The canal was formed by "fencing in" a portion of the river-bed by an
embankment built about a hundred feet out from the north shore and
deepening the intervening space where necessary. There are two
locks--one placed a little above the foot of the rapid (see map), and
the other at the end of the dam. Wooden piers are built at the upper and
lower ends--the former being 800 ft. long, and the latter 300 ft; both
are about 29 ft. high and 35 ft. wide.
The embankment is built, as shown by the cross section, Fig. 6. On the
canal side of it there is a wall of rubble masonry F, laid in hydraulic
cement, connecting the two locks, and backed by a puddle wall, E, three
feet thick; next the river there is crib work, G, from ten to twenty
feet wide and the space between brick-work and puddle filled with earth.
The outer slope is protected with riprap, composed of large bowlders.
This had to be made very strong to prevent the destruction of the bank
by the immense masses of moving ice in spring.
The distance between the locks is 3,300 feet.
In building the embankment the crib-work was first put in and followed
by a part (in width) of the earth-bank. From that to the shore temporary
cross-dams were built at convenient distances apart and the space pumped
out by sections, when the necessary excavation was done, and the walls
and embankments completed. The earth was put down in layers of not more
than a foot deep at a time, so that the bank, when completed, was solid.
The water at site of it varied in depth from 15 feet at lower end to 2
feet at upper.
The locks are 200 ft. long in the clear between the gates, and 45 ft
wide in the chamber at the bottom. The walls of the lower one are 29 ft.
high, and of the upper one 31 ft They are from 10 to 12 ft thick at the
bottom,
The locks are built similar to those on the new Lachine and Welland
canals, of the very best cut stone masonry, laid in hydraulic cement.
The gates are 24 in. thick, made of solid timber, somewhat similar to
those in use on the St. Lawrence canals. They are suspended from anchors
at the hollow quoins, and work very easily. The miter sills are made of
26 in. square oak. The bottom of the lower lock iis timbered throughout,
but the upper one only at the recesses, the rock there being good.
[Illustration: MAP OF THE OTTAWA RIVER AT CARILLON RAPIDS.
SECTION OF RIVER AT DAM. NOTE.--THE LOWEST DOTTED LINE IS LOW WATER
BEFORETHE DAM WAS BUILT. THEN THE LINE OF HIGH WATER WAS ABOUT A FOOT
ABOVE WHAT IS CREST OF DAM NOW.]
The rise to be overcome by the two locks is 16 ft., but except in medium
water, is not equally distributed. In high water nearly the whole lift
is on the upper lock, and in low water the lower one. In the very lowest
known stage of the river there will never be less than 9 ft. on the
miter sills.
As mentioned at the beginning of this article, four locks were required
on the old military canal to accomplish what is now done by two.
The canal was opened in May, 1882, and has been a great success, the
only drawback--although slight--being that in high water the current for
about three-quarters of a mile above the upper pier, and at what was
formerly the Chute a Biondeau, is rather strong. These difficulties can
be easily overcome--the former by building an embankment from the pier
to Brophy's Island, the latter by removing some of the natural dam of
rock which once formed the "Chute."
The following are, in round numbers, the quantities of the principal
materials used:
Earth and puddle in embankment ...cub. yds. 148,500
Rock excavation, " 38,000
Riprap, " 6,600
Lock masonry " 14,200
Rubble masonry, " 16,600
Timber in cribs, lock bottoms and gates " 368,000
Wrought and cast iron, lb ................. 173,000
Stone filling cu yds ...................... 45,300
Concrete " 830
The total cost to date has been about $570,000, not including surveys,
engineering, etc.
The contractors for the canal, locks, etc., were Messrs. R. P. Cooke &
Co., of Brockville, Ont., who have built some large works in the States,
and who are now engaged building other extensive works for the Canadian
Government. The work here reflects great credit on their skill.
On the enlarged Grenville Canal, now approaching completion, there
are five locks, taking the place of the seven small ones built by the
Imperial Government. It will be open for navigation all through in the
spring of 1884, when steamers somewhat larger than the largest now
navigating the St. Lawrence between Montreal and Hamilton can pass up to
Ottawa City.--_Engineering News_.
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