“New” McIntyre Furnace

“New” McIntyre Furnace. Cross Section Through Furnace. , TRIAL AND ERROR , This "new” furnace was first fired in 1854. It was called "new” because it was the McIntyre Iron Company's 4th and most recent attempt at a furnace design that would produce quality iron efficiently. Its design was the result of a combination of on-the-job training and technologies developed in Britain. At a time when the industry was smelting iron with coal, this modern design was adapted to use charcoal., Sections of the Furnace (left to right) , CHARGING BRIDGE - The charging bridge provided a level access from the top of the hill behind to the top of the furnace. , FURNACE - In the heart of the furnace, called the bosh, the ore was melted. , CASTING HOUSE - In the Casting House the iron cooled in sand molds called pigs., HOW IT WORKED , 1. Drop stamps crushed the ore down to pebble-sized chunks. , 2. Workers introduced ore, charcoal, and lime (flux used to remove impurities) into the furnace through the tunnel head. , 3. The charcoal was ignited, and air, heated in the hot blast stove, was blasted on the fire through cast-iron nozzles called tuyeres (twe yârs'). , 4. Temperatures in the bosh reached 2500°F; the ore melted and puddled in the furnace hearth. , 5. Twice a day a dam stone was opened and the molten iron flowed into the casting house through a channel called the sow., Right Inset , Hard Work , MINING THE ORE , Hand drills, hammers, and black powder were used to extract raw ore from veins close to the surface. The ore was roasted to burn off impurities, washed, and carted to the west end of the charging bridge., MAKING CHARCOAL , Loggers cut and split the mature hardwoods with axes and wedges. Split logs were dried in brick kilns. In 1854, 250,000 bushels of charcoal were stored in the sheds near the charging bridge., CHARGING THE FURNACE , Fist-sized chunks of ore were loaded by hand into the ore stamps. The crushed ore was shoveled into carts, carted to the tunnel head, and shoveled into the furnace., Upper Left Inset , TUYERE ARCH , Arched openings on all four sides of the structure allowed access to the hearth. Three accessed the blast air nozzles (tuyeres) and cooling water controls. The fourth arch, shown here, accessed the dam stone to release the molten ore.,