New-York tribune., 1900-09-09
coming resistance equal to about forty feet

coming a resistance equal to about forty feet
head
Forward of this pump is a large compound
condensing pump of the StiIlweI-Bierce duplex
type, of which the steam cylinders are Is inches
and 80 inches in diameter. and the water cylin-
ders "a inches in diameter with stroke of 24
inches, which aCtuateS the hydraulic Jets on
the suction drag and in the discharge valves OF
the hoppers A hydraulic duplex pump, Capa-
BILE Of pumping against one thousand pounds
pressure, is used Tor operating the hydraulic
cylinders TO the discharge valves and also the
hoist for the suction pipe.
Aft of the hOppers is the boiler room. The
boilers are constructed for a working pressure
OF $50 pounds. and are fitted with the Ellis &
Eaves induced draught A small donkey boiler
is placed between the main boilers. Aft of the
boilers are the two prOpelling engines, driving
twin screws. The engines are OF the inverted
cylinder, direct acting, triple expansion type
The high and intermediate cylinders are pro-
vided with piston valves and the low pressure
cylinders with slide valves. The engines are
built with cast iron columns tront ana PACK
and the condenser Is independent with vacuum
and circulating pump. An electric lighting plant
and evaporator and disttller are also supplied
HOW THE MACHINERY WORKS.
After lowering the suction tube into the water
and exhausting the air from the centrifugal
pump and connections by the air ejector. the
pump is charged and ready to start After start
ing the pump is run until the hoppers are flIed
with water and overfiOwing the expansion tanks.
during which time the suction pipe is lowered
until it is about ten feet below the bottom. the
materials being taken by the suction as fast as
ii Is lowered into the sand After the suction
is, lowered sufficiently deep into The material.
the boat is moved forward at the rate of - or
80 feet minute thereby giving the suction al
the material that it raise and deliver into
the hoppers. When the hoppers are filled with
material the suction pipe is raised and the
pump stopped. and the dredge goes to sea-
When near the dumping grounds the Iarge
to the Jets In the discharge valves. thereby
tightening uD the sand IN the hoPpers and free
ing the valves from the packed sand, that
they be raised more easily When ready 10
dump. the pressure from the hydraulic pump
is turned TO the hydraulic cylinders. one OF
which is over the centre OF each hopper. These
cylinders are connected by side rods TO the
long,, extending through the sand 70 a seat at
the bottom OF the inclined hopper outlets, there
by raising the valves about three feet. allowing
the sand 10 be discharged. through the DISCHARGE
ports. into the sea
While the valves are being raised the lets
referred 20 acting upon the sand with a
pressure OF about sixty pounds a square inch,
greatly facilitating the discharge Of the ma
tertals. AS soon the valves are opened the
suction pipe is lowered into the water and the
centrifugal pump is started. the volume Of clear
water is pumped through the distributing pipes
and through outlets into the flushing pipes
which are at the top Of the Inclined bottoms OF
with perforatiOns. thereby greatly increasing
the discharge OF material and washing the
hoppers clean before closing the valves The
trunk valves and the expansion tanks are in
accordance With the patents OF Anthony G.
Lyster. chief engineer Of the Liverpool docks.