Comparison of Cargo Capacity Between Trucks, Trains and Bargesby Rich Finzer
Viewed together, America's highways, navigable waterways and railways compose the nation's surface transportation network. Highways carry truck traffic, rivers move barge traffic, and railroads carry all manner of freight. Comparing the cargo capacity of the various components making up the transportation network is an interesting exercise to engage in. For a strictly apples-to-apples comparison, assume that each vehicle's cargo will be dried, shelled corn, which weighs 56 pounds per bushel.
Dry Van Trailer
Semitrailers, referred to in the trucking industry as "dry vans," have a maximum length of 53 feet. Dry vans of this size are permitted to operate on most highways without special Department of Transportation permits. With a maximum carrying capacity of approximately 26 tons, a dry van can carry roughly 910 bushels of corn, or 52,000 pounds. The advantage enjoyed by the semitrailer and the truck-tractor hauling it is that they are capable of traveling practically anywhere.
Freight such as shelled corn might be transported in either jumbo hopper cars or freight cars, also called box cars. A jumbo hopper car can carry about 100 tons of cargo, or 3,500 bushels, which equates to roughly 200,000 pounds. A 125-ton freight car can carry 125 tons, or about 4,450 bushels, which equals about 250,000 pounds. The train is capable of traveling at higher speeds, and a truck must wait at a crossing, while the train always has the right of way.
A standard-size barge operating on the Mississippi River has a cargo capacity of 1,500 tons, or 52,500 bushels, which works out to a colossal 3 million pounds. While the barge carries as much as 15 jumbo hopper cars, floods or periods of low water may limit when or where it can operate. Barges are normally tied together into 15 barge "tows."
Barges vs. Trucks
The 15-barge tow has a total cargo capacity of 22,500 tons, or 787,000 bushels. It would require a fleet of 870 53-foot dry vans to haul the same quantity of freight. But the barge is captive to the river, whereas the truck can travel virtually anywhere.
Barges vs. Trains
In comparing the 15-barge tow to the jumbo hopper car, you would need 225 of them to carry the equivalent amount of cargo. But like the dry van trailer, the advantage the train enjoys is access to more locations along with fewer environmental limitations. This comparison clearly demonstrates why all three elements of surface transportation infrastructure must work in concert.
- photo_camera barge image by Roman Jankovski from Fotolia.com