A fastener used to secure a racking system to the concrete floor slab, so it maintains its position. The types of anchors most commonly seen in racking are wedge, screw, concrete strike and sleeve anchors. Typically made of steel, anchors vary in size and length depending on factors such as the weight and height of the rack, the levelness of the floor and seismic activity.
Base plate or footplate
A plate welded to the foot of a rack upright or repair unit to distribute the weight of the rack to the floor and allow it to be anchored. Base plate sizes vary from 3"x 5" to 5" x 7" in seismic zones and from 1/8" to 1/2" in thickness. Qualified engineers are required to assess the effective area and thickness of the base plate to ensure that the rack is supported and that the load is transferred to the concrete slab.
A bay refers to the space between two upright columns, in a racking system. A bay corresponds to the vertical superposition of cells. Bays can have a varying number of beam levels. Some companies use the number of bays in a warehouse as a means to estimate the price of the rack inspection and the engineering services.
A horizontal structural component of the rack system, usually arranged in pairs that bears the weight of the stored loads and transfers it to the uprights it is connected to. Common beam shapes are box beam, step beam and c-shape beams. Variations of these shapes exist. Ultimately, the beam's capacity depends on factors such as the beam shape, size, and material.
Beam connector (beam clip, beam bracket, end plate)
The rack component that facilitates the safe fastening of the support beam to the upright frame. The beam connector is a formed, stamped or punched metal part that may be clipped or bolted to the upright
A rack cell is a space between two uprights, on one beam level, which generally accommodates two pallet positions along its width. The size of the cell varies depending on the type of racking system.
Cross aisle tie
A horizontal component used to connect the top of two opposing rack frames to provide stability in the cross-aisle direction. It can span across the warehouse aisle. Cross-aisle ties are specified by the designer of the rack system in the Load Application and Rack Configuration Drawings (LARCs).
Diagonal or horizontal members bolted or welded between frame columns in a specific pattern to resist cross-aisle forces imposed on the rack's frames and to improve the stability of the racking system.
Column / Upright column
The vertical component of a racking system, on which horizontal and diagonal braces are welded, and beams are attached. An upright column may bend or twist as a result of an accidental impact with material handling equipment, or buckle from excessive loading.
A prevention device designed to protect against impacts to the rack column. Generally installed at its base, the column guard or post guard can be fixed to the floor slab in front of the rack column. It may also be tied or bolted directly onto the upright column. It is made of materials such as structural steel, shock-absorbing rubber or polyethylene (plastic).
A component that is either welded or bolted to the columns diagonally. They add resistance and rigidity to the upright frame, as they resist cross-aisle forces.
The front or rear frame columns are sometimes doubled to a certain height and usually welded together to create a built-up column section. Doubled columns can be used as reinforcement or for additional load capacity.
Floor system / Floor slab
The majority of racks are installed on a concrete slab. Like racking systems, a floor also has a maximum load capacity. The concrete slab must resist and transfer static and dynamic loads from the surface to the subsoil. The bearing capacity of a floor is found in the builder's original building specs or the contractor's plans for construction. If you cannot obtain this information, you can ask an engineer to determine your floor's capacity.
A component that is either welded or bolted to the columns horizontally. They add resistance and rigidity to the upright frame, as they resist cross-aisle forces.
A method used to display the load capacity of the racking system. The information on the labels comes from the Load Application and Rack Configuration Drawings, aka LARCs. Load capacity labels are typically installed on the first beam level of each bay, at eye level. If beam levels have varying capacities, multiple labels can be printed and installed to inform the forklift operators.
Load capacity plaque
A plaque is a type of signage used to communicate the rated load capacity of a pallet rack system and the maximum weight it can hold. It should include the maximum beam capacity, the maximum bay capacity and the rack manufacturer's information. Moreover, a reference to drawing(s) or other approved documents that establish the maximum permissible load for a given rack bay can be included on the plaque. It should be placed where operators can read it. If all the information contained in the load plaque is standard for a bay, the aisle or a section of the rack, one plaque is sufficient for that area.
A flat structure used as a base for the storage and unitization of goods in the supply chain. Pallets are made of materials such as wood or plastic. They come in different sizes and configurations (two-way and four-way entry) based on the country and the industry they are used in.
A rack accessory used to stop a pallet from going too far into the rack and damaging it. A beam stop is fixed on the back of the system, and an angle stop is also set on the end with screws. Both devices prevent the fall of pallets, which may occur while placing or pushing a pallet into a bay. Pallet stoppers will also prevent excessive pallet overhang.
Pallet support bars
Steel components installed perpendicular to the load-supporting beams. They are intended to support a loaded pallet's weight in cases where the pallet cannot be placed directly onto a pair of beams.
Palletized unit load
A palletized unit load is defined as one or more items secured to a pallet or skid so that it may be handled and stored as a single unit.
A component used for the spacing of back-to-back pallet racks that provides added stability to the racking system and maintains an even spacing between the racks. The vertical distance between row spacers should be between 8' to 12' or 2.4 m to 3.6 m. They should be located at elevations that provide a direct load path between the columns of back-to-back frames.
A component installed perpendicular to the load support beam to prevent a load from falling through the rack. The bars may be attached to the beams or dropped over them. Safety bars are a recommended fall protection accessory, but they are not mandatory.
A small device or mechanical fastener (shear pin, screw bolt, etc.) installed on the beam connector will help prevent its accidental dislodgement from the upright frame column. In warehouse areas accessible to the public, it is advisable to use bolts. The type of safety pin, including size, material, and installation requirements, must be approved by the manufacturer or a qualified engineer.
Inserted between the concrete floor and the base plate of a rack, they must always match the size of the base plate. The material must have equal or greater bearing strength than the floor slab. To maintain the levelness of the racking system, stacking multiple shims is allowed. However, in no case shall the total thickness of a shim stack exceed six times the diameter of the largest anchor bolt used in the base plate. Moreover, shim stacks having a total thickness greater than two times the anchor bolt diameter under bases with only one anchor bolt shall be interlocked or welded together to allow for load transfer.
The word strut or rack strut is sometimes used to refer to the rack's diagonal and horizontal bracing components.
Upright frame / End frame / Rack frame
These terms refer to 2 upright rack columns (front and rear) and the bracing members that connect them. Their depth can vary.
The upright column is the vertical part of the racking system or frame. Upright columns are commonly roll-formed and made of steel, in a "C" shape. Holes or slots are punched into the upright during the manufacturing process to allow for load support beams to be fixed or mounted to the upright columns.
Wire mesh decking
An accessory installed on pallet rack shelves to prevent stored merchandise from falling through the rack. This decking is made from welded-wire mesh and generally has reinforcing channels or support wires. Sizes of wire mesh decking vary depending on the manufacturer. Common sizing is 24", 36", 42" or 48" deep by 46", 52" or 58" long.