New blowers were installed in 1902, new boilers in 1906 and 1914 and the furnaces completely rebuilt with modern equipment between 1927 and 1929. In 1909 James Pickering Dovel had become the superintendent of construction. For the next 21 years, Sloss was Dovel's workshop for invention. He developed gas cleaning equipment, modified the design of the furnaces, and improved the linings of the furnaces. In all, some 17 patents are credited to Dovel. Sloss's No. 2 Furnace, rebuilt in 1927, included many of these inventions, earning Dovel and Sloss a national reputation for innovation. Through this aggressive campaign of modernization and expansion, including furnace and mining and quarrying operations all around Jefferson County, Sloss-Sheffield became the second largest seller of pig-iron in the district and among the largest in the world. During this period the company built 48 small cottages for black workers near the downtown furnace — a community that became known as "Sloss Quarters" or just "the quarters".