A stacker crane is the central component of most AS/RS systems (automated storage and retrieval systems). It is an automated crane that travels within a rack aisle, picking up and depositing pallets, boxes, or containers with millimeter precision. If you have ever seen images of a modern warehouse with 20- or 30-meter-high racking and machines moving between them without operators, that is a stacker crane. In Argentina and Chile, the growing adoption of industrial automation is leading more and more companies in logistics, manufacturing, food, and pharmaceuticals to evaluate this technology for their warehouses and storage facilities.
In plain terms: what a stacker crane does and why it matters
Think of a stacker crane as a robot that does the work of both a forklift and an operator, but on its own, nonstop, and without making mistakes. It moves down an aisle between tall racks, rises to the exact position, grabs the pallet or box, and delivers it to wherever you need to assemble the order. You don't send anyone to fetch goods or climb 15 meters on a machine: the system brings the product to the operator (this is known as goods-to-person). What does this mean in practice? It solves the three things that hurt in any warehouse. You gain space (storing vertically, up to 3 times more in the same square meters), you gain time (the robot doesn't walk kilometers the way an operator does), and you stop making errors (every movement is controlled by software, with accuracy above 99,9%). That is why the stacker crane is the heart of most automated warehouses: it turns a building full of racking into an operation that runs on its own, 24 hours a day.
Types of stacker crane: unit-load and miniload
There are two main families of stacker cranes. The unit-load (or pallet) stacker crane is designed to handle heavy load units: EURO, ISO, or American pallets weighing up to 1.500 kg. It operates in high-bay warehouse aisles (7 to 40 meters), with travel speeds of up to 160 meters per minute. It is the reference system for distributors, 3PL operators, and manufacturing plants that handle large pallet volumes. The miniload stacker crane, in turn, is optimized for smaller loads: boxes, totes, and trays weighing up to 50 kg. It operates in narrower aisles (600 to 800 mm) and reaches travel speeds of up to 180 meters per minute. It is the standard system for high-speed picking in e-commerce, pharmaceuticals, and manufacturing with many SKUs. Both share the same basic architecture but have completely different structural, fork, and control specifications.
How a stacker crane works, step by step
The operating cycle begins in the software. The WMS (warehouse management system) receives the order — either a storage or a retrieval request — and passes it to the WCS (warehouse control system). The WCS calculates the exact position of the product in the rack and assigns the mission to the most efficient available stacker crane. The stacker crane moves simultaneously in the horizontal plane (on rails on the floor and ceiling) and the vertical plane (raising the load platform) until it reaches the correct cell. The telescopic fork extends, captures the pallet or container, and retracts. The stacker crane travels to the delivery point — a load/unload station or a conveyor — and sets down the load. The entire cycle, from mission to delivery, takes between 45 and 90 seconds in a 20-meter-high warehouse. Every movement is automatically recorded in the WMS: inventory 100% tracked in real time.
Stacker crane vs. shuttle: when to use each
The choice between a stacker crane and a shuttle depends mainly on two variables: the required throughput and the storage density needed. A stacker crane operates in a single aisle with one machine: it is sequential, running one cycle at a time. This makes it well suited when throughput is not extremely high but the available height is considerable (10+ meters). A shuttle, on the other hand, can have multiple robots on different levels of the same aisle, operating in parallel — which gives it potentially much higher throughput per aisle. However, a shuttle requires more investment per aisle and has greater maintenance complexity. The rule of thumb: a warehouse with moderate throughput (up to 200 movements/hour per aisle), great height, and many positions — stacker crane. A warehouse with very high throughput, lower height, and high density — shuttle. For many operations, combining the two in the same facility is the most efficient solution.
How much a stacker crane costs and its ROI in Argentina
The cost of a DELIE unit-load stacker crane for a mid-scale warehouse aisle (15 meters high, 500 pallet positions) runs between USD 180.000 and USD 280.000, not including the racking or the WCS. A complete 2-aisle project with conveyors, racking, WCS, and integration with the existing ERP in a warehouse in Argentina ranges from USD 800.000 to USD 1.500.000. With Decree 513/2025 (0% tariff on AS/RS equipment) and RIMI (100% accelerated depreciation in the first fiscal year), the net cost of a project drops by 25% to 35%. The typical ROI of a stacker crane project in Argentina is between 18 and 36 months, depending on the current labor cost of the manual operation it replaces.
Is a stacker crane worth it for a small or mid-size warehouse?
This is one of the most common questions, and the short answer is: height matters more than floor area. A stacker crane needs at least 7 meters of clear height to be worthwhile; if you have that height, the warehouse doesn't need to be huge. For small or mid-size operations that handle boxes rather than pallets, the miniload is the entry point: it fits in narrow aisles and starts at a more accessible scale than a full pallet system. And you don't have to automate everything at once — you can start with a single aisle or module and grow later, adding aisles as the operation expands. The rule of thumb is simple: if your warehouse has run out of floor space but you have height to take advantage of, a stacker crane — or a miniload — almost always belongs in the conversation. STOKA's free assessment tells you in the first consultation whether your case makes sense or not.
The first step is a free assessment
The decision to install a stacker crane in your warehouse doesn't start with the budget: it starts with understanding whether the system is the right fit for your operation. STOKA carries out the technical assessment — throughput analysis, SKU profile, available height, and ROI projection — at no cost and with no obligation. If a stacker crane isn't what you need, we'll tell you. If it is, we build the complete technical proposal in 2 to 4 weeks.
Frequently asked questions
Can a stacker crane operate in an existing warehouse, or only in new construction?
It can be installed in existing facilities as long as there is enough clear height (a minimum of 7 meters) and the floor slab can support the structural loads. Most of STOKA's projects are in existing warehouses. It requires floor leveling and minor civil anchoring work.
What happens if the stacker crane fails in the middle of operations?
DELIE stacker cranes have an MTBF (mean time between failures) of over 8.000 operating hours. If a failure occurs, the aisle can be run in emergency manual mode with a forklift while the issue is resolved. STOKA keeps spare parts in Argentina to resolve most failures in under 24 hours.
How many stacker crane aisles does my operation need?
The number of aisles depends on the required throughput (movements per hour) and the storage capacity needed (number of pallet or container positions). With those two figures, STOKA sizes the system in the first free technical consultation.
Does the stacker crane integrate with my existing WMS or ERP?
Yes. The DELIE WCS connects to any WMS or ERP via REST API, SOAP, or EDI. Certified integrations with SAP, Oracle, Microsoft Dynamics, and Infor. STOKA manages the technical integration as part of the turnkey project at no additional cost.
What is the difference between a stacker crane and a forklift?
A forklift is operated by a person and is used to move pallets one at a time, at low height. A stacker crane is automatic: no one drives it, it operates within a fixed rack aisle, reaches heights of up to 40 meters, and works 24 hours a day without errors or breaks. In short: a forklift is a tool used by an operator; a stacker crane is a robot that replaces the manual travel and stores at heights far beyond a forklift's reach.
How much does a stacker crane cost?
It depends on the type and scale, so it comes as a range rather than a fixed figure: a mid-scale unit-load (pallet) stacker crane runs between USD 180.000 and USD 280.000 without racking or software. A complete multi-aisle project — with racking, controls, and integration — usually ranges from USD 800.000 to USD 1.500.000. With the reduced tariff (Decree 513/2025) and RIMI, the net cost drops considerably. The figure for YOUR case comes out of the free assessment, based on your operation.
Is it worth it for a small warehouse?
Yes, as long as you have clear height (ideally 7 meters or more): what matters is not the square meters but the height you can take advantage of. For small or mid-size warehouses that handle boxes, the miniload is the most accessible option, and you can start with a single aisle and grow later. If you've run out of floor space but have height, it almost certainly belongs in the conversation.