The rational configuration of main and secondary racks is a core component of optimized warehouse space design. Different application scenarios require tailored configuration strategies to maximize the efficiency of the racking system. In practical warehouse planning, the ratio between main and secondary racks, their arrangement patterns, and height combinations must all be scientifically designed based on factors such as the characteristics of stored items, warehouse space parameters, and logistics operation needs—ultimately achieving the optimal balance among space utilization, operational efficiency, and cost control.
 

Scenarios where the main frame is used independently typically arise in several specific situations. First, there are shelving systems that require frequent relocation or rearrangement, such as temporary warehouses, seasonal storage facilities, or distribution centers needing regular layout adjustments. Because the main frame boasts independent structural stability, moving it doesn’t necessitate considering its connection with other units, making operations far more flexible. Second, these frames are often deployed in areas storing particularly heavy or high-value items—such as machinery, precision instruments, or hazardous materials—where their enhanced load-bearing capacity and stability provide a safer storage environment for such specialized goods. Finally, independent main frames are commonly installed at warehouse end sections, corner locations, and along both sides of major aisles, as these areas are more prone to external impacts and vibrations.

The most common storage configuration involves using a main rack combined with a secondary rack, which is especially suitable for large, fixed storage areas. In this configuration, the "one main plus multiple auxiliary" model is typically used—where one main frame is paired with several auxiliary frames to extend into a long row of shelving units. For instance, in a warehouse requiring ten shelving units, you could opt for a setup of "one main frame + nine auxiliary frames," which would only need 11 upright posts in total (two for the main frame and one for each auxiliary frame)—a significant cost-saving compared to using only main frames throughout. This arrangement is not only economical but also enhances overall structural stability, as the interconnected multi-unit design creates a continuous framework supported by multiple points of contact. In practice, the main frame is usually placed at the beginning of each shelving row, with auxiliary frames then connected sequentially to form a sturdy, unified shelving line.

In heavy-duty shelving systems, the configuration of main and secondary frames requires particular attention to load capacity and safety factors. Heavy-duty shelving is primarily used for storing large, heavy, palletized goods such as construction materials, machinery equipment, and bulk commodities. In this scenario, the main frame, serving as the core load-bearing unit, should be positioned in areas with concentrated loads or high-frequency handling activities—such as near forklift aisles. Meanwhile, the secondary frames act as extension units, helping to maximize storage capacity without significantly increasing costs. The connection points between the main and secondary frames must be specially reinforced to ensure efficient load transfer and even distribution. According to FEM standards, the design of heavy-duty shelving systems must account for dynamic load factors, impact loads, and safety margins—factors that all need to be factored into the calculations when configuring the main and secondary frames.

The main and secondary rack configurations for medium-duty shelving are relatively flexible, as their load-bearing requirements are lower than those of heavy-duty shelving. Medium-duty shelving is typically used to store medium-to-small-sized items, such as electronics, tool accessories, daily necessities, and more, often featuring a pallet-style design. In this system, the main frame provides structural stability, while the secondary frames help maximize storage space. A common configuration involves placing one main frame after every 3 to 5 secondary frames, ensuring continuous support for stability. The combination of main and secondary frames in medium-duty shelving offers significant advantages, including efficient use of warehouse space, enhanced capacity utilization, and expanded storage capabilities. Additionally, this setup facilitates easy classification, management, and access to goods, enabling the implementation of the first-in, first-out (FIFO) logistics principle.
Spatial configuration for warehouses with special shapes requires tailored solutions based on the specific site conditions. For narrow and elongated warehouses, a linear layout can be adopted, featuring a single row of main racks extending into secondary racks. In contrast, square-shaped warehouses with large floor areas are better suited to a grid-like arrangement, where the main racks serve as structural nodes while the secondary racks act as connecting elements. Around warehouse columns or other obstructions, it may be necessary to adjust the positions of both main and secondary racks to fit the available space effectively. Notably, rack arrangements should ideally avoid aligning directly with warehouse pillars, thus preventing unnecessary waste of space. Meanwhile, main racks can be strategically placed closer to the pillars, leveraging these columns as additional support points.

The main and secondary racking configurations in automated stereoscopic warehouses have their own unique characteristics. Automated warehouses typically utilize monolithic welded racking systems, where the main frame concept differs significantly from that of traditional modular racks. In this system, the main frame refers to independent structural support units, while the secondary frames serve as intermediate storage compartments. Given the extremely high precision requirements for racking in automated warehouses—specifically, a vertical deviation no greater than 1/1000 of the total height and an absolute deviation not exceeding 10 mm—the manufacturing and installation of both main and secondary frames demand rigorous error control. Moreover, the configuration of these main and secondary frames must be carefully coordinated with automated equipment such as stackers and conveyor systems, ensuring adequate clearance for safe operation and maintaining the structural integrity of the racking system.
In safety-sensitive areas, the primary and secondary racking configuration requires additional consideration of protective measures. For instance, in zones with high pedestrian traffic, near cross-aisles, or in high-value goods storage areas, you can increase the proportion of primary racks or install standalone primary racks as protective units. Additionally, safety accessories such as anti-collision guardrails and corner protectors can be mounted on the primary racks to minimize the impact of accidental collisions on the racking system. For high-rise shelving systems (height exceeding 5 meters), it is recommended to place one primary rack for every 3 to 4 secondary racks, and to add connecting rods at the top to enhance the overall lateral load resistance.

The height configuration strategy for main and secondary racks also deserves attention. In real warehouses, cargo heights often vary; thus, a stepped arrangement—where the main rack is taller than the secondary rack—or a horizontal arrangement with both racks at the same height can be employed. The former is ideal for display-oriented storage or scenarios involving items with differing access frequencies, while the latter is more suitable for standardized pallet storage. When configuring, it’s also crucial to consider factors such as warehouse clearance height, forklift operating height, and architectural obstructions, ensuring that the rack heights align perfectly with the spatial characteristics of the facility. According to national standards, the typical height range for heavy-duty shelving main racks is between 3,000 mm and 10,000 mm, and the heights of both main and secondary racks can be adjusted within this range based on actual needs.

The future trend in the configuration of main and secondary racks is moving toward智能化 (smart) and 模块化 (modular) solutions. With advancements in logistics technology, the next-generation shelving systems will place greater emphasis on seamless integration with automated equipment. The main rack may incorporate smart components such as sensors and positioning devices, transforming it into an information hub and functional center for the entire shelving system. Meanwhile, the secondary rack will serve as a scalable storage module, allowing flexible configurations based on specific needs—and together, they’ll create a more dynamic, highly responsive warehousing system. This intelligent setup will deliver more efficient and safer storage solutions for modern logistics operations.