Diesel Creek

Michelle asks: And you really expect to find machines here that aren't beyond repair?
The four are walking into a valley in a large forested area.
Jack replies: Right now, I'm not even sure this is the place – everything looks so different – but, if it is, we'll have plenty to choose from and a bunch more for spare parts.
James gestures to the side and says: Look, over there.
He points out a group of very rusty and completely overgrown machines.
Annie wonders: How did they get inbetween the trees?
Jack says: They didn't. This wasn't a forest back then.
They make their way over to them.

Jack says: Looks like these were already out of order before they were abandoned.
He turns to Annie and James, patting the side of one of the machines.
This is an excavator. We're looking for a big one like this, maybe a bit smaller, but not as small as that one over there.
He points to a small excavator that has a tree growing through its cab.
Do these excavators where the cab is the biggest part have a specific name?
James asks: Why not just use this one then? What's wrong with it?
This thing's just done for. Looks like it was used as a spare parts donor. Tracks? Treads? are missing, hydraulics for the bucket as well, and it looks like the inside of the cab got completely dismantled.
They take a quick look at the other machines around them. There is the other, much smaller excavator, a Kipper?, a Wie heißt diese Maschine mit Förderband, die Material sortiert?, and two Radlader? Baccos?. All of them are missing significant parts.

A bit further down the valley, they approach a much larger collection of machines, parked in rows and parted out like the first ones they saw.
Jack says: Welcome to the machine graveyard. If memory serves right, there should be a few buildings back there and one of the main parking lots behind them.
While they make their way through between the machines, Annie asks:
So these machines dug out the dome?
Well... no. That was mostly done using explosives, the machines were there to collect the rubble and load it onto trains. But they also played a big part in construction after the digging was done.

research that needs to be done: When were hydraulic excavators invented? When did they get the ability to use a jackhammer attachment? When did the cable-driven ones go out of fashion?