The Anthracite Iron Industry
Without question, it was the development of the iron industry – employing anthracite coal as fuel – which propelled the United States into a world power for more than a century. The vast iron and steel industry was born; fortunes were made, hundreds of thousands of workers gained employment and the product was used in the building of railroads, ships, skyscrapers and munitions. This evolution – begun in the late 1830s -- was made possible by the development of the Pennsylvania anthracite coal fields and the harnessing of the powers of the Lehigh, Schuylkill and other rivers for transportation and power.
Prior to the development of anthracite as a blast furnace fuel, charcoal was the fuel of choice for furnaces. Charcoal furnaces could be found everywhere. But charcoal was frangible – large/tall furnaces could not be employed – the charcoal would be crushed by its own weight, then block the passage of air through the furnace. (See Temin, Iron and Steel in the 19th Century – The Hot Blast.) Coal – Òstone coalÓ – did not suffer from this mechanical deficiency. The ironmasters of the day recognized this. But anthracite coal had a problem that which has been addressed on a previous page – it would not burn in a blast furnace environment.
The first of the large anthracite-fired blast furnaces
erected at the Crane Iron Works in Catasauqua, Pa. in 1839 – 40. It was
45 feet tall. A description of the erection is given in Thomas, Samuel, Reminiscences
of the Early Anthracite-Iron Industry. Click
here for an enlarged view of the drawing where the details of the drawing
can be read.
The history of the events which led to the successful establishment of the technology required to perfect the anthracite-fired blast furnace has been thoroughly documented. In this page, the highlights are given along with links to publications which provide thorough documentation. The bottom line is that although many, many talented and industrious men contributed to this effort, the individual that is credited with successfully implementing the processes in a commercially-viable operation was David Thomas, a Welshman, at the Crane Iron Works in Catasauqua, Pa. in July 1840.
David Thomas, The Father of the American
Anthracite-Fired Iron Industry. ThomasÕs
biographies can be accessed here.
The real key to the use of
anthracite was employment of what is known as the Òhot blastÓ. Here, the air
that is blown into the base of the furnace is heated to a temperature of at
least 300F prior to injection into furnace through pipes known as tuyeres.
Credit for the first implementation of this hot-blast process is given to
Scotsman James B. Nielson who was seeking to improve the operation of
coke-fired furnaces in his native land. Nielson received a patent covering the
process in 1828 – a dozen years before the technology was employed by
Thomas at the Crane works. Information of NielsonÕs success reached George
Crane at Yniscedwin,
near Swansea in Wales, where he and his ironmaster, David Thomas were
experimenting with anthracite. (There were anthracite fields in that area of
Wales.) Thomas visited Neilson,
received a license for the process, and succeeded in employing the technology
at Yniscedwin in 1837. Word of that success reached the Lehigh Coal and
Navigation Co. who dispatched Erskine Hazard to Yniscedwin to negotiate a
contract whereby the technology would be brought to America. The result was that David Thomas agreed
to emigrate to America and it was he that had the Crane Iron Works built in Catasauqua.
How
was the hot-blast actually implemented?
In the beginning, Nielson simply employed a modest-sized stove, fired
with coal, through which ran metal ducts carrying the blast air. The amount of
temperature rise achieved was quite modest, perhaps 200 F, but it was adequate
for NielsonÕs purpose (his furnaces were fueled by coke.)
NielsonÕs early stoves. The tapered pipes are the
tuyeres (twyers in England). Source, Turner, Metallurgy
of Iron.
Other
experimenters recognized that the waste gases from the blast furnace could be
used to heat the air, and mounted heat exchangers at the top of the blast
furnace stacks. Again, a modest temperature rise was achieved.
Example of a heat
exchanger placed on top of a furnace for
preheating air for the blast. Hot gas emerging from the top of the
furnace (1) was deflected by the iron plate (7) into the chamber (2) containing
cast iron pipes (5) and passed out the stack covered with the damper (3). The
blast engine pumped air up the sheet-iron pipe (4), through the iron pipes,
where it was heated, and down the cast iron pipe (6) to the tuyere. Source: Gordon,
American Iron.
It
is not clear what type of construction that Thomas used either at Yniscedwin or
at Catasauqua, but in Reminiscences Samuel Thomas comments that the structures were
substantial. According to Johnson,
the blast was heated in four ovens, each having twelve arched tubes of
five inches interior diameter, and two inches thickness of cast iron. No
indication of the oven size is given. Eventually,
(ca. 1850) furnaces built in Pennsylvania and elsewhere employed what were
known as CowperÕs Stoves and Whitwell stoves. These were almost the size of the
blast furnace itself, were used in pairs with a spare included so that three
stoves per furnace was common place. Indeed, the stoves sometimes dominated the
scene of the iron works. These stoves were of the regenerative type where the
hot waste gas from the furnace heated a lacework of brick inside the tower for
a period of time, then the hot gases were routed to the second furnace while
the blast air valve was opened and the blast air picked up the heat from the
brickwork. The details of this
process have been documented by Turner
– an excerpt of his work which covers the evolution of hot-blast furnace
design is available here.
An illustration of a CowperÕs Stove.
The unit on the left is being heated by waste gases; the unit on the right is
heating the blast air. Source: Turner, Metallurgy of Iron
During this time period, when the effectiveness of the hot-blast had been recognized, there were other experiments being conducted in Pennsylvania on firing furnaces with anthracite coal. A complete accounting of these activities is given by Johnson, Notes on the Use of Anthracite in the Manufacture of Iron, 1841. (That account can be accessed here. A concise accounting was given by William Firmstone in an AIME paper in 1874.)) Some of these efforts partially succeeded but none demonstrated the sustained operation that was necessary to attract investors. Why did Thomas succeed where others failed? The answer seems to be in the thoroughness and attention to detail which Thomas applied in the construction of the Crane Iron Works – not only with respect to the hot blast, but to the construction of the blast furnace itself, the capabilities of the blowing machinery, the raw materials employed, etc. That is the conclusion of W. Ross Yates in his thorough review of the subject in Discovery of the Process for Making Anthracite Iron published in 1974. (That review can be accessed here.)
The Crane Iron Works, The Thomas Ironworks in Hockendauqua, Pa. (founded by David Thomas after his contract with George Crane had been fulfilled), and many other anthracite works in the Lehigh Valley and vicinity prospered for many years. Fortunes were made by the owners of these installations. The decline of the industry began along with the Panic of 1873, as financial conditions deteriorated and competition from other regions of the country where coal and ore were cheaper began to take a hold. Larger and more efficient operations integrated the open-hearth and Bessemer processes for making steel. Eventually, in the 1920s, the only furnaces operating in the Lehigh Valley were those of the Bethlehem Steel Company.
A news article published in 1875 described the
industry decline. Click here to view the
article.
Our specific focus in this very brief overview of the anthracite iron industry has been on the Crane Iron Works, not only because it marked the initial commercial success of the industry, but because it was at the Crane Ironworks where Hopkin Thomas completed his career begun 50-years previously with his friend David Thomas at the Neath Abbey Ironworks in Wales. In 1853, after his engineering successes in the locomotive-building business and the coal mining business, Hopkin Thomas came to serve as Master Mechanic (Chief Engineer) at the Crane. Those activities are described in the following chapters.
Details of what has been highlighted above appear in many publications. Following is a list of the more useful sources.
Johnson, Walter R., Notes
on the Use of Anthracite in the Manufacture of Iron. This
early (1841) account provides data on the use of anthracite in early blat
furnaces – at the time industrialists, entrepreneurs, and capitalists
were all striving to have the industry succeed as a commercial activity.
Johnson was a mining engineer and professor of chemistry, so the account is highly
technical.
Yates, Ross R., Discovery
of the Process for Making Anthracite Iron.A
scholarly review of the early developments in the anthracite iron industry.
Yates was a professor at Lehigh University. The article is thorough with
references cited for all significant events described.
Bartholomew, Craig L. and Lance E. Metz, The
Anthracite Iron Industry of the Lehigh Valley. Published in 1988,
this publication deals with iron production activities in the Lehigh Valley
from the early beginnings to the date of publication. It is a complete
compendium of the activities conducted by many industrial operations.
Turner, Thomas, The
Metallurgy of Iron. This
publication gives a thorough accounting of the development of the hot-blast
process up to the late 1800s. Other subjects including steel making are covered
in this comprehensive work.
Bining, Arthur Cecil, Pennsylvania
Iron Manufacture in the Eighteenth Century. This scholarly work deals with the iron industry
during the period before anthracite was developed as a primary fuel.
Gordon, Robert B., American
Iron, 1607 – 1900. Part of a series on the history of
technology, this 340 p. book covers developments in the industry throughout the
entire country.
Temin, Peter, Iron
and Steel in the Nineteenth Century, An Economic Inquiry. A well researched review of the industry published
in 1964 – including a section on the hot blast.
Swank, James M., History of
The Manufacture of Iron in All Ages.
An often-cited classic history published in 1892 covering
activities throughout the word. A chapter on the development of anthracite coal
as fuel is comprehensive, covering many activities in Pennsylvania, including
David ThomasÕs contributions.
Williams, Peter N., David
Thomas: Iron Man from Wales. A
monograph devoted to David Thomas with emphasis on the social conditions
existing in Wales at the time of ThomasÕ emigration. The final chapter
emphasizes the difficulties that Thomas overcame in the building of the Crane
Iron Works.
Guide-Book
of The Lehigh Valley Railroad, Appendix B. A thorough examination of who
should be given credit for the first successful use of anthracite coal in the
smelting of iron. Letters written by those involved in the various efforts are
the central theme of this examination.
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Contents
About
The Hopkin Thomas Project
Rev. February 2010