58 THE POWER-FORGING OF CHAIN CABLES. 
a stationary mandrel of the size and shape of the inside of the bent link. The bolt 
is clamped into the press with one of the scarfed ends fitting one end of the man- 
drel snugly, as shown in Fig. 13, Plate 43. When the press comes forward, the 
small wheel shown in the figure as nearly touching the link simply wipes the bolt 
around the mandrel, leaving it in the position shown in Fig. 14, Plate 44. This 
small wheel is on an arbor which it attached to a toothed wheel revolving about the 
geometrical center of the mandrel. This toothed wheel is rotated by a sector which 
rotates about an arbor fixed to the sole piece of the mechanism, being pushed and 
pulled by a link secured to its end and to the head of the press. As soon as the chain 
link has been wiped around the mandrel, the scarfs are pried apart by a man with a 
crowbar. 
WELDING THE LINK. 
The description of the process of welding the link begins at the completion of 
a link in the chain. Immediately thereafter a helper brings a link from a pre- 
heating furnace—that is, a furnace in which the scarfed and bent link has been 
brought to a bright red heat—and threads it into the last link made, as indicated in 
Fig. 15, Plate 45. The chain being made is carried on a low jib crane with a trough 
running from the end of the jib to a point on the mast about 4 feet from the ground. 
This crane is very easy to slew, and handles the chain in a very satisfactory manner 
indeed. The matter of the development of a suitable crane was one of the knot- 
tiest problems, peculiarly enough, that had to be solved. - 
The new link having been threaded in, the crane is swung over to the large ham- 
mer. Here it should be said that each welding plant consists of two hammers, and 
the plant in the photograph, which was the first plant used at this yard, consists of 
a 3,000-pound double-frame steam-forging hammer, and a 350-pound single-frame 
steam-forging hammer, both hammers being operated, however, by compressed air. 
The 3,000-pound hammer is fitted with dies similar to drop-forging dies, in which 
there is an impression of the shape of the link. It should be noted that this is not 
the shape of the completed link; its shape has to be such that when the link is stretched 
to proof stress in the testing pit it will take the shape specified on the standard 
plan. 
It is to these dies that the threaded link is brought, and the link, which has been 
spread apart at the hydraulic press enough to permit of threading it, is closed 
down. The crane is then swung over until it plumbs the fire, and the link is lowered 
into the fire for the first welding heat. 
The oil forge used is of the ordinary type, except that it has an unusually large 
area of flame duct and combustion chamber, in order to reduce as much as possible 
the velocity of the gases, as it was found early in the development of the process 
that small areas with high velocities caused localized heating and serious wasting 
of stock. 
The mechanic watches the link and feels it occasionally with a pricker, and, 
when hot enough, the members of the gang go to their stations. One man is sta- 
