Thanks Pat for the dissertation and history about the volume of a barrel.
It shows how much the SI is needed.
The use of kilolitre (kL) is a much desired unit of volume measurement for
the large quantities involved; however, the barrel is very entrenched. We
also see oil reported in tonnes which is a unit needed to include the
density of the fluid. In fact, mass is used in aviation because mass is
critical to the weight-lifting (mass) capability of airplanes.
Stan Doore
----- Original Message -----
From: "Pat Naughtin" <[EMAIL PROTECTED]>
To: "U.S. Metric Association" <[email protected]>
Cc: "U.S. Metric Association" <[email protected]>
Sent: Tuesday, February 06, 2007 1:43 AM
Subject: [USMA:37927] Re: Oil barrel
Dear Sam,
Thanks for your question.
I have interspersed some remarks.
On 6/2/07 12:39 PM, "Sam" <[EMAIL PROTECTED]> wrote:
Hi Pat,
I read your site and check regularly for updates however in your
article on "What is metrication" (and mentioned in previous articles I
believe) you state that the oil barrel (unit) never exited and has no
size.
What I said, on the 'Why metrication?' web page, was:
**
The first thing to know about the oil barrel is that it never existed. Oil
is not put into standard barrels when it is pumped out of the ground < and
it never was! An oil barrel is a simply made up container that, in theory,
holds 42 American (USA) gallons and this rounded whole number translates to
34.9726 Imperial gallons, 5.6146 cubic feet, 158.984 litres or 0.136 tonne
(approx). When you notice that the West Texas crude oil price is (say)
$63.60, how can you relate this to the $1.30 per litre that you are paying
when you fill up your car? (By the way, $63.60 is equivalent to 40 cents per
litre and $1.30 is equivalent to about $4.10 per gallon in the USA.)
**
So let me be clearer. The oil barrel never existed. There never was a
standard oil barrel supported by any international authority.
As to the idea of a unit called a 'barrel of oil', not only has this existed
there have been many of them.
As you say, the Standard Oil Company chose one as did most (perhaps all) of
the other oil companies. I believe that British Petroleum used one that was
35 gallons, Royal Dutch Shell used one that was 159 litres, and so on. As
the idea of a unit called 'a barrel of oil' is not supported
internationally, it is the decision of each company as to the size of a
barrel.
My source for the information that 'the oil barrel never existed' is the
Permian Basin Oil Industry Museum near Midland in Texas (See:
http://www.petroleummuseum.org/).
http://en.wikipedia.org/wiki/Barrel_of_oil
According to wikipedia, a Barrel of Oil is exactly 158.9873 litres (42
US Gallons).
"However, the Standard Oil Company shipped its oil in barrels that
always contained exactly 42 U.S. gallons. Customers began to refuse to
accept anything less and by 1866 the oil barrel was standardised at 42
U.S. gallons."
Clearly the Wikipedia writer is using the decision made by the Standard Oil
Company to use the 42 gallon figure for their own sales, and then assumes
that this is an international 'standard'. The writer at
http://www.slate.com/id/2115219/ also falls into the same trap. As a point
of interest the date you mention, 1866, was the year when pipelines, tanker
rail cars, and bulk oil barges effectively killed off any need for all of
the differently sized barrels.
Coincidentally, 1866 (July 28) was also the year that President Andrew
Johnson signed The Kassen Act (codified as 15 USC 204 et seq.) into law.
This Act made it lawful throughout the USA 'to employ the weights and
measures of the metric system'.
Sec. 204. Metric system authorized:
'It shall be lawful throughout the United States of America to employ the
weights and measures of the metric system; and no contract or dealing, or
pleading in any court, shall be deemed invalid or liable to objection
because the weights or measures expressed or referred to therein are weights
or measures of the metric system.'
As a side issue, the writer at http://www.slate.com/id/2115219/ also falls
into the trap of the 55 gallon steel drum (and the 42 gallon barrel) when he
writes:
'Though barrels may be close to extinct, companies still ship some oil in
55-gallon steel drums. (Volumes for these are still given in 42-gallon
"barrels.") The steel drums used in calypso music are made from these
55-gallon containers. The first appeared in Trinidad, shortly after the end
of World War II.'
When the steel oil drum was developed in Germany in the 1930s, it was
specifically designed to hold 200 litres of petroleum product and also allow
for a small air space for expansion.
After the second world war, these drums travelled widely from their native
Germany because of their usefulness. As they crossed each international
border, the local people dumbed down 200 litres to local volume measures.
For example, the 200 litre drum became the 55 gallon drum in the USA to suit
the old Queen Anne wine barrel in use there. At the English border the 200
litre drum became the 44 gallon drum to suit the 1824 Imperial decimal
gallon. You can find a lot more misinformation about this -- look at how the
50 millimetre and 20 millimetre bung sizes have been changed to nominal inch
sizes for example -- at: http://en.wikipedia.org/wiki/44_gallon_drum
"The Standard Oil monopoly was broken up into 34 different companies
in 1911. Oil has not been shipped in barrels for a very long time[2]
but the "blue barrel" is still the standard unit for measurement and
pricing of oil in the U.S. today."
This does not make sense. Petroleum products are quite sensitive to changes
in temperature so if you want to buy or sell large amounts in volume units
-- and you don't want to be cheated -- you need to apply temperature density
factors that effectively mean that you are buying by mass (kilograms and
tonnes) rather than by volume. All oil traders know this, they know that
they need to adjust for temperature sensitivity so they effectively buy in
mass (kilograms and tonnes) and, because the public is not so aware of
temperature changes, the oil traders sell by the more variable volume
(litres all around the world or gallons in the USA).
Whereas you wrote:
"...they simply calculate a theoretical oil price based on a
theoretical oil barrel of unspecified size.."
158.9873 litres (42 US Gallons)
"- and that never existed -"
"However, the Standard Oil Company shipped its oil in barrels that
always contained exactly 42 U.S. gallons. Customers began to refuse to
accept anything less and by 1866 the oil barrel was standardised at 42
U.S. gallons."
Looking forward to hearing from you,
I am concerned that I have not made myself clear in my original article. I
will try to rephrase my thoughts along the lines outlined above as soon as I
can.
Thanks again for your question.
Cheers,
Pat Naughtin
PO Box 305, Belmont, 3216
Geelong, Australia
Phone 61 3 5241 2008
Pat Naughtin is the editor of the free online monthly newsletter,
'Metrication matters'.
You can subscribe at http://www.metricationmatters.com/newsletter
Pat is also recognised as a Lifetime Certified Advanced Metrication
Specialist (LCAMS) with the United States Metric Association. He is also
editor of the 'Numbers and measurement' section of the Australian Government
Publishing Service 'Style manual for writers, editors and printers'. He is
a Member of the National Speakers Association of Australia and the
International Federation for Professional Speakers. See:
http://www.metricationmatters.com
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