09/02/2026
This the Largest Library Sorting System in all of North America, and it’s located just south of Seattle in Renton, Washington. King County Library System (KCLS) supports 50 community libraries, and in 2025 they had over 25 million checkouts (digital and physical).
So here’s how it works:
The Central Sorter is an automated materials-handling system, allowing KCLS to move thousands of books and other items to its libraries faster and more reliably. It can sort up to 8000 materials per hour.
These 2 de-stacking robots can separate a tote every 15 seconds.
Staff at 6 ergonomic stations feed items into the sorter, the scan routes the item to the destination automatically. Sorted items fill totes at any of the 186 chutes, stacked 4-high, ready for delivery drivers to load and take back to their local library.
This scalable system has reduced noise, is more reliable, and gentler on materials. Since books can circulate faster, this lowers wait times on our holds with the library.
Lastly, for KCLS employees, this improves ergonomics, has less repetitive handling, and a more efficient workflow.
What book are you going to read next?