a bucket wheel excavator is 200 to 350 metres tall
A backhoe excavator is one that has a loading bucket on the front and a hoe on the back. Such as a Case 580 backhoe
Searching for this seems to lead to just one result, which is eBay. There are thousands of sellers on eBay, so you have a chance of finding an excavator bucket. You might also try some tractor stores.
The bucketwheel excavator gang appear in two novels by David Pownall. African Horse and The Raining Tree War
Badger 228
The way any other excavators does it's the same
A bucket crusher is a crusher inside a bucket that is attached to an excavator and so used. To clarify, you can view a video demonstration of how they work here... http://www.bucketcrusher.co.nz/?page_id=201
why swing and bucket not working properly
The main thing that comes up when you look for an excavator bucket is www.ebay.com. They have lots of new and used ones for good prices. You will also be able to find all your farming needs there as well.
To backfill a trench using an excavator, first ensure the trench is free of debris and any loose materials. Use the excavator's bucket to scoop soil from a nearby pile, and then slowly lower the bucket to deposit the soil into the trench. It's important to layer the soil in increments, compacting each layer as you go to prevent settling. Finally, use the excavator to grade the surface for a smooth finish.
7.34 cu yds.
It should not be more than 10% of the bucket size of the excavator.