The sun., 1908-12-06

high pressure idea the Rsgiev OF ReUieigS
writer pays nnerited attention TO the big
project that u soon 10 be put through by
San Francisco. Having once suffered
20 terribly because its water system failed
II In emergency the Pacific Coast city
has bonded Itself TO the extent OF - 200 ,OCO
pressure 6re protection and an auxiliary
salt water system.
For FIRE purposes II has been decided
to install an independent. system with
mains aRgregating over ninety miles In
length. These are to be fed by two great
reservoirs, each Of 5000. 900 gallons Ca
pacity which are TO be constructed at
height Of 765 feet above the lower portions
Of the city.
Two complementary reservoirs are TO
be constructed ct lower elevations which
will supply the ordinary pressure on the
city's mains. but the highest reservoirs
will be able to keep, through force OF
gravity, q constant high pressure head
upon all the fire mains. This system
promises to be capable Of throwing from
single block within the area Of the high
pressure service.
The salt water emergency plants are
TO be built on rock near the shore OF the
bay 30 a. to be In as great measure as
possible earthquake proof, Each OF the
two stations projected will be fitted with
oil burning centrifugal pumps OF maxi
mum capacity OF 10000 gallons minute
under 800 pounds pressure, The salt
water stations will be independent Of each
other 20 that the failure Of one will not
impair the work of the other or the sys-
tenn as o whole.
The writer gives the main outlines OF
New York's high pressure system, citing
some facts not generally known To the
public. Mr. Wade says:
~In Manhattan the problem was natu-.
rally more extensive and complicated
than in Brooklynl. for here was region
Of congested risks for their extent and
character probably uneoualled anywhere
in the world. 1t was necessary TO in
crease greatly the fire protection and the
amount OF water, especially In certain
downtown districts, and accordingly 1t
was determined to install high pressure
bounded by Twenty-third street. Third
avenue and the Bowery. Chambers street
and North River, with two pumping sta
tions, one at Oliver and South streets
on the East River and the other at Ganse-
WORT and West streets on the North
River.
"In July Of the present year this system
was put into operation and involves some
sixty three miles Of extra heavy cast iron
mains through which can be forced more
water than all the fire engines in the
borough can pump. and what ie more, this
supply can be concentrated on any single
block. In other words. when the five
centrifugal pumps at each station are
working together the combined capacity
exceeds 80, ,0OO. 600 gallons minute. and
space has been left at each station Tor
installing three additional units.
an the Manhattan system great care
has been taken to remedy the previous
grave defects Of the distribution systems
and hydrants The protected district.
which amounts to i,454 acres or about
Done-tenth the area OF Manhattan Island
is surrounded by tw enty -four inch mains.
while mains Of that or smaller size
down to tw welve inches in diameter COM
pletely gridiron the district.
sOn these 1,272 hydrants are so placed
that there is always one within 400 ieet
Of any single building and in sufficient
number 10 enable sixty streams OF water.
each amounting to 500 gallons. 70 be
brought to bear on any single olook
without employing hose OF any greater
length than 400 10 500 feet in any case.
sThus, for the block bounded by
Twenty-third street, Fifth and Sixth
avenues and Twenty second street there
are available sixteen hydrants. from
which in one day, with the pumps work,
ing at full capacity, enough water could
be obtained to cover the block to depth
Of thirty-six feet-in other " ords. e.7oO,oOo
cubic feet, or 4s, 900 900 gallons