Bulk packages, tank vehicles and cargo tanks
This domain tests bulk packaging and tank vehicle operations: what makes a package bulk, cargo tank types and markings, inspection and tire checks, filling limits, and safe unloading. Highway tank rules are in Parts 173, 177, 180, and 397.
Bulk definitions and cargo tanks
- A bulk package has capacity greater than 119 gallons (450 L) for liquids, greater than 882 pounds (400 kg) for solids, or greater than 1,000 pounds water capacity for gases (171.8).
- Common cargo tanks: MC-306/DOT-406 for flammable liquids; MC-307/DOT-407 for low-pressure chemicals; MC-312/DOT-412 for corrosives; MC-331 for high-pressure gases; MC-338 for cryogenics. Use the tank designed for the material.
- Cargo tanks must be inspected and tested; check the specification plate and inspection date before loading.
- Do not fill a cargo tank beyond its filling limit; liquids need outage space for expansion.
Driving and unloading
- Inspect tires at each stop (397.17). A flat or leaking tire on a tank vehicle must be repaired before moving.
- Before unloading, set the parking brake, chock wheels, shut off the engine, and attend the transfer. No smoking.
- Check hoses, valves, and grounding or bonding requirements; follow the employer procedures for static electricity.
- Placard the tank on both sides and both ends; bulk packages need ID numbers on both sides and both ends or on placards.
Worked example
A driver is assigned an MC-306 cargo tank loaded with gasoline. The MC-306 is a low-pressure tank for flammable liquids. Before departure, the driver checks the specification plate, current inspection date, tire condition, FLAMMABLE placards on both sides and both ends, shipping papers, and emergency phone number. At a stop, one tire is flat. Under 397.17, the driver must not drive the tank until the tire is repaired or replaced; a flat tire on a tank vehicle can lead to loss of control or rollover. At the terminal, unloading requires brake set, wheels chocked, engine off, no smoking, and attendance.
Traps
Treating any large drum as bulk when it is under 119 gallons; using a corrosive cargo tank for a flammable liquid; ignoring the inspection date; skipping tire checks; and leaving a tank unattended during transfer. Do not assume a placard alone provides the ID number if the bulk package marking is missing.