Pallet Shuttle Racking System
Semi-automated, high-density and high-throughput system that uses a motor-driven shuttle to place and remove pallets within racking structure.
The product
The evolution of high-density pallet storage systems: greater capacity, speed and throughput
The Pallet Shuttle is a semi-automated high-density storage system in which a shuttle with an electric motor runs along rails within the storage channels to load and unload pallets. The process is controlled by an operator, who places the shuttle in the racking using a forklift and controls it via a tablet.
Compared to other high-density solutions, e.g., drive-in racking, the shuttle rack system increases storage capacity, goods-in/goods-out flows and the number of products to be stored. The system is also available in a fully automated version, which features either stacker cranes or transfer cars.
Advantages of the Pallet Shuttle system
- Time savings and productivity gains: the shuttle executes orders speedily, and the forklift operates in the aisle without entering the racking. This shortens loading/unloading times and raises the number of cycles/hour.
- Space savings: storage channels can exceed 60 m in depth, while clearances between levels are minimal, increasing storage capacity.
- Cost savings: the optimal use of space reduces the system’s footprint, thus keeping down land costs. And in cold storage warehouses, this means less surface area to be cooled, resulting in lower energy consumption.
- Multiple SKUs: grouping SKUs by channels as opposed to complete lanes allows for greater product diversity in the storage system.
- Compatible with LIFO and FIFO: the system can operate in line with the LIFO (last in, first out) or FIFO (first in, first out) inventory management strategies.
- Easy to use: all system functions are activated from the control tablet, which is equipped with an intuitive user interface.
- Safety: as the forklifts do not operate inside the racking, the metal structure remains free from damage, and the risk of accidents is minimized.
Compared to other high-density storage solutions, the Shuttle racking system is faster, more agile and safer
Pallet Shuttle system applications
For companies that need high-density storage and maximum throughput
The Pallet Shuttle is the perfect storage solution for boosting productivity in warehouses looking to considerably increase storage capacity while facilitating and streamlining loading and unloading operations.
Facilities with many pallets per SKU
The Pallet Shuttle is ideal when managing a large number of pallets per SKU. Each channel can hold a different SKU.
Warehouses with massive inbound/outbound flows
The system notably speeds up pallet storage and retrieval for businesses with a fast-paced turnover of very homogeneous goods.
Cold stores
Thanks to space optimisation, the volume to be cooled is reduced, resulting in significant savings in energy costs.
Facilities with seasonal product demand
Streamlining dispatches makes it possible to respond quickly to demand peaks concentrated in short periods of time.
Warehouse buffer
This system is ideal for storing goods temporarily, e.g., in production centres.
Facilities requiring space optimisation
Its compact structure leverages all available surface area, especially in depth.
How does the Pallet Shuttle racking system work?
Semi-automated solution consisting of a shuttle, a forklift and an operator
Using a forklift, the operator positions the pallet shuttle car at the entrance to the channel. Next, they deposit the pallet on the rails, just above the shuttle. The shuttle then raises the pallet slightly and transports it, placing it in the first free location. Operators issue commands to the shuttle from a tablet.
An instruction is received
The operator receives the order to store a number of pallets. With a forklift, the operator first picks up the Pallet Shuttle car and moves it to the assigned storage channel.
The shuttle is placed in the channel
The forklift raises the shuttle unit and deposits it between the rails of the storage channel.
The pallet is positioned at the entrance to the channel
The forklift deposits the pallet at the channel entrance, resting on the rails, just above the shuttle. At no time does the forklift enter the racking.
The shuttle moves the pallet to its storage location
Using a tablet, the operator issues the command for the shuttle to raise the pallet slightly and move it to the deepest location, where it is then deposited.
The storage channel is filled
The shuttle returns to the channel entrance, repeating this operation until the entire channel is filled. Before placing the pallet in the last location, the operator removes the shuttle.
Pallet retrieval
To unload pallets, the operation is reversed. If a FIFO configuration is used, the pallets are removed from the aisle opposite the entry aisle.
Testimonials
We’re thrilled with the Pallet Shuttle by Mecalux because it’s enabled us to cope with our business’s high rate of activity.
The Pallet Shuttle has raised our productivity because the motorised shuttle automatically moves the pallets inside the channels. Our operators have adapted to it very quickly. From day one, I’ve noticed that work is done faster and more safely.
We chose the semi-automated Pallet Shuttle storage system because it was the ideal solution for ramping up our daily throughput. Thanks to this solution, we’ve gained in warehousing capacity, in efficiency when storing and dispatching pallets and in operator safety.
With the Pallet Shuttle, we’ve increased our storage locations, reduced goods loading and unloading times and saved on racking and forklift maintenance work.
The Pallet Shuttle racking system has substantially cut material handling times. Plus, it’s reduced the risk of accidents by preventing reach trucks from entering the storage lanes.
“We’re thrilled with the Pallet Shuttle racking and the software that runs the shuttles. Since their installation, the warehouse has turned out excellent results.
Case studies
Semi-automatic Pallet Shuttle in SaarGummi warehouse in Madrid
SaarGummi, a rubber manufacturing company, has renovated its distribution centre in Madrid to better serve its customers throughout the Iberian Peninsula. This overhaul includes the implementation of the semi-automated Pallet Shuttle system, which provides capacity and speed in operations. Read more
A bottled goods warehouse with the semi-automated Pallet Shuttle system
Case study of a warehouse with bottled olive oil using the Pallet Shuttle system, which provides high storage capacity and raises productivity. Read more
The dairy producer SLVA manages the handling and storage of more than 7,400 pallets with nine Pallet Shuttles in up to 20 m deep channels
Success story of the Pallet Shuttle system in the SLVA warehouse in France developed by Mecalux and other examples of storage systems. Read more
Rockwool Peninsular stores its over-sized product with Pallet Shuttle system
Rockwool Peninsular needed to store over-sized product on 1,000 x 2,400 mm pallets, Mecalux equipped the warehouse with compact pallet racks that have wider than usual channels for the motorised Pallet Shuttle. Read more
Semi-automatic Pallet Shuttle at the Red Cross warehouse in France
Recently, Croix-Rouge insertion - Logistique has renovated one of its distribution centres in Pantin (France) with Mecalux's semi-automated Pallet Shuttle system. This installation can hold 2,322 pallets filled with staple products that can help countless families. Read more
Mecalux has completed the storage project for a new 20,000 m² logistics centre in Portugal
Luis Simões is a comprehensive logistics provider and market leader in goods flows between Spain and Portugal. With the aim of boosting its internationalisation drive, the company has recently opened a new logistics centre in Portugal. To achieve maximum storage capacity and increased operational speed, Mecalux has equipped the new facility ... Read more
Storage configurations with Pallet Shuttle racking
Different distribution possibilities to find the solution that best meets your company’s logistics needs
Choosing which configuration to implement will depend on factors such as the size of your facility, the number of SKUs, the storage capacity needed, the load management system and the required flow of goods.
Solution with 1 aisle and 1 racking unit
The storage system consists of a single racking unit for the shuttle with a single front access aisle. Loads are managed according to the LIFO method: pallets enter and leave on the same side. This is particularly advisable for high volumes of pallets with few SKUs.
Solution with 1 aisle and 2 racking units
The storage system consists of two racking units with a working aisle between them. This set-up also uses the LIFO management method. It achieves a larger number of storage channels that are less deep than in the previous configuration, making it possible to increase SKU variety.
Solution with 2 access aisles
Storage system comprising a single racking unit with two access aisles: one for incoming goods and the other for outgoing goods. Loads are thus managed in line with the FIFO method. This is the perfect choice when the system acts as a buffer (temporary storage for full loads with short stays).
2 access aisles and picking on lower levels
Solution made up of a racking unit combined with levels of live pallet racking for picking and an access aisle on each side. This option forfeits storage capacity in favour of picking. The higher racking levels are used to supply the lower picking levels and also to dispatch full pallets.
Pallet Shuttle components
The Pallet Shuttle racking system consists of one or more shuttles, the racking unit in which the shuttle operates, a control tablet and a series of safety elements that protect the integrity of the operators, the goods and the structural assembly.
The Pallet Shuttle car is the core element of this storage solution. It moves mechanically and autonomously thanks to various electronic components (PLC, batteries, antennas, sensors, etc.). It also has a number of safety features to prevent incidents.
Shuttle racking is a high-density structure specially designed to ensure the safe, smooth movement of the shuttle inside it. It has a set of rails along which the shuttle moves and on which the pallets rest.
In addition to the various safety features incorporated in the car, the Mecalux Pallet Shuttle racking system also has a set of accessories that help to reinforce the safety of operators and goods and to comply with regulations in force.
Lifting platform
Located on the top surface, it lifts the pallet to transport it through the channel. Contact with the pallet is made on the lifting pads.
Wheels
The four main wheels rest on the base of the rails and make it possible for the shuttle to travel. They are located under the lifting platform.
Contrast wheels
These small four wheels make contact with the side of the rail to guide the shuttle in the longitudinal direction. These ensure smooth, safe movement.
On-board PLC
The programmable logic controller (PLC) is the Pallet Shuttle’s main processor: it executes the movements of the shuttle and receives information from the sensors.
Antenna
This allows the shuttle to receive via Wi-Fi the orders that the operator transmits from the control tablet.
Battery
The shuttle runs on lithium batteries that provide up to 10 hours of autonomy at full capacity, depending on temperature and load conditions.
Battery compartment
The battery is stored in an easy-access compartment on the top of the shuttle for fast, simple removal. It can be recharged in the compartment itself or at an external station.
Shuttle/forklift locking system
Electromagnets located at the base of the shuttle car reinforce its attachment to the forks of the forklift, preventing it from moving during handling.
On-board pallet detectors
Four vertical laser sensors located on the top of the shuttle help to ensure that the pallet is correctly positioned.
In-channel pallet detectors
Ultrasonic sensors that detect the position of the last pallet deposited in the channel.
End-of-channel sensors
Sensors that enable the shuttle to determine the distance until the end of the storage channel.
Shuttle stops
These are placed on the ends of the front of the shuttle to cushion the contact with the racking at the end of the channel.
On/off switch
Push button to switch the shuttle on and off. It turns green when on and red when off.
Fault indicator
This communicates the status of the shuttle. The steady red light indicates that the equipment is ready for operation, and the flashing red light indicates that there is an error or malfunction.
Battery status indicator
This signals that the state of the battery charge is low. When flashing, the battery needs to be replaced or recharged.
Safety bumper
Element located on the front and rear of the shuttle unit to prevent possible entrapment or crushing. It acts by cutting the power through simple contact.
Emergency stop button
Button ensuring that the shuttle stops immediately. It is essential before carrying out any maintenance work.
Positioning camera
Facilitates the insertion and centring of the shuttle in the channel. Extremely useful in high-bay pallet racking.
Charging station
Charging equipment with straightforward slide-in housing where batteries are snapped into place. It also includes a separate cable to charge the shuttle without removing the battery.
Load structure
Independent of the rack structure, this is used to store the shuttles and to charge their batteries (either on the shuttle itself or by removing them).
Beams and uprights
The racking consists of a framework of beams, uprights and rails that form the storage channels through which the shuttle moves and in which the pallets are stored.
Rails
Each storage channel has a pair of rails with two support levels: a lower one that the shuttle runs along and an upper one on which the pallet rests.
External rail supports
These anchor and fix the rail to the outer upright, i.e., at the entrance/exit of each channel.
Internal rail supports
These fix the rails to the beams at all points except the channel entry/exit.
Rail-end stops
Elements detected by the shuttle to slow and stop its movement in normal working conditions. They also serve as a reference point for the shuttle, as they indicate the end of each channel.
Pallet centralisers
Fitted to the storage channel entrance/exit points, these facilitate the positioning and centring of the pallet.
Front and side protectors
They mark the limit the operator can reach with the forklift to avoid hitting the racking.
Safety enclosures
These must be installed in all open spaces where the channels can be accessed, except for the front of the storage system, where the channel faces the working aisle.
Rack safety mesh
This must be fixed to the full height of the racking that coincides with passageways or work areas when there is a risk of loose loads falling. Only the front of the racking is exempt from fitting.
Painted floor markings
These limit the area restricted to people, except for maintenance work. These lines must be painted in the front of the racking (where the forklifts operate).
Safety signs and pictograms
These warn operators of the existing risks and describe the characteristics of the storage system.
Passageway protection
When passageways for evacuation or maintenance are enabled underneath the racking, safety enclosures must be installed on both sides, and safety mesh must be fitted at the top.
Protection for aisles with picking on lower levels
Aisles allocated to picking tasks on the lower level of the racking must be protected with mesh on the upper part to prevent objects from falling on the operators.
Functions of the Pallet Shuttle control system
High operational versatility thanks to a wide range of functions
The Pallet Shuttle control system is responsible for issuing orders to the shuttle via a Wi-Fi-connected tablet. The software has a very intuitive user interface, making it very easy to use. All functions can be executed from the tablet, and the assignment actions are touch-based.
Shuttle indicator
Shows the identification number of the car in operation and its status.
Operating mode selector
Allows you to choose the working mode: automatic or manual (for maintenance tasks).
Pallet selector
Used to choose the type of pallet to be handled.
Continuous loading/unloading
When this function is activated, the system performs the storage or retrieval operation continuously until the channel is completely loaded or unloaded.
Partial loading/unloading
With this function, you can indicate in advance the exact number of pallets to be stored in or removed from the channel.
LIFO/FIFO configuration
Selection of the load management strategy: LIFO (one working aisle) or FIFO (two working aisles).
Space-saving high-density storage
If the channel is not unloaded completely, this function enables you to regroup all the pallets at the beginning of the channel (LIFO mode) or towards the end (FIFO mode) to save time on future retrieval manoeuvres.
Change work aisle
Used to select the side of the racking you want to work on (only in FIFO mode).
Pallet counter
This function allows you to count the pallets stored in the channel.
Locking system
This activates the electromagnets at the base of the Pallet Shuttle unit, strengthening the contact between the shuttle and the forks of the forklift.
Tiltmeter
This triggers a warning when the shuttle has been inserted into the channel incorrectly. To solve this error, the shuttle must be repositioned in the channel.
Low battery warning
This icon warns the operator that the shuttle battery is about to run out.
Location signal
This activates an audible signal to identify the car and locate its position. It emits a series of sounds, while the fault light flashes.
Rescue
This function makes it possible to recover a shuttle from inside the channel using a rescue shuttle in the event of a breakdown or total discharge of the battery.
FAQs
The Pallet Shuttle — also known as radio shuttle racking or satellite shuttle racking — is a semi-automated high-density storage system that makes the most of the available surface area to achieve a higher storage capacity. It consists of an electrically powered shuttle that, controlled remotely by an operator, moves on rails inside the storage channels to insert and extract pallets autonomously.
The Pallet Shuttle is an evolution of other more traditional high-density storage systems. Compared to drive-in racking, for example, the Pallet Shuttle system makes it possible to house a wider variety of goods. This is because instead of allocating the entire lane to one SKU, each storage channel can accommodate a different SKU. Moreover, forklifts do not enter the Pallet Shuttle racking. This streamlines loading and unloading tasks and makes operations safer by considerably reducing the risk of collisions and accidents. Meanwhile, with regard to push-back pallet racking or pallet flow racks, the Pallet Shuttle allows for deeper channels and better leveraging of the facility’s height, respectively.
Absolutely. Different storage systems can coexist within the same warehouse (selective pallet racking, drive-in racking, Pallet Shuttle, etc.). A common combination, for instance, is to have one area with pallet racking to store a wide range of SKUs with few pallets and another section equipped with Pallet Shuttle racks to house more homogeneous goods with many pallets per SKU.
Yes, by adding the necessary beams and rails to allow the shuttle to move inside the racks.
The Pallet Shuttle is a semi-automated system featuring a shuttle that moves inside the racking automatically. However, it requires an operator to place or remove the shuttle from the rack, to deposit or retrieve the pallets from the entrance of the channel, and to select from the tablet the operation to be carried out.
Nevertheless, Mecalux does offer a completely automatic alternative: the automated Pallet Shuttle. With this solution, forklifts are replaced by a stacker crane or a set of transfer cars, which transport the shuttle and the pallet from the entry point of each storage channel in a completely autonomous way. In addition, in this solution, all operations are orchestrated directly by a warehouse control system (WCS).
Yes, that is precisely one of its main advantages. First and foremost, operators do not have to drive the forklifts inside the racks, as is the case with drive-in racking. In addition, the shuttle itself, which is delivered with the corresponding CE marking, is equipped with multiple devices that ensure its correct positioning within the rails and immediate stop in the event of encountering an unexpected object. The system is also equipped with safety enclosures to limit operator access to the areas in which the motorised shuttle operates and rack safety netting to protect passageways and work areas against the risk of falling loads.
First, the operator uses a forklift to place the shuttle at the entrance to the designated storage channel. Next, the operator places the pallet on the channel rails, just above the shuttle. Using a control tablet, the operator issues the command. The shuttle then raises the pallet slightly to move it to the deepest available location, where it is deposited. This procedure is repeated until the channel is full. Before placing the pallet in the last location, the operator removes the shuttle. To retrieve pallets, the procedure is reversed. However, when working in FIFO mode, unloading is done from the opposite side of the racking.
Yes, the Pallet Shuttle system can operate according to the FIFO (first in, first out) load management strategy, where the first pallet stored is the first to be removed. For this purpose, two working aisles must be set up: a front or loading aisle, where the pallets are deposited, and a rear or unloading aisle, where the goods are retrieved. This prevents interference between the two operations.
The system is scalable, and Pallet Shuttle cars can be added as needed. The recommended number of shuttles is determined by the number of cycles/hour required and by the number of operators actively involved in each work shift. Up to 18 shuttles can be controlled from a single tablet.
Yes, although to do this, the half pallet or odd-sized pallet needs to be placed on a standard pallet, which acts as a slave pallet.
This is highly unlikely, as the Pallet Shuttle car has a battery status indicator that warns the operator when the charge level is low. If the battery were to become completely discharged with the shuttle at the entrance to the channel, a spare battery can be used to bring the trolley back into operation. If, however, the vehicle were to stall at a deeper location, a second shuttle would be inserted to tow it by means of a rescue hook.
Mecalux’s Easy WMS warehouse management software features the WMS & Pallet Shuttle Integration module, a functionality that simplifies and speeds up the operator’s work by consolidating the control of the WMS and of the Pallet Shuttle in a single screen.
Each shuttle can support up to 1,500 kg.
The Pallet Shuttle car can reach a maximum speed of 90 m/min unloaded and 45 m/min loaded.
The shuttle platform lifts the pallet in approximately 2 seconds.
Yes. On the one hand, there are two types of shuttles based on the operating temperature: those that work at ambient temperature (from +5 °C to +45 °C) and those that operate at refrigerated and freezing temperatures (from -30 °C to +5 °C). Shuttles designed to operate in cold environments come equipped with electronic components that are protected and heated to prevent damage.
On the other hand, each type of shuttle comes in three sizes, adapted to the most common pallet measurements. In each configuration, the front measurement of the shuttle is the same, given that in Pallet Shuttle systems, pallets are handled on the wider side (1,200 mm). What varies is their depth, with each configuration corresponding to a different pallet depth measurement (800, 1,000 or 1,200 mm).
The Pallet Shuttle’s lithium batteries provide an autonomy of up to 10 hours at full performance, depending on the temperature and load conditions.
The charging time for the Pallet Shuttle’s lithium batteries is between 4 and 5 hours.
Spare batteries are recommended to ensure uninterrupted operation of the system.
There are no technical limitations on the height or depth of the racking. The dimensions will depend on the particular needs of each warehouse. The depth of the channels will be determined by the homogeneity of the goods and the number of pallets per SKU. The height of the system, meanwhile, will hinge on the maximum lifting capacity of the forklifts used and the height of the facility.
Ask an expert