Evening star., 1911-08-19
UNIQUE SYSTEM IN
SEWER CONSTRUCTION
Contractors in Brooklyn Cope
Successfully With Several
Problems in Laying Pipe.
From the Municipal Journal.

A piece of sewer construction Is near
ing completion in Brooklyn, n. y, which
is remarkable. both for the fact that 1t
is believed to be the largest vitrified pipe
sewer ever built, and also that it is being
laid with comparative ease In fine sand
ten feet to fifteen feet below tidewater
level. This sewer, which is about 1900
feet long. serves the outlet line for a
system draining a considerable area Of a
new part Of the city. which IS rapidly ex-
tending out over the meadows adjacent
to Jamaica bay. 1t ends at a sewage dis
posal plant which has been In service
for about eighteen years. and is enor-
mously overtaxed and must speedily be
replaced with some larger and probably
different kind of plant
The sewer is being laid through salt
meadows. q considerable part of which
is overfowed by the highest tides. and at
few, If any, points IS the land more
than three feet higher than this. The
depth of the trench ranges from twelve
to sixteen feet, or about ten to thirteen
feet below high tide. The material ex-
cavated has been sand, in some places
very fine running sand. in others II coarse
sand mixed with a small amount OF fine
gravel. On top Of this, in the lower
levels is a mass of sod. roots and muck
extending to a depth of three TO five feet,
while on the higher ground the sand is
covered with coarse grass deeply rooted.
The line lies entirely through unused
meadow land, along the line of what will
some day be street.
Pipe Bedded In Concrete.
The sewer is made Of forty-two-inch
vitrified clay pipe three inches thick.
bedded in concrete UP to the horizontal
diameter. this concrete having vertical
outer sides and resting upon plank plat
form. and being seven inches thick under
the invert and fourteen inches wider than
the outside diameter Of the pipe barrel
For the purpose Of connecting future
buildings there are inserted at intervals
of twenty feet upright "standpipeS" OF
six inch vitrifed pipe which rest on the
forty-two-inch pipe in sockets formed
around openings in the top OF the pipe
constructed for this purpose. At each
such standpipe the concrete is carried up
in a transverse wall sixteen inches wide
and the full width of the cradle concrete,
surrounding the standpipe and carried up
to the level of the bell of the first length
of pipe: thus supporting the pipe and
preventing the weight from crushing the
sewer The remainder of the standpipe
| is surrounded by square envelope or
| chimney of concrete which supports it
| against dislocation by the back till These
| standpipes are temporarily plugged at
| the top, and will be provided with a Y
/ pipe for receiving a connection from each
| side of the street.
The forty-tWo-inch pipe is 1ointed with
| oakum dipped in cement grout and caked
/ solidly into the bell with wooden pad
| dies, following which the bell space is
| filed with cement mortar applied by hand
and well packed into place and beyeled
on the outer face. After the outer joints
have been completed the points are point
ed up from inside of the pipe with similar
mortar. completely filing all annular
| spaces between pipes.
Tight Joints Essential.
| After the excavation has been com
| pleted foundation platform composed Of
| two layers of two-inch plank is put into
| place and the pipes lowered onto this and
/ blocked up seven inches from the plat
| form by block OF wood and two wooden