Starting on LEVEL 2, where you enter this area, use the console to call the elevator. It gets stuck partway down.
When it stops, the first gear is exposed. Climb onto the crate on the right in order to reach it.
Use your axe to pry it off.
The lift then falls a little farther but not far enough.
Jump into the elevator.
Cross to the back right corner and climb up through the rectangular opening near the hanging lightbulb.
Drop down on the other side and head up the stairs.
As you approach the 3rd-floor landing, look up to find a salvage net. Shoot it with a rope arrow and collect the salvage inside.
On the landing with the jumble of blue barrels, there's some pistol ammo and a document (2/3), a mysterious telegram from the GPS Secrets set.