A cargo wall, also known as a shoring beam or load bar, is a bracing device specifically engineered to lock into tracks or rails installed on the interior walls of a trailer. These systems, such as E-track or A-track, have slots at regular intervals that the ends of the cargo wall engage with. This creates a solid, adjustable barrier to prevent cargo from shifting forward or backward. The functionality of a cargo wall is therefore entirely dependent on the presence of these interior rails for proper and safe installation.

A. rope: Ropes are a versatile securement method that can be tied to various anchor points like cleats or D-rings and do not specifically require interior rails.

B. airbags: Airbags, or dunnage bags, secure a load by inflating to fill void spaces, bracing the cargo against itself and the trailer walls, requiring no rails.

C. straps: Straps can be attached to multiple types of anchor points, including D-rings or the trailer chassis itself, not exclusively to interior rail systems.

1. Coyle, J. J., Langley, C. J., Novack, R. A., & Gibson, B. (2016). Supply Chain Management: A Logistics Perspective (10th ed.). Cengage Learning. In Chapter 11, "Transportation Management," the text discusses equipment and load planning, explaining that devices like shoring beams and decking systems are designed to fit into logistical tracks (interior rails) to compartmentalize and secure freight.

2. Federal Motor Carrier Safety Administration. (2013). Driver's Handbook on Cargo Securement. U.S. Department of Transportation. Section 3.7, "Blocking and Bracing," illustrates and describes the use of shoring bars (cargo walls) which are shown interfacing with logistical tracks on trailer walls to prevent cargo movement.

3. Massachusetts Institute of Technology (MIT) Center for Transportation & Logistics. (2018). Introduction to Logistics and Supply Chain Management. MITx Courseware, 1.260x. Module 4: "Freight Transportation," discusses various cargo handling and securement technologies, noting that modular systems like shoring beams require compatible trailer infrastructure, such as interior rails, for use.