The record-union., 1898-04-10

ieved to have capacity of | coo cubic
yards per hour, requires a crew Of
from forty to forty-fve men when run
ming double shifts, and the monthly
running expenses are estimated at
little over $1,000 each. Should these
machines come up to expectations. it
can be calculated on the above basis
that the monthly output would be
about 800 600 cubic yards, and the cost
would be about i cent per cubic yard
There are two good hydraulic
dredgers in California, whose perform
ances are well known. They have from
250 to 30 horsepower each; either can
be duplicated at an estimated cost of
$50 .G30 They have been working at
Oakland harbor and elsewhere. Their
working expenses, running one shift
per day, are about 81, 300 each per
month. They have worked in depths of
twenty feet Of water, have pumped
material ashore through 5000 feet Of
pipe, and deposited the same at nights
varying from three TO fifteen feet above
water level. Their output. per hour
and cost of delivery in material of lif-
ferent character has been as follows:
soft, plastic mud-300 cubic Yards
per hour; cost, 6 cents per cubic yard
Mixed sandy clay and mud-100 cubic
yards per hour; cost, 10 cents per cubic
yard Soft hard pan-90 cubic yards
per hour; cost, 10 cents per cubic yard
Hard pan-40 cubic yards per hour
cost p cents per cubic yard
The Government dredge which has
for years been working in the rivers of
this State is a combination of an end
less chain bucket dredge, with d hy-
draulic apparatus for carrying mate
rial ashore Her original cost was $50, =
00G the average cost of all work done
by this machine has been S4 cents pr
cubic yard.
1T is known that the most modern
types of cIamshell and bucket dredgers
now in use in the rivers of this state
generally used for reclamation, levee-
building and channel rectification, cost
not to exceed $24 900. Their average
output exceeds 100 cubic yards per
hour; their monthly running expenses
are less than 81 900, from which we
deduce that the average cost for hand
ling material and placing it ashore
does not exceed ! cents per cubic yard.
In fact, contracts can be made O do
work of this character at from ) to c
cents per cubic yard.
"A dredging-ma owned by the
State would hardly be in use during
one-half the time in year; the cost
of maintenance is constant, repairs
frequent and expensive; deterioration,
whether in use or not, is rapid, and the
work which may be required in the riv
ers of this State is of such a varied
character that no one type of ma
chine can do it all economically Ma
chimes. suitable in character, can near
Iy always be obtained for hire, OF for
doing a certain piece of work by con-
tract, at a reasonable price over actual
cost.
I'VE do not know of any place on the
Sacramento or San Joaquin Rivers
where, with the improvements in con-
temptation by the State, it is advan-
tageous to either purchase or build a
hydraulic or any other type of dredg-
ing-machine.
For reasons above stated, and locke i
at simply as a business proposition,
with the amount of money apprOp1 i
ated by the State, and available 70" the
purposes mentioned in the Act, we do
not feel warranted in recommending
the purchase and maintenance of any
dredging plpant."
m. A NURSE, Chief Engineer.
CIV H. HEUER, Con. Engineer