i worked at a data center when these guys were playing football.. one guy tripped knocking over thousands upon thousands of data tapes.. he was fired immediately.. I spent the next 2 week OT refiling all the tapes, it was a 24 hr process taking double shifts.. Funny funny funny ...
the large one is a reel< its rocked back and forth with air pressure drives< they are old and outdated still used by some.. the smaller is the same thing but it is feed into a machine with less human intervention.. errors are called "Interventions" when tapes jam ect.. the little ones are the ones that fell everywhere..
http://upload.wikimedia.org/wikipedia/commons/c/c9/StorageTek_Powderhorn_tape_library.jpg what the little one look like inside the robot drive..