The Jersey City news., 1906-06-05

Submitting report Of streets cleaned
from May p to May 27, 1906, both dates
inclusive.
Received and ordered fled.
From e. Kuiehling, Consulting Engi-
neer:-
New York, May 16, 1905.
To the Honorable the Board Of Street
and Water Commissioners of Jersey
Gentlemen-In accordance with your
request to submit to you In writing my
reasons for preferring a rivited steel pipe
to a reinforced concrete conduit for the
contemplated storm-water relief sewer
for the Newark avenue Hoboken avenug
and New York avenue sewer districts,
beg to leave to present the following
considerations.
1. The total area of the three districts
mentioned is about GA acres; but az
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 61O acreas. Most
of the sewers have such grades and
sizes as will produce average velocities Of
approximately feet per second when
flowing full and the districts are shaped
so as to bring the surface drainage from
the most distant points to the mouths Of
the outlet sewers in less than 30 minutes.
2 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 overhowe OF
| increasing magnitude will 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 fiat
part of the city, cannot be tolerated
much longer, and that relief must sooD
| be provided in the manner proposed by
Mr.. Van Keuren.
3. This relief consists in collecting IN
suitable auxiliary steel pipes the surplus
storm drainage from the said three dis
tricts at the ends of the outlet sewers
near the top of the bluff, and combining
the flow into single steel pipe 6.5 #. in
diameter to be laid through Twelfth
I 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 1t
least 40 fit. IN the s feet pipe at Mon
mouth street; also that this head may be
maintained for half an hour. and that It
will gradually reduce in going down
Twelfth street from Monmouth street to
the river.
4. If the said feet steel pipe were to
be replaced by a covered masonary con-
duit not adapted to resist a relatively
large internal liquid pressure, and laid on
the very fat grade that is here available
| for a 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
bluH' COMMUNICATING with the river at its
ends and adapted to daily flushing
by tidal action. Such procedure, how
ever, appears to be impracticable on ac-
| count of the expense involved; and hence
recourse must be had to conduits which
| can be subjected to pressure.
3. 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, by contraction due to reductions
| of temperature and by becoming dry
| To 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 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 a serious de-
feet or crack, much damage may be donss
to the street pavement and also to the
| foundations of adjacent buildings; and
| fourthly, repairs to such a 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 constructions
; which has been planned by Chief Engi-
neer Van Keuren.
Respectfully submitted,
e. KUICHLING.