56 THE POWER-FORGING OF CHAIN CABLES. 
been vastly improved. Standard thermocouples have been manufactured and in- 
stalled; potentiometers purchased, to use instead of galvanometers; and the use of 
the equipment studied, with the result that in the large, car-bottom, over-fired, chain- 
annealing furnace, where finished chain is treated, nine thermocouples are installed, 
and it is found practicable to keep the temperature variation, between different parts 
of the furnace chambers, within 10° C. 
NOW ON MANUFACTURING BASIS. 
During the fiscal year ending June 30, 1916, there were manufactured at the 
Boston Navy Yard practically 9 miles of chain, of diameters 21% inches to 33% inches, 
inclusive. No better confirmation of the statement that the problem has been solved 
can be asked for. The cost of 3%4-inch chain, for example, has been practically 
$6.00 per foot, or $0.06 per pound. Even this cost is considered high, because the 
process is not yet wholly beyond the experimental stage; that is to say, that a very 
great improvement will be made, probably in the near future, in the methods of 
bending the link, in trimming the link after welding, and in other directions, so that 
the cost will shortly recede to a considerable extent. Even if the cost were greater 
for properly made and welded chain, it would be offset by the gain in amount and 
regularity of production, and in quality. Taking the case of 3%4-inch chain, for ex- 
ample; when the 34-inch iron for the Pennsylvania cables was first delivered to the 
Boston Yard—those being the first 34-inch cables made—two chainmakers’ gangs 
were assigned the job of making a test triplet each. Each gang took a whole day 
to make its triplet, and laid off the next day, claiming that they had worked so hard 
that they were incapacitated and required a day’s rest. It was stated that a produc- 
tion of three links in two days for one gang would be about the best that could be ex- 
pected of hand-welders. At that rate it would take a single gang seven years to 
make the cables for a battleship of the Pennsylvania class. The present produc- 
tion is at the rate of twenty links per welding gang per day, every day. Were the 
hand-welding process still in vogue at the Charlestown Navy Yard, a shop of ap- 
proximately four times the area at present engaged in chainmaking would be re- 
quired in order to equal the rate of production now obtained. This estimate is in 
proportion to the difference in production, which takes into account the difference 
in space requirements for the hand-welders and for the power-welders. Figs. 8 and 9, 
Plates 38 and 39, give two views of a test triplet of 34-inch stud chain. The re- 
quired ultimate strength is 612,000 pounds, which is uniformly exceeded. 
When the 3-inch open-link chain for the Panama Canal was being manufac- 
tured, the cost per link, direct labor, ran about $1.37 by hand, and about $1.20 by 
power. The job was wound up so quickly that there was not time to bring about 
cost reductions, but on 3-inch stud-link chain made for the Commission, the figure 
of $0.86 was attained. This was subsequently still further reduced. 
A brief description of the process follows, illustrated by photographs of the ma- 
chines and their operations. 
