System 07 · Where density becomes automation
Radio shuttle and mobile racking: density at scale, when the cold costs more than the steel.
These are the two systems that go beyond what static racking can do. A radio shuttle is a battery-powered carrier that moves pallets inside a deep lane under remote control, so the forklift never enters. Mobile racking puts entire selective runs on motorised bases that travel on floor rails, opening only the aisle you need. Both become economic at scale — particularly in large cold stores, where the volume you avoid refrigerating is worth more than the equipment.
In brief
A radio shuttle is a battery-powered carrier that moves pallets inside a deep lane under remote control. Mobile racking puts selective runs on motorised bases that travel on floor rails, opening only the aisle in use. Both become economic at scale, particularly in large cold stores.
- Shuttle lanes run 10–40+ pallets deep and can be configured for FIFO or LIFO; the forklift never enters the lane.
- Mobile racking reaches 80–90% floor utilisation — the highest of any system — with full selectivity when an aisle is open.
- Both typically start to repay above roughly 3,000 pallet positions, where refrigeration energy and land value are large enough.
- Battery performance falls at freezer temperature, so charging routine and spares are part of the design, not an afterthought.
01 — Radio shuttle
Radio shuttle racking: the forklift stays in the aisle
A forklift places the shuttle into a lane and then delivers pallets to the lane mouth. The shuttle collects each pallet, carries it to the correct position and returns. To retrieve, the sequence reverses. One shuttle serves many lanes and is moved between them by the forklift.
Lanes of 10 to 40 or more pallets become practical, far beyond drive-in, because nothing has to drive inside the structure.
Configurable as FIFO or LIFO depending on whether lanes are loaded and picked from one end or from both. This flexibility is one of the system’s main advantages over drive-in.
Impact damage largely disappears, since the truck works only at the lane face. In freezer applications this also removes the need for a driver to work deep inside a cold, low-visibility lane.
The shuttle is battery powered, and battery performance drops at freezer temperatures. Charging routine and spare battery provision are part of the operational design, not a detail to be settled after handover.
02 — Mobile racking
One aisle at a time, opened where you need it
Selective racking runs are mounted on motorised mobile bases travelling on rails set into the floor. Runs are parked closed against each other; an operator opens a single aisle by remote or panel and works it conventionally.
Because only one aisle exists at a time, floor utilisation reaches 80–90% — the highest of any system — while every pallet remains directly accessible when its aisle is open.
Almost always cold storage. In a freezer, every cubic metre of aisle is refrigerated continuously; eliminating most of the aisle volume produces energy savings that compound every year of operation.
Access is slower because you wait for the aisle to open, so mobile racking suits lower-frequency, high-value storage rather than high-pick-rate operations. Rails must be embedded in the slab, which makes this a permanent installation.
03 — The dense systems compared
Drive-in, shuttle, mobile
| Criterion | Drive-in | Radio shuttle | Mobile racking |
|---|---|---|---|
| Floor used for storage | 60–80% | 60–85% | 80–90% |
| Lane depth | 4–10+ pallets | 10–40+ pallets | 1 pallet (selective on bases) |
| Selectivity | Low | Per lane | 100%, with aisle opening delay |
| Rotation | LIFO | FIFO or LIFO | FIFO or LIFO free |
| Truck enters structure | Yes | No | No |
| Impact risk | High | Very low | Low |
| Moving equipment | None | Shuttle units | Motorised bases and rails |
| Relative investment | Moderate | High | Highest |
| Cold storage suitability | Very good | Very good | Best |
Access speed also differs: shuttle systems are fast at the lane face, while mobile racking trades speed for maximum density. Match the choice to your picks per hour, not only to your pallet count.
04 — Project inputs
What we need to quote a semi-automated system
- Total pallet positions required, now and at your three-year projection.
- Operating temperature, and whether the room is chilled, frozen or ambient.
- Daily pallet movements in and out — this drives shuttle count and lane configuration.
- SKU count and pallets held per SKU.
- Slab thickness, grade and flatness; mobile racking additionally needs rail embedment detail.
- Available power supply and space for charging, including a location that is not inside the cold room where possible.
Questions buyers ask
Frequently asked questions
How many shuttles do I need?
It depends on daily pallet movements and the number of lanes worked simultaneously, not on the number of lanes installed. Many operations run a small number of shuttles across a large block. We size this from your throughput figures.
Does a radio shuttle work at freezer temperature?
Yes, with components and batteries specified for low temperature. Battery capacity falls in a freezer, so charging routine and spare battery provision are designed in from the start rather than added later.
Is mobile racking worth it outside cold storage?
Occasionally, where land is exceptionally expensive or a controlled-environment room is costly to maintain. In ambient warehouses on affordable land, the payback is usually too long and VNA or a density system is the better answer.
What happens if a shuttle fails inside a lane?
Recovery procedures are part of commissioning: lanes are designed so a shuttle can be recovered from the face, and operators are trained on the procedure. We hold spare units and parts for the systems we supply.
Can shuttle racking be added to existing drive-in racking?
Rarely as a direct conversion, because rail profiles, tolerances and lane lengths differ. It is usually more sensible to plan a shuttle block as a new structure and repurpose the drive-in elsewhere in the building.
What is the lead time for these systems?
Longer than static racking. Structure fabrication runs in parallel with equipment procurement, and galvanising adds time. Bring us in early — at the point you are still sizing the cold room — and the programme is far easier to hold.
Talk to engineering, not a call centre
Large cold store, high throughput, few SKUs?
This is where the arithmetic changes. Send the pallet count, temperature and daily movements, and we will compare drive-in, shuttle and mobile on capacity, handling time and refrigerated volume.