There are a number of key elements that make up a racking system.
You need to understand not only the basic elements but also what they are called. Remembering and using the correct terminology will allow all users of the racking system to communicate using a common language.
The basic elements can be defined as follows:
All of these elements are crucial in the makeup of the racking, a failure of any one of these can have a disruptive effect on the whole of the racking.
Racking Components
Key components of a racking system include:
Baseplate
– Bearing plate bolted or welded to the underside of the upright to transmit vertical and horizontal forces into the floor, and to provide structural fastening of the upright frame to the floor.
Frame bracing
– A system of bracing or batten members used to link a pair of uprights in the vertical plane and in the cross-aisle direction to provide frame stability in the cross-aisle direction.
Pallet beam
– Horizontal member securely locked into the upright frame by means of pallet beam connectors and designed to support vertical loads and resist horizontal loads.
Pallet beam safety lock (device)
– A positive locking device secured to the pallet beam connector to prevent dislodgement of the pallet beam from the upright frame when subjected to upward forces.
Upright
– Vertical members that comprise the upright frame and are subject to predominantly compressive forces parallel to their longitudinal axes and have provision for systematic attachment of pallet beams.
Upright frame
– Vertical assembly composed of uprights and bracings to support design loads transmitted through pallet beams and operating equipment.
General Glossary of Terms
Adjustable Pallet Racking
– Storage system comprising upright frames perpendicular to the aisles and independently adjustable, positive locking pallet beams parallel to the aisles, spanning between the upright frames, and designed to support unit load actions.
Aisle width
– Space along which the unit load handling equipment operates.
Bay height
– Maximum vertical distance from the ground to the highest point of the unit loads in a racking structure.
Bay width
– See definition of pallet beam length.
Ceiling clearance
– Minimum vertical distance between the highest part of the upright frame or the highest part of the unit load on the top pallet beam level and the underside of the ceiling or the support steelwork for the ceiling.
Closed-face racking
– Adjustable pallet racking where the unit loads are supported by pallet beams.
Cross-aisle
– The direction perpendicular to an operating aisle or parallel to an upright frame.
Diagonal frame brace
– Diagonal member in the vertical plane that supplements horizontal braces to join uprights together and form a trussed upright frame that is stiff and stable, and designed to withstand applied design loads.
Down-aisle
– The direction parallel to an operating aisle or perpendicular to an upright frame.
End frame extension
– The protrusion of the uprights of an end frame beyond the top surface of the uppermost pallet beam. Where it is required, an end frame extension should be at least 50% of the unit load height.
Finished tolerances
– Tolerance of the unloaded racking after fabrication and erection prior to initial loading.
Frame spacer (back tie)
– Horizontal member, usually bolted to upright frames to maintain distance between upright frames in a double entry (double-sided) racking layout and designed to resist applied design loads.
Fully automatic operation
– Operation, without manual interference, of fully remote-controlled robots for storing and retrieving pallets in a racking system.
Horizontal frame brace
– Horizontal member that joins twouprights together in a frame by bolting or welding.
Load
– The value of a force appropriate for an action
Load (stub) arm
– Short load support arm attached to the uprightto support the pallet rail.
Manual operation
– Operation of machines and positioning of equipment controlled by an operator.
Open-face racking
– Adjustable pallet racking where the unit loads are supported by load arms attached to the uprights and rails spanning between the support arms.
Operating clearance
– Nominal clearance dimension between static and moving parts to ensure safe operation.
Pallet beam connector
– Device at the pallet beam ends, secured to upright frames by means of boltless or bolted connections and designed to transmit forces into the upright frames and provide stability within the racking structure.
Pallet beam deflection
– Maximum vertical distance measured from the beam ends to the lowest point of the pallet beam in a loaded condition.
Pallet beam depth
– Vertical distance from the top to the underside of the pallet beam
1. A safety device that protects against unintentional load movement within the racking and prevents unit loads from protruding or falling into an aisle or into an area accessible to people.
2. A safety device, usually placed at the back of a storage compartment, to prevent accidental collision of a pallet or its load with other equipment, such as sprinklers.
Pallet beam length (bay clear entry)
– Horizontal distance between the inner faces of columns in adjacent upright frames(note: This dimension is needed to conveniently maneuver pallets into a bay taking into account unit load width and minimum clearance required)
Pallet buffer backstop
– A buffering backstop which is specified as an aid for use by forklift truck drivers to deposit a unit load in the correct position in the rack. The impact forces arising from the backstop’s use as a buffer must be quantified in the specification if this type of aid is required.
Pallet rail (runner)
– A horizontal load-bearing member used to support pallets, which normally runs parallel to the palletplacement direction. The rail may be fitted directly to the upright,a load arm or a beam.
Pallet safety backstop
– A safety backstop used to preventaccidental damage. The two possible types of safety backstops areas follows.
Plan (horizontal) bracing
– A horizontal bracing system which,when used with spine bracing, provides the stabilizing effect to theunbraced upright in front.
Rack (row) length
– Maximum horizontal length of continuouslyconnected bays in a racking structure, equal to the sum of uprightwidths plus bay widths
Spine (vertical or back) bracing
– A bracing system providing the down-aisle stability for racking. The bracing is normally provided in the vertical plane at the rear of the racking.
Tolerance
– Permissible positive or negative variation from nominal dimension or position, resulting from either manufacture or erection, or both
Unit load
– Individual stored item that can be placed or retrieved in one operation.
Unit load action
– Laden individual pallets or equivalent load action modules
Unit load upright clearance
– Minimum horizontal distance from the inside face of the upright to the nearest part of the unit load in the down-aisle direction
Unit load depth
– Horizontal dimension of the unit load in the cross-aisle direction
Unit load depth clearance
– Minimum horizontal distance between adjacent unit loads in the cross-aisle direction of a double entry (double-sided) racking situation.
Unit load height
– Maximum height measured from the underside of the pallet to the highest point of the unit load.
Unit load height clearance
– Minimum vertical distance between the highest point of the unit load and the underside of the pallet beams immediately.
Unit load overhang
– Maximum horizontal distance the unit loadprotrudes beyond the outer edge of the pallet.
Unit load width
– Horizontal dimension of the unit load measuredparallel to the operating aisle.
Unit load width clearance
– Minimum horizontal distance between adjacent unit loads on a common pallet beam in the down-aisle direction.
Upright frame height
– Maximum vertical height of an upright frame assembly including base plates and packing (levelling) plates[when required]
Upright protector
– Component in front of an upright frame that is secured either to the floor or an upright, or both, and designed to resist minor impact loads as specified.
Upright splice
– Vertical member used to splice two uprights together to form a composite column and designed to support vertical loads and resist horizontal loads.
Upright width
– Maximum horizontal distance of an upright measured from flange to flange (outside)
Vertical clearance
– Minimum vertical distance between the floor and the underside of the lowest pallet beam; or minimum vertical distance between the top of a lower pallet beam and the underside of an upper pallet beam
Wall tie (ceiling tie)
– Horizontal or vertical member that connects the upright to a wall (or ceiling) to provide stabilising forces and reduce overturning moments.
