_The Worthington wrecking pump_, Fig. 448, was constructed many
years ago, for wrecking, drainage, or irrigating purposes, and has
proved itself to be remarkably well adapted to such service. It is
used generally by the Wrecking Companies on the Atlantic and Pacific
coasts and the lakes, and is constructed with special reference to
reliability, portability and general efficiency.
It is also well adapted for other services requiring the delivery of
large quantities of water within the range of lift by suction. It
has no forcing power, the water being delivered over the top of the
pump into the curb surrounding it. It is single-acting, although the
discharge is practically constant, by reason of the quick return of
the piston to the bottom of the cylinder, during which inactive stroke
the water continues to flow by the momentum already acquired, thus the
effect of a double-acting pump is almost produced.
[Illustration: FIG. 448.]
The ordinary slide valve is employed, moved by an arm striking against
tappets on the valve rod. No auxiliary valves are used in connection
with it. The water valves are of rubber, the lower ones being upon a
permanent plate at the bottom of the pump. The plunger also is covered
with valves. These last open for the passage of water when the piston
descends.
On account of its short stroke and large diameter, this pump is
extremely efficient, running on comparatively low pressure of steam,
and with a very small percentage of loss from friction or leakage. It
is also simple and durable, with few parts.
The stated capacities of the pumps given in the table can be exceeded
in cases of emergency.