Vermont phÅ“nix. [volume] (Brattleboro, Vt.) 1834-1955, 1922-09-22
DEERFIELD RIVER
FLOWS In TUNNEL
Diverted from Centuries Old Bed
in Nottingham
Completion Of Dam Many Months Away
-Trainloads of Earth Dumped Into
River Crowd Water Into Tunnel,


ant stage in the progress of the con-
struction of the great earth dam at
Davis Bridge, near Nottingham, by the
New England Power Co., was the di-
verting of the historic. Decrfeld river
from its bed Sunday through a 1000
foot tunnel which has been cut into the
mountainside on the east side of the
river to carry the water around the site
of the dam.
1t was an all-day job, beginning at S
o'clock in the morning and continuing
until $40 in the afternoon while many
visitors in addition to officials and
workmen looked on with fascination.
The fascination increased in intensity
as the dumping of rocks and earth
from the west side gradually narrowed
the river channel and forced the water
into the tunnel, reaching its highest
intensity when, as only a tiny trickle
of water ran down the course of the
old river bed. j. j. Baker. the resident
engineer of the Power Construction Co..
threw an empty cement bag into the
gap and entirely closed it by placing a
rock thereon.
The river was closed by hydraulic
sluicing. Trainload alter trainload of
earth was dumped down the steep bank
on the west side. Two streams of
water under l25 pounds of pressure
were turned on the loose earth and the
material forced into the, river bed;
down the bank and gradually filled up
the bed of the river. About 200 feet
below the point where the sluicing took
place, where the river bed had been
partly closed, large rocks were rolled
down the bank to form small rock
dam between the fill and the east bank
The slit from the sluicing moved down
the river. until it collected at this rock
dam. The river became smaller and
smaller and more and more water went
through the tunnel. Finally the whole
river bed narrowed to few inches. As
gineer Baker threw in the cement bag
in the gap. piled a rock on top of it.,
and the gap was entirely closed
This completed one of the Outstand-
ing events of the construction to date.
Unless unforeseen circumstances occur
the Doerfcld river will never again flow
through this l.G00-foot section of its
old he'd.
The tunnel is lined with concrete
throughout leaving the inside diameter
% feet. In places the concrete is five
feet thick. About 10000 barrels of CO
mcnt were used to line the tunnel. 1t
is figured that greater volume of wa
ter will pass through the tunnel on ac-
count Of the concrete lining than would
20 through without the concrete lining
ns the friction which would be caused
bv the Jagged rocks is reduced to a min
imum. The danger of debris collecting
against the Jagged edges and forming
an obstruction also is eliminated
The entrance of the tunnel is shaped
like a photograph horn. and in places
the concrete at the entrance is IL feet
thick.
Work on the tunnel has been going
on since February. The desire for
sent through almost before the concrete
had hardened at the southern portal.
The last concrete was put in during
Saturday night. To- prevent this con
crete from being secured. four-foot
dam made of timbers was constructed
green concrete.
The next step is to completely fill in
the toe, or northern end, of the dam to
the present height of the fill on the west
side, which is about 80 feet above the
river level. This will be accomplished
by dumping earth from trains on both
sides of the river. No earth has been
dumped from the east side up to now.
The wish for speed in diverting the
river was to permit as little water as
of the dam. Work will start immedi-
atcly to remove all vegetation from
that central part. which is to be hy-
draulically, ,puddled. To, make sure
that good foundation will be obtained
notch will be cut back into the
a. good foundation for the vital part OF
the dam.
An immense V-shaped pond will ther
be started in the middle of the dam
and earth will be sluiced into it. Little
by little the level of this pond will ris'
until the pond finally is closed many
months from now at the crest of the
dam 200 feet above the present level
Steam shovels are at work on boil
sides of the river in the borrow pits
filling the trains which run back ant
terial into the dam. About 25O,OO(
cubic yards have been dumped already
but it will take 800. 900 cubic yards tt
complete the job. Thus far only pre-
liminary fill has been made. but now
after the proper foundation, has beer
huge enterprise will start in earnest.
When the dam is finished the uppe
part of the diversion tunnel will bt
blocked and then the work of connect
ing, the overflow shaft, or GLORY hole
with the lower part of the diversion
flow shaft. which runs down perpen
dicularly, will merge into the diversion
tunnel on the gradual curve. This
curve is constructed to reduce waite
friction to minimum. At the poin
where the upper part of the tunnel i
DiOcheu, lHere VIII DE installed Dl
valve which will permit the water goinl
through if desired. 1t can be under
stood readily how strong this valv
will have to be to hold back the enor
nous pressure of water under 200
foot head.
The contract for making 10000 foo
supply tunnel through the mountain t.
come out near Sherman (Vt.) has bee
let to Mason & Hanger of New Yorl
city and Louisville, Ky. This suppl,
tunnel will start about l25 feet abov
the present river level or about Is fee
below the crest of the dam. and will
ne IA feet in diameter The contract 70
building the power house at the othe
end Of this two-and-a- half mile tunne
will bc let soon, probably within tn
next week
The herd to he secured will bo abou
200 feet. 1t is thought that at first tw
large ugits, that is. water wheels an
generator, will be installed at tn
power house with provision made fo
the installation of third unit. A
though the power house will not be a
large as the one at Vernon, the powe
generated will be equal to or create
than that of Vernon plant. Strange a
it may SEEM by the two plants bein
tied in together the Vernon plant o
the Connecticut river will be heneftte
Il.