By Eamonn Ryan
In the first article of this series examining the design of next-generation cold stores, we looked at why cold storage facilities demand a fundamentally different approach to conventional warehousing and why getting the basics right can determine the long-term success of an operation.
© Cold Link Africa
Drawing on insights shared by Martin Bailey of Industrial Logistics Systems during a presentation in Cape Town, we now turn to one of the most important design decisions facing cold store operators: how to store product effectively.
If there is one lesson Bailey emphasised repeatedly, it is that there is no perfect storage system. Every option offers advantages and disadvantages, and the correct choice depends entirely on the nature of the operation.
Too often, operators are sold on the latest technology or the highest-density storage solution without fully considering how products actually move through their facilities. Bailey argued that storage decisions should always be driven by operational realities rather than by marketing claims.
The simplest approach remains block stacking. It is inexpensive, straightforward to implement and can be highly effective when dealing with large volumes of a relatively small number of products. However, as product ranges expand and customer demands become more complex, block stacking can quickly create operational challenges. Accessing specific stock becomes more difficult, stock rotation becomes harder to manage and picking efficiency can suffer significantly.
Mobile racking has often been presented as the answer to space constraints because it allows operators to eliminate most fixed aisles. By opening only the aisle required at a particular time, facilities can achieve exceptionally high storage densities. Yet Bailey noted that the reality is often more nuanced. While some clients have been delighted with their mobile racking systems, others have ultimately asked for them to be removed. Operations that require intensive case picking or frequent access to multiple stock locations can find mobile systems restrictive and slower than anticipated.
For many cold stores, narrow aisle racking offers a more balanced solution. Bailey highlighted facilities operating at heights of up to 18m that use narrow aisle systems to achieve both excellent storage density and high levels of accessibility. Every pallet location remains available, allowing efficient stock management and replenishment while maximising the use of vertical space.
These systems, however, place significant demands on building quality. At such heights, even minor floor imperfections can affect equipment stability. The warehouse floor effectively becomes part of the storage system itself, requiring exceptional flatness and construction quality.
The economics of equipment are also changing. Bailey pointed to the growing popularity of articulated forklifts, which offer many of the benefits associated with traditional narrow aisle operations but at substantially lower capital cost. Their flexibility allows operators to perform a wider range of tasks while still working within relatively narrow aisles, making them attractive for facilities that require both storage density and operational adaptability.
Where very large volumes of a limited product range are involved, high-density solutions continue to play an important role. Drive-in racking remains common in sectors such as frozen poultry storage, where the focus is on maximising pallet positions rather than product selectivity. However, Bailey warned that these systems have a long history of operational damage and failures caused by improper equipment operation.
Increasingly, radio shuttle systems are replacing traditional drive-in configurations. By automating pallet movement within deep storage lanes, these systems offer similar density advantages while improving safety and operational efficiency. They can be particularly effective in frozen environments where large batches of homogeneous products need to be stored and retrieved efficiently.
Live storage systems also continue to have a place in the cold chain. Although expensive to install, they provide excellent stock rotation and high throughput capabilities. For operations where first-in, first-out inventory management is critical, the investment can often be justified.
Perhaps the most visible trend in modern warehousing is the growth of automation. Automated Storage and Retrieval Systems, or ASRS, are becoming increasingly common in large-scale cold storage developments around the world. Bailey noted that once pallet volumes reach a certain scale, automation often becomes the most economical option. High-bay automated facilities can store enormous volumes of stock within relatively compact footprints while reducing labour requirements and improving consistency.
Yet automation is not without its drawbacks. One of Bailey’s key observations was that automated systems often sacrifice flexibility. Once an ASRS has been designed around a specific pallet size, product profile and operational model, changing those assumptions later can be difficult and expensive. For third-party logistics providers, whose customer requirements can change dramatically over time, that rigidity may become a significant disadvantage.
The challenge, therefore, is not simply choosing the most advanced storage technology available. It is selecting a system that aligns with both current operational requirements and future business needs.
Storage may determine where products are held, but it is only part of the equation. Moving those products efficiently through the facility is equally important.
In the next article, we examine internal transport systems, order picking technologies and why, despite decades of automation development, people remain at the heart of most cold storage operations.