The Benson signal., 1918-09-14


York, remarkable both for its
pictureSQueneSS and for the
engineering difficulties over
k ~ come in construction. which
60 links the Great Lakes with tn ,
Atlantic ocean was formally celebrated
recently. The completion of this great
inland waterway, which required IL
years to build and involved the lx-
penditure of approximately $15O,OOO,-
600, will be q wonderful boon to war
time transportation. 1t will relieve
the railroads of a tremendous guam
tity of nonperishable freight. Its ca
pacity is estimated at ten million tons
annually, which is the equivalent Of
half million carloads.
The canal is made up of four different
channels, all of which have the same
general dimensions, the depth being
about IL feet and width varying from
rs feet in earth sections of 'land line"
to a minimum of 200 feet in the beds
of canalized rivers and lakes. These
channels are The Erie canal, or main
line, between Buffalo and Troy; the
Oswego, running from Syracuse to
Lake Ontario; the Champlain, extend
ing from Troy up the Hudson to Lake
Champlain, and the Cayuga-Seneca,
connecting the so-called Finger
Lakes with the main channel. BY
means of the Hudson river, New York
city and the municipalities and vii
lagos south of Albany are brought into
touch with the system.
This new channel was constructed In
accordance with principles radically
different from those which governed on
old Canals. On these old channels the
idea was to keep the hillside above the
rivers and streams and to use animal
power for towing purposes. In the
present work, however, the practice in
vogue on the Continent, where the low
water routes available in natural
streams are used, has been followed
wherever practicable. In fact, the
larger part of the new system consists
of the canalization of the rivers and
lakes.
In order to make navigation possible
on the rivers and lakes it was neces-
sary to maintain a specified minimum
depth and provide what is termed
slack water navigation This was
accomplished by the construction Of
dams and locks, the dams holding the
water at q more or less fixed elevation
above the level of the stream and the
locks permitting the barges to move
from one level to another. Between
Little Falls and Troy, on the Erie
canal, ten dams have been constructed,
which provide for navigation on the
canalized Mohawk river. Two of these
structures are of the fixed type" while
eight are movable. These actually
make the river a series of lakes, the
water between the dams being prac-
tically level and ordinarily without
much current. A lock is constructed at
one side of each dam to enable the
barges to pass from the different lev
els.
Many travellers across the state have
wondered at the movable dams which
appear to be steel bridges, yet have
no approaches. This type Of Struc-
ture was necessary, however, because
from the bridge floor of each structure
the controlling works, which swing
underneath, are operated. These works
consist of heavy steel frames and gates
which may be lowered or raised at
will by operating electric winches run
ming on the bridge floor of the dam.
The particular function of the movable
dam is that when the gates are raised,
during the winter months and spring