Will Drive-In pallet racking work for you? I recently took a call from a customer (Graeme) who wanted to get a price on “…a Drive-In pallet rack to hold 1,000 pallets…”. As always, my reply was a series of questions rather than answers, designed to understand Graeme’s desired outcomes – a much better proposition to us than diving in and getting it wrong.
It turned out that Graeme was looking for more pallet storage than was physically available in his current Selective Rack layout – “the desired outcome”. Graeme had been informed by another rack supplier that Drive-In racking was the solution because it offered much denser storage than Selective rack. Whilst it is generally true that Drive-In rack offers the more dense storage, it is not always suitable for the products stored or for the business and warehouse operations. In this case, it would have been a disastrous outcome had Graeme refitted his warehouse with Drive-In rack. Graeme had a high SKU count with a low inventory to SKU ratio. In this case, we were able to satisfy Graeme’s needs and provide the desired outcome by converting some of his existing racks to Double-Deep and adding some new racks.
So where does Drive-In rack apply? Well let’s imagine that Graeme’s inventory included some SKUs – say only 6, where typical inventory was 25 pallets of each. So a total of 150 pallets could be efficiently stored in a dense storage system like Drive-In rack, while the remainder of his inventory would be better suited to Selective or Double-Deep racks.
How deep can Drive-In rack lanes be? As there are clear differences in the application of engineering and design concepts amongst the Drive-In pallet rack brands found in Australia today, we can only comment on our trusted Colby brand. The Colby brand Drive-In rack is the only Australian manufactured brand which conforms to the FEM 10.2.07 , and lane depth of the current Colby Drive-In rack is only limited to the practicality of design. Regardless of brand, the important question is how deep should Drive-In lanes be? And there is no short answer here as the answer demands an analysis of the inventory stored, including stock turn, warehouse operations and indeed forklift operations within the rack. But there is something we can consider in the next part of this article.
Should occupancy rates be considered? Absolutely! Low occupancy rates of around 65%-75% are often applicable to Drive-In pallet racking. This is usually due to deficient accommodation strategies which can be forced through undesired inventory movements or poorly designed storage systems. Let’s imagine Drive-In racks were suitable for Graeme’s 1,000 pallets because his entire inventory was a low SKU to high inventory ratio. Based on the typical 70% occupancy rate for Drive-In racks, Graeme would need to have 1,429 pallet positions in his rack system. The aforementioned average occupancy rate of Drive-In rack can sometimes be improved upon through smarter analysis and design. Example…
Here is one scenario which forces the occupancy rate down (towards the general averages mentioned earlier). One lane of Drive-In rack designed as 4 pallets deep x 3 pallets high holds 12 pallets. Graeme has allocated one SKU to one lane and Graeme’s usual inventory count on this one SKU is 10. Because Drive-In rack is Last-In First-Out (LIFO), Graeme tries to empty the lane before new stock is introduced. But all attempts fail and Graeme receives a fresh 10 pallets while he still has 4 pallets of old stock remaining. Graeme has no choice but to occupy a second lane, as his total is now 14 pallets. So Graeme now has 14 pallets occupying a potential storage space of 20 pallets – 70% occupancy.
To better manage such a scenario would be to have a mix of Drive-In racks with different lane depths or a mix of Drive-In rack, Double Deep and/or Selective racks. An intelligently designed system should be capable of up to an 85%-90% occupancy rate.
What are the downsides of using Drive-In pallet rack? While in low to medium sized warehouses Drive-In pallet rack provides the most cost effective high density storage of pallets, there are limitations on operational issues. Where Drive-In rack is seen to be suitable for the operation, these “limitations” should not present any problems. So here are some of the limitations which may hinder the selection or use of Drive-In rack…
- There is no natural stock rotation in Drive-In rack as last in, first out (LIFO) operation is forced;
- Drive-In rack provides very limited selectivity, as in normal operation each lane is occupied by only one SKU. Note: An exception to this rule may apply where Drive-In pallet racking is used for staging outbound goods;
- Pallet type and condition is paramount to the safe operation of Drive-In rack. Damaged pallets should never be used, and only pallets as approved by the rack manufacturer should be used. Note: Many of the European pallet designs are not suitable for use in Drive-In rack;
- Drive-In racking requires the use of suitable forklift trucks – many are not suitable;
- Drive-In racks require additional discipline, care and skill in operation by forklift truck drivers;
- Without adequate rack protection equipment (the cheaper option), Drive-In racks are more highly susceptible to damage during operation.
Correct Loading and unloading sequences for Drive-In rack:
For professional advice on all your drive-in pallet racking needs, contact the team at Elbowroom today. Delivery available throughout Brisbane and Australia wide.
Elbowroom (Aust) Pty Ltd