Carrie Blast Furnace Number 6 and 7

Carrie Blast Furnaces Numbers 6 and 7 are two steel-frame iron-producing stacks on the north bank of the Monongahela River, a short distance east of Pittsburgh, in the boroughs of Rankin, Munhall and Swissvale. Built in 1906-1907, they formed part of the integrated Carrie plant that supplied basic iron to the open-hearth furnaces of the Homestead Steel Works from 1907 to 1978. The furnaces operated as a pair, sharing ore storage, hot blast stoves, blowing engines and gas-processing equipment. Their gas was cleaned and used to fire boilers and generate electricity for the mill. Most of the original equipment dates from the 1920s to the 1940s, a level of integrity uncommon among furnaces built before World War I. The district also includes the Hot Metal Bridge, built in 1900-1901, which carried molten iron across the river. The property is significant for its engineering and its role in industrial production.