Could a giant excavator (like Bagger 293) breach an armored wall in a siege?

Question

I am writing a siege battle that takes place on a fallen world. The defenders are behind a large steel reinforced wall (20m by 8m). The attackers, after suffering heavy losses, decided to bring in the big toys: “THE FORT BREAKER” (cooler name will be decided). The fort breaker is just a slightly bigger and more armored version of the Bagger 293 (see picture down below).

What I want to know is: Would this really take down a wall with people shooting at it or just add to the already high death count of the attackers?

To have a better understanding of the defenders' capabilities, it may help to read this question; it’s based on the same faction the defenders are. To sum it up: Firearms and combustible fuels are commonplace in society, but tactics are more tribal/feudal in nature (people can shoot and throw bombs at you but no one is pulling an RPG out of their pants

Considering that its 96m tall and 225 meters long and weights 14000 tonnes, you could put your entire army onto it, and just drive it into the fort. If you want a more analytical answer I would recommend adding what you actually mean by a large reinforced wall, because unless its made out of solid metal, I can't imagine it would be much more than a large speed bump. Also name recommendation? The Gouger? — Shadowzee, Jan 9, 2019 at 6:31
How are the defenders armed? ie do they have any means of inflicting significant damage on the excavator while it crawls up to the wall? If that thing can work unchallenged it doesn't matter what the wall is made of. It will simply remove the ground underneath it... — Guran, Jan 9, 2019 at 7:15
If this had a science-based or hard-science tag attached to it, then the whole thing would be up to debate. In the absence of those, the answer is yes, due to The Rule of Cool. — The Square-Cube Law, Jan 9, 2019 at 12:51
Given the size of that machine, wouldn't it be easier to forget about all the digging parts and just use it as a bridge? — David Richerby, Jan 9, 2019 at 17:51
"i was already doing designs ideas to make the Fort Breaker to be more combat effective (i was worried the buckets would not cut it) - story i was going for : a fear type of thing. a slow encroaching horror" – the OP (you should add this. that Badger is pretty much it - I'd be interested in any better beast of a machine that actually exists, or what could you do to this thing to make it work) — Mazura, Jan 10, 2019 at 4:33

The Square-Cube Law · Accepted Answer · 2019-03-07 13:29:29Z

32

+100

While the Bagger 293 is an awesome piece of machinery, it is mostly static, and meant to displace large quantities of dirt. For destroying a wall it would be extremely impractical.

The mad inventor labs would like to introduce you to the "MOLE":

Tunnel boring machines have several advantages over the Bucket wheel excavator:

It is a much squatter machine, specially if you don't need to create a long tunnel: most of the structure you see behind the shield is for creating the supports, so a wall boring machine would be much shorter.
Is easier to armor: The front face shield is already heavily armored, for the rest you can cover it with plates

Think of the TBM as a highly advanced ram.

Of course, it is still quite heavy and a warfare oriented version will probably have tracks instead of wheels.

EDIT: Sebastian Lenartowicz points that in fact, someone had already this idea. In Avatar, the last airbender, the fire nation uses what would be a heavily armored tunnel borer to perforate a giant wall. It also solves one of the problems an aboveground TBM: the machine uses a kind of wormlike displacement where some kind of metal hooks perforate the earth to keep the bore moving forward instead of following the path of least resistance and stop moving when it arrives to the wall.

(and yes, I watched the episode to write this :D)

edited Mar 7, 2019 at 13:29

The Square-Cube Law

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answered Jan 9, 2019 at 9:32

Stormbolter

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$\begingroup$ hmm that is interesting a +1 for thinking outside of the box. not sure if it would go well with the story i was going for a fear type of thing. i may have to choice between a slow encroaching horror with the Excavator or a surprise attack like with the MOLE. giving me something to think about $\endgroup$
– Creed Arcon
Jan 9, 2019 at 9:44
2

$\begingroup$ You can also use this tech to dig a tunnel below the fortified wall :) - work through dirt rather than steel. This concept was already used in TMNT with Shredder's Transport module $\endgroup$
– G0BLiN
Jan 9, 2019 at 9:50
2

$\begingroup$ This is biblical wall tearing down. So dig a tunnel under a wall, plant explosives, set it. With such thing you don't need tunnel and this machine can be basically bomb that dig itself under the wall. $\endgroup$
– SZCZERZO KŁY
Jan 9, 2019 at 10:05
3

$\begingroup$ It should be noted that Avatar: The Last Airbender actually had a variation on this, though rather than running underground it ran on the surface and dug into the wall as if it was an oversized power drill. $\endgroup$
– Sebastian Lenartowicz
Jan 9, 2019 at 11:01
2

$\begingroup$ Dammit. Now I want to rewatch Avatar. $\endgroup$
– Joe Bloggs
Jan 10, 2019 at 12:48

| Show 6 more comments

Community · Accepted Answer · 2020-06-16 11:03:12Z

21

Can it breach a wall? Especially with extra armour and features? Probably with no problem.

The problem in this case are twofold:

This thing moves veeeeeeeeery slowly. And the main problem with any siege machine is that it can be destroyed (or stopped) before it arrive at point. Making a wolf pit in it's path with explosives would probably stall the machine for days if not weeks
Why would you need to break the wall if this machine would make it much easier to go over it. Look at this! This is moving tower giving you (attackers) two advantages. Higher ground, so you can shot, throw, spit, plummet, cast, hurl or fling anything at the defenders. Second thing is that you just need to extend the plank to find your troops behind enemy walls. And it's hard to stop the landing when you have people shooting at you.

This machine would be much batter as a siege tower than bettering-ram. Because a) destroying walls take precious time b) when you siege that "castle" you have a wall to fix. With just hopping over the wall you gain time and save some in the future.

edited Jun 16, 2020 at 11:03

CommunityBot

1

answered Jan 9, 2019 at 9:28

SZCZERZO KŁY

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$\begingroup$ If you wanted to hold the fortification afterwards, which your statement about fixing the wall suggests, you'd also have to get rid of the machine. - Or get it behind the walls. - Or any subsequent attacker will not attack your fortifications directly, but the machine to overcome them. $\endgroup$
– I'm with Monica
Jan 9, 2019 at 10:51
$\begingroup$ An imaginary minus one for postulating that a machine designed to remove over burden could even make a dent in the wall proposed by the OP. $\endgroup$
– Mazura
Jan 9, 2019 at 22:42
1

$\begingroup$ @Mazura at the time of my answer the question involved changing the wheel to one able to destroy steel wall. $\endgroup$
– SZCZERZO KŁY
Jan 10, 2019 at 8:52
1

$\begingroup$ Deserves a +1 for the first point alone, these super heavy things are bound to be very stoppable if you attack the wheels or the terrain. It's so heavy you probably just need a well placed tunnel under it to tip it over permanently. $\endgroup$
– AmiralPatate
Jan 10, 2019 at 9:46

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L.Dutch · Accepted Answer · 2019-01-09 06:38:40Z

15

The major problem I see is not if the thing can tear down a wall (I think it can with little effort), rather how to take it there and how to take it away.

Super-heavy tanks have often been proposed in the past, and always slammed against the problem of their size, see for example the Panzer VIII Maus:

Development of the Panzer VIII Maus had highlighted significant problems associated with very large vehicles, such as their destruction of roads/rails, their inability to use bridges and the difficulty of strategic transportation by road or rail. The bigger the vehicle, the bigger these problems became.

In a mine you have a dedicated surface to move the machine, while around a city you might lack the infrastructure to allow the machine to move. Moreover, its large footprint is subtracting space to other troops, so while it moves in you have to move away someone else, and once it has opened a breech in the walls you have to move it away quickly (the thing is all but fast) to ensure your troops can access the breech.

Else it might be taken by the defenders and act as an outpost for them.

answered Jan 9, 2019 at 6:38

L.Dutch♦

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$\begingroup$ that was some of the problems i encountered. in fact i was going to write that some of the defenders climb onto the Excavator in a attempt to blow it up before it can reach the wall $\endgroup$
– Creed Arcon
Jan 9, 2019 at 6:43
1

$\begingroup$ Of course, the mining equipment overcomes this in a rather simple (though lenghty and expensive) fashion - it's disassembled, shipped in parts, and reassembled. This is also how siege equipment was often handled in earlier times - it was assembled on the spot. The main problem here is that something like Bagger 293 is a massive overkill, way too expensive to be useful unless you just happen on one in a good condition close to the enemy base. And the additional armoring would need to be pretty significant against well equipped defenders, even if they only have small arms. $\endgroup$
– Luaan
Jan 9, 2019 at 10:18
3

$\begingroup$ @Luaan For Bagger 288 it was cheaper and faster to cover autobahns and railways with sand, and build makeshift bridges over rivers using steel pipes covered with earth, among other things, than disassemble it for the 22km move from Hambach to Garzweiler. $\endgroup$
– Alexander
Jan 9, 2019 at 11:02
1

$\begingroup$ @Luaan That is generally also the way that siege machinery was taken to the battle. Just load up the supplies needed and build the siege gear in place. Often, a nearby forest was used to cut down on supplies needed. $\endgroup$
– Michael Richardson
Jan 9, 2019 at 15:45
$\begingroup$ An imaginary minus one for postulating that a machine designed to remove over burden could even make a dent in the wall proposed by the OP. $\endgroup$
– Mazura
Jan 9, 2019 at 22:42

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Chris the Hairy One · Accepted Answer · 2019-01-10 00:33:14Z

When you say 'like' the Bagger 293, are you talking about a re-purposed mining machine or something that looks similarly cool but was designed from the tracks up as a siege tool?

As Mazura has mentioned (more than once ;-) ) a standard bucket-excavator isn't really the right tool for attacking reinforced walls. Replace the bucket wheel with a smaller diameter, toothed cutting wheel and you would have something that can chew through walls - when it eventually reaches them. It's still going to be slow.

If, on the other hand, this monster is purpose-built for siege work, there are all sorts of things you can do to make it more effective:

Replace the cutting wheel altogether and fit a multi-disc boring-head, similar to the Mole described in another answer.
Design your motive unit so it can advance on the walls at a reasonable speed (things like the Bagger don't need to move more than 0.5km/h; the mine isn't going anywhere)
Fit steel plate armour around the boom to provide safe passage for your invaders and have turret mounts to provide covering fire.
Design the Fort Breaker such that it can be transported to the siege in easily moved pieces and assembled near to the target. For example, each of the Bagger's track units could become a self-propelled carrier unit, small enough to fit onto a tank-transporter size vehicle. The mining-head could fit into the a same size vehicle.

You could even go the Transformers route and have each Track unit act as a battle-tank in it's own right until the siege engine was needed. Then you line them up; fit the battle-harness, boom and mining-head; then charge!

Your Iron Guard wouldn't stand a chance against that!

yes a very well done answer. i was already doing designs ideas to make the Fort Breaker to be more combat effective (i was worried the buckets would not cut it) the new ideas that come from all the answers are very helpful — Creed Arcon, Jan 10, 2019 at 0:47

Community · Accepted Answer · 2020-06-16 11:03:12Z

6

Use the right tool for the right job.

If the cab is close enough to be in range of flaming oils, you'll have to run snorkels out the back until they are out of range, for both the air intake and the exhaust.

This is a demolition shear that goes on the end of the arm. It's designed to cut scrap steel, but it will cut anything you put between its jaws. If those were fireproof steel braided hydraulic lines there'd be nothing anyone could do to stop it eating walls.

This is an excavator with a hydraulic chisel attached to it. Steel reinforced concrete walls have rebar inside them, so you'll need to crack it into pieces that are still stuck to each other, and then finish up with the shear.

If it's still in range of the enemy, erect a tower crane that can pick it up and move it between two work sites. If they also have an 'excavator', by the time they move their crawler over to ours, we'll be picking it up, swapping heads, and carrying on. That is, unless they also have a tower crane (if they do, none of these above ground solutions work).

edited Jun 16, 2020 at 11:03

CommunityBot

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answered Jan 9, 2019 at 23:13

Mazura

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$\begingroup$ "If those were fireproof steel braided hydraulic lines there'd be nothing anyone could do to stop it eating walls." At the very least, you'd need to prevent me from using a smaller version of the same thing to cut your hydraulic lines. Also, the 40m boom you show would be rather susceptible to just being knocked out of the way: it's not designed for use against buildings that fight back. $\endgroup$
– David Richerby
Jan 10, 2019 at 12:05
$\begingroup$ Also, it's not clear that demolition shears are the right tool. The shears can only open so far. If every feature of my wall has diameter greater than that maximum aperture, your shears can't do a whole lot of damage. Of course, you could come back with bigger shears but that seems to be the sort of arms race that would have diminishing returns for you. $\endgroup$
– David Richerby
Jan 10, 2019 at 12:09
$\begingroup$ "Why didn't somebody tell me he had one of those... things!" $\endgroup$
– Mazura
Jan 11, 2019 at 0:07

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John · Accepted Answer · 2019-03-07 14:09:49Z

The only problem with the bagger is it is designed to work on softer rock, however there are other large impressive bucket wheel excavators that will work on harder rock. Basically the only difference is the size and configuration of the bucket wheel.

The machines are not quite as big as the bagger but they are still impressively huge and also more mobile.

The steel reinforcement may be a problem, their will be a tendency to hang up rebar, and steel plate will stop it entirely. Of course if they design it with those materials in mind rebar will not be much of an issue. Steel plate still will be, if the fort uses steel plate, explosives are your only choice.

Tom · Accepted Answer · 2019-01-10 08:58:26Z

3

Why worry about breaking the wall at all? (after conquering the fortress, you want to use it for yourself, right?)

The thing is high enough that it can easily serve as a bridge over the wall. Instead of punching a hole through, make a pathway on top and walk in, then slaughter the defenders inside, and enjoy an undamaged fortress.

answered Jan 10, 2019 at 8:58

Tom

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Hobbamok · Accepted Answer · 2019-03-07 08:41:47Z

3

Opposed to everyone here:

NO IT ABSOLUTELY COULD NOT breach an "a large steel reinforced wall" [as by OP]

That thing is made vor moving DIRT. As in normal, regular soil. Brown coal (which this excavates) is NOT in rock, it's at most buried in gravel or dirt.

It can barely break frozen soil, how would it be able to destroy concrete, let alone steel-reinforced one?

Sorry op, but at least the front part would have to be replaced by actual mining equipment in order for this to work.

Alternatively: Use the big arm as a siege tower, from which your army runs onto the wall.

edited Mar 7, 2019 at 8:41

answered Jan 10, 2019 at 11:45

Hobbamok

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$\begingroup$ I imagine them finally getting it there and then blaming Starscream for the idea. $\endgroup$
– Mazura
Jan 11, 2019 at 12:20

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Community · Accepted Answer · 2020-06-16 11:03:12Z

Trojan Horse

It's already inside the wall - doing, or sitting where it used to do, its thing. It's a 100 million dollar piece of equipment. That's why there's a wall.

There could be some good plot stuff about how your guy knows this ancient tech and thinks he can at least get the tracks working again. Saying that even if the treads broke right out of the gate, it'd still go about forty feet and then we just wiggle the arm until it breaks if we can't get it to move down.

Capture it and then creep over to the wall until it kinda smashes through and/or falls over and makes a ramp. Yea! Charge!

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Could a giant excavator (like Bagger 293) breach an armored wall in a siege?

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Could a giant excavator (like Bagger 293) breach an armored wall in a siege?

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