St. Lawrence River
The St. Marys River has always been con-
sidered one of the key links in the Great
The first effort in the study of ice booms for
LakesSt. Lawrence Seaway transportation
the winter navigation program began 30 Septem-
system. Both the United States and Canadian
ber 1971 with a meeting in Massena, New York,
governments, as well as commercial concerns,
attended by representatives of the St. Lawrence
have made considerable investments to en-
Seaway Development Corporation, the Power Au-
sure safe and economic transportation of
thority of the State of New York, Ontario Hydro
goods and materials through the St. Marys
of Canada and the Cold Regions Research and
River, especially in the Sault Ste. Marie area.
Engineering Laboratory. The meeting resulted in
Besides its involvement in building four of
approval to use a crane boom weighing cell (100
the five navigation locks, which bridge the
kips capacity) at the shore anchor of the South
20-plus ft of fall at the St. Marys Rapids, and
Galop (Island) ice boom. A new design called a
in erecting powerhouses and a compensat-
tension link was conceived and developed in
ing works in the same area, the United States
government has constructed the Little Rap-
1972 and used in the Main Galop ice boom (Perham
ids Cut, which is a 600-ft-wide channel be-
1974). The tension link could be used in-line in
tween Sugar Island and the mainland of
ice boom structures without needing a supple-
Michigan. Prior to the winter of 1975-76, ex-
mental safety loop. It was electrically operated,
perience had shown that winter ship traffic
submersible, sensitive and fairly light. Eventu-
produced some restriction of normal travel
ally the tension link design, including signal
and commerce between Sugar Island and the
cable, recorder, etc., was adapted for use in 1974
mainland. These restrictions were caused by
by Hydro Quebec in their forebay boom on the
broken, floating ice entering Little Rapids Cut
Beauharnois Power and Ship Canal 25 miles west
from the harbor at Sault Ste. Marie (Soo),
of Montreal, Canada, by Arctec, Inc. for use in
Michigan and Ontario, causing ice build-up
the Copeland Cut test boom (Uzuner 1975) and
in the Cut. Periodically this would hinder
as an integral part of the St. Marys River ice boom
normal ferry operations.
since 1975 (Perham 1977). This study program
In addition to the influx of ice floes and brash
has provided a wealth of information about ice,
ice, substantial quantities of frazil slush were of-
ship and boom interactions, about how booms
ten generated in Little Rapids Cut, and (on occa-
are designed, built, installed and removed, about
sion) snow storms would aggravate the situation.
how they work, and about their contribution to
Acres American, Inc. of Buffalo, New York,
ice cover formation.
conducted physical hydraulic model studies and
analytical studies of the area. The purpose of the
Lake Erie
study was to select and evaluate possible reme-
The Lake Erie ice boom was patterned after
dial measures in alleviating the problems that arose
the Galop Island booms. The floating boom was
a series of 22-in.-wide 14-in.-thick 30-ft-long
from too much ice collecting in the Little Rapids
Cut section of the St. Marys River. Cowley et al.
Douglas fir timbers. Its primary functions are to
(1977) provide an excellent summary of the work
hold back lake ice from the Niagara River and
done in the study.
reinforce the easterly downstream ice edge to help
Acres built a scale model of the Soo Harbor
it resist breakup from wind and wave action (Bryce
and Little Rapids Cut Area and developed a ca-
and Berry 1967). The effects of this ice boom on
pability of simulating the harbor ice breakup
the local climate have been a recurring theme of
phenomena that were responsible for the move-
study (Acres, Ltd. 1972, Rumer et al. 1983), but
ment of ice floes and the subsequent formation
its main purpose of improving the use of water
of ice jams in the Cut (Acres American, Inc. 1975).
for generating electric power in winter has been
The 1:120-scale Froude model of the 4.5-mile reach
very beneficial to the area (Perham 1976).
from Soo Locks to below Frechette Point limited
studies to macroscale effects and provided pri-
St. Marys River
marily qualitative rather than quantitative results.
A perspective of the St. Marys River portion
Ice was simulated by using plastic pellets 0.1
of the Great Lakes navigation route and a sum-
in. on a side, with the same density as ice, to form
mary of the ice problems that developed there is
a layer on the water. The layer was sprayed with
illustrated by a quote taken from one of the an-
a chemical compound to cause interpellet adhe-
nual reports:
40
Previous Page
