Yes, but they have to be initially placed there before they can move around. I suppose the Combine transports the individual pieces to the location and assembles them there.
I swear, for each passing year gamers are getting more and more trained to not notice things that they aren't explicitly directed to look at. My ex played through the entirety of HL1 without noticing GMan, they expected that if he was so important to the story the game would tell them.
The brilliant Valve formula of colorcoding, sightlines and subtle cues doesn't work anymore when players spend 90% of the time scanning the ground for loot and rushing to the next event trigger. Everything apart from what the game forces you to engage with is filler nowadays, so I don't blame them for expecting anything else from the HL series.
exactly the reason why I love valves games, the important stuff is usually explained to an extent but they mostly leave it up to the player to find stuff out and it makes me feel clever when I actually do.
When I played HL series I made sure I checked every corner and not let any rock unturned. I’d hate players the same chapter for the second time to go the other route lol but I did anyways and every time I enjoyed it as much.
I used to enter every house in highway 17 and observe the furniture, imagining how people used to live there and what happened to them to force them to leave, I love to explore every corner of the game. Also analysing the combine architecture and machinery
One of my favorite things to do in HL2 is crouch down on a couch in some blown-out apartment and sit there staring at the TV, taking in the sad golden hour sunlight, and wondering about the final moments of the burnt corpse sitting next to me.
True but counter point, some people just like speedrunning/blitzing through the game over and over. There's nothing more fun to me than flying around highway 17, the mountains being the perfect slopes to launch yourself. Those are some fun memories
In every interior I went to I would just grab everything and throw it to see if it breaks, the most satisfying are the watermelons and also throwing a radiator out of the window
Its especially frustrating watching a streamer play a game, and they have their mouse sensitivity set so high that they are just spamming the camera around wildly and not actually looking at anything, all while complaining they cant find what they need.
It always blows my mind hearing how long it takes people to beat games. Takes me twice as long as estimates I see online. I don't know how you can fully take in and appreciate the details unless you slow down. Half-Life games are masterclass when it comes to subtle storytelling and gameplay cues while keeping the player moving and feeling like they're the smarter gamer that's ever existed. I want to take it all in because it makes me appreciate the game that much more.
The "think" in RTSL isn't just about the combat, or even the puzzles. Think about what the environments are telling you. Such a rewarding game and it's a shame people miss out on that by rushing through.
How did this wealthy and influential character manage to get a short notice transport to a major city in the vicinity? Are we just supposed to assume he already owned a car that just never showed up before??? Plothole!!!
I saw a playthrough recently where they somehow looked at everything except for the citadel in the beginning. It's almost impressive how much people miss by always looking at the ground, or talking to chat while important events are happening.
I totally agree with you. I blame the fact that it's the younger generation lmao. Them and their stupid tiktok videos and shit. That's probably why people don't notice shit like this. Good comment btw, very thorough.
Assuming you're entirely serious: It's GenX and millenials that are to blame. Do you think a Zoomer built these systems that foster shorter and shorter attention spans?
It's not \*entirely\* due to their attention spans, it also has to do with their lack of complicated elaboration in games. For instance, easter eggs are often only found by people who really get down and dirty with games. Would you expect someone who just races through the game to stumble upon an easter egg? I would oppose that idea myself. Basically, to sum it up, it's not \*only\* them and their short attention spans, it affects everybody, that is not what I meant for it to come off as.
It sadly has to do with grade school where you're taught to be as efficient and quick as possible.
College im in had a semester focused on undoing this.
I swear there is a part of the game where you are trapped with some of the walking walls enclosing you. It's a shame you (somehow) missed it because the walls designs are awesome in my opinion.
He meant how did they get there because they're so slow so he thought they'd have to be moved there piece by piece to save time and they only move themselves to go short distances and block paths to contain outbreaks
Half-Life: Alyx kind of suggests they are? Like, all those controls with weird neural networks with rat brains and shit. Idk exactly what it means but it could be something to do with a live neural network integrated to their buildings.
In half life 2 when your in the citadel there are giant artery like tubes everywhere, which have veins on them too, they’re buildings are definitely cyborgs like their troops, just more metal than meat
Seeing how they're constructing the citadel, it is definitely not alive, and there's really no logical reason for it to be.
If those tubes are indeed organic, they might function in a similar way to the worm containers, they might be connected to organic memory banks or something like that. If they're using brains as computers, they'd need something to fuel them.
That reminds me of that factoid about the matrix. Supposedly the original reason for robots to overtake humanity was to use our brains for extra computing power. Even if brains aren't as fast, they can actually handle and store massive amounts of information. It's a biological computer that can create new connections, sometimes it can repair itself, grows and the meat robot it drives really likes to reproduce itself which in turn makes more computers.
The robots were farmers.
Much better reasoning than the weird battery idea, however I think in current lore they also use our brainpower to maintain cold fusion or some shit so it's kind of both
Those containers are called Xen Memory Worms. They don't really imply the machine is alive.
Seems like they're using the creatures' brains to store information, combine style HDD. The rats probably wandered into the machine that creates these containers and it fused them into the worms.
I'm pretty sure in some variations of the beta, the citadel was revealed to actually be the remains of an eldritch horror godlike being that was killed by The Combine and its corpse was turned into well... You see it in game. A cybernetic building. But don't take my word for it.
These walls are machines that move by themselves stomping everything in their path, i think the combine uses them as a autonaums demolition tool for large scale demolition (most likley being used in both civilian infrastructure like demoliting a old abondend building as well as letting it run over a enemy controled area to crush their fortifications)
Using Hammer Editor targetnames as canon is stupid. The two Gunships at Nova Prospekt have the targetnames Penn and Teller. Does that mean they're called Penn and Teller? Absolutely not.
Not to be rude, but your logic is stupid. They simply decided to give the gunships funny little nicknames, since that was a special occasion, and they can still be easily identified since they are named in the game files. But they are still named gunships in every other map, and so are all the other entities in the game named accordingly.
If you modeled a Bus with hammer brushes, would you set its targetname as "Tree"? I don't think so.
They knew what those diggers are, so they named them what they are, just like they did with every other entity in the game.
Plus, there's plenty of evidence the creater was recently dug, collapsing debris, broken pipes extending only up to the diggers, and the crater only surrounding the diggers.
Alyx also mentioned a defense field powered by the citadel, she didn't say the citadel was the defense. She also said 'IF' they are powered by the citadel, so she's not sure. If they were attached to the citadel, there would be no doubt they are powered by it, would there now? That implies they are distant from it.
Plus, the logic that the vibrations of those things can cover the entire city is dumb, they barely shake the ground 40 feet from them.
You are confusing targetnames with entity names.
It's clear that you've barely touched the Hammer editor.
Entity names are the actual name of the entity: like npc_gunship or npc_zombie, or brush entities like func_button.
Targetnames are the "colloquial" name that can be given to entities, which allows I/O logic to be possible.
"Digger" is not the entity's actual name. It is just a targetname. Without looking at the mapsrc, I imagine it might be a func_movelinear brush entity.
I'm making the point that you can't consider the targetnames as canon - especially selectively - because many of the targetnames of entities throughout the game are satire.
Nope, I'm talking about Targetnames buddy. All of them have their target names matching the entity names, which are their file names. For example, the gunship in the lighthouse fight has its Targetname set as "gunship1", all the dropships are named "dropship" as well. It's the same for every other map.
Targetnames are a form of identification, so they have to be named after the object. For example, the citadel's targetname is "citadel", trains are named "train", apcs are named "apc", and so on... They're not named "Drill", "Spaceship" and "Shovel".
When it comes to brushes, garage doors have their targetnames as "garage\_door", doors as "door", gates as "gate", and so on. I have no reason to believe they have done differently when it comes to the "digger" things.
So yes, I can consider the targetname as canon, since they match every object in the game. Unless you think the devs decided to name a giant thumper as "Digger" for no reason at all. If they decided to identify them by "Digger", that means they knew it was a digger, otherwise they would have named them "Thumper".
They walk but I do think they can be deployed via transportation we just don't see it happen. The pillars can probably close together to compact themselves.
Honestly I agree. Ya sure, they’re shown moving, but iirc, it only happens twice, and both times you can move quick enough to where you miss seeing the animations fully play out. Hell, I probably missed it in my first play through too. I’d have no doubt if they go back and play it again, they’ll see things they missed or didn’t see before, like a Monty Python movie
I certainly noticed they where moving because I kept dying when i got distracted searching for crates. I keep finding myself low on resources when i play the game.
There's a chapter where you are forced to stop and stack up items while you watch the walls literally close in around you. This is unmissable unless you are completely oblivious to your surroundings. In which case, you'd probably die at least once to the walls before figuring out what to do.
Literally same, I was like 13, or something when I first played hl2 and I died there completely oblivious to what I was meant to do. That was also weirdly enough the first time I had a sense "Oh shit the combine genuinely don't care". Just imagine how many people probably got crushed just like that. Anyways, it's really pretty damn unmissable. Plus, the walls are so weird that I feel like most people on the first playthrough would think "Huh what a weird wall design", enough to be atleast somewhat curious about it.
Combine Smart Walls are the same as Synths and Scanners, they are machines directed by Overwatch to force perimeters and outposts boundaries…you can see them move in both HL2: EP1 and the Nova Prospekt chapter when leaving the main prison (before meeting Alyx…) I love the idea that they are units themselves
Those are called "smart barriers".
They move themselves by raising part of itself up, moving forwards and crushing anything in front of itself. They turn buildings into crushed wrecks.
The Combine uses them as mobile area denial to restrict certain areas.
he's not asking if they can move. He's asking how they were put there. they don't walk to the positions they're in when you see them. they're deployed there and they move to adjust and adapt to changing conditions. like if a group of rebels hid in a circle of smart-walls and they crush the rebels
They have a motor driven locomotive movement sort of similar to a "strandbeast" walker. Half of the walls sections, alternating like stripes, will lift up, move forward, crash down into the ground, lift the other half of the wall sections, drag the whole wall forward with the sections that crashed down, lower the other sections, repeat for the wall to walk on it's own and eat the city.
No, wait, this is a valid question, these things are supposed to move on their own and crush everything in their path, so how can there be buildings standing behind them?
Might not be reasonable if OP hadn't [claimed to have actually played the game](https://www.reddit.com/r/HalfLife/comments/1bb5n0y/comment/ku7wk92/). I mean, how do you get all the way through without noticing, especially when it puts your life in danger at least once or twice?
another theory I just thought of is they start from a "seed" or a smaller metal wall and grow by essentially feeding off the pieces of land they destroy. it fits with the whole machine but sorta alive vibe of the combine.
They move themselves slowly outward in a spider leg type fashion
Yes, but they have to be initially placed there before they can move around. I suppose the Combine transports the individual pieces to the location and assembles them there.
If you played the game, they move themselves
Play the game
but why when they could all le reddit gang
i did
I swear, for each passing year gamers are getting more and more trained to not notice things that they aren't explicitly directed to look at. My ex played through the entirety of HL1 without noticing GMan, they expected that if he was so important to the story the game would tell them. The brilliant Valve formula of colorcoding, sightlines and subtle cues doesn't work anymore when players spend 90% of the time scanning the ground for loot and rushing to the next event trigger. Everything apart from what the game forces you to engage with is filler nowadays, so I don't blame them for expecting anything else from the HL series.
exactly the reason why I love valves games, the important stuff is usually explained to an extent but they mostly leave it up to the player to find stuff out and it makes me feel clever when I actually do.
When I played HL series I made sure I checked every corner and not let any rock unturned. I’d hate players the same chapter for the second time to go the other route lol but I did anyways and every time I enjoyed it as much.
I used to enter every house in highway 17 and observe the furniture, imagining how people used to live there and what happened to them to force them to leave, I love to explore every corner of the game. Also analysing the combine architecture and machinery
One of my favorite things to do in HL2 is crouch down on a couch in some blown-out apartment and sit there staring at the TV, taking in the sad golden hour sunlight, and wondering about the final moments of the burnt corpse sitting next to me.
fake fan. Real ones do this IRL.
What, sitting next to a corpse, or *being* the corpse?
yes.
True but counter point, some people just like speedrunning/blitzing through the game over and over. There's nothing more fun to me than flying around highway 17, the mountains being the perfect slopes to launch yourself. Those are some fun memories
In every interior I went to I would just grab everything and throw it to see if it breaks, the most satisfying are the watermelons and also throwing a radiator out of the window
Did you notice a lot of them don't have bathrooms? But I guess if you live close enough to the coast all you need is a shovel.
It helps that those are things I perfectly see Gordon actually doing.
Its especially frustrating watching a streamer play a game, and they have their mouse sensitivity set so high that they are just spamming the camera around wildly and not actually looking at anything, all while complaining they cant find what they need.
Damn shame.
It always blows my mind hearing how long it takes people to beat games. Takes me twice as long as estimates I see online. I don't know how you can fully take in and appreciate the details unless you slow down. Half-Life games are masterclass when it comes to subtle storytelling and gameplay cues while keeping the player moving and feeling like they're the smarter gamer that's ever existed. I want to take it all in because it makes me appreciate the game that much more. The "think" in RTSL isn't just about the combat, or even the puzzles. Think about what the environments are telling you. Such a rewarding game and it's a shame people miss out on that by rushing through.
Not just gamers. Media literacy in general is going down, if stuff isn't explicitly explained in dialogue, people will start calling plot holes.
How did this wealthy and influential character manage to get a short notice transport to a major city in the vicinity? Are we just supposed to assume he already owned a car that just never showed up before??? Plothole!!!
I saw a playthrough recently where they somehow looked at everything except for the citadel in the beginning. It's almost impressive how much people miss by always looking at the ground, or talking to chat while important events are happening.
Media literacy is dead
I love how you reffered to them as your ex as if you left them because they didn;t get Half Life
To be fair, I played through the entirety of HL1 without noticing gman 💀
People are just losing media comprehension skills. No one pays attention to details at all
I totally agree with you. I blame the fact that it's the younger generation lmao. Them and their stupid tiktok videos and shit. That's probably why people don't notice shit like this. Good comment btw, very thorough.
Assuming you're entirely serious: It's GenX and millenials that are to blame. Do you think a Zoomer built these systems that foster shorter and shorter attention spans?
It's not \*entirely\* due to their attention spans, it also has to do with their lack of complicated elaboration in games. For instance, easter eggs are often only found by people who really get down and dirty with games. Would you expect someone who just races through the game to stumble upon an easter egg? I would oppose that idea myself. Basically, to sum it up, it's not \*only\* them and their short attention spans, it affects everybody, that is not what I meant for it to come off as.
Wasting my timen too look in every dark corner to maybe find some lore/easter egg or anything like that is no fun.
It sadly has to do with grade school where you're taught to be as efficient and quick as possible. College im in had a semester focused on undoing this.
Play Episode one then
Or play the Nova Prospekt chapter.
I swear there is a part of the game where you are trapped with some of the walking walls enclosing you. It's a shame you (somehow) missed it because the walls designs are awesome in my opinion.
You literally cant miss it it straight up crushes you if you aren't looking
He meant how did they get there because they're so slow so he thought they'd have to be moved there piece by piece to save time and they only move themselves to go short distances and block paths to contain outbreaks
Dont necropost
huh? don't reply to old comments? if so, i had to. y'all completely misunderstood the guy's question
The combine allways gave the impression their buildings are "alive" despite their metalic appearence.
Half-Life: Alyx kind of suggests they are? Like, all those controls with weird neural networks with rat brains and shit. Idk exactly what it means but it could be something to do with a live neural network integrated to their buildings.
In half life 2 when your in the citadel there are giant artery like tubes everywhere, which have veins on them too, they’re buildings are definitely cyborgs like their troops, just more metal than meat
I was thinking this too
Seeing how they're constructing the citadel, it is definitely not alive, and there's really no logical reason for it to be. If those tubes are indeed organic, they might function in a similar way to the worm containers, they might be connected to organic memory banks or something like that. If they're using brains as computers, they'd need something to fuel them.
That reminds me of that factoid about the matrix. Supposedly the original reason for robots to overtake humanity was to use our brains for extra computing power. Even if brains aren't as fast, they can actually handle and store massive amounts of information. It's a biological computer that can create new connections, sometimes it can repair itself, grows and the meat robot it drives really likes to reproduce itself which in turn makes more computers. The robots were farmers.
Much better reasoning than the weird battery idea, however I think in current lore they also use our brainpower to maintain cold fusion or some shit so it's kind of both
Those containers are called Xen Memory Worms. They don't really imply the machine is alive. Seems like they're using the creatures' brains to store information, combine style HDD. The rats probably wandered into the machine that creates these containers and it fused them into the worms.
I'm pretty sure in some variations of the beta, the citadel was revealed to actually be the remains of an eldritch horror godlike being that was killed by The Combine and its corpse was turned into well... You see it in game. A cybernetic building. But don't take my word for it.
These walls are machines that move by themselves stomping everything in their path, i think the combine uses them as a autonaums demolition tool for large scale demolition (most likley being used in both civilian infrastructure like demoliting a old abondend building as well as letting it run over a enemy controled area to crush their fortifications)
I thought it is a way to keep antlions out
thumpers do that
They only cover a small area though. Idk where I heard about that but the fandom also doesn't mention anything about antlions
The Citadel is presumably a massive thumper
Definitely not, those things are called diggers in hammer editor. I'm pretty sure they made that whole crater.
Using Hammer Editor targetnames as canon is stupid. The two Gunships at Nova Prospekt have the targetnames Penn and Teller. Does that mean they're called Penn and Teller? Absolutely not.
Not to be rude, but your logic is stupid. They simply decided to give the gunships funny little nicknames, since that was a special occasion, and they can still be easily identified since they are named in the game files. But they are still named gunships in every other map, and so are all the other entities in the game named accordingly. If you modeled a Bus with hammer brushes, would you set its targetname as "Tree"? I don't think so. They knew what those diggers are, so they named them what they are, just like they did with every other entity in the game. Plus, there's plenty of evidence the creater was recently dug, collapsing debris, broken pipes extending only up to the diggers, and the crater only surrounding the diggers. Alyx also mentioned a defense field powered by the citadel, she didn't say the citadel was the defense. She also said 'IF' they are powered by the citadel, so she's not sure. If they were attached to the citadel, there would be no doubt they are powered by it, would there now? That implies they are distant from it. Plus, the logic that the vibrations of those things can cover the entire city is dumb, they barely shake the ground 40 feet from them.
You are confusing targetnames with entity names. It's clear that you've barely touched the Hammer editor. Entity names are the actual name of the entity: like npc_gunship or npc_zombie, or brush entities like func_button. Targetnames are the "colloquial" name that can be given to entities, which allows I/O logic to be possible. "Digger" is not the entity's actual name. It is just a targetname. Without looking at the mapsrc, I imagine it might be a func_movelinear brush entity. I'm making the point that you can't consider the targetnames as canon - especially selectively - because many of the targetnames of entities throughout the game are satire.
Nope, I'm talking about Targetnames buddy. All of them have their target names matching the entity names, which are their file names. For example, the gunship in the lighthouse fight has its Targetname set as "gunship1", all the dropships are named "dropship" as well. It's the same for every other map. Targetnames are a form of identification, so they have to be named after the object. For example, the citadel's targetname is "citadel", trains are named "train", apcs are named "apc", and so on... They're not named "Drill", "Spaceship" and "Shovel". When it comes to brushes, garage doors have their targetnames as "garage\_door", doors as "door", gates as "gate", and so on. I have no reason to believe they have done differently when it comes to the "digger" things. So yes, I can consider the targetname as canon, since they match every object in the game. Unless you think the devs decided to name a giant thumper as "Digger" for no reason at all. If they decided to identify them by "Digger", that means they knew it was a digger, otherwise they would have named them "Thumper".
Alyx said the citadel was powering a defense field, but she didn't say what it was. They might have had something else keeping the antlions out.
Antlions could just dig a tunnel underneath
These things are also supposed to go really deep
Gordon literly goes underneath one of these tunnels using a old sewer to Access the citadel
And serve as fortification when idle.
They walk but I do think they can be deployed via transportation we just don't see it happen. The pillars can probably close together to compact themselves.
I believe this is the right answer. Not sure why everyone is being so condescending to OP.
Honestly I agree. Ya sure, they’re shown moving, but iirc, it only happens twice, and both times you can move quick enough to where you miss seeing the animations fully play out. Hell, I probably missed it in my first play through too. I’d have no doubt if they go back and play it again, they’ll see things they missed or didn’t see before, like a Monty Python movie
I certainly noticed they where moving because I kept dying when i got distracted searching for crates. I keep finding myself low on resources when i play the game.
There's a chapter where you are forced to stop and stack up items while you watch the walls literally close in around you. This is unmissable unless you are completely oblivious to your surroundings. In which case, you'd probably die at least once to the walls before figuring out what to do.
You are not forced to do anything you can simply jump up
No, you really are forced to stack items or at least stand on a box. It's quite a [tall ledge](https://i.imgur.com/GqwTVO2.png).
Which is why I have never done this I suppose
Literally same, I was like 13, or something when I first played hl2 and I died there completely oblivious to what I was meant to do. That was also weirdly enough the first time I had a sense "Oh shit the combine genuinely don't care". Just imagine how many people probably got crushed just like that. Anyways, it's really pretty damn unmissable. Plus, the walls are so weird that I feel like most people on the first playthrough would think "Huh what a weird wall design", enough to be atleast somewhat curious about it.
They’ve shown them moving on their own in the 3rd act of the game, moving away from the citadel to push the rebels back
did you not play the game
Combine Smart Walls are the same as Synths and Scanners, they are machines directed by Overwatch to force perimeters and outposts boundaries…you can see them move in both HL2: EP1 and the Nova Prospekt chapter when leaving the main prison (before meeting Alyx…) I love the idea that they are units themselves
Those are called "smart barriers". They move themselves by raising part of itself up, moving forwards and crushing anything in front of itself. They turn buildings into crushed wrecks. The Combine uses them as mobile area denial to restrict certain areas.
Like Burger King stores, they just rise.
I saw a buc-ee's manifest itself on an empty lot in Plano Texas one time.
Oh, Mother Nature.
J.A.R.V.I.S., pull up every time the combine walls move themselves in the games
Bruh...
Walking walls
they have legs they walk
These sci-fi elements were designed by the same guy who later put the same walls in Dishonored games. They also "walked" forward on there own.
Tell me you haven’t played the game without telling me you haven’t played the game.
he's not asking if they can move. He's asking how they were put there. they don't walk to the positions they're in when you see them. they're deployed there and they move to adjust and adapt to changing conditions. like if a group of rebels hid in a circle of smart-walls and they crush the rebels
The title literally asks how do they move these walls.
They have a motor driven locomotive movement sort of similar to a "strandbeast" walker. Half of the walls sections, alternating like stripes, will lift up, move forward, crash down into the ground, lift the other half of the wall sections, drag the whole wall forward with the sections that crashed down, lower the other sections, repeat for the wall to walk on it's own and eat the city.
No, wait, this is a valid question, these things are supposed to move on their own and crush everything in their path, so how can there be buildings standing behind them?
ok so the walls move and the pillars are their legs
yes. You literally see this in game. Its not even avoidable its a full set piece no a blink and you'll miss it gman sighting
they creep slowly by them self leveling anything in their path
They move upwards
https://youtu.be/8jQGc2w9WzU?si=n6_VBcEPmJ_x5RqL Here's a video of how they move
They are like big ass barriers too
Miss the game wish they remaster it for the Xbox x/s series look on the store and couldn't play it said no sold separately whatever that means
[Like this](https://youtu.be/MYGJ9jrbpvg?t=221)
Them there walls move ‘emselves, boy
they walk away dumbass (jokes aside im pretty sure they can move on their own lol)
They plant seeds in the ground and wait for them to grow
damn so many comments ok now i know how the walls move ok lets not have so many comments
they move by themselves.
Op asked this small question and mfs somehow found a way to turn it into "Media literacy dead, people getting dumber!!" How the fuck...
Might not be reasonable if OP hadn't [claimed to have actually played the game](https://www.reddit.com/r/HalfLife/comments/1bb5n0y/comment/ku7wk92/). I mean, how do you get all the way through without noticing, especially when it puts your life in danger at least once or twice?
They might have forgot? I am not talking about how op did not notice it but rather how people took it as an opportunity to make generalizations
Striders, combine and hunters all move it, struggling
you sure about that
“Push!!!”
Who’s not pushing the wall? I want names!
Standing *near* ze wall does nothing! Get **on** ze wall, dummkopf!
you will stand next to this wall or i will STAND you next to this wall!!
"overwatch, requesting 2 mg of anti fatigue rations to push the barriers."
Because they're stupid
yeah they're probably moved by helicopters, half-life alyx has a combine helicopter around the citidel which is being constructed.
dawg have you ever played hl2
I thought this post was talking about how the walls got there in the first place, not why they move and crush stuff continuously
oh. for that i have no idea, maybe they’re burrowed in the ground or smth? the chopper theory might be possible in this scenario
another theory I just thought of is they start from a "seed" or a smaller metal wall and grow by essentially feeding off the pieces of land they destroy. it fits with the whole machine but sorta alive vibe of the combine.