Omaha daily bee., 1908-12-27

AnlM uIasE nOAkitS ana connected At us
base with three lines Of three-ineh hose
leading to a hydrant 100 feet distant. II a
pressure Of 25 pounds to the square inch
were applied at the hydrsnt the three noz-
zlos on the roof OF the building. twelve or
fourteen stories above the street. would
deliver a total Of 2.O6S gallons of water a
minute at a pressure of sixty pounds. over
200 pounds pressure would be used up in
overcoming friction in the hose. %standpipe
and nozzles and in raising the column of
water $50 feet.
A change in any one of the conditions
in length. diameter or number Of hoses,
|standpipes and nozzles-would mean a ma
terial change in the resultant volume Of
water and amount Of pressure. The water
supply officials are now conducting a series
OF tests the results OF which will enable
them to prepare accurate tables Of losses
due to friction in standard sizes. types and
lengths of hose. The partially completed
tables show that an average OF fifteen
pounds pressure is lost in overcoming fric-
ton in every 100 feet of regulation two and
one-half-inch hose. The loss varies widely
at different distances. In the first 100 feet
it may be only four or five pounds; IN the
fifth hundred-foot length It may amount
to twenty or thirty pounds.
Stnuuntpes n FactOr.
The size OF the standpipe is also an Inn
%portant factor. Greater diameter gives
greater efficiency not only in the size of
the stream. but also in the amount Of pres
sure at the nozzle. In the case just cited
twenty-six pounds pressure was lost in
friction in a six-inch standpipe i50 feet
high. In a twelve-inch pipe the loss would
have been proportionately less and the flow
Of water proportionately greater.
S~tandpipes in a majority of downtown
skyscrapers are only six inches in diam
eter. The officials say that this pipe IS
too small to carry an adequate supply of
water to the top levels and that too much
energy is used up in overcoming ftic-
ton. They maintain that a standpipe
must be at least twelve inches in clam
eter in order to be effective.
Furthermore, the water supply officials
are not quite sure that office building
standpipes are strong enough to with
stand the maximum pressure that could
be brought to bear upon them. For these
reasons they have not established direct
connection between the city's mains and
big office buildings in the protected dis
trict. and for the same reasons they are
loath to Join even temporarily the two
systems by lengths of hose.
In a recent test the department oven
went so far as to obtain a signed agree
ment from the owner of a building in
which a standpipe demonstration was
made. in order to escape responsibility
for any accident that might occur be-
cause of possible defects in the stand
pipe. Fortunately, the pipe stood the
test without signs of weakness in any
detail.
Under Working Test.
With a twelve-inch standpipe and TN
der favorable conditions the high pres
sure service could raise water to the top
of the highest building in the city and
give sufficient pressure and sufficient
volume TO fight almost any fire success
fully. At a recent test on West street
twelve high pressure streams were shot
from the street level straight up in the
air far above the top of a twelve-story
building, from the roof of which spcuted
four additional streams from a standpipe
connection. over %, 1000 gallons of water
a minute was being spread over the land
scape by these fourteen lines, and yet the
pumping stations were delivering only 60
per cent of their total capacity.
t a second test, held in Union square,
twelve white plumes Of water sprang forth
from as many MOBILES clafnped to iron
tripods, curved upward and outward In a
long graceful arc and cascaded against
the ninth floor of a building q block away
This means that in the future there need
be no fear of a fire like that in the Parker
building, where streams of water trained
on the blazing structure failed to reach
beyond the seventh story.
The protected district includes 1,456 acres.
in which are laid fifty-six miles of heavy
cast iron mains varying in width from
twelve to twenty-four inches. Throughout
the area are scattered LIZA %hydrants. There
is at least one hydrant within 400 feet OF
any building in the district. Sixty streams
can be concentrated on any single block
without using a length Of hose greater
than 500 feet. In one day 40,O00,000 gallons
Of water could be poured into a single
block from these sixty nozzles.
This places the fire department in the
position of having more water than the
men can handle. Indeed. the present fear
is not that a fire will get beyond control.
but that the surplus water will do more
damage than the flames would have done
If unmolested. The firemen. though. are
every day becoming more familiar with
the workings of the new system and are
learning through experience Just what pres
-