Ellsworth American. [volume] (Ellsworth, Me.) 1855-current, 1911-10-18
THE AUSTIN FLOOD.


Looks as II the Expected Happened
when Dam Broke.
The recent breaking OF the concrete dam
at Austin, Pa, which resulted in the wip-
ing out OF the town, one apd one half
miles below the dam, with the loss Of
about 100 lives, naturally created consider
able speculation in Ellsworth as to what
would happen II the big concrete dam of
Bar Harbor & Union River Power Co.
should break. The Aastin dam was built
two years later than the Ellsworth dam.
Comparisons between the Austin and
Ellsworth dams are not fair to the latter,
the foundation OF which is in solid bed
rock, with both ends of the dam, to the
very crest, anchored in solid ledge. The
Ellsworth dam site mas been pronounced
| by engineers as ideal. In the Austin dam,
the weakness OF the foundation was
known by engineers, and was at once
manifest when the water was turned on
the dam. The breaking of the dam was
simply the happening Of the expected.
The following from en- article in the
Engineering Netcs should be reassu.ing to
any Ellsworth people who imagine like
catastrophe here.
The cause Of the Austin disaster will be
clear to every engineer from the account of q
previous partial failure Of this structure on
Jan. Is, 1910, which was published In our issue
OF March II, 1910.
In February. 1910, local newspaper accounts
| reached us describing in language more SEN
sational than technical the dynamiting Of .
portion Of q concrete dam to save IL from de-
struction by food.
This impressed us - . most unusual method
| Of treating dam, particularly one just COM
pleted, and we were especially curious to
learn what sort Of damn 1t was which could
be so imperiled by . food. We therefore re-
quested information from the designer Of the
dam, T. Chaikley Hatton, Of Wilmington,
Del, and received from him . statement, with
drawings and photographs, from. which the
article referred to was prepared and pub
lished.
As related in that article, the dam was
founded on strata Of soft sandstone inter-
spersed with layers Of clay and shale. and
was carried down into the bed rock only
about four feet. The dam itself was built
very rapidly, part of it in freezing weather,
but judging from the photographs of the
broken dam, the concrete on the whole gave
very good account of itself, much better than
rubble masonry dams have under similar
circumstances.
We have heard intimations that Mr.. Hatton.
the engineer who designed the dam, desired
in the original construction to carry cnt-off
wall deep down through the soft rock strata
so as to cut of possible percolation under the
dam. but that he was overruled on account of
the expense which would be involved. That
he did fear percolation underneath the struc-
ture from the start is shown by the fact that
he built an earth embankment against the
upper face of the dam with as good material
as was available in the vicinity, hoping by
this means to prevent water percolating down
to the porous strata beneath the dam.
This means, however, proved futile. As
stated by Mr.. Hatton himself, as soon as the
pond behind the dam filed, "water in large
quantities began coming up through the
ground from fifteen to Fifty feet downstream
from the toe Of the DAM
Within twenty-four hours after this flow
under the dam appeared, the structure
showed several great cracks and had moved
downstream. the maximum movement being
about eighteen inches at the base and eleven
inches more at the top. ~ ~ - ,ssss. ss.zT
The people Of Austin were greatly alarmed,
and in the light OF subsequent events they
had reason to be. Apparently. the owners
Of the dam shared in this alarm. At least,
they yielded enough to have . part of the
dam dynamited near the top SO as to somewhat
lower the water back Of the dam and reduce
the pressure, and also to blow OF the cap OF
the draw-off pipe and empty the pond behind
the dam entirely.
Shortly afterward they concluded (on what
engineering advice. il any, we know noD that
the dam was still strong enough TO hold water
safely. The draw-on pipe was closed and the
reservoir was filed again. Within . month
Of the original failure they had raised the
water within two feet Of the overflow. This
produced leakage under the dam Of about
600 gallons per minute, yet no one seems to
have considered that Of any importance as q
danger warning.
That the owners had some ideas that they
ought to do something to make their structure
more respectable is shown by the fact that
they did ask the advice of Mr.. Hatton, the
original designer, as to what repairs should
be made.
The plan Of strengthening proposed by Mr..
Hatton was to sink trench and build q cut
off wall above the dam to stop the water per-
colating beneath it and to reinforce the down
stream face to prevent further movement. 1t
was proposed to reinforce the dam by dump
ing q heavy rock fill on the downstream face
as a means Of satisfying the desire of the
owners to keep the cost OF repairs low.
1t is . year and nine months since Mr..
Hatton's recommendations for Strengthening
the structure were submitted. but the re-
commentators were never carried out.
When Lost in the Woods.
Let the man who 10 lost in the woods be