Material Handling Equipment - Industrial and Systems Engineering

8. STORAGE EQUIPMENT• Dead-reckoning (e.g., odometers), laser, and/or optical sensors used for guidance• Position error increases over time using just dead reckoning, so most free-ranging vehiclesuse some type of other sensor to obtain estimates of absolute position to correct deadreckoningerror• RF (radio frequency) or infrared modems typically used for communication8. Storage EquipmentStorage equipment is used for holding or buffering materials over a period of time. Some storageequipment may include the transport of materials (e.g., the S/R machines of an AS/RS, or storagecarousels). If materials are block stacked directly on the floor, then no storage equipment isrequired. Storage racks are used to provide support to a load and/or to make the load accessible.Table 11. Storage Equipment1. Block stacking (no equipment)2. Selective pallet rack(a) Single-deep rack(b) Double-deep rack3. Drive-in rack4. Drive-through rack5. Push-back rack6. Flow-through rack(a) Carton-flow rack(b) Pallet-flow rack7. Sliding rack8. Cantilever rack9. Stacking frame10. Bin shelving11. Storage drawers12. Storage carousel13. Vertical lift module14. A-frame15. Automatic storage/retrieval system (AS/RS)(a) Unit load AS/RS(b) Miniload AS/RS(c) Man-on-board AS/RS(d) Deep-lane AS/RS1. Block stacking (no equipment)Block stacking is the storage of loads on top of each other in stacks placed in lanes on the floor(a.k.a. floor storage)Adv: Easy to implement and very flexible. Low investment cost since no storage medium isrequired.Disadv: Honeycomb loss can be significant since, on average, half of one lane will be empty foreach item. In most cases, only LIFO retrieval is possible in each lane unless there is an aisle atthe back. Damage to loads might cause instable stacks.Two to ten rows of storage typically usedWidth of each lane limited by vehicle width, not load width55