The morning call., 1893-04-13
HOW To CLEAR OUR RIVERS.

What Liverpool is doing to remove the
bar at the mouth of the Mersey California
may do to remove the bars at several points
on her rivers. Liverpool has succeeded in
this work, and is going to persevere until
the bar is wholly dredged and pumped
away, leaving an unobstructed channel at all
states OF the tide for the largest vessels afoat.
The work was begun two years ago, and
probably within three years more there will
be no bar left, so rapid is the new process.
The same methods applied to our rivers
with apparatus having not one-fourth of
the power would in all likelihood clear
them of every form of obstruction In sand
and gravel de.ritus and in mud. Only solid
rock stands in tho way of being scooped up
and removed. but there is very little of that
in the California valleys. The gain to this
State which would be represented by OPEN
ing up the San Joaquin and Sacramento
and their main tributaries to unlmpeded
navigation cannot be measured within
many millions.
The fortunes of Liverpool have turned
upon an entirely new type of dredger by
which sand is sucked up a tube by con-
tinuous pump action and emptied into hop
pers. New York suggested the principle,
dredgers Of this form having recently been
tried on the bar there. The MeTsey Harbor
Board put q couple of small dredgers at
work two years ago. They had only pump
ing capacity of from 400 to 500 tons Of sand
per hour, but persistent operations have re-
dneed the bar by e number of feet, and it is
found that the reduction is permanent. The
tides and river current acquire increased
securing force, and fresh precpitations of
sediment and silt have n0s thus far been
observed. From having little dredgers AT
work the board is now in possession of the
largest sand-pump dredger in the world.
Strictly speaking it is ship as well as a
dredger, for itcan carry cargo of 5000 tons,
but its great merit in the engineering sense
is its ability to hoist up from the bottom in
an unceasiHg stream 1000 tons of sand aud
mud per hour, or the gigantic total of
$4,000 tons in twenty-four hoursi Such
dredger would in fact keep pace with the
hydraulic tailiDgs in California, ana of a
certainty 1t would soon clear a waterway of
fair depth over all the sandhars on the Sac
ramentO and deepen accessibly the mud
channel of the San Joaquin.
The new dredger has been built at Bar
row, in the north of England. 1t is 800
feet long, 46 feet 10 inches broad, 20 feet 6
deep, has a gross register tonnage of $3.50
and is built of steel Amidships are eight
large hoppers which will hold 5000 tons of
sand. In the center a pump-suctiOn tube
feet inches in diameter is let down through
the bottom, and may be lowered by hydrau-
lie engines for action at forty-fve feet
depth. Two centrifugal pumps with sue
tion and discharge pipes feet in diameter
are driven by powerful triple-expansion
engines working under boiler pressure of
l60 pounds, and are adapted TO raise 1000
tons OF sand per hour There are rudders
fore and aft. and propulsion is obtained
from twin screws operated by triple-expan-
sion engines. The BTancker fills her hop
pers In three-Quarters of an hour She is
fitted with LISTERS patent hydraulic dis.
charging apparatus.
III need were n suction-pump dredger
would soon cut a channel q good mile wide
through the bar outside OF San Francisco
Bay. It is not positively necessary yet
even for a vessel drawing nearly thirty
feet; but If that WORK is 10 be undertaken
tile Government al Washington is to assume
the expense and esponsibillty. In San
Francisco Bay itself the Harbor Commits
sioners would get ahead much more rapidly
With such an bstructiOn-remover than they
do with diving-scoop clasp, which only
lifts about p couple of tons at a time very
slowly. There are many sb0al places in
tile bay which could easily be deepened. A
few such dEedgers on a smaller scale put
simultaneously at work on the rivers of CAL
fornIa would solve the problem which our
delegation to the Trans Mississippi Con-
gress seek to have wrought out. We shall
all be delighted II the Federal Government
can be induced to spend million a year ON
our water highways for ten years; but
failing action and the needed appropria-
tions, which would be unrelentingly on
posed by the Southern Pacific, are we to let
matters drift as they are doing? The Traffic
Association has resolved to put It's shoulder
to the work of freeing our rivers for COM
merce, and the whole State is deeply inter-
ested In the matter. 1t is an enterprise in
the service of the whole community and not
in favor of any particular section, and it
should be pushed forward with energy and
earnestness and an unfagging determine
ton to succeed. The Federal power may
lend hand. but we should not stand mac
tive if action Is paraly zed at Washington.