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Oregon's First Iron Smelter

Last Updated: 5th Aug 2010

By Bill Tompkins


The remains of Oregon's first iron foundry can still be seen beside the Willamette River at George Rogers Park in Lake Oswego, Oregon.

Having earned a spot in the National Registry of Historic Places, a plaque at the site reads:

Oregon's First Iron Smelter.
The first pig iron made west of the Rocky Mountains was smelted here on August 24, 1867 by the Oregon Iron Company.
This stack, within which was the furnace, is constructed of native basalt.
It measures 34 ft. at the base, 26 ft. square at the top, and is 32 ft. high.
Ore mined from Iron Mountain, west of Oswego, was transported to the furnace by oxen, later by narrow gauge railroad.
Water for power was obtained from Oswego Creek.
Charcoal for fuel was made from Oregon fir trees.
The plant was closed November 1885.
During operation it produced 40,625 tons of iron.

The Ore Beds Near Lake Oswego, Oregon

Iron ore was first discovered in the area in 1841. Early reports named the ore hematite, but later reports called it limonite (2Fe2 03 3H2O), a hydrated form of hematite. The ore was deposited as a sedimentary layer some 12 to 15 feet thick called bog-iron ore which extends from Lake Oswego to St. Helens, Oregon, a stretch of about 25 miles with the richest beds at each end. Ore was mined near the furnace at the Patton strip mines and was also mined underground on Iron Mountain at the Prosser mines. The strip mines were closer and cheaper to operate and transport while the other mines produced a higher grade of ore, all of which was monitored very carefully.

The Furnace At George Rogers Park

The Oregon Iron Company was formed in 1865 with hopes of turning the area into the "Pittsburg of the West". An expert was brought in to construct a furnace patterned after the Barnum stack at Lime Rock, Connecticut. The foundation was laid on bedrock some 16 feet below the surface and was made of solid, dry stone-work 36 feet square. The stack was built with hewn stone, obtained at the site and was 34 feet square at the base, 32 feet high, and 26 feet square at the top. On top of the stack was built a chimney of brick 40 feet high which contained the oven for heating the air for the blast.

The Chemistry Of Iron Founding In Oregon

Simply put, iron smelting here involved heating the iron ore and introducing oxygen, limestone, and carbon in a controlled, three-stage process aided by heat and pressure.
In Stage One of the process: 3 Fe2 O3 + CO is changed to 2 Fe3 O4 + CO2
In Stage Two of the process: 2 Fe3 O4 + 2CO is changed to 6 Fe O + 2 CO2
In Stage Three of the process: Fe O + CO is changed to Fe + CO2
The hot air blast with the charcoal reduces 2C + O2 into 2 CO
The limestone flux changes from Ca CO3 into Ca O + CO2

However, the actual making of iron was not as simple as heating a batch of ore, throwing in some limestone and charcoal, blowing in some air, and waiting for iron to flow out. Every ingredient had to be carefully introduced at the correct time, in the correct quantities, and at the correct temperature and pressure.

The Mechanics Of Iron Founding In Oregon

The mechanical process of pig iron smelting at this site involved a brick-lined crucible, loaded with a monitored mixture of crushed ore, charcoal and limestone that was heated to between 600 and 1000 degrees Centigrade for several days to allow moisture in the brick lining to evaporate to prevent damage to the furnace. After the furnace was heated, the smelting process became one of adding more ingredients to the top while drawing off iron from the bottom in a continuous cycle. The size of the mix was limited by the furnace. It had to be tall enough to allow the chemical reduction process and small enough for the fuel to support.
Iron was drawn from the bottom of the crucible through a tap hole and cast into pigs. This was done by laying sand on the foundry room floor and shaping the sand into a main channel called a sow and side drifts called pigs. Half of the foundry room was filled at a time so the pigs could cool while the new ones were being prepared. This casting cycle was done every 12 hours.
The byproduct of casting was slag. From this smelter the slag was used for road bed and track bed fill or simply thrown into the river. The purple slag can still be found today in many road excavations and along the river.

The Economics Of Iron Founding In Oregon

Iron ore from nearby was brought originally by oxcart and later by narrow gauge railroad and heated in the furnace using nearby Douglas Fir trees for fuel and charcoal. Limestone was brought in from the San Juan islands for use as a flux to liquefy the silica in the ore, allowing the slag to float on the molten ore where it could be drawn off and hauled away or dumped into the Willamette River. The oxygen had to be compressed and preheated before being introduced. All of these factors and more contributed to why iron is no longer made here.
First, the ore. As is common in bog iron deposits, the ore was more concentrated around the edges of the deposit, so that as mining continued the percentage of iron in the ore decreased. This meant that better ore had to be mined from more expensive, underground mines to supplement the cheaper, strip mined ore.
Second, the fuel. Old growth Douglas Fir trees were found nearby and the original iron company owned 3000 acres. However, 1.3 acres a day were being consumed to make charcoal and heat the furnace. The cost of producing the charcoal amounted to half of the cost of smelting a ton of pig iron. Producing iron with charcoal instead of coke also made a difference in the end product. Pig iron made from coke is more brittle than charcoal smelted pig iron. This made Oswego iron a specialty product and was advertised as such.
Third, the limestone. The closest source of flux was in the San Juan islands and had to be brought in by steamers through Tacoma, Washington costing about 5 times the comparable for other smelters.
Fourth, the labor. At it's peak in 1888 this smelter employed 325 men, 150 of which were Chinese.
Fifth, the furnace. In building the stack, an error was made that limited the amount of iron that could be produced to 8 tons per day, instead of the planned 10 tons.

By October 1867, the Oregon Iron Co. had produced 224 long tons of iron. That production cost them $28.98 per ton, exclusive of taxes and interest. At the same time pig iron imported from Scotland, brought over as ballast, was selling for $25 per ton. All of these factors added up to economic disaster. With the above economic reasons considered, the furnace was stopped in 1908 and dismantled in 1929. All that remains now is the stack.

But the story of the Lake Oswego Iron Smelter does not end there.

In 1902, a part-time miner who lived next to the property that the iron smelter owned was taking a short cut across their land and noticed a large, peculiar rock. A huge meteorite. So begins the second half of this report.

The Willamette Meteorite

Ellis Hughes, a Welsh coal miner struck the large rock with a hammer and it gave a deep, hollow ring. Quickly identifying it as a meteorite and realizing it's value, he spent the next three months building a wooden cart and dragging the 16 ton rock to his own property where he charged visitors 25 cents apiece to view it. But when an attorney for the Oregon Iron and Steel Company noticed the cleared path leading from their property to Ellis Hughes', the Oregon Iron and Steel Company sued for ownership and won the return of the meteorite in 1905.
The meteorite was moved up the Willamette River for the Lewis and Clark Exposition and then the largest meteorite ever found in the U.S. was sold to a New York philanthropist, Elizabeth E. Dodge II, who bought it in 1906 for $20,600 and donated it to the Museum of Natural History. In 1935, the Hayden Planetarium was built around the meteorite.
The meteorite, Iron IIIA, recrystallized octohedrite, has a flattened semi-circular shape, humped on the upper side, with huge smooth cavities throughout and is about the size of a Volkswagen. It is a nickel and iron meteorite believed to have originally landed in Idaho's Pend d'Oreille region. Carried to Oregon in the Great Missoula Flood, it ended up near the Falls of the Willamette River. There, Clackamas Indians believed it was sent to Earth as a representative of the "Sky People" and tribal hunters would dip their arrows in rainwater collected in its basins. They call it "Tomanowas" or "visitor from the moon".
In June 2000, the Museum of Natural History and Oregon's Grand Ronde Tribal Council signed an agreement after four months of negotiations to share custody of the 10,000 year old meteorite that is a centerpiece of the museum's new planetarium. Under the agreement, the meteorite will remain in New York, but the tribe will receive access for an annual ceremonial visit to the museum.

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