As an example, maximum at-plant storage for a three-day supply is calculated as follows.

1.75 racks/h x 72 h = 270 racks

Racks will be stacked two high in “units” with two rows of 24 spaces each, thus there are 48 storage spaces in each unit. Each unit stores 96 racks. Three units are required for a 270-rack storage.

If a seven-day at-plant storage is required, the total number of racks required is 630, or seven 96-rack units. This implementation of the rack system is not believed to be a cost effective choice. The rack system competes best when the racks are filled and emptied as

many times as possible in a given time period, not when they are used as storage units. Other multibale handling units (Figure 13.10) are more suitable for a larger at-plant storage.