pa1778data.pdf
pa1778data.pdf
pa1778data.pdf
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U.S. STEEL DUQUESNE WORKS<br />
HAER No. PA-115<br />
(Page 224)<br />
complex was laid out linearly on a north-south axis near the<br />
northwest corner of the upper works. The process began when<br />
wholly or partially solidified steel ingots were stripped from<br />
their moulds by an overhead stripper crane and subsequently<br />
charged into one of eleven regenerative soaking pit furnaces.<br />
The gas fired soaking pits or deep chamber furnaces were utilized<br />
in such a manner as to ensure that the entire ingot reached a<br />
uniform rolling temperature. A single pit furnace was made up of<br />
four holes capable of accommodating four ingots. After a period<br />
of one to six hours, depending on its metallurgical composition<br />
and its temperature upon charging into the furnace, the ingot was<br />
lifted by an E.O.T. crane from the pit and placed into a motor<br />
powered pot car which delivered it by rail to the 40" mill entry<br />
table.<br />
The 84 f long entry table, consisting of a number of 12"<br />
diameter solid transfer rollers powered by a 50 hp motor,<br />
delivered the ingot to the 40" roll stand. The rolls themselves<br />
were grooved into five shapes and were powered by a Mackintosh-<br />
Hemphill 44" x 70" x 66" twin tandem compound condensing steam<br />
engine. The ingot was passed back and forth through the rolls<br />
for as many as nineteen passes before it was reduced in cross-<br />
section to a size ranging from a 22" x 2" slab to a 4" x 6"<br />
bloom. The machinery governing the operation of the entry table<br />
and roll stand was controlled by men located in a pulpit above<br />
the roll stand.<br />
After the rolling was complete, the material passed to the<br />
number one shear table which lay immediately beyond the 40" mill<br />
delivery table. From the shear table the section was passed<br />
through a hydraulic shear. This shear was intended for cropping<br />
the ends of the material that may have split from being rolled,<br />
and to serve as a back-up shear in the event that the adjacent<br />
steam driven shear was not in operation. The steam driven shear,<br />
powered by a Mackintosh-Hemphill 18" x 20" vertical steam engine,<br />
cut the blooms or slabs into specified lengths.<br />
Following the shearing operation, the product was passed<br />
over the rear shear table onto the adjacent loading table. An<br />
adjustable and removable stop placed at the end of the loading<br />
table, stopped those pieces that were slated to be loaded in the<br />
shipping yard. A steam driven pusher subsequently moved the<br />
pieces for shipping across the loading table and down an incline<br />
onto rail cars. If blooms were slated to be rolled down into<br />
smaller billet shapes, the stop was raised and the blooms were<br />
passed directly onto the entry table of the 14" continuous billet<br />
mill. The motors which powered the rear shear table and the<br />
loading table were controlled by an operator located on an<br />
elevated platform with a clear view of all the machinery. This