Understanding AAR Levels for Dunnage Bags
The Association of American Railroads (AAR) rating system classifies dunnage bags based on their construction, pressure rating, and intended application. Understanding these levels is essential for selecting the right bag for your cargo and transport mode.
AAR Level 0
Designed for lighter void-filling applications where cargo weight and dynamic forces are moderate. Level 0 bags operate at lower working pressures and are commonly used in truck transport and light containerised freight. DunLash Level 0 bags have burst pressures starting from 6psi.
AAR Level 1
Suitable for standard container and truck cargo securing where moderate to heavy loads require reliable void filling. Level 1 bags operate at working pressures of 2–3psi with burst pressures up to 8psi. These are the most widely used dunnage bags across South African logistics and export operations.
AAR Level 2
Engineered for heavy-duty cargo securing in containers, trucks, and rail wagons. Level 2 bags operate at higher working pressures of up to 5psi with burst pressures up to 17psi. The thicker inner bladder (100μm vs 80μm in Level 1) provides greater puncture resistance for demanding transport conditions. Level 2 bags are required for rail freight in many jurisdictions.
Dunnage Bag Construction and Materials
All DunLash dunnage air bags feature a two-ply construction designed for durability and reliability:
- Outer shell — Polywoven material providing tear resistance and protection against rough cargo surfaces
- Inner bladder — Multi-layer PA+PE (polyamide + polyethylene) laminated construction for airtight inflation and puncture resistance
- Valve — 30mm inner diameter for fast inflation using a standard Inflator-A type airgun
- Bladder thickness — 80μm for Level 0 and Level 1 bags, 100μm for Level 2 bags
This construction ensures the bags maintain inflation pressure throughout the transport journey, even when exposed to temperature fluctuations and rough handling.
How to Select the Right Dunnage Bag
Choosing the correct dunnage bag involves matching the bag size, AAR level, and inflation pressure to your specific cargo and void dimensions:
- Void size — measure the gap between cargo loads to determine the required bag dimensions (90×120cm through to 90×225cm)
- Cargo weight and transport mode — heavier cargo and longer transport distances typically require Level 2 bags with higher burst pressures
- Compliance requirements — rail freight often requires Level 2 AAR-rated bags; containerised sea freight typically uses Level 1 or Level 2
- Temperature exposure — our bags operate from −20°C to 60°C, covering most global shipping routes including African coastal, inland, and cross-border transport
DunLash provides application guidance to help you select the correct dunnage bag specification for your cargo type, void dimensions, and transport conditions.
Applications of Dunnage Air Bags in South Africa
DunLash dunnage air bags are used extensively across South Africa’s logistics and export sectors:
- Container freight — preventing cargo movement during port handling and sea transport through Durban, Cape Town, Gqeberha, and Richards Bay
- Truck transport — stabilising loads during long-distance road freight on the N3, N1, and N2 corridors
- Rail freight — securing cargo in rail wagons for intermodal transport between inland hubs and ports
- Warehousing and distribution — pre-loading void fill in distribution centres and pack houses
- FMCG, chemical, and industrial cargo — protecting palletised goods, drums, and fragile products from transit damage
