The 4 way shuttle automatically moves pallets in all four directions within the AS/RS

The 4 way shuttle for pallets

September 19, 2025

The 4-way pallet shuttle, or four-way shuttle, is one of the latest breakthroughs in automated storage solutions for pallets. Unlike traditional systems, it can move in every direction within the warehouse: forward, backward, left, right — and vertically, with the help of elevators. This full range of motion maximizes space utilization while streamlining operations. At Interlake Mecalux, this innovation takes shape in the 3D Automated Pallet Shuttle (APS), an intelligent, flexible solution for warehouses that demand high-density storage, top performance, and easy scalability.

In this post, we’ll break down what the four-way pallet shuttle system is, how it works, and why it’s a game-changer for automated pallet storage.

What is a 4 way pallet shuttle?

A four-way shuttle is an automated storage and retrieval system (AS/RS) designed to move pallets autonomously in four directions: forward, backward, and sideways (left to right). This means it can enter storage lanes to deposit and remove pallets and switch aisles with ease. In addition to those four movements, it can also travel vertically, using elevators to change levels. What sets the 4-way shuttle apart is its multidirectional mobility, giving it a versatility unmatched by traditional shuttle systems.

Shuttles travel straight along the storage lane
The 4 way shuttle automatically moves pallets in all four directions within the AS/RS

This type of solution is designed for facilities that require high-density storage and advanced automation. Examples are fulfillment centers, production plants, and freezer warehouses, where efficiency, fast load handling, and optimal space utilization are critical to operational performance.

How does the four way shuttle work?

The system is made up of intelligent shuttles that move in four directions. These electric vehicles are coordinated by fleet management software, which enables fully autonomous and efficient operation. Their main movements include:

  • Aisle navigation. The shuttles travel lengthwise along each aisle to reach the different storage lanes and position themselves where a pallet needs to be deposited or retrieved.
  • Lane movements. Once in the correct aisle, the shuttles move sideways to enter the target storage lanes, placing pallets in their assigned location (or retrieving them). To switch aisles, they either use transfer lanes (when carrying a pallet) or storage lanes (when traveling empty).
  • Level changes. Elevators carry shuttles between the different racking levels, maximizing vertical space and enabling high-bay storage.

These operations are coordinated by fleet management software, which plans movements, assigns tasks, and manages energy recharging — whether at fixed stations or on the go.

The software behind the 4 way shuttle

Interlake Mecalux’s 3D Automated Pallet Shuttle combines advanced hardware with a suite of digital solutions that coordinate all system movements efficiently and safely. The main software layers that manage the AS/RS are:

  • WMS. The Easy WMS warehouse management system oversees inventory, storage locations, and logistics flows. To coordinate all operations, it communicates with the ERP and execution systems.
  • Fleet management software. This sends instructions to each shuttle to transport goods and track their positions within the AS/RS.
  • WES. The warehouse execution system prioritizes and organizes tasks based on workload, optimizing available resources and ensuring smooth operational flow.
  • WCS. The warehouse control system carries out orders issued by the WES, accurately managing shuttle, elevator, and conveyor movements.

Differences between a 4 way shuttle and other shuttle systems

What sets a 4-way shuttle apart from other pallet shuttle systems is its mobility and operational autonomy.

Feature Pallet Shuttle (semi-automated) Automated Pallet Shuttle with stacker crane Automated Pallet Shuttle with transfer cars

4-way Pallet Shuttle (3D APS)

Automatic movement in storage lane Yes Yes Yes Yes
Automatic movement in aisle No Yes Yes Yes
Automatic vertical movement No (requires forklift) Yes (via stacker crane) No (one shuttle per aisle level) Yes (via pallet elevators)

Automatic aisle change

No No No Yes
Multiple shuttles per aisle No Yes (one per level) Yes (reassignable as needed)
Multiple shuttles per level No No Yes (reassignable as needed)
Automation level Partial High High Full

 

Thanks to its multidirectional mobility, the 4-way shuttle doesn’t need forklifts or transfer bridges, resulting in a faster, fully automated workflow.

Interlake Mecalux’s 4 way pallet shuttle

Interlake Mecalux’s 3D Automated Pallet Shuttle is a 4-way shuttle solution. Its vehicles move in multiple directions within compact racking systems, enabling fast, precise, and flexible pallet handling. This technology delivers full automation and high storage density, reducing pallet handling times while optimizing available space.

The 3D APS combines multidirectional shuttles, pallet elevators, and a WMS that coordinates all movements. The result is a continuous, safe, and efficient flow of goods-in/goods-out operations fully tailored to the needs of each facility.

Key advantages include:

  • High-density storage. Operating within compact racking structures, the system maximizes available space, eliminates unnecessary aisles, and increases storage locations per square foot.
  • Full automation. The 3D APS automates most pallet handling tasks in the warehouse. This reduces the risk of error, improves traceability, and limits reliance on manual operations.
  • Modular and scalable. The system’s capacity can grow with the business by adding new shuttles, elevators, or racking levels without interrupting operations.
  • Cold and freezer compatibility. Designed for demanding environments, Interlake Mecalux’s 3D APS works in temperatures below 32 °F, ideal for food and pharmaceutical warehouses.
Interlake Mecalux’s 3D APS fully automates pallet handling
Interlake Mecalux’s 3D APS fully automates pallet handling

Facilities with the 4 way shuttle

Four-way shuttle systems, like Interlake Mecalux’s 3D Automated Pallet Shuttle, are especially effective in industrial and logistics environments that require high-density storage, fast pallet turnover, and rapid response times. Multiple shuttles working together on each level and aisle keep pallets moving quickly and effortlessly. Four-way pallet shuttle systems are also ideal for hard-to-access spaces and extreme conditions (e.g., cold storage and freezer warehouses).

A practical example of the 3D APS is Clavo Food Factory’s new AS/RS in Tordesillas, Spain, which automatically manages thousands of frozen-food pallets.

The company turned to Mecalux technology to maximize space in a freezing environment and handle its annual production of over 15,430 tons of frozen and refrigerated goods. Full automation improves product traceability, reduces errors, and ensures 24/7 operational availability — even in temperatures as low as -13 °F.

Moving to intelligent automation

The 4-way shuttle is one of the most advanced AS/RS solutions for high-density storage. At Interlake Mecalux, we’ve developed this technology as part of our 3D Automated Pallet Shuttle, designed to deliver flexibility, speed, and high performance in challenging environments.

Our team of engineers and consultants evaluates each project individually to recommend the solution that best fits your needs. If you’re considering warehouse automation, be sure to contact us. An Interlake Mecalux advisor can guide you through every step — from design and engineering to installation and post-sale support.