The quantity of water to be
carried was about 32 cubic feet a second (1,250 miner's inches), which
could be diverted from Texas Creek at a point 480 feet vertical above the
Bloomfield flume. An aqueduct about 4,000 feet long, partly of ditch and
partly of flume, was needed to bring the water from the catchment dam on
the creek to the brow of the gorge. The vertical head for the pipe could
therefore be from a maximum of 460 feet down to any lesser head; with a
head of 460 feet, the pipe would be 4,790 feet long; and with a head of
220 feet, the length would be 4,290 feet. Assuming a maximum tensile
strain upon the iron of 16,500 pounds per square inch, with the formula
for the greatest head of about
d = (.359 l/h)^{1/5}, [or, v = 68 (dh/l)^{1/2}, and Q = 32],
and a lower value of the coefficient in the last equation for the lesser
heads, it was found, by calculation, that the least cost could be obtained
with a head from 300 to 350 feet. The head fixed upon was 303.6 feet, with
a length of 4,438.7 feet. A profile of the pipe, with nearly the same
horizontal and vertical scales (horizontal scale, showing slope lengths),
is given in Fig. 14; details are given in Figs. 15 and 16. The pipe was of
double riveted sheet iron, made in lengths of about 20 feet, and of the
following thicknesses:
1,349 linear feet, 0.
Pages:
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116