Yeah on top of this tube is right, she'll want to see what the machinery does before getting into it. Any clues?
Down at the far end of the machines, beyond where the defective turrets are going, metal frames carrying what are probably newly-made turret frame and casing parts are carried in and unloaded by arms.
The parts in between are mostly blocked by various structural elements from this viewpoint — only bits of moving arms and conveyor bases are visible.
What's this facility doing with defective turrets? She tries to find a better viewpoint.
The defective turrets are — being put back right into the production line.
“Watch and learn, everybody. Watch and learn.”
Machines try to attach the shiny white housing, and it falls off. Machines try to pour cartridges into the turret, and they fall right through. (That's not many bullets considering the capacity, either. No wonder the ones that can shoot are running out during testing.)
“I'm gonna make you proud!”
And there they go right back into the testing section, along with the non-defective turrets.
...so how come the whole track isn't chock-full of defective turrets?
She could attempt to walk the edge of the track she rode before, balancing above a bottomless pit.
Or she could try heading in a different direction and hoping she can find an indirect path. There's a catwalk on the far side of this end of the factory, or she could explore the end where the new parts are coming in.
She's only so comfortable balancing on edges above bottomless pits. Indirect path it is.
If she wants a ride, she'll have to wait a bit for one to go left instead of right. Or she could walk on the metal structure supporting the conveyor. Or crawl. Crawl might be a good idea with all those bottomless pits. Or is it properly considered one big bottomless pit?
make a left turn and are merged into the line of normal turrets, which is visible ahead moving rightward! Either Aperture Science is being especially nonsensical today, or someone went to a lot of effort to sabotage this system while still keeping its elements intact.
Would she like to stop hugging that turret and jump off before she ends up closer to a bunch of turrets, or continue along? (They'll be facing to the left side, so she won't be in their field of view, either way.)
She's now standing on the conveyor support structure, watching the back sides of turrets pass by up ahead. There are no catwalks or portalable walls nearby. Below is not quite bottomless, but it's a bit of a fall to the nearest pipes-and-whatnot. The perpendicular conveyor ahead does have a floor underneath it, and beyond (that is to say, where the turrets are looking) there is a perfectly respectable walkway parallelling the conveyor. With a white wall beyond it.
She's not really afraid of a fall whose bottom she can see. She drops.
Down is more of the same and then bottomless pit. Looking around from this slightly better perspective for an overview suggests that most of the machines and catwalks and so on are above the height she's at now. Unless there's something interesting hiding in the murk below.
...fine, then. Climb climb climb (continuing to show herself pretty nimble for someone who spent who knows how many years in suspension).
She wants to move on and go somewhere else. How about that place where she'd be right in front of the turrets, can she run fast enough not to be shot?
If she doesn't want to attempt that, another option is continuing to follow the turrets, just walking on the right side of the track so none of the turrets are anywhere close to facing her.
...she'll just attempt that, she's fast enough and those bullets only really leave bruises.