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The Double Deep Racking Mystery…

In the past when I have written a blog post or been interviewed for a magazine, I normally talk about technology – robotics, advanced material handling equipment, or fancy IT systems. Today, however, I am going in a completely different direction and plan to write about the most basic of warehouse equipment, the humble Reach Truck. In fact, this is not really a blog post for you but rather a chance for me to ask for help regarding something strange that has bothered me for many years, a mystery if you will. I am searching for answers… Maybe someone out there can help me solve the riddle: “Why are there no Double Deep Reach Trucks in Europe?”

Let me backup a bit and explain my strange question. I have been lucky enough to work on projects in well over 30+ countries around the world, but I started my career with St. Onge Company in the United States. As a young engineer, I worked on DC design projects for companies such as Pepsi, Procter & Gamble, and Kraft Foods that each stored a large number of pallets. To help with this engineering work, St. Onge Company developed advanced tools and analytical techniques to identify the most economic and efficient storage method for each SKU. As I would run these analyses for consumer goods type clients, an older and very experienced engineer named John would walk by and say “the answer is Double Deep Rack, it is always Double Deep Rack” and he was typically right.

Double Deep Pallet Rack is simple in concept – you put two pallets into back to back pallet rack, one behind the other. Both pallets should be the same lot and SKU to avoid double pallet moves and hidden inventory. By doing this, you can effectively remove half of the aisles in your warehouse allowing you to save space with only a minimal labor penalty. If you have many pallets of one batch, it is quite easy to fill up double deep rack with a high storage utilization. The pallet racking does not cost much more than ‘normal’ rack but you do need special reach trucks that will allow a driver to reach far back into the racking to the second pallet, often with special forks or mechanical extenders built into the truck. The trucks are a bit different in other ways as well – for example the front wheels are on little legs called outriggers that extend out in front of the truck to keep it from tipping forward when reaching the second pallet. Due to these legs, you can’t put pallets directly on the floor but rather the first pallet needs to be up on a pallet beam just high enough for the outriggers to drive under the racking a bit to help the driver reach the back pallet.

In the United States, this is a very common solution in distribution centers that store a lot of pallets without a correspondingly high SKU count.   The balance between the costs of land, labor, and equipment tends to put double deep rack in the ‘sweet spot’ of economic viability for many warehouses. Most WMS systems can support these operations, all of the forklift vendors sell a specialized double deep reach truck, and the racking vendors offer this solution every day. In the early 2000’s, I helped to design several warehouses utilizing double deep rack which are still in operation.

And then I moved to Europe and I never saw a proper double deep reach truck again…  I wondered, why was such a common solution in the US seemingly unknown in Europe?

I would talk about the concept and people would claim that it could not possibly work. I was told “that is an American solution not a European solution” and “our WMS could never support that” or “It is impossible to clean the warehouse with the extra beam on the bottom” and “We can’t find anyone trained to operate those trucks”. I once was told “our skylights won’t line up with the aisles.” Every flimsy excuse that I heard only made me only more curious as to why it can work in the US but not Belgium or Germany.

To be fair, you can find a bit of double deep rack in Europe but the solutions don’t work very well or are very expensive. Sometimes you see double deep rack applied using expensive push back rack or roller track that can sometimes have operational or maintenance issues. Other times you see normal moving mast European Reach Trucks with telescopic extendable forks which can be slow, with hydraulics that may be prone to leaking, and can cause the truck to tip or become unstable. The telescopic forks can also shake and bounce with heavy pallets since they are so long. If this is all that you know in the market, I can fully understand why people would not like double deep racking solutions. The typical double deep trucks in the United States tend to solve these issues through specialized mechanical design including the outriggers and pantograph extension devices. The surprising thing is that several forklift vendors won’t sell or support a double deep reach truck in Europe but will in the United States, some going so far as making them in Germany for the US market but refusing sell one in the same town as the factory.

One legitimate challenge is that European pallets are narrower than the typical US or UK pallets. You typically put three pallets on a racking beam in Europe but only two in the US. Having only two pallets on a beam makes it easier for a double deep reach truck driver to align pallets into the racking as they can use the upright beams as a visual guide in a way that is not possible with a middle pallet, but modern camera systems on forklifts have helped to solve this issue and you can put simple but helpful alignment marks on pallet beams. The narrower pallet may be difficult for the US pantograph mechanism which may be of similar width, but surely someone could develop a narrower design for smaller pallets.

So, the mystery for me continues regarding this quirk in the global material handling equipment marketplace. The best answer that I have gotten so far came from an old French warehouse manager in a small industrial town. He told me that due to the outriggers, most US Reach Trucks are configured in such a way that the operator has to stand rather than sit like in a European truck. His theory was that all of his workers would quit if they had to stand up all day when driving a Reach Truck, so Double Deep would never work in his country. I had no way to argue that point, so I gave up and the mystery continues.

If you have any thoughts or ideas to share about this topic please let me know, I would be happy to learn more and maybe get the elusive answers for which I have been searching!
-Tom Bonkenburg, St. Onge Company

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