Triples – a tractor and three short trailers (usually 28 feet) – maximum weight up to 110,000 pounds.Turnpike Doubles – a tractor and two long (usually 48 feet) trailers – maximum weight up to 147,000 pounds.Rocky Mountain Doubles – a tractor with two trailers: a long front trailer (usually 48 feet) followed by a shorter second trailer – maximum weight up to 129,000 pounds.To carry higher weights though, the truck axle specification and rating must allow for the heavier weights to be carried.
Individual states also have additional weight carrying limits for intrastate commerce, which allow for much higher payloads based on additional axles being installed. Of course, the maximum allowable weight is still 80,000 pounds for trucks hauling spread axle trailers. heavier machinery or pallets can be loaded towards the back of the trailer rather than at the front, which would cause the closed drive axle tandems to exceed the legal limit of 34,000 pounds. This helps when a trucker has cargo that has varying weights across its many components i.e. In cases where the trailer axles are 10’ 2” apart each axle can weigh 20,000 pounds on the scales allowing for the trailer axles to weigh a total of 40,000 pounds compared to 34,000 pounds for closed tandem axles.
There are some exceptions including trailers that have the tandems spread apart, knowns as “spreads”. Trailer tandems: 34,000 pounds or 4,250 pounds per tire.Drive axle tandems: 34,000 pounds or 4,250 pounds per tire.Steer axle: 12,000 pounds or 6,000 pounds per tire.When a big rig pulls onto a set of scales to weigh, the maximum amount over each of the three axles groups (one steer axle and two tandems) is as follows: No, the 80,000 pounds has to be spread across all five axles but not evenly, and there are exceptions. Is the 80,000-pounds spread evenly across all 18 wheels? Refrigerated trailers are even heavier than dry vans as they require insulation inside the fiberglass walls to keep freight cool or frozen plus they have to carry a massive refrigeration motor on the front of the trailer and an extra diesel tank under the trailer. Dry vans have more to them including a fiberglass body on top of the trailer adding weight and reducing the payload by a few thousand pounds. Flatbed trailers are usually made of aluminum and as such are very light offering the highest possible payload within the 80,000-pound maximum limit. The reason for the different payloads across the three most common trailer types is the weight of the trailer.
- Refrigerated trailers or reefers: 42,500 to 44000 pounds.
- Dry vans trailers: 44,000 to 45,000 pounds.
- Flatbed trailers: can load up to 48,000 pounds of cargo.
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Big rigs are limited by federal regulation to a maximum loaded weight of 80,000 pounds including cargo, so the actual amount of cargo a big rig can carry really depends on the type and weight of the truck when empty.īut generally speaking, cargo payloads for big rigs or 18-wheelers are as follows: