How Much Does a Ton of Iron Weigh? by Victor Rolando

Editor's Note:  One of of our favorite "Ironmasters" is good friend Victor Rolando whose love of all things related to industrial archeology is an inspiration to the leadership of Friends of Taconic State Park in their work preserving the Copake Iron Works.  In this fascinating article, Vic asks the time honored question...

How much does a ton of iron weigh? (or, “Let the researcher Beware!”)

                                                                 by Victor R. Rolando

Vic Rolando, Friend to Troubled Furnaces Everywhere!

   One of the problems in attempting to compare the tons of iron made by 19^th-century blast furnaces are the various definitions of a “ton.” There was, for example, an English long ton, which weighed 2,240 pounds (also called a “gross ton”) and contained 20 hundred-weights (cwt) of 112 pounds (lbs) each. Although called a “hundred-weight,” it weighed 112 lbs so it could be evenly divided into halves, quarters, and eights (an eighth of a cwt is 14 lbs, called a “stone”). This weight system carried over to Colonial America and continued in use for the iron industry well into the early to mid-1800s. After the American Revolutionary War, the 112-lb cwt was dropped in favor of a 100-lb hundredweight, which translates into a 2,000-lb ton, avoirdupois (advp), also known as the short ton (some in Britain call the US hundredweight a “cental”).

   It’s not unusual to see tonnages of early blast furnaces listed in 19^th-century hand-written ledgers as, for example: 2T, 14Cwt, 2Q, 18 lbs, or simply “2.14.2.18” (4,000  + 1,400  + 50 + 18 lbs) which totals 5,468 lbs or 2.734 short tons. Although the US and Europe adopted various “weights & measures standards” by the 1860s, many local industries that did little or no interstate or foreign trade maintained their own archaic bookkeeping systems. By the late 1800s the European iron industry was using a “centner” as the common unit of pig iron measure, in which 1 centner = 110.23 lbs, or exactly 5% of a metric ton that equals 1,000 kilograms (kg) or 2,204.6 lbs advp. The metric ton is used in today’s commodities market for iron and steel.

   History books abound with tonnages of various commodities without identifying which tonnage systems they refer to. Even books relating specifically to the iron industry rarely make the distinction. And although most iron researchers realize that the long ton has long been the rule for the iron industry, paragraphs dealing with tons of iron, ore, charcoal, blasting powder, lumber, and molding sand beg the question whether the actual weights of all those items are based on 2,000-lb, 2,204.6-lb, or 2,240-lb tons. By reading closely how some tonnages are described in terms of value per ton and total values, whether they are short or long tons can sometimes be estimated, at best. Using this scrutiny of data, one 1966 history of the early iron industry in downstate New York was found to quote furnace outputs in terms of short tons. On the other hand, a 1911 survey of Maryland ironworks was found to define outputs in long tons. If one is unaware of these differences, direct comparisons of pig iron production and furnace efficiency could be difficult at the least, or completely erroneous at worst. 

   For example: of the various historical accounts of how much iron was made at the Copake blast furnace, the only two reliable detailed 19^th-century accounts come from reports by William G. Neilson (1842-1906) and J.P. Lesley (1819-1903).

   In Neilson’s report on the charcoal iron industry in New England, compiled for the American Iron and Steel Association in 1866, he stated that the furnace “at Copake Station” made “about 2800 tons (gross)” in 1865.  His tables of various furnace specifications elsewhere in the report indicate the furnace made from 1743 tons in 1854, 505 tons in 1855, and 1513 tons in 1856 (among tonnages up to 3387 tons in 1866 with none made from 1857 through 1860). To his credit, his tables also identify tonnages listed at 2,000 lbs, so then why did he write “about 2800 tons (gross)” above, possibly inferring short tons?

   Lesley, an earlier chronicler of the US iron industry and Secretary to the America Iron Association in 1857, reported iron production at Copake at 160 tons “more or less” for each of 1854, 1855, and 1856 without identifying whether long or short tons. But in his 1859 report he stated that 1,556½ tons were made during 41 weeks in 1854; 451 tons during 14 weeks in 1855, and 1,350½ tons during 38 weeks in 1856. Analyzing the weekly output one finds the 3-year average is 35¼ tons/week, or essentially 5 tons a day within a very acceptable +7.7% to -8.5% variance, indicating an unexpectedly consistent level of production – “unexpectedly” given the number of things that could go wrong in a mid-19^th-century blast furnace operation. But attempting to apply this interesting piece of data is complicated by neither of Lesley’s 1857 nor 1859 publications identify whether his numbers reflect long or short tons. Although most of Lesley’s tonnages are smaller than Neilson’s, Lesley’s probably being long tons, unfortunately not nearly enough of Lesley’s tonnages convert very close to Neilson’s short tons. So whose are the more accurate figures?

   Starting in 1873, The American Iron & Steel Assn (founded in 1864 as successor to Lesley’s 1859 American Iron Assn), initiated publication of the biannual Directory of Iron and Steel Works of the United States. However comprehensive the publications were, vague references to tonnages persisted and comparisons between nearby like-capacity furnaces elude dependable conclusions. Regardless, the following on page 8 of the 1884 Directory under the heading of Charcoal Furnaces in New York State proves interesting:

Copake Iron Works, Frederick Miles, . . .  One stack, 32 x 9, built in 1872; open top; warm blast; steam and water power; ore, limonite, mined near the furnace; Specialty, car-wheel iron; annual capacity, 4,500 net tons. Brand: “Copake.”

There’s new one - a “net” ton!