Cargo Securement, Weights and Dimensions
What this domain tests
Cargo questions combine the federal cargo securement standard with Quebec weight and dimension limits. The exam wants the arithmetic: working load limit, number of tiedowns, axle loads.
Securement rules
- Working load limit (WLL) of a tiedown assembly is 50% of its breaking strength.
- The aggregate WLL of all tiedowns must be at least 50% of the weight of the article.
- Minimum tiedowns: one for an article 1.52 m or less and 500 kg or less; two for an article longer than 1.52 m but not more than 2.44 m; three for anything longer than 2.44 m. Tiedowns must be attached within 1.2 m of each end.
- Tiedowns must contact the article directly, not be stacked on one another, and be protected from sharp edges.
- Commodity rules override the general ones: coils, logs, dressed lumber, vehicles, boulders, hay and containers each have their own requirements.
- Re-check the load shortly after departure and at every stop.
Weights and dimensions
- Quebec general limits: width 2.6 m, height 4.15 m, tractor-trailer length about 23 m. Anything beyond needs a special permit and a planned route.
- You must respect both gross vehicle weight and each axle group limit. A load placed too far back lightens the steer axle and destroys steering grip; too far forward overloads it.
- Scale the load when in doubt; an overloaded axle is both an offence and a handling problem.
Worked example
A 9,000 kg machine, 3 m long, goes on a flatdeck. At 3 m it needs at least three tiedowns. You plan four chains, each with a WLL of 2,300 kg. Aggregate WLL is 9,200 kg, well above half the cargo weight (4,500 kg), so the chains are strong enough - but only if they are attached within 1.2 m of each end and in direct contact with the machine.
Traps that cost marks
Quoting a chain's breaking strength instead of its WLL; using only two tiedowns on a 3 m article; and forgetting that the rear of a long load needs its own tiedown.