The Jersey City news., 1906-06-06

From Inspector of Street Cleaning
Submitting report of streets cleaned
from May q to May 27, 1906, both dates
Received and ordered filed.
From E. Kuichling, Consulting Engi-
neer:-
= New York, May 16, 1905.
To the Honorable the Board of Street
and Water Commissioners of Jersey
CITY, N. IL
Gentlemen-In accordance with your
request to submit to you in writing my
reasons for preferring a rivited steel pipe
to reinforced concrete conduit for the
contemplated storm-water relief sewer
TOT the Newark avenue, Hoboken avenue
and New York avenue sewer districts. /
beg to leave to present the following
considerations
l. The total area of the three districts
mentioned is about GA acres; but as
this includes the land occupied by the
water distributing reservoirs, and also
some adjacent to the high bluff which
cannot be drained into the local sewers,
the actual area from which the rainfall
Is now collected by the outlet sewers of
SAID districts is about $40 acreas Most
OF the sewers have such grades and
sizes as will produce average velocities of
approximately feet per second when
hOHAAS LUZ anu lue U1SIr1cIS are SQdDeQ
50 as to bring the surface drainage from
the most distant points to the mouths of
the outlet sewers in less than 80 minutes.
z. A study of the rainfall records Of
Newark and New York combined with
numerous observations made by Chief
Engineer Van Keuren of the discharge Of
the said outlet sewers during heavy
showers, and the prospective greater
density OF population of the territory,
Lead to the conclusion that overhows Of
increasing magnitude viii take place In
the future, and that the present method
OF allowing such water to spread over the
low lands at the foot of the high bluffs,
or to engorge the sewers in the fat
part OF the city, cannot be tolerated
much longer, and that relief must soon
De provided in the manner proposed By
Mr.. Van Keuren.
8. This relief consists in collecting IN
suitable auxiliary steel pipes the surplus
storm drainage from the said three dis
trlctS at the ends of the outlet sewers
| near the top of the bluff, and combining
the How into single steel pipe 6.5 IT. in
diameter to be laid through Twelfth
| street from Division street to Monmouth
street. and thence to the Hudson river
by steel pipe 80 ft. in diameter. The
computations show that in the future the
quantity of water thus collected from
showers of extraordinary intensity may
become such as to produce a head of at
least 40 fit. in the s feet pipe at Mon
mouth street; also that this head may be
mairtained for half an hour. and that it
VIII gradually reduce in going down
Twelfth street from Monmouth Street to
the river.
f. If the said 8 feet steel pipe were to
be replaced by a covered Missionary con-
dult not adapted to resist a relatively
large internal liquid pressure, and laid on
me very fiat grade that is here available
TOT distance of nearly one mile the size
would obviously have to be made very
much greater, and the resulting expense
would also be greater. The best solution
of the drainage problem would be suit
able canal or other open channel of ade-
quate size along the foot of the high
bluff, communicating with the river at its
ends and adapted to daily flushing
Dy tidal action. Such a procedure how.
ever, appears to be impracticable on ae-
count OF the expense involved; and hence
recourse must be had to conduits which
can be subjected to pressure.
D. Conduits made of concrete strongly
reinforced with steel rods have been
built to withstand considerable internal
pressure, but this type of construction iS
attended with several serious objections.
In the first place. it is admitted by all
authorities that concrete alone is not
adapted to resist the tensile stresses
which are induced by internal water
pressure, Dy contraction due to reduction
of temperature, and by becoming dry.
10 prevent rupture from these causes.
| steel rods of sufficient size must accord
ingly be embedded longitudinally and
transversely in all the sides of the con-
duit and the weight of the metal thus
used is probably more than one-half of
that which is required for a riveted pipe
OF equal size. Secondly, the cost of
depositing the concrete is largely in
creased by the presence of the network
of rods, and hence the resultant cost of
the conduit will not be materially less
than that of an equivalent steel pipe.
Thirdly. it is extremely difficult, if not
impossible, to insure absolute water
tightness of the material and freedom
from cracks due to reduction of tempera-
ture; and if the water escapes under con-
siderable pressure through serious de-
feet or crack, much damage may be Done
to the street pavement and also to the
foundations of adjacent buildings; and
tourthly. repairs to such conduit will
be very costly owing to the difficulty of
uniting new concrete or cement to old
material.
6. In view of these considerations, as
well as a variety of others which have
not been mentioned, believe that it will
be much preferable to use for the pur-
pose indicated the steel pipe construction
which has been planned by Chief Engi-
neer Van keuren.
n Ill