4-Way Tote Shuttle
The only tote shuttle that leaves its aisle. Cross-rails at the rack ends let one machine serve locations across the whole structure, so capacity is added by shuttle rather than by aisle.
SLS900 Series · 4-Way
Coverage instead of concentration.
The other three models put a shuttle in an aisle and make that aisle fast. This one spreads a smaller fleet across the whole rack. It is the right machine when locations are scattered and duty per aisle is too low to justify dedicating a shuttle to each.
One shuttle, every aisle
Cross-rails at the rack ends let a machine leave its aisle and work anywhere in the structure. Capacity is added one shuttle at a time instead of one aisle at a time.
Flexible layouts
Columns, level changes and awkward footprints stop being a constraint when the fleet is not tied to a fixed aisle grid. One vehicle serves multiple aisles/zones.
168 hours between charges
A lithium titanate pack carries seven days of running. This is the one tote model that leaves its track, so it takes its power with it rather than drawing from a conductor rail.
| Movement | Four-way multi-aisle |
|---|---|
| Payload | 50 kg max |
| Throughput, per aisle | 1,000 boxes/hr |
| Continuous Runtime | 168hr self-charges between breaks |
| Max speed | 6 m/s (2 m/s lateral) |
| Position accuracy | ±3mm |
| Positioning method | DC servo + positioning photoelectric sensor + RFID |
Typical deployments
Where the SLS900 4-Way excels
These are operations with a lot of locations and no single hot aisle. Spreading a small fleet across the structure costs less than equipping every aisle for a peak that only some of them ever see.
Irregular buildings
Existing structures with columns, level changes or awkward footprints, where a uniform aisle grid wastes as much space as it creates.
Long-tail assortments
Many SKUs, low movement each. Coverage across the rack is worth more than speed within one part of it.
Phased growth
Capacity added a shuttle at a time as volume arrives, rather than committing to a full aisle of equipment ahead of demand.
Multi-zone sites
One fleet serving several rack areas rather than a dedicated set of machines standing idle in each.
The complete system
The complete 4-Way Shuttle system
Tote shuttles handle every horizontal move inside the rack. Servo lifts carry cases between levels, and interface lines connect the rack to the rest of the building. Throughput is set by how many shuttles and lifts you run rather than by the structure, so density and speed are specified separately.
01 · Box shuttle
Travels the rack on rail, bidirectionally on the Standard, Variable and Sorting & Buffering shuttles, and across aisles on the 4-Way. Positioning to ±3 mm by DC servo, photoelectric and RFID.
02 · Layer-changing lift
Servo belt drive carrying up to 100 kg across two cargo compartments, positioning to ±2 mm, at 6 m/s unloaded.
03 · High-density racking
Multi-deep, multi-level rack from 2 to 30 m tall with aisles from 10 to 100 m long, reconfigurable as the SKU profile changes.
04 · Interface lines and charging
Because it leaves its track it cannot draw from a conductor rail, so it runs 168 hours on an onboard pack and returns to a charging bay.
Specs
The 4-Way, in full.
| Specification | 4-Way |
|---|---|
| Movement | Four-directional, multi-aisle |
| Rack configuration | Multi-aisle |
| Payload | Rated 35 kg / max 50 kg |
| Throughput, per aisle | 1,000 boxes/hr |
| Max speed, along aisle | 6 m/s |
| Max speed, cross aisle | 4 m/s |
| Acceleration, along aisle | 2 m/s² |
| Acceleration, cross aisle | 1 m/s² |
| Case size (L×W×H) | 200–850 × 200–650 × 160–500 mm |
| Lift fork speed, in / out | 10 / 36 m/min |
| Lift fork positioning | ±1.5 mm |
| Positioning accuracy | ±3 mm |
| Continuous runtime | 168 h (7 days) |
| Operating temperature | −25 to 45 °C |
| Specification | 4-Way |
|---|---|
| Power supply | Onboard battery, no track charging |
| Battery | Lithium titanate, 2.9 Ah |
| Supply voltage | DC 48 V ±10% |
| Battery cycle life | 15,000 cycles |
| Drive | Synchronous belt, electric braking |
| Travel motor | 1,000 W |
| Fork motor | 400 W |
| Positioning method | DC servo, photoelectric and RFID |
| Communication | 5 GHz / 2.4 GHz dual band, RS-485 |
| Structure | Q235B steel, ≥235 MPa yield |
| Certification | CE · 2006/42/EC, SGS verified |
| System availability | ≥97% to FEM 9.222 |
| Rack height range | 2 to 30 m |
| Aisle length range | 10 to 100 m |
Safety and certification
What protects people and stock.
Obstacle detection
HWA sensors stop the shuttle before contact, whether the obstruction is a load, a person or another machine.
Anti-fall and end stops
HWA sensors and mechanical end stops hold the shuttle on rail at the limits of travel.
Emergency stop
Red emergency stop on the machine, halting the shuttle immediately.
Battery protection
Over-temperature, overcharge and over-discharge protection on the onboard lithium titanate pack.
Alarm and interference
Onboard alarm function, with dual-band wireless chosen for resistance to interference across a busy rack.
Certification
CE to Machinery Directive 2006/42/EC, verified by SGS across the shuttle, the shuttle lift and the tote AS/RS system. Manufacturing certified to ISO 14001:2015.
Frequently Asked Questions
The SLS900 4-Way, specifically.
Why does the 4-Way need charging when the other tote shuttles do not?
Because it leaves the aisle. The Standard, Variable and Sorting shuttles draw power continuously from a conductor rail along their running track, which only works while the shuttle stays on that track. A four-way machine crosses between aisles, so it carries its own lithium titanate pack instead and runs 168 hours between charges.
Is one 4-Way better than several single-aisle shuttles?
Rarely on throughput, often on cost per location. A single-aisle fleet will move more cases per hour; a four-way fleet covers more locations per machine. The four-way wins where duty per aisle is low enough that dedicating a shuttle to each one is hard to justify, or where the building shape makes uniform aisles impractical.
How does a shuttle move between aisles?
It travels on cross-rails at the end of the racking, at 4 m/s against 6 m/s along the aisle. The transfer costs time, which is why the four-way suits operations where locations are spread widely rather than ones where a single aisle is saturated.