Vermont phÅ“nix. [volume] (Brattleboro, Vt.) 1834-1955, 1907-12-20
AT THE DAM SITE
Things Are Doing Down There
These December Days
the High Water SubsIded-How the
Foundation Of the Dam VIII Be Laid.

Rapid Progress Has Been Made since
the High Water subslded-How the
Foundation Of the Dam viii Be Laid
Things are happening at the dam site
these days and the visitor who goes there
two weeks from now will hardly know
the place from the changes which have
been wrought by the 1926 workmen and
| the powerful machinery. If everything
goes on as well as it has in the past few
days the actual work on the dam can be-
gin in a few weeks The cofferdam is
now completed, all the cribbing being
| planked and weighted. In a few days the
big pumps will be started for a trial to
see whether there are any bad leaks in
the cOfferdam. The panking is tight, as
| it is tongued and groOved together but
| there may be crevices beneath where
the water will rush through when the water
! in the interior is pumped out. II sucn
! leaks develop they will be stopped by
! filling the outside. Bags of sand win
! be placed on the outside Of the planking
| where the pressure of the water will
| force them into the crevices. Gravel
| dumped on these bags after they are in
! place will complete the stoppage of the
! leaks.
The pumps which will be used to empty
| the enclosure of water are one 12-inch and
| two 6-inch centrifugal pumps and a g.
]
effective. but it will throw out at
least 1000 gallons of water a minute.
| The other three will do more
than this, but just how much more will
depend on the conditions which develop.
| Two of the pumps will be set up on the
lower and two on the upper section Of
the cofferdam and all will throw their
! big streams of water over the cofferdam
f. into the river. If no large leaks make
! themselves evident on the first trial the
pumps will be kept at work night and day
| until the enclosure is emptied. II large
leaks beneath the planRing snow they
will be stopped up before any attempt is
| made to pump out all the water inside
the cofferdam. After the pumps are once
. at work 1t is expected that they will
| empty the enclosure in four or five days.
The water inside the cofferdam varies
| from two feet deep, where the sand and
gravel washed on at the time Of high
water, to 20 feet deep. Even If no large
| leaks develop one or more of the pumps
will have to be kept going constantly to
pump out the water from the small
| leaks and what comes up through the
river bottom inside the enclosure.
After the water is pumped out work
will be pushed rapidly in preparation for
the beginning of the actual concrete
work of the main dam. The ledge on the
river bed will be cleared of all debris,
sand and gravel, and the drill gang will
be put at WOrK eXCaVatlnR the uencn or
channel for the concrete foundation. This
trench has already been finished for the
section of the spillway over what is now
dry land on the New Hampshire shore.
On this section the trench is IL feet
wide and four feet deep. The concrete
foundation will be started in this trench
and with the tremendous weight above IL
will become as solid as the rock bed it.
self and continuous with 1t. In the river
bed, inside the cofferdam, the dam will
be much wider and the trench will vary
in width according to the depth of water,
the height of the dam at any place gov
erning the width of the base In it's
widest part, where II will rest on a 40
foot base, the trench win not be exca-
waited the entire width but two trenches
along each edge of the foundation will
be blasted out of the solid rock. This
will give the concrete a sufficient hold on
the ledge to resist any pressure that the
Connecticut can bring to bear on it.
When the trenches have been exca-
waited the concrete work will begin and
operations will be carried on day and
night until this section of the dam is
completed up to the high water line. An
electric light system has been installed
and powerful arc lights have been placed
at intervals all over the scene of ac-
tivity. Last night the drilling gang work.
ed all night and when occasion demands
. night forces will be put on temporarily
at any time now. Wherever any part of
, the work gets behind or is hindering other
, parts of the work, night and day gangs
, will be put on until it is abreast or anead
of the other work again. 1t is not prac-
, ticable to work night and day on all
, kinds of work, but the concrete can be
, laid well by night as by day. The
, only thing that may hinder the concrete
: laying is the inability of the carpenters to
build timber forms fast enough. 1t is
, the common experience in such construc-
! ton work that all the carpenters that can
, be obtained cannot build enough forms in
/ | a day to keep ahead of the concrete
, workers if both day and night shifts are
, | employed. big effort is to be made here
, to avoid any hindrance from this cause.
. In preparation for the beginning OF the
, | concrete work 5000 cubic yards of broken
. stone are lying by the big crusher ready
to he ground into fragments for the con-
, | crete mixer. The crusher will handle
from 200 to 300 tons of rock a day, but
it is feared that it may delay work ever
at that seemingly enormous output. Every
y cubic yard of concrete which is laid will
: take more than a ton of crushed rocI
besides the sand and cement. The crush
er will have to be worked to its limi
after the concrete is started
s In preparation for the winter and th'
4 big operations to come a large supply o.
d coal is being put in. From 300 to 40i
" tons have already been delivered anC
e there are about 1900 tons more on thu
road. Supplies of all kinds are beinl
stored up as fast as possible At pres
ent about 1925 men are employed, whicl
Z. is about As many as can be worked 4
h advantage. A large number of tramp
n are drifting to the dam site in searcl
A. of employment and more particularly
good food and lodging through the col
months, but the greater part Of tnen
have to be turned away.
The cost of municipal government 1