The [del]Bagger 288[/del] Bagger 288, if you haven’t seen it by now, is a gigantic excavator used in coal mining - except according to the Wikipedia page, it’s not used to mine the coal itself, but rather to remove the “overburden” of earth covering that delicious, delicious coal.
So why don’t they also use it to extract the coal itself? 
From your link–
Coal has a density of 1346 kg/cubic meter, so 240,000 tons (assuming metric tons since they talk about cubic metres in the same sentence) is 178,300 cubic meters. If these numbers are right, it can dig dirt about 130 times as fast as it can dig coal. They may end up using it to dig the coal, but other machines might be faster at it, and make it worthwhile switching to a different machine. It may also be not as well-suited for digging coal if it breaks it up into smaller pieces than desired, or leaves it in bigger chunks. Also, Germans: “The Bagger 288 was built for the job of removing overburden before coal mining”. “This is the job we built it for, so this is what it will do.”
How many bagger-type overburden machines are there? Can they be spared to mine for coal or would they be immediately repositioned to another area to remove overburden there, leaving the coal for other purpose-built machines?
On top of the comments above, which I think are all relevant, I think it will be driven primarily by the discharge mechanism of the machine. The bagger (and kin) remove dirt onto a portable conveyor belt. I assume this travels some distance and then is nearly restacked with a radial or traveling stacker just next to the coal field. Suitable for easily placing back into the mine once the coal is removed.
Coal, on the other hand, needs to be transported to a coal handling plant for washing, sizing, grading etc for its future use. Dumping the coal in a crusher is a single step using a normal haul truck. Further, the coal presented to the coal plant may need to be blended using coal from multiple different pits, or by selectively using pockets of high and low quality throughout the one pit. This is to achieve a consistent product with the desired qualities. A body of coal is not necessarily homogeneous.
Traditional hauling methods make this far easier.
Can it be used for shoveling cocaine into keith richards?
Also, how would it fare in a fight with an M1A2 Abrams?
The statistics of "240,000 tons of coal or 240,000 cubic metres of overburden daily " seems to be mixed up.
But yes coal is about 1.2 tonnes per cubic meter, and rock is 2 to 3 tonnes per cubic meter and quite different in properties. eg They’d want to cover up the coal handler so that it doesn’t produce lots of coal dust, as coal dust is flammable,even explosive.
But the basic job of the overburden remover is to throw the overburn up and over there… which is totally different to carefully and safely producing a stream of coal and depositing it into the relatively tiny train wagon. The bagger 288 is just incompatible with coal. To make it compatible would cripple it as an overburden mover. You only need one bagger 288 per mine, you aren’t going to make a second one just to move coal. While they remove 150 metres of overburden to get to coal, they get around 10 metres of coal. So you can easily make use of an overburden machine around 10 times more capacity than your coal handling equipment. (no precise numbers… I mean “around” for any stats.)
The Abrams can certainly move faster than the machine as a whole, and it can probably move faster even than the end of the boom (I can’t imagine why they would design it to be able to move that fast, at least). This prevents the Bagger 288 from effectively using the only thing it has that might be considered a weapon. Meanwhile, the tank wouldn’t need to take out very many struts to collapse the whole thing, and while I’m not sure whether they can reliably hit a target as small as a single strut, they have enough ammo to afford a fairly low hit ratio.
Like most bucket wheel excavators, the bagger is counter balanced and quite finely engineered, despite its size. A single shot into the counterweight arrangement or bucket would very likely lead to its total collapse and failure. Such collapses are semi regular occurrences with massive bucket wheel machines.
I used to work for the company that operated huge strip mining shovels like the Silver Spade and the GEM of Egypt to remove overburden from coal seams. Much smaller loading shovels followed behind the big shovels to remove the coal and load it into trucks to take to the preparation plants.
The buckets on the stripping shovels were 110 to 130 cubic yards in size while the loaders had 8-yard buckets.
The overburden was between 50 and 200 feet deep, the coal seam between 4 and 6 feet. The big shovel would uncover the seam, dumbing the rock and dirt to one side as the loaders took out the coal, then the stripping shovel made another pass the opposite direction, placing the overburden in the area where the coal had been removed.
The wikipedia numbers are NOT correct. Per the manufacturer: “In lignite mining they achieve capacities of up to 240,000 m[sup]3[/sup] (bank) per day…”
No idea where wikipedia came up with “23,240,000 cubic metres of overburden.” It’s not supported by any of their references. Looks like a typo.
The densities mentioned for coal is in situ. When blasted or broken up it’s easy work for a bucket wheel. Some coals are soft enough to be mined without breaking up (ex. peat).
I’m not a mining engineer but as I understand it. A bucket wheel excavator is good for a continuous process with little disruption, such as a sudden thinning of the coal seam, or a displacement due to faulting. Mining of the coal itself is often selective, so a different extraction is needed, like a dredge shovel (ex: “big muskie.”) Removing soft overburden over a large area does seem ideal for a bucket wheel mining.