bbl

Often thought to be modified from bl for barrel (b⸺l), reflecting a way of abbreviating that was used especially in previous centuries (compare do for ditto), wherein a doubled letter indicated plural count, as also with p.=page but pp.=pages and l.=line but ll.=lines; this method was used not only in English but also in scholarly New Latin and other modern languages heavily affected thereby, such as with Spanish EE. UU. According to this idea, addition of the suffix -s, as sometimes seen (e.g., 5 bbls or 5 bbls.), would seem to have come from writers who left the unit abbreviation itself unanalyzed (unparsed), thus adding a venially redundant marker of plural, somewhat like with MPGs for miles per gallon.

bbl (plural bbl or bbls)

1. Abbreviation of barrel, as:
   1. (especially in the 20th and 21st centuries, most often) Volumes of crude oil pumped, stored, or sold (in bulk).

      measured in 1000-bbl units

      • 1920 May 8, H. T. Carlton, “New design for oil tankage”, in Engineering and Mining Journal‎, volume 109, number 19, retrieved 2023-03-05, page 1079:

        At present prices, cylindrical steel tankage in 55,000-bbl. units costs approximately 73c. per barrel storage.

   2. (especially in previous centuries) Numbers of barrels (casks) transported or sold, or the volume that they represent.

      5 bbls. flour

      • 1815 Niles Weekly Register volume 8, Supplement, p. 152. From an inventory of the frigate Confiance:

        […]5 hhds. rum/ 5 bbls. flour/ 1 bbl. sugar/ 9 do. pork/ 1 do. suett/ 3 do. cocoa/ 6 do. peas/ 2 ullage bbls. vinegar[…]

      • 1881, Ulster County, New York, County Legislature, Minutes of the Board of Supervisors of Ulster County‎, page 234:

        4 bbl. vinegar $32.00, 3 bbl. cider part full $6.50

   3. (internal combustion engines) Numbers of venturis in carburetion.

      1-bbl carburetor

      4-bbl carburetor

      three 2-bbl carbs

• hhd. (twice the volume)

bbl

1. (Internet) Alternative form of BBL