BS. The foot size of the robot to get a PSI higher than 30 let alone 50 is small enough that I am HIGHLY skeptical that any robot can be honestly argued to have them.

<Edit>
It was pointed out to me that the Spider Skull Walker has absurdly tiny feet. But barring the few things like that I am unconvinced.

How did you calculate the ground pressure did you account for the increase in pressure based off movement speed?
If the force increase was the same as a human (should be much higher do to higher speed) then an 18 ton robots foot would be applying 55+ tons of force on movement.
So many people are calculating standing weight not moving weight.
Typical peak force would be at points where reduce foot surface is on the ground push off and impact while running.

[dragonfett]

I think that standing ground pressure is being considered first because if the ground can't even support the weight of a giant robot simply standing still, then there is no way it would support the robot walking.

[say652]

Makes the Banshee that much more desirable. A flying Giant Robot from Rifts Earth.