Dunnage Bag Performance Levels
Picking the proper dunnage bag for your load plan
Posted on February 7, 2019 by Erik Burden
Are you using the proper dunnage bags in your load plan? When using dunnage bags to secure your product during transit, certain dunnage bags should be used depending on your load plan, the product being shipped, how the product is being shipped, and the weight of shipment. There are six types of dunnage bags; Over-the-Road (OTR) bags and bags leveled 1 through 5. All dunnage bags come in a variety of sizes to fit your load plan. Over-the-road dunnage bags are intended for use in truckload shipments only. Whereas, Level 1 dunnage bags to Level 5 bags are intended for rail and intermodal shipments. The performance level of each bag can be seen in the chart below from the AAR’s publication Closed Car Loading Guide – Minimum Loading Standards for Freight in General Purpose Boxcars:
The chart shown above should be used by loaders as a reference for the minimum requirements each type of dunnage bag meets. In some cases, higher precautions should be taken, exceeding the minimum requirements. For example, Complete Packaging Systems suggests using Level 5 bags in horizontal applications with cylindrical voids, instead of Level 4 bags, regardless of the shipment weight. Complete Packaging Systems suggests using Level 5 bags in cylindrical voids with horizontal applications because the bags will have pockets they can expand into. The higher pressure building in these pockets can cause the Level 4 bag to decrease in strength by 50%, compared to when positioned in flat wall voids. The contour of the bags that causes these pressure pockets can be seen in the diagram below. In addition to the minimum guidelines in the chart above, each dunnage bag has different PSI requirements and the user should follow the manufacture guidelines printed on the dunnage bags. In section 6.7.18 of their publication Closed Car Loading Guide – Minimum Loading Standards for Freight in General Purpose Boxcars, the AAR also recommends leaving the railcar open after loading the shipment and checking the dunnage bag PSI after 30 minutes for leakage. Finally, the size of the dunnage bag you are using should cover at least two thirds of the adjacent product around the bag. In conclusion, there are many factors that can affect which bag is the right fit for your load plan, so let us help; to find out more about the use of dunnage bags in cargo securement and how they should be applied in your load plan, contact us toll free at 866-858-8800.