PUSH-BACK RACKING

Cart, Rail and Incline: What Actually Makes Push-Back Work

A push-back lane is a set of nested steel carts on wheels sitting on rails pitched at roughly 3 to 4 degrees. Each cart carries one pallet and slides inside the cart behind it. Depth is limited by physics: at four deep the rear pallet needs enough head-height for the stacked carts, so a four-deep lane requires around 300 mm more vertical clearance per level than plain beam-and-deck storage. We check that against your building's clear height before quoting.

Wheel choice is the detail that separates a lane that runs for fifteen years from one that jams every fortnight. We specify sealed polymer or nylon-tyred bearings for ambient sites and stainless-race wheels for chilled stores, because standard bearings pick up condensation and seize. Rails are galvanised and drilled on 50 mm pitch so levels can be reset if your pallet height changes.

Pallet quality matters more here than in any other system. Broken bottom boards catch on cart lips. Any site running repaired or non-standard timber pallets should tell us at survey stage so we can specify carts with full-width support decks instead of open channels.

• Lane depths of 2, 3, 4, 5 or 6 pallets
• Cart capacity typically 1,000–1,500 kg per pallet
• Selectivity of one SKU per lane, every lane at the pick face
• No truck entry — dramatically lower frame damage than drive-in
• Suits standard counterbalance and reach trucks, no special truck spend
• Galvanised carts and rails available for chilled and freezer stores

Push-Back vs Drive-In vs Pallet Live

Push-back gives you around 75% floor utilisation against drive-in's 85%, but it hands back something drive-in cannot: every lane is pickable from the aisle at all times. A 40-lane push-back block presents 40 SKUs to the picker; a 40-lane drive-in block with the same footprint presents the same 40 SKUs but each one takes a truck excursion into the structure, roughly doubling handling time per pallet.

Pallet live storage — gravity flow — is the FIFO cousin, loaded at one end and picked at the other. Where stock is date-coded, live storage is the right answer and we will say so. Where the same SKU is being put away and picked from a single face by a single truck, push-back is faster, cheaper per position and needs only one aisle.

In cost terms, expect push-back to sit above adjustable pallet racking and below pallet live per pallet position. On a typical Midlands distribution unit converting a 300-position selective block to push-back gains roughly 180–220 additional positions in the same footprint.

Installation, Commissioning and Ongoing Inspection

Floor flatness is the make-or-break. Push-back rails need a level datum along the full lane length; on older slabs we shim frames and, where a slab dips more than 10 mm over the lane, we recommend localised grinding rather than living with carts that run away or stall. We survey the slab with a laser before installation, not after.

On handover we run every lane loaded to full rated weight, check cart return speed, and fit end stops and a load notice showing pallets per lane, weight per cart and lane depth. Push-back still falls under HSG76 and SEMA guidance: weekly recorded visual checks by your PRRS and an annual inspection by a SEMA-approved inspector. We hold cart, wheel and rail spares for the common UK systems so a jammed lane is a same-week fix.