It would seem inevitable that all libraries will eventually run out of space at one point or another. Every year, thousands of new books are written while older ones are still kept on shelves.

Cornell University was facing just that situation with 19 libraries on its Ithaca, N.Y. campus. The university collects an average of 112,000 additional printed volumes each year.

While infrequently used books are stored at an annex library to make space on main library shelves for high-demand books, the annex was also running out of room. The solution that increased space and stayed within the budget was high-density storage serviced by two rail-guided orderpickers.

The annex library has three levels totaling 29,300 square feet. Initially, it contained static storage units holding up to 1 million volumes of printed materials. With the addition of high-density shelving and very narrow aisles, the annex can now store over 2.5 million volumes.

Despite certain volumes being infrequently used, there is still limited demand for them. On average, the library staff receives and stores up to 2,000 books per day. The increase in volume capacity of the annex hasn't slowed down the ability to retrieve all student requests for annex volumes within 24 hours.

"With our small fleet of trucks, we can't afford to have a truck down when we need it," says Pat Schafer, deputy director of Olin, Kroch, Uris Libraries at Cornell.

The orderpickers easily man-euver in the 30-foot shelves. The staff can locate any volume easily because books, trays and shelves are all labeled. Not only has the time needed to retrieve a volume decreased, but user safety has increased since the arrival of the rail-guided system.

"The controls are easy to learn and operate," says operator Cammie Hoffmier. "Their safety program not only provided training on how to dive the trucks but boosted our confidence."