Cantilever Racking

Overview

Cantilever racking stores long and awkward loads on horizontal arms that project from a row of upright columns, leaving the storage face completely free of front columns. Because there are no vertical obstructions across the open span, a single bundle of pipe, a length of structural steel, or a stack of plywood can be loaded along the full row by forklift or sideloader without weaving between uprights. This is the defining advantage over selective pallet racking, where front columns interrupt every bay and make long loads impractical to place.

A cantilever system is built from repeating towers. Each tower is one upright Upright Column standing on a forward-projecting Base Member, with several load arms keyed into the column face at chosen heights. Towers are spaced along the floor and tied together with a Bracing Set so the row behaves as one rigid structure. Loads then span from arm to arm across adjacent towers, which is why arm spacing is set by the length and flexibility of the stored material rather than by any fixed bay module.

Structural principle

The arm carries its load as a cantilever, so the stored weight creates a bending moment that tries to rotate the whole tower forward. Two elements resist that moment. The Base Beam projects forward under the arms, moving the floor reaction point ahead of the column so the rack sits on a wide footing rather than tipping on its toe. The Floor Anchor Kit then fixes the base to the slab and supplies the uplift resistance at the rear that the base alone cannot. The combination means arm capacity, column height, and base projection are linked: a longer arm or a taller column demands a longer base and stronger anchoring for the same rated load.

Arms are deliberately inclined three to five degrees upward toward the tip. The slope is small but enough to keep round stock such as pipe and tube from rolling off the front, and to seat loose bundles back against the column rather than creeping outward under vibration from passing traffic. Where stock is fully loose or unbundled, an Arm End Stop is added at the arm tip for positive retention.

Columns, arms, and adjustment

The Column Section is either a hot-rolled I-beam or a heavy cold-formed channel, chosen for the load and height. Its face carries Arm Slot Plate features on a regular pitch, typically 100 to 150 mm, so arms can be relocated as stored items change. Each Load Arm connects through a keyed Arm Connector and is held against vertical dislodgement by an Arm Locking Pin. Because arms move independently, one tower can be set with widely spaced arms for bulky panels while the next is set with closely spaced arms for thin bar stock, all on the same column pitch.

Soft, painted, or finished goods are protected from steel-to-steel contact by an Arm Rub Strip in UHMW polyethylene laid along the arm top. For small parts that would fall between arms, mesh or plank Deck Panel sections bridge the gap and convert the cantilever bay into a shelf.

Bracing and stability

A single tower is stable front to back through its base and anchors, but a row needs longitudinal stability as well. The Bracing Set supplies it: Horizontal Brace members tie the column tops and bases together so the towers share load, and Diagonal Brace members triangulate the row against sway from forklift braking, load placement, and, where specified, seismic acceleration. The braces transfer their forces into the columns through Brace Gusset plates. In seismic zones the whole assembly is engineered to the relevant rack standard, which sets anchor count, base length, and brace sizing well above the static minimum.

Materials and finish

Columns, bases, and arms are structural steel in the S355 or A572 Gr50 class, sized so working stresses stay well below yield at rated load with a code safety factor. Outdoor and corrosive installations use hot-dip galvanizing; indoor racks are usually powder coated, which also makes damage and impact easier to spot during inspection. Anchors are proprietary expansion or chemical types with published pull-out ratings matched to the slab thickness and concrete grade.

Variants and applications

Single sided racks stand against a wall and store from one face; double sided racks place two columns back to back on a shared base line and store from both aisles, doubling density where floor space allows. Light duty roll-formed systems suit timber yards, building merchants, and furniture warehouses; heavy structural systems carry steel bar, pipe, and coil in metal service centers. Outdoor versions add a roof and side cladding to become a covered storage building in their own right. Across all of these the appeal is the same open storage face that lets long loads be handled quickly and safely.