_The sizes of nozzles named below_ will give the most satisfactory
results, those in italics being the ones best adapted for fire duty.
Also see page 93 for standard sizes of steam fire engines and page 117
for table of effective Fire Streams.
1, Extra first size engine.—1,100 to 1,150 gallons capacity. Through
short lines of hose: _One 1-1/2-inch smooth-bore nozzle, for one
stream_; one 1-3/4-inch ring nozzle, or one 2-inch ring: nozzle;
_1-5/16-inch ring nozzles for two streams_. With 1,000 feet of hose,
one 1-5/16-inch ring nozzle.
2, First size engine.—900 to 1,000 gallons capacity. Through short
lines of hose: _One 1-3/8-inch smooth-bore nozzle, for one stream_; one
1-1/2-inch ring nozzle, or one 1-5/8-inch ring nozzle; _1-1/4-inch ring
nozzles for two streams_. With 1,000 feet of hose, one 1-1/4-inch ring
nozzle.
3, Second size engine.—700 to 800 gallons capacity. Through short lines
of hose: _One 1-1/4-inch smooth-bore nozzle, for one stream_; one
1-3/8-inch ring nozzle, or one 1-1/2-inch ring nozzle; _1-1/8-inch ring
nozzles for two streams_. With 1,000 feet of hose, one 1-1/8-inch ring
nozzle.
4, Third size engine.—600 to 650 gallons capacity. Through, short lines
of hose: _One 1-1/8-inch smooth-bore nozzle, for one stream_; one
1-1/4-inch ring nozzle, or one 1-3/8-inch ring nozzle; _1-inch ring
nozzles for two streams_. With 1,000 feet of hose, one 1-inch ring
nozzle.
5, Fourth size engine.—500 to 550 gallons capacity. Through short lines
of hose: _One 1-1/16-inch smooth-bore nozzle, for one stream_; one
1-1/8-inch ring nozzle, or one 1-1/4-inch ring nozzle; _7/8-inch ring
nozzles for two streams_. With 1,000 feet of hose, one 1-inch ring
nozzle.
6, Fifth and sixth size engines.—300 to 450 gallons capacity. Through
short lines of hose: _One 1-inch smooth-bore nozzle, for one stream_;
one 1-inch ring nozzle, or one 1-1/8-inch ring nozzle, _7/8-inch ring
nozzles for two streams_. With 1,000 feet of hose, one 7/8-inch ring
nozzle.
_The Ahrens steam fire engine_ is not presented as a whole, but Figs.
426-428 show parts of this interesting and widely known apparatus.
[Illustration: FIG. 426.]
The boiler, Fig. 426, is radically different from others, and the
special features making it so popular in the past are the absence of
a crown sheet and smoke flues, coupled with the advantageous manner in
which the water-tube coil sections can be withdrawn from the containing
shell of the boiler. The peculiar arrangement of the tubes compels a
forced circulation of the water, and for which purpose an independent
steam pump is provided. Water drawn from the fire-box leg is forced
through the water tubes, and this relation between the circulating pump
and the other elements of the boiler will be more readily understood by
reference to the illustrations, where Fig. 426 is a sectional, 427 a
top, and 428 a bottom view.
[Illustration: FIG. 427.]
[Illustration: FIG. 428.]
[Illustration: FIG. 429.—See page 141.]