System 04 · Density without entering the rack
Push back racking: gravity does the lane work.
Push back stores pallets on nested carts running on inclined rails, two to six deep. Loading a new pallet pushes the row back; removing one lets gravity roll the next pallet forward to the face. The forklift never enters the structure, which removes the impact risk that makes drive-in racking demanding to operate — and it gives you selectivity per lane rather than per block.
In brief
Push back racking stores pallets on nested carts running on inclined rails, two to six deep. Loading pushes the row back and gravity returns the next pallet to the face, so the forklift never enters the structure and impact damage largely disappears.
- Density close to drive-in, but the truck stays in the aisle — far lower impact risk and faster loading.
- Several lanes per level means several SKUs per bay, which drive-in cannot offer.
- Purely gravity driven: no motors, no controls. The wear items are cart wheels, rails and stops.
- Pallet quality matters — pallets travel on carts, so damaged stringers cause hang-ups.
01 — Mechanism
Carts, rails and a working incline
Each lane holds a set of carts that nest inside one another. The deepest pallet sits on the lowest cart, the next on the one above it, and so on, so the face pallet always presents at the same height.
Rails are set to a slight incline so a loaded cart rolls forward under gravity when the pallet in front is removed. No power, no controls, nothing to maintain electrically.
The truck lifts a pallet to the face and pushes the existing pallets back one position. Everything happens from the aisle, with the mast within the aisle envelope.
Take the face pallet and the next one arrives by itself within a second or two. Retrieval is as fast as selective racking at the face, which is why push back suits high-throughput buffers.
02 — Push back against the alternatives
Choosing between the dense systems
| Criterion | Push back | Drive-in | Pallet flow |
|---|---|---|---|
| Lane depth | 2–6 pallets | 4–10+ pallets | 4–20 pallets |
| Rotation | LIFO | LIFO | FIFO (true) |
| Forklift enters rack | No | Yes | No |
| Impact risk | Low | High | Low |
| Loading speed | Fast | Slow | Fast |
| Selectivity | Per lane, several per level | Per block | Per lane |
| Moving parts | Carts and rails | None | Rollers and brakes |
| Relative investment | Higher than drive-in | Moderate | Highest |
Rule of thumb: choose push back when you need depth of three to five pallets with several SKUs per bay and want the truck to stay in the aisle. Choose drive-in when lanes run deeper than six and the SKU count is genuinely small.
03 — Where it earns its cost
Applications that suit push back
Production buffers
Finished goods coming off a line in batches, held for a few days before despatch. Depth matches the batch, and the face is always ready for the next truck.
Regional DC buffer stock
Fast-moving SKUs held two to four deep behind a selective pick face, so replenishment is a short move rather than a trip across the warehouse.
Chilled rooms with mixed SKUs
Density close to drive-in without sending a truck and driver into a cold, poorly lit lane. Specify galvanised carts and rails.
Bottling and canning
High volume per SKU with several SKUs per bay, and loading speed that keeps up with a production line.
Cartons, film and preforms
Light but bulky pallets where depth costs little in structure and space saving is significant.
Promotion and seasonal stock
Blocks of stock held for a defined campaign, cleared in the same order they arrived.
04 — Specification notes
What to check before ordering push back
- Pallet quality matters. Pallets sit on carts and travel; damaged stringers, protruding nails and inconsistent footprints cause hang-ups.
- Confirm the unit load weight range per lane — cart and rail sizing follows the heaviest pallet, not the average.
- Allow for the incline: usable clear height per level is slightly greater at the back of the lane than at the face.
- Specify galvanised carts, rails and structure for chilled and frozen rooms.
- Agree a cart inspection interval; carts and wheels are the wear items in this system.
Questions buyers ask
Frequently asked questions
How deep can push back racking go?
Commonly two to six pallets. Beyond that, the incline needed to keep carts rolling reliably starts to eat into usable height, and drive-in or a shuttle system becomes the better answer.
Does push back racking need power?
No. It works on gravity and the forklift’s own push. There are no motors, sensors or controls — the maintenance items are cart wheels, rails and stops.
Is push back racking FIFO or LIFO?
LIFO within a lane: the last pallet loaded is the first retrieved. If you need true first-in-first-out, use pallet flow racking, which loads on one side and picks on the other.
Can push back be used in a freezer?
Yes, with hot-dip galvanised structure, rails and carts, and wheels rated for low temperature. Tell us the operating temperature at enquiry stage so components are specified correctly from the start.
Why is push back more expensive than drive-in?
Because you are buying carts and rail assemblies for every lane, not just structure. In exchange you get faster handling, far lower impact risk and more SKUs per bay, which is often worth more than the difference over a system’s life.
What is the lead time for push back racking?
Plan on four to six weeks of fabrication after drawing approval, longer with galvanising. Cart assemblies are the pacing item, so early confirmation of pallet weights and dimensions genuinely shortens delivery.
Talk to engineering, not a call centre
Production buffer, batch storage or mixed SKU depth?
Push back often beats drive-in for warehouses that need density but cannot accept the operational discipline of driving into the structure. Send your throughput figures and we will model both.