By Klaus-Dieter Wurm, VP and Managing Director of Materials Handling at SSI Schaefer

Learn how your company can double the amount of pallet positions in the same warehouse space, avoiding costly and time-consuming building expansions, and why this technology deserves more attention.

Mobile Pallet Racking by SSI SchaeferIn North America, selective racking is probably the most commonly used storage method for traditional, non-automated pallet warehouses. However, due to conventional 12-foot wide aisles, selective racking is not necessarily the best utilization of space; it is certainly not the most economic storage method offering the largest possible number of pallet storage locations.

With the exception of the deep-channel shuttle storage technology, the one storage method offering more pallet locations than any other storage system is Mobile Racking. Mobile Racking is a conventional, selective pallet rack mounted on carriages which moves on rails embedded into the concrete floor. It offers more pallet location storage than drive-in racking, pallet-flow and VNA racking. So why is Mobile Racking not more commonly found in warehouses and distribution center operations across North America? Two reasons: lack of familiarity with those systems currently in use and a misunderstanding of Mobile Racking technology in general.

Out of necessity, Mobile Racking has been around for 30 years in Asia and Europe. Consider the geographic size of some European and Asian countries compared with the United States and Canada. With a population of approximately 127 Million people, Japan is about equal in size to California. France, with a population of 65 Million people, is the geographic size of Texas. Germany, with a population of 82 million people, has the equivalent land mass of Montana. Compare the size of the entire European Union with that of the United States. The US has a population of 315 Million people and is about 2½ times the geographic size of the European Union. Many European and Asian countries ran out of space decades ago, and as a result were forced to find better and more efficient storage methods allowing greater storage density and more pallet positions in the same amount of space. North America is blessed with plenty of size and readily-available green-field industrial real estate, both allowing for the construction of larger buildings with more square footage. As a result, requirements of higher density storage, cubic feet storage (the z-axis), or higher levels of automation have not been primary concerns in North America. In Asia and Europe, large industrial property parcels for warehouse or plant expansions are limited, not as readily available for use, and prohibitively expensive compared with parcel availability in North America.

80% Increased Storage Space when using Mobile Pallet Racking

In today’s economy however, funding for new construction and building expansion on this side of the pond is not as readily available. Project and budget approvals require a long, drawn out process here, too. As a consequence, supply chain and logistics managers have to find better ways to increase storage capacities within the existing building walls at a fraction of the cost of new construction. That is where Mobile Racking can make a huge impact, doubling the amount of pallet position in the same existing area.

If Mobile Racking offers benefits that the traditional storage methods cannot provide, why has this technology not found more acceptance and users in North America? It is worth noting that the South American countries of Brazil and Argentina (both geographically-large) have for some time embraced Mobile Racking as the better logistics solution.

Let's talk about how your warehouse or distribution center can benefit from Mobile Racking technology:

  1. To start, Mobile Racking should almost never be used for super-fast “A” movers, but rather for medium-fast “B” and slower “C” movers. Remember the Pareto Principle which applies to warehouse and distribution center operations: 80% of inventory turn-over comes from 20% of SKUs (“A” movers), but 20% of inventory turn-over comes from 80% of SKUs requiring much more space and pallet locations (number of “B” and “C” movers is always growing). A typical warehouse designed by SSI Schaefer would therefore use 2-deep push-back or drive-in racking for the fastest “A” movers, selective racking for other medium-fast “A” movers, and Mobile Racking for the “B” and “C” movers. One U.S. example is the early-November timeframe (Thanksgiving and holiday months) when demand for frozen turkeys is very high. Supply chain managers will reallocate storage locations to the faster moving areas of the warehouse, typically closest to the loading docks, to adjust for changing inventory demand and sales.
  2. Another misunderstanding is that Mobile Racking allows only one picking aisle to be open and operational at any given time, therefore the misperception that the replenishment and picking processes is slowed. But quite the opposite is the case with Mobile Racking. Modern Mobile Racking storage designs include as many aisles as the pallet through-put requires (pallets in and out/hour). Multiple independent Mobile Racking zones allow multiple lift trucks to operate at the same time, ensuring that the desired throughput rate and the highest possible warehouse efficiency are reached.
  3. If the warehouse business model provides that full pallets are moved in and out during the day shift, but the warehouse switches to a case and split-case picking operation during the second or third shifts, the answer again is very simple. With the push of a button, all carriages move outward and lock in place to create picking aisles so that pickers with pallet jacks or picking carts can safely enter the aisles to retrieve product.
  4. If a warehouse operator needs to pick and replenish full pallets while simultaneously picking cases or single pieces, then we can integrate a multi-level pallet flow system with mezzanine floors right into the Mobile Racking layout. This allows operators to pick cases onto a conveyor belt which takes the orders via spiral conveyor down to the ground floor for shipping.

Build smaller and/or double the storage capacity:

Particularly in temperature-controlled warehouses, using high-density Mobile Racking allows you to use a smaller building footprint. The smaller building footprint results in a real estate reduction of 45% while offering about the same amount of pallet positions as conventional warehouses with selective racking. If the goal is to increase the number of pallet positions, or to gain another client and consequently double revenue, Mobile Racking is the perfect solution to increase the number of pallet positions in the same footprint by up to 100%. With a good SKU analysis and a smart storage organization method, Mobile Racking can also achieve higher throughput rates than VNA storage systems. The result: lower construction costs, lower operating costs, and increased profits

When designed correctly, Mobile Racking from SSI SCHAEFER is not only a better high-density storage solution, it will also significantly improve your warehouse efficiency, your throughput, and your profitability.

Klaus D. Wurm, Vice-President & Managing director of Materials Handling at SSI SCHAEFER, is a leading expert in Mobile Racking technology. He can be reached at