The Seattle post-intelligencer. [volume] (Seattle, Wash. Terr. [Wash.]) 1888-1914, 1894-07-20
Making q grand total of

amcteTl ............... o.. q. l25
On the Bush street sewer near Irving avenue. 5
Making grand total of...................22 i
The inspector has since discovered that
over 100 of the is and 20-inch pipe are also
broken. In the Kenney street sewer
there IS group of pipe north of Barclay
street and about fifteen pipe about 10 feet
south of Barclay; in Park avenue some
fifteen to twenty pipe; and between
Park avenue and Prince William street
two groups of fifteen to twenty pipe each !;
in the Weller street sewer, which was
built about two years ago, there is group
OF about twenty pipe broken between
Twelfth and Fourteen streets.
The breaks are evidently quite recent,
for some of the small chips are still lying
in the sewers, so that there has been no
heavy storm to carry them away. In
every large group where more than four
or i've lengths are broken there appears
to be pipe at the center which is
almost completely shattered, with
cracks running in every direction,
pieces of every shape broken out, some of
which are still in position while Others
have fallen in to such an extent as to
block the way for a man to crawl
through. From this center the break
age shades off in each direction, grow
ing less in each length of pipe until it
ends. This is the character of the break
age as seen from the outside on the
Twelfth avenue sewer. between Hayes and
Hazel streets, which Is the only one that
has been opened so far in the investiga-
ton. Others are so blocked with broken
pipe that il is impossible for a man to
crawl through.
That the break is not duo to any defect
in the pipe is evident from the fact that
every length was put to the most severe
test before il was placed in the ground. 1t
was subjected to a crushing test of 6, 900 to
1909 pounds and in some cases has stood
test Of 10000 pounds without showing
sign of breakage. There are very few
spaces where the weight of the earth
above bearing down on it would equal
200 pounds, and In no place has il
been affected by street traffic, in
fact some OF the breakages have
occurred in enclosed ground, where
there is no traffic. Pieces of the broken
and unbroken pipe taken from the sewers
near the point of the breakages have been
tested to the same pressure and have
stood it equally we'll.
The first theory which naturally occurs
to the mind in such a case is that an ex-
plosion of sewer gas has occurred, but il is
eaoly disposed of from the tact that none
of the sewers have been used except
that on Weller street and the
sewers are all so thoroughly ventilated
that there is no possibility for the ac-
cumulation of gas. and a man would be
-. FL as. At fTse ~
No drainage has passed through the
sewers except surface water.
There are three theories by which the
breakage might be explained, two
bv natural causes and one by
the evil work of man. The first
is that of a vibratory movement oc-
casioned by the regularly succeeding
strokes of earth thrown from the shoyels
of the workmen into the trench during the
time OF back filling the pipes were broken
by percussion. This has been known TO
happen in peculiar conditions of the
ground, and was found in experiments
made by Sir Joseph Bazalgette near London
in 1886, but there ere no records of sub
seonsnt instances The matter has not
been investigated enough 10 determine
whether the conditions are identical.
However, breaksge by percussion would
be uniform in each pipe, aud thus this
theory seems To be ruled out.
Another theory is that toe breakage was
due 10 the unequal expansion of the pipe.
None OF the breakages occurred in grayely
soil. bat al are in Wet blue clay or vet
sandy sol. Such a soil would give the
outer surface . low temperature. v bile
the warm currents Of air passing over the
inner surface in warm weather would ex-
pand II so much more rapidly as to cause
fracture.
The third theory - most favored by
those who have made an examination OF
the pipe. and il is that the fractures were
brought about by dynamite or gi-
ant powder placed IN the sewers
for the malicious purpose IF destroy
ing them. IL appears 10 be the cause from
a superficial examination. All the
wrecked sewers are large enough
for = man 10 crawl through them
easily and they have constant cur
rent Of AIR towing IN and oat st
he manho!es. IL would Re \ simple
thing fsr a man TO place a charge Of
s,nIo.ives with q time fuse attached
in the sewers and make BIS ESCAPE
before the explosion occurred BAT ne
might do the mischief without even
this trouble. There Is always several
inches OF wafer lowing through the
savers and standing ia the man
holes from surface drainage, aud
charge Of dynamite Stih lighted
fnse could be placed on board and
set floating through the sever until
a aid is work OF destruction. IAis
,heorv "a supported By tas fact
that the breakage spreads from q
central point IN both directions.