pa1778data.pdf

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