Safe Loading and Cargo Securement
What the exam checks
This domain tests weight distribution, axle limits, cargo securement, and load inspection on double and triple trailers. The exam focuses on how loading one trailer affects the whole combination and on keeping cargo from shifting into air lines, brakes, or the dolly.
Core rules
Distribute weight so no axle, tire, or suspension is overloaded and the kingpin load stays within the tractor's rating. Keep heavy freight low and centered, and load each trailer so it tracks and brakes predictably. Use tiedowns with an aggregate working load limit of at least half the cargo weight, and secure articles so they cannot shift forward, rearward, or sideways. Close and latch trailer doors; check that cargo does not block the dolly, air lines, electrical cord, or landing gear. Recheck securement after the first few miles and after any hard stop. Illinois weight limits and registration apply to the combination, not just to one trailer.
Worked example
A driver puts dense pallets at the rear of the second trailer because the first trailer is already full. The rear axle may become overloaded and the dolly may be light, reducing traction and braking stability. The better plan is to spread dense freight over the dolly axle and first trailer within axle ratings, then use lighter cargo at the rear. The reasoning is that the dolly carries the second trailer's nose load, so loading changes the load on the dolly, tractor drive axles, and steering axle.
Traps that cost marks
Do not count only total gross weight; axle and tire limits can be exceeded first. Do not secure cargo to air lines or brake chambers. Do not leave dolly access blocked. Do not assume one tiedown pattern fits every load.