Diesel Creek

Michelle asks: And you really expect to find anything here that can be salvaged?
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 parts.
James takes a sudden step to the side and rips the ivy off a roughly knee-high, square concrete post.
This of any use to you?
The post has numbers engraved in all four sides.
Jack reads two of them: 1581, 8480. Yup. This is indeed the place.

A bit further down the valley, they come across a large, rusty machine.
Annie wonders: How did this thing get between the trees?
Jack says: Someone drove it here before the they grew. There were large cleared areas and access roads through the forest back then.
They walk up to it and take a look.
Jack turns to Annie and James, and says: This is an excavator. We're looking for a big one like this, but in better condition.
James asks: What's wrong with this one?
This thing's just done for. It's more rust than steel, missing its tracks, the hydraulics up there have been removed, and it looks like someone got a bit carried away trying to do the same with the cab.
Why'd they do that?
Todo: rephrase above question
Probably parted out to fix other machines.
They continue walking.

After a while, they find themselves in a large, flattened area at the bottom of the valley. It is full of machines standing between the trees, forming long rows and parted out just like the excavator 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 over, Annie asks: So these machines dug out the dome?
Well... no. That was mostly done using explosives, conveyor belts, and trains. They used loaders to get the stuff onto conveyors but most of the machines here were used in construction after the digging was done.

The buildings are in rough shape, some much worse than others. Most don't have rooves, a few have been completely reduced to piles of rubble on a foundation. On the other side, as Jack had said, is a parking lot. Instead of a forest, they find it mostly overgrown with bushes and young trees. They split up and start roaming the area.

research that needs to be done:
→When were hydraulic excavators invented?
→When did they get the ability to use a jackhammer attachment?
→When did cable shovels go out of fashion? (Apparently never, depending on use case. From a quick image search, modern ones seem to be huge industrial machines.)

Annie calls the others over to one of the buildings.
Look what I found...
Michelle arrives first and has a chuckle. Jack arrives a moment later and peeks inside. There sits a cable shovel, a machine that looks like a hybrid between a crane and an excavator, partially covered in rubble from the caved-in? fallen-in? roof. It is rusty on the outside but looks otherwise surprisingly intact.
He says: That's ... uhhh ... kind of a historical artifact.
James, who is just arriving, hears it and says: I mean, everything here is a historical artifact...
Jack responds: Fair enough, but this thing especially so.
They step into the building.
Michelle says: Looks like it could just work if we tried.
Jack says: I think we should look for a more modern option first.
I agree we should look for something more modern, but might as well take a free win.
She climbs onto the back of the machine and opens an access panel.
Just about mint condition in here. This thing might fire right up. Anyone see a crank for this baby?
She pats the side of a small engine that sits on top of a much larger engine.

They start looking around in the rotting shelves and in the rubble on the floor. Michelle jumps down and joins them. After a while, Jack spots some rust right behind the rear end of the machine. He moves some leaves aside and picks up a metal rod with two bends.
You mean this one?
Michelle comes over.
Yup, that'll do.
She climbs back onto the the machine and shoves it into a protrusion on the small engine. Then, she proceeds to crank it over. First carefully, then more translate: energisch. After a moment, it fires up for a brief instant... then nothing.
Aww. Almost but not quite.
She unscrews the cap from the small fuel tank on top of it and peeks inside.
Well that can't work.
She jumps down and checks the tank for the main engine.
Nope.

Research todo: On engines that had a pony motor, was it common to use the same fuel across both engines or was it sometimes a mix?
They scavenge some gasoline from a nearby truck by loosening the translate: Überwurfmutter on a fuel line and letting it drip into a glass bottle that James had found on the ground. Michelle takes it back inside while the others continue looking for diesel fuel.

Things that need research: Did early hydraulic excavators have starter engines (what were they called again?) or was that a thing of the past by then?
Events:
-> they take off some access panels
-> they manage to get the starte engine going
-> large engine won't start (why?)