Fig. 3034.
“Second Method.—This method builds the middle first, and is called “turning the shaft end for end.” The shaft is begun from a stave, by the addition of slabs, as shown in [Figs. 3034] and [3035]; [Fig. 3034] shows it with iron added in slabs, till a butt is formed, as at b, to form the nucleus of the crank; slabs s s s are then piled on it to bring the crank up to the height.
Fig. 3035.
Fig. 3036.
“These are beaten down and welded, and more are added, as at s s s, [Fig. 3035], till the full height of the crank is reached. Should the web (or edgeway of the crank) be thick, two slabs are frequently used to make up the breadth, placed edge to edge, as shown in [Fig. 3035] on the right hand of the figure; the widths of these slabs are limited by that at which the shinglers can conveniently work and turn them under the steam hammer. The crank, however, is completed without any “side slabs,” for the beating down of the slabs on the edge will broaden out the mass, and give sufficient material to forge out the crank to the proper height by hammering on the flat. The crank is afterwards cut at the off gable at g, [Fig. 3036], the body b pieced out and rounded, the collar welded on, and then a small stave s is drawn upon the end, to enable the forgeman to handle the piece when he “turns it end for end” to complete the other end of the shaft.