Bulk hauling: liquid, dry and aggregate freight, the trailers and how it pays

Types of bulk hauling

In hazmat terms, bulk packaging means a container with no inner packaging, such as a cargo tank, and for liquids a capacity over 119 gallons. Source That definition matters when bulk freight is hazardous, because bulk loads are placarded at any amount.

Weight sets the load

Bulk is heavy for its volume. On the Interstate the truck may gross 80,000 lb, with axle groups limited by the bridge formula. Source Source Dense products, such as cement, sand, gravel and many liquids, reach that limit with space to spare, while light ones like plastic pellets or wood chips fill the trailer first. That makes the empty weight of the truck and trailer important: every pound saved is more product hauled. Check axle groups with the bridge formula calculator.

Worked example: one trailer, two products EXAMPLE

A pneumatic trailer and tractor weigh 33,000 lb empty, leaving 47,000 lb for product. Hauling cement, it takes about 23 tons and the tank is far from full. Hauling plastic pellets the next day, it fills the tank before it reaches the weight limit. Same trailer, two different limits, and two different ways to price the load: by the ton for cement, by the load for pellets.

Liquid bulk

Tank trailers haul fuel, chemicals, food-grade liquids and water. Tanks over the size threshold make the vehicle a tank vehicle, which needs the N endorsement. Source Liquids are never loaded to the brim: at least 1% outage, or 5% for poison inhalation hazards, leaves room to expand. Source Partly full tanks surge, so liquid bulk drivers brake and corner with extra care. See the tanker truck guide.

Dry bulk

Pneumatic trailers carry powders and pellets and unload by air into closed silos, which keeps products like cement and flour clean and contained. Hopper bottoms carry grain, feed and fertilizer and unload by gravity into a pit. Both are common in agriculture, construction and manufacturing. See pneumatic trailers and grain trucks.

Aggregate and construction bulk

Dump trucks, end dumps and belly dumps haul gravel, sand, base, asphalt and dirt between pits, plants and job sites. The work is mostly local and paid by the hour, ton or load. Converting cubic yards to tons uses typical factors, such as about 1.42 tons per cubic yard for gravel and 1.45 for sand in one state table. Source Many dump trucks are single units rated over 26,000 lb, which need a Class B CDL Source, while tractor-trailer dumps need Class A. Source See the aggregate material weight calculator.

Cleaning and product history

Bulk trailers carry the last product inside them. Food-grade loads need clean, often dedicated trailers, and food shippers check wash tickets; the FDA sanitary transportation rule requires carriers to keep equipment sanitary for food. Source Chemical shippers check the previous products for compatibility. A trailer that can't prove its history can't take the load. Bulk carriers keep a record of the last few loads and washes for every trailer.

Local and long-haul bulk

Much bulk hauling is local or regional: cement from terminal to plant, gravel from pit to job, fuel from rack to station. Drivers who stay within 150 air-miles of their reporting location and return within 14 hours can keep time records instead of logs. Source Chemical and food-grade bulk often runs longer, plant to plant across several states. The equipment and the customer decide which kind of week a bulk driver works.

Safety in bulk hauling

• Use fall protection when working on top of tanks and trailers, where sites require it.
• Never open hatches or fittings on a pressurized pneumatic or gas tank.
• Watch for overhead power lines when raising dump bodies.
• Keep clear of moving grain in pits and bins; it can trap a person in seconds.
• Respect surge in partly full liquid tanks.

How bulk hauling pays

Bulk pays in different ways: per mile or per load for tankers and long-haul dry bulk, per ton or per load for aggregate and grain, per hour for local dump work. Specialized bulk, such as chemicals, food-grade liquids and pneumatic freight, often pays more because fewer carriers have the trailers, endorsements and experience. Local work trades higher rates for home time. Bulk owner-operators win by keeping the trailer full both ways, which is hard when most bulk runs loaded one way and empty back.

Backhauls in bulk

The hardest part of bulk economics is the empty trip back. A tanker that delivers fuel returns empty to the rack; a grain trailer runs empty back to the field. Carriers improve the numbers by finding compatible return loads, such as fertilizer back to the farm in a hopper that hauled grain to the elevator, or by keeping runs short and frequent. Any return load has to fit the trailer's cleaning rules, which is where product history and wash records decide what is possible.

Getting into bulk hauling

1. Choose a bulk type that is steady in your region: grain, aggregate, cement, fuel or chemicals.
2. Get the license it needs, plus the tank or hazmat endorsement if it applies.
3. Learn loading and unloading with an experienced bulk driver.
4. As an owner-operator, buy or lease the right trailer and build relationships with the plants and pits that ship.

Bulk hauling sits next to heavy equipment hauling and heavy haul trucking in the construction world, and next to tankers in the energy world; see our hauling guide for the whole picture. When you dispatch with us, we look for bulk loads that fit your trailer and its product history, and you approve every one. See tanker dispatch and hopper bottom dispatch.