What Are the Dimensions of a 55-Gallon Oil Drum?

When deciding which shipping container to use for your products, it helps to know the history and evolution of favorite designs. The 55-gallon barrel has served as industry standard since its first patent in 1905. Its precursor, the 42-gallon tierce, hearkens back to the reign of King Richard III of England. Changes in the shipping industry make it a good idea to weigh the benefits and drawbacks of universal container designs to ensure that you make maximum profit on every unit sold.

If you've ever wondered how and why the 55-gallon barrel became a unit of measure for transporting crude oil, you have to start with the tierce. The tierce was one of many containers used to ship wine. King Richard III of England standardized liquid measurements between 1483 and 1484. Wine imports at the time came in a variety of sizes, and not all of them contained the same amounts, making both pricing and tax calculation a nightmare. By decree, the King set the volume of a tierce at 42 gallons. A tierce weighs about 300 pounds when filled; the weight one worker could reasonably handle alone.

By the 1700s, shippers used the 42-gallon watertight cask known as the tierce for everything from salted fish to wine, butter, molasses and whale oil. When Edwin L. Drake discovered oil in Titusville, Pennsylvania in 1859 and began distilling kerosene, dispensing and shipping it in empty tierces seemed natural and logical.

Making watertight wooden barrels consumed time, labor and resources. Only eight of them fit on a standard horse-drawn cart and there was wasted space between each barrel that could have been filled with billable commodities to help offset shipping costs and increase profits. Elizabeth Jane Cochran, better known as journalist Nellie Bly, noticed that shippers in Europe filled steel containers with glycerine. She decided that her Iron Clad Manufacturing Company would produce a watertight steel container for use in the United States.

Bly set her employee Henry Wehrhahn of Brooklyn, New York, the task of designing the desired barrel which he patented in her name in 1905. The raised bands around the body of the barrel made it stronger and easier to handle than wooden tierces. The reinforcing ridges fit into grooves on some factory floors so that they could be rolled from one end of the warehouse to the other with just a push.

Nellie Bly's steel barrel remains an industry standard for hazardous materials and has a UN safety rating. A similar design exists that lacks the characteristic reinforcing ridges. This lack of reinforcement makes the smooth barrels unsuitable for transporting anything unstable, toxic or potentially explosive. Other 55-gallon drums include an all-plastic version; carbon steel with a chemical-resistant, epoxy-phenolic lining; and standard unlined, cold-rolled carbon steel. Barrel producers also make 55-gallon drums from stainless steel and composite, which means a carbon-steel drum with a plastic lining. Manufacturers paint salvage drums yellow for easy identification and informed, safe disposal.

Standard 55-gallon drums have a radius of 11.25 inches on the inside, which means that the inner dimensions of these barrels measure 22.5 inches in diameter. The steel adds another half-inch, making the external measurement a full 23 inches. Internal height measures 33.5 inches, with an extra half-inch for the steel making the barrel 34-inches-tall. Spacing the barrels one inch apart means four of them fit on one standard 4-foot-by-4-foot shipping pallet.

Historical designs no longer fit seamlessly into today's shipping practices as well as they did in the past. The use of supertankers and shipping containers means wasted space between each barrel. Centra Foods challenged the status quo and began shipping their olive oil in 330-gallon square totes instead of the traditional 55-gallon oil barrel. This single change raised total transported oil per pallet from 1,676 pounds to 2,511 pounds of olive oil, 50 percent more product-per-pallet, with a 33-percent reduction in shipping costs. These totes usually consist of high-density polyethylene and may include a steel cage for additional protection against shipping damage. These totes fit well when using intermodal transport from ship-to-shore-to-store.