Pallet racking is the backbone of warehouse storage infrastructure. Understanding the different types of racking systems is essential for maximizing storage density, picking efficiency, and operational safety.
Types of Pallet Racking Systems
1. Selective Pallet Racking
The most common type, offering direct access to every pallet position.
Configuration: - Single-deep or double-deep configurations - Adjustable beam heights - Compatible with various forklift types
Advantages: - 100% selectivity - access any pallet anytime - Easy stock rotation (FIFO or LIFO) - Simple installation and reconfiguration - Lowest cost per position
Limitations: - Lower storage density (typically 30-35% floor utilization) - More aisle space required
Best For: Operations with high SKU counts and frequent picking, or where FIFO stock rotation is critical.
2. Drive-In / Drive-Through Racking
High-density storage where forklifts drive into the rack structure.
Configuration: - Drive-in: Single entry point (LIFO) - Drive-through: Entry from both ends (FIFO possible) - Typically 5-10 pallets deep
Advantages: - High storage density (up to 85% floor utilization) - Cost-effective for bulk storage - Good for seasonal inventory
Limitations: - Limited selectivity - Slower picking speeds - Requires careful forklift operation - Single SKU per lane recommended
Best For: Bulk storage of homogeneous products, seasonal inventory, cold storage facilities.
3. Push-Back Racking
Pallets stored on nested carts that roll on inclined rails.
Configuration: - 2-6 pallets deep - Gravity-fed cart system - LIFO operation
Advantages: - High density without forklift lane entry - Faster operation than drive-in - Multiple SKUs per bay possible
Limitations: - LIFO only - Higher cost per position than drive-in - Weight limitations on deeper configurations
Best For: Medium-density storage with moderate SKU variety, operations wanting density without drive-in complexity.
4. Pallet Flow (Gravity Flow) Racking
Pallets flow on roller conveyors from load to pick face.
Configuration: - Inclined roller beds - FIFO operation - Separate load and pick aisles
Advantages: - Perfect FIFO rotation - High density storage - Automatic pallet presentation - Reduced forklift travel
Limitations: - Highest cost per position - Single SKU per lane - Requires careful slope calculation
Best For: FIFO-critical operations like food and beverage, pharmaceuticals, high-volume distribution.
5. Mobile Racking (Powered Mobile Bases)
Racking mounted on powered mobile bases that create aisles on demand.
Configuration: - Selective racks on mobile carriages - Single working aisle - Remote or automatic control
Advantages: - Maximum storage density (up to 90% floor utilization) - Maintains full selectivity - Ideal for cold storage (reduces refrigeration costs)
Limitations: - Highest initial investment - Slower access (aisle opening time) - Requires flat, level floors - Maintenance of drive systems
Best For: Cold storage, high-value inventory, space-constrained facilities with lower throughput requirements.
Comparison Matrix
| System | Density | Selectivity | Cost | FIFO | Throughput |
|---|---|---|---|---|---|
| Selective | Low | 100% | Low | Yes | High |
| Drive-In | High | Low | Medium | No | Low |
| Push-Back | High | Medium | Medium-High | No | Medium |
| Pallet Flow | High | Low | High | Yes | Medium |
| Mobile | Very High | 100% | Very High | Yes | Low |
Selection Criteria
1. Inventory Profile - SKU count and velocity distribution - Pallet dimensions and weights - Storage duration patterns
2. Operational Requirements - FIFO vs. LIFO needs - Picking frequency and order profiles - Throughput requirements (pallets/hour)
3. Facility Constraints - Available floor space and clear height - Floor condition and load capacity - Temperature requirements
4. Budget Considerations - Capital investment available - Total cost of ownership over equipment life - Potential productivity gains
Safety Standards
All pallet racking in the EU must comply with: - EN 15512 (Steel static storage systems) - EN 15620 (Tolerances, deformations, clearances) - EN 15629 (Specification of storage equipment) - EN 15635 (Use and maintenance)
Regular rack inspections (at least annually) are mandatory, with documented assessment of damage and load notices prominently displayed.