CACH has 127 unload doors as I recall, and 1000 outbounds. As was said, its the biggest ground hub and can run well about 125,000 packages per hour. The purpose of the CACH hub was to reduce hub handlings.
Before CACH, most packages had to be sorted 2 or more times to get to the destination. With CACH, a load is made for CACH with a big mix of packages. CACH could then make a load that goes direct to the destination center. That's why it has 1000 outbounds. That's also why it had to be automated. No person could remember every 5 digit split in the united states.
Louisville, is the same concept for air. Louisville is now called Worldport. (GradeLane is a different hub very near Worldport, but not the same.
Worldport can run over 300,000 packages per hour today. It is currently being expanded. When the expansion is complete, Worldport will be able to run over 500,000 packages per hour.
These really are impressive engineering achievements.
P-Man