I went on a field trip the other day. To the library's offsite storage facility. Now, I had seen pictures of these places before--robotic arms that gather materials that are so closely spaced no human being could ever get in.
Our storage facility is not that crazy, although it does have 40 ft. ceilings and can store about 1.3 million volumes. but the gathering is still done by actual, live people in a cherry picker. The staff there called it an order picker, but I've seen cherry pickers (my dad liked to switch out the engines between his pickup trucks) and that is what they use at the storage facility. except that it's SUPER tall and instead of an engine attached, it's a person. And a booktruck that's 6 ft tall (it has a forklift attachment on the front to hold the booktruck and a platform to stand; it's not like you're just dangling off the thing like that Batman ride at Universal Studios).
Anyway, let me describe this place. The facility is nice, with landscaping outside, birch trees (which are not native to this area, but there they are) and bamboo plants. You can't get in the outer gate without a code, and you can't get into the building without a code. It's like they're storing gold, not old, underused books.
They duplicate the barcodes that are on the book, slap the new barcode on the outside, then sort the books by size, put them in little cardboard racks, and shelve them. Oh, and they vaccuum the books first with this big industrial vaccuum. It's pretty neat.
The room where they're stored is, like I said, 40 ft high and really long and big. Two big air conditioners and a desiccator run constantly to keep it at 50 degrees F, and 30% Rh. Dry and cold, just like the books like it. The shelves go up 35 ft, and the order picker will also go that high, obviously.
They're at about 40% capacity, and keep both archival and library materials there. They do runs twice a day back to the library, to pick up books headed to the facility (250 per day or so) and drop off requests (30 per day or so). It's nice, because if you order something at the right time of day, you can literally just hang out for an hour and it will come to you. Automatic email notifications are sent out when the book is placed on hold at the circulation desk.
All in all, an extremely efficient system.