The price of a barrel of crude oil is often a central topic in the news and its price directly affects the price of petrol and diesel. But how many litres does a barrel actually contain? Why a barrel and what does the abbreviation bbl mean in stock exchange charts?

The origin of the word barrel can be found in the Latin word “barriclus” used to name a small barrel. Later, the word barrel referred to containers of various sizes in which liquid and bulk materials were stored and transported. The volumetric size of a barrel was therefore not clearly defined, as it varied from region to region, vessel to vessel.

Given the focus of this site, you will undoubtedly be most interested in the oil barrel, which originated in Pennsylvania, USA.

The volumetric size of an oil barrel:

Oil companies trading on exchanges set the price of oil on a per barrel basis. This oil barrel has the international designation bbl and a fixed volume:

1 oil barrel = 42 US gallons =
35 UK gallons = 158,987294928 litres

History of oil production:

The first European sources of oil are documented in Pechelbronn, Alsace, as early as 1498. However, the method of oil extraction was quite different then. Oil was extracted from oil sands, which were mined in adits. The oil was then separated from the sand using boiling water. Then, through distillation, oil, paraffin and tar were gradually extracted. The crude oil extracted from the so-called Pechelbronn beds was first used medicinally for skin diseases.

Commercial exploitation of the oil sands began in 1735, and as early as 1742 drills were used to search for oil deposits. Around 1865, the depth of the Pechelbronn mine continued to increase, and the oil became more and more fluid as the depth increased. The method of extraction may therefore have changed from oil sand extraction to leachate extraction. In 1879, seepage extraction was replaced by the safer and more efficient extraction by drilling.

In 1859, the first ever commercial crude oil well, now known as the Drake Well, was drilled in Pennsylvania, USA. It was owned by Edwin Laurentine Drake, an American inventor and, above all, a pioneer in the field of oil extraction and drilling. His innovative method of extracting oil overcame the setbacks of extracting oil in the unconsolidated subsurface. Above all, well self-filling. Edwin Drake solved this problem with a drill bit that he placed in a cast iron pipe. The pipe then formed the walls of the borehole and prevented the strata from collapsing and thus plugging the borehole.

While his pioneering work led to the development of the oil industry in the US and made many people fabulously rich from the oil they extracted, it did not make Edwin Drake. Unfortunately, he did not patent the method of extraction he discovered, nor did he have a good business mind. He eventually lost all his savings in oil speculation and died in poverty in 1880.

Let us remember that at that time, of course, oil had quite different uses. Crude oil was mainly used to make kerosene for lamps, which was a much cheaper option than the whale oil used up to that time.

The history of the barrel as a unit of crude oil volume:

In the early days of crude oil production, there was no standardized container for trading the oil produced. Extracted oil and petroleum products were stored and transported in wooden barrels of various sizes. Over time, however, the major oil producers in the US came to the conclusion that this method of distributing and selling oil caused distrust among customers.

Therefore, in August 1866, some of the first American oil producers met in Titusville, Pennsylvania. They agreed that a barrel of oil would henceforth be 42 US gallons. Thus, they unofficially set the size of the future crude oil barrel.

Why 42 gallons and not the round 40 gallons, you may ask? No doubt the conversion of US gallons to imperial gallons (UK) and the desire to avoid counting with decimals played a part, we are in the 19th century. 1 US gallon = 0.8326738 UK gallons. Rounded to the nearest UK gallon, we would lose 0.1673262 UK gallons. However, if you convert 6 US gallons to imperial, you get 4.9960428 UK gallons. That’s almost a whole 5 gallons, and by rounding off at the trade we only lose 0.0039572 UK gallons, which is a very small variation.

However, smaller barrels are not very profitable and large barrels are difficult to handle. Therefore, the proposal was for a multiple of six, i.e. a 42 US gallon barrel, at that volume of barrel, rounding gives a fairly small variance of 0.0277 UK barrel. In 1872, therefore, a uniform oil barrel size was also adopted by the Association of Petroleum Producers and fixed at 42 US gallons.

Conversion to the metric system (litres) was not yet addressed at that time.


The origin of the abbreviation bbl for barrel of crude oil:

The abbreviation “bl”, the first and last letter of the name, is used for barrel in English-speaking countries. Some sources say that the added letter “b” was added to the abbreviation by the Standard Oil Company. which was the first oil giant in the US, founded in 1870 by John Davison Rockefeller. The company used blue barrels to store and transport oil, hence the bbl” for “blue barrel. But why blue barrels?

It is documented in logbooks that the abbreviation “bbl” was already in use before the birth of the oil industry in 1859. So let’s go back to Pechelbronn in Alsace, where the first commercial oil production began in 1735. At that time, it was not beer or wine barrels that were used to transport the extracted oil, which would have deteriorated, but purified herring barrels. Salted herring were transported inland in large quantities at that time, so that these barrels could be bought cheaply. To prevent confusion and later filling the oil barrel with food, the bottom of the barrel was painted blue.

Later mammoth companies like the Standard Oil Company merely adopted this custom. Thanks to their monopoly, the abbreviation bbl was humanized.

The first steel crude oil barrel:

Making the original watertight wooden barrels was not easy and was a job for the most skilled coopers. Thus, they were relatively expensive to produce. Therefore, in 1902, the Standard Oil Company introduced a steel version of the 42-gallon oil drum. In appearance, the new steel barrel resembled its wooden predecessors rather than the cylindrical oil barrels of today. These early steel barrels had riveted seams, fluted walls, and were not very tight.


The next advance came in 1904, when the Iron Clad Manufacturing Company obtained a patent for a straight barrel improved with hoops. The hoops strengthened the barrel and also made it easier to roll and handle the heavy barrel. This barrel became the design blueprint for today’s modern barrels. The Iron Clad Manufacturing Company was run by a woman at the time, which is unusual even today. Elizabeth Jane Cochrane eventually became a major industrialist in 18th century America! Read her abbreviated story.


Nellie Bly

Elizabeth Jane Cochrane is a very interesting historical figure. She took the name Nellie Bly, after a very popular song at the time. She first came to prominence as the first investigative reporter working for Joseph Pulitzer himself (Pulitzer Prize). Her most famous case was a report from a mental institution in New York City, where she volunteered to be confined in order to report on the horrific practices there.

This was followed by a journey around the world in 80 days, inspired by Jules Verne’s novel of the same name. She set off on her journey on 14 November 1889, sixteen years after the novel’s publication. During her journey, she met Jules Verne himself in France. Her actual journey even surpassed the novel’s protagonist Phileas Fogg’s time and briefly became a world record.

In 1895, Nellie Bly married millionaire industrialist Robert Seaman. At the time of their marriage, Nellie was 31 and Robert was 73! Due to her husband’s ill health, Nellie joined the management of his Iron Clad Manufacturing Co. This industrial firm manufactured steel kettles and other containers. From there it was not far to the design of the straight barrel mentioned above. In addition, Nellie Bly ran her company in an unprecedentedly modern way – elaborate welfare, health benefits and recreational facilities. However, her friendliness did not pay off, and the employees, led by the manager, drove the factory into bankruptcy.