Ellsworth American. [volume] (Ellsworth, Me.) 1855-current, 1924-05-07
NEW DAM SAFE.
state Engineer Reports Construction
Safe and ADEQUATE.

Safe and Adequate.
Last year, following the collapse of
the new Brimmers Bridge storage
dam of the Bar Harbor G. Union
River Power Co., and before the work
of reconstruction was begun, the city
| government made application to the
State for State inspection of the plans
and construction of the new dam.
This was followed by petition to the
same effect signed by ten taxpayers
| of Ellsworth.
William N. Black, State inspector
of dams and reservoirs, took up the
matter, and on May 2 submitted his
| report, the substance of which fol-
| lows
Mi. Black visited the dam several
times during the preparation for re
building, carefully inspected the llnal
plans, and watched the work OF con-
struction by frequent visits. HIS last
visit was on April %, when he found
the dam practically completed, the
work to be done in the way of grad.
inc having no material effect upon
The dam itself He says in his re-
port:
This dam consists OF long earth
portion with a core wall made of steel
sheet piling and concrete. The spill
way section is made of reinforced con-
crete carried to bed rock 1t is com
posed of log sluice and three gate
openings The flow through these Is
regulated by Taintor gates which may
be raised or lowered TO vary the guam
tity of water flowing from the reser-
yotr. The contention was made that
an earth dam should have in addition
to the gate section rollway or spill
way section where the water could now
from the reservoir when it mad
reached a certain height, regardless of
the operation of the gates | have
carefully considered all the contingent
cies which have been brought to my
attention and have made study OF the
possibility of mischance in the opera
ton of the gates.
l find that with all gates closed there
is a chance for the water to flow over
thc" TOP of them when the water sur
face rises above elevation 105. Actu-
ally. then. there is an emergency vent
which viii take care OF the flow OF
this stream at any time except during
flood conditions TO my mind a dam OF
this type if properly constructed
should fail only by overlapping, mat Is
TO say. because the water rises TO an
elevation above the top of the core wall
and flowing over washes away the
earth fill on the downstream side In
this case the water would have to rise
more than nine feet above the top OF
the gates before it would oVertop the
earth section. Under these conditions l
can hardly conceive of series OF ac-
cidents coming in conjunction with an
extreme flood which would fiji this dam
to overlooking before adequate vent
could be obtained through the gate
section.
/. therefore, feel that the general
plan of the structure as it is now re-
built is adequate to meet the situation
and purposes of this storage reservoir
Returning to the question of the
structural stability of the dam, l find
chat the gate section is rebuilt in such
a manner that securing of the earth fill
of either the upstream or the down
stream side is not likely to occur when
water IS ulSClldISt Gu tlA Ohs9Ai Ni'N 9''N-'
that the concrete portions are carried
to bed rock and properly bonded there
to; and that these sections are formed
and reinforced in a manner to provide
ADEQUATE strength to resist the pres
sure put upon them. My visits have
never disclosed any signs of inferior
workmanship, in fact, there has been
evidence that the construction en-
qeineers in charge of the reconstruction
have taken unusual care to produce
trustworthy structure, The earth por-
ton of the dam was built in 1922, be
fore | had any occasion to follow the
processes of construction, so that my
opinion as to the adequacy of this part
must be based on the Information dis
closed by the original plans and the
general appearance of the completed
structure. There is every indication
that the earth fill viii function proper
Iy and have a wide margin of safety.
/, consequently, must come to the
| conclusion that this dam as it is re-
| built is a safe and adequate structure.
1t is, therefore, ordered that said
Brimmer's Bridge dam may be used for
| the purpose of storing water without
| further alterations or additions there
| to-
-O--