Breakbulk Rail BoL + AAR Loading Rules: Securement Compliance (2026)

When you ship steel coil on a gondola, lumber on a centerbeam flatcar, or pipe on a bulkhead flatcar, the cargo securement is governed by the AAR Open Top Loading Rules. When you ship machinery on a boxcar floor, AAR Closed Car Rules apply. Tank cars get Pamphlet 34. The BoL has to reference the specific rule the load complied with. Here's the mapping and the language.

The AAR Loading Rules Library

The Association of American Railroads (AAR) publishes loading and securement standards for each equipment type and cargo profile. The main references:

What to Render on the BoL

On the special instructions block of the BoL, render the verbatim securement reference. Common patterns:

Steel coil on gondola:

"Loaded and braced in accordance with AAR Open Top Loading Rules Section 1 (Coil Steel)."

Lumber on centerbeam flatcar:

"Loaded and braced in accordance with AAR Open Top Loading Rules Section 6 (Lumber and Forest Products)."

Pipe on bulkhead flatcar:

"Loaded and braced in accordance with AAR Open Top Loading Rules Section 3 (Pipe)."

Hazmat tank car:

"Loaded in accordance with AAR Pamphlet 34 (Safe Loading and Unloading of Non-Pressure and Pressure Tank Cars)."

OT-55-R Key Train Considerations

If your hazmat lines tip the train into Key Train status (20+ loaded hazmat carloads OR 1+ PIH/TIH carload), AAR Circular OT-55-R operating restrictions kick in:

• 50-mph maximum speed
• Roller-bearing cars only
• Route risk assessment required
• Additional yard handling protections

OT-55-R is an operating restriction on the railroad, not a BoL field per se. But the BoL drives whether the carrier classifies the train as a Key Train. Surface accurate hazmat counts and STCC codes so the railroad's routing engine identifies the trigger correctly.

Why This Matters

Three concrete reasons securement compliance language goes on the BoL:

1. Carrier acceptance. The originating railroad may refuse to accept a breakbulk car without a securement reference on the BoL. The reference shows the shipper followed an established rule rather than improvising.
2. Inspection authority. Railroad mechanical inspectors check loads against the cited rule. A securement that doesn't match the referenced rule fails inspection.
3. Carmack defense. If cargo shifts in transit and damage results, the shipper's compliance with the AAR rule is a defense element. Without the reference, the shipper has a harder time showing it loaded to industry standard.

Finding the Right Section Number

The AAR Open Top Loading Rules Manual is organized by cargo type. Each section covers a specific commodity profile (coils, lumber, pipe, plate, structural shapes, machinery, military equipment, etc.). The full manual is gated to AAR/Railinc members; non-member shippers usually work from their carrier's published references or from secondary references provided by industry trade groups.

The free Rail BoL Builder exposes a "Breakbulk / Open-Top" toggle that surfaces a dropdown of common AAR section references. Selecting a section auto-populates the "Loaded and braced in accordance with..." language into the special instructions block.

Closed Car Loading

For boxcar / refrigerator car shipments, AAR Closed Car Loading Rules (Pamphlets) cover dunnage, blocking, and bracing for various cargo types. The BoL language follows the same pattern: "Loaded in accordance with AAR Closed Car Loading Rules Pamphlet [number]."

Tank Car Loading

AAR Pamphlet 34 is the consolidated reference for non-pressure and pressure tank cars. Covers loading procedures, securement of valves and fittings, unloading safety, and emergency response. Hazmat tank cars cite Pamphlet 34 in the special instructions block along with the §172.604 emergency phone, §172.204 certification, and §172.704 training acknowledgment.

Related: our hazmat rail BoL compliance guide covers the broader §172 hazmat requirements; the rail BoL template walkthrough covers every field on a standard rail BoL.