Racking 101
By: Maureen Paraventi
The right type of racking can increase productivity and maximize space. © Petinovs – stock.adobe.com
What is made of steel, able to handle 1,000-pound loads and is an essential fixture in warehouses and distribution centers? Racking, of course. Racking may seem basic – especially when compared to the robotics, automated storage and retrieval systems (ASRS) and multitude of forklifts, cranes and shuttle carts found in these facilities. However, racking’s seeming simplicity may obscure the fact that it is not a one-size-fits-all proposition. There are a number of different types of racking, and choosing the wrong kind for your particular facility and applications could be costly in terms of the time it takes to move products around and the space being utilized. Here are some of the racking options available:
Selective racking is one pallet deep, so it provides easy access to every pallet. That makes it ideal for low turnover/high differentiation products. It is low cost, but has the lowest overall storage capacity. (The aisle width and type of pallet handling vehicles used will help determine the actual storage capacity.) Selective racking is useful for SKUs with a short shelf life because it enables First In First Out (FIFO) inventory management. It is not a good fit for high volume applications and involves increased loading and unloading times.
As their name suggests, drive through racks enable forklifts to drive through them – from either direction – in order to deliver or retrieve pallets. This makes managing material through the FIFO process a good choice, especially when material doesn’t have to be moved frequently or the order of delivery is important. Because they have aisles at both ends that take up floor space, drive through racks don’t use space quite as efficiently as drive in racks.
Drive-in racking maximizes both space and height, but it is mainly good for the storage of pallets holding the same item or similar items. Forklift operators can enter from one side only. Some warehouses and distribution centers that reconfigure their space to accommodate drive-in racking systems find their storage density increases significantly.
Pushback racking is used in industries with large numbers of pallets and moderate SKU counts, like food and beverage, cold storage and grocery. A pallet is loaded from the front and then pushed back when a second pallet is loaded in front of it – up to a total of six pallets per lane. The process is reversed when pallets are removed.
Gravity is the key ingredient in pallet flow racking. Gravity roller tracks create a gravity flow lane that moves pallets from the in feed side (rear) to the pick side (front). The speed of movement is controlled by dynamic brakes. Pallet flow racking is a high-storage solution for facilities with limited space. It is another FIFO inventory control system and works well for products that need to be moved quickly, like perishable items.
Carton flow racking is also a gravity-driven, FIFO system, and a fit for applications involving many SKUs. Full case and split case cartons that are loaded at the back of the rack flow to the front. Carton flow racking is relatively affordable and uses considerably less floor space than standard pallet racks. Cold storage, grocery and food and beverage applications are good candidates for carton flow racking.
Shuttle racking has a self-powered shuttle that runs on rails and facilitates the loading and unloading of pallets, as directed by a forklift driver using a remote control. Shuttle racking can handle whole pallets and operate as either FIFO or LIFO. In warehouses with workforce shortages, shuttle racking can be an invaluable assist to productivity.
Cantilever racking is heavy duty enough to store large, heavy and bulky items like boats, iron, PVC, steel or plumbing pipes; wire coils, sheet rock, wood and furniture. It is also known as lumber racking or industrial pipe racking. There are three main kinds of cantilever racking:
- Light duty, for soft goods
- I-Beam, for easy accessibility
- Structural, which is durable, strong and versatile enough to handle medium to extra heavy loads
Whatever type of pallet rack system you use, making sure that it is and remains in sound condition – especially if alterations or reconfigurations are made – is important to the welfare of the personnel who perform tasks near it. ANSI/RMI 16.1 applies to the safety and repair of industrial pallet rack systems, steel stacker racks and movable shelf racks, but not to drive-in or drive-through racks, cantilever racks or portable racks. This standard calls for a qualified rack design engineer to oversee any repairs that are made. It also requires owners to conduct regular inspections of the columns, beams and other structural components, to ensure structural integrity. It is also a good idea to check for damage to horizontal and diagonal struts, footplates, beams and anchors. WMHS
