MODERN BLAST FURNACE PRACTICE 89 



While it is true that furnaces of greater (cubic) capacity 

 than the present American furnaces were constructed as 

 early as 1870, as for example the two Ormeshy (English) 

 furnaces constructed about that period, which had a volume 

 of about 40,000 cubic feet, as compared with 26,500 cubic 

 feet in the case of the Youngstown furnaces, we hnd their 

 weekly output equaled by the daily product of the latter. 

 The development then, of the high pressure, high tonnage 

 furnace, as we understand the term to-day, has been accom- 

 plished during tlie last few years. With this increased ton- 

 nage, the demand — or rather the necessity — for apparatus 

 supplementing or displacing manual labor grew apace. When 

 we rememl)er that the digestive capacity of one of these mon- 

 sters, expressed in tons, approximates 2,000 tons daily, the 

 task of supplying its capacious maw is more fully appreciated. 



The Duquesne plant of the Carnegie Steel Co. was one 

 of the fii*st examples of this type. A 600,000 ton stock yard, 

 1,085 feet long, having an effective width of 226 feet, was 

 provided for the four furnaces comprising this group. The 

 stock yard is spanned by three bridge cranes built b}' the 

 Brown Hoisting Machinery company of Cleveland. During 

 the stocking season, hopper bottom cars are unloaded in 

 bins behind the ore piles. These bins form one of two par- 

 allel rows; the row nearer the furnaces is used for supplying 

 immediate demands, while the row facing the stock pile is 

 used for transferring the ore from the cars to the ore buckets, 

 wliich when filled are picked up by the crane and automatically 

 dumped on the stock piles. The reverse operation is accom- 

 plished by means of 5 ton drag buckets, which pick up the 

 ore from the face of the pile, delivering it either into the bins 

 or bin filling cars as may be desired. The cars so loaded are 

 then placed over the proper bins and there unloaded — the 

 bottoms dropped. A more recent plan is that adopted at 

 Neville Island, Mingo Junction, and Youngstown, where 

 a Hulett ore bridge was built by Webster, Camp & Lane, 

 of Akron, Ohio. The clear span is 260 feet, with a cantilever 

 extension of 41 feet commanding the ore bins. The method 

 of handling the ore with this system may be briefly outlined 

 as follows: The ore car, which may be either gondola or 



