Ship Technology
The Canadian contractor was primarily responsible for the first phase, the
second phase was a joint responsibility, and the third phase is being completed,
primarily by the U.S. contractor.
A hull loads data acquisition system was installed on the CCGS Louis S.
St-Laurent to acquire strain gauge data from three locations on the hull: the
bow (24 strain gauges), the shoulder (28 strain gauges) and the bottom (11
strain gauges). To support the load measurements a ship navigation data acqui-
sition and video monitoring system was also installed.
The data acquisition system
was designed to trigger the data
recorder to record significant
impact events when a predeter-
mined load was exceeded. It si-
m u l t a n e o u s l y re c o r d e d t h e
speed, power and direction of
the ship, as well as ice thickness
and strength, for later correlation
to ice condition and vessel oper-
ations.
Louis S. St-Laurent
The data acquisition system was operational from when the ship entered
breaking ice.
the ice on 26 July (70.08N, 168.38W) until it exited on 31 August. A total
of 4037 separate events were recorded during that period. Ice observations
were made continuously from the bridge of the Polar Sea. The forward-look-
ing video system recorded the encountered ice, and the after-looking video
system recorded the interaction of broken ice at the location of the strain
gauges. Physical ice data were collected on an opportunity basis by ice science
partners from the Institute of Marine Dynamics, St. John's, Newfoundland,
to establish the thickness and strength of the encountered ice. The average ice
thickness varied from 1.0 m (3.2 ft) on entry to 2.0 m (6.7 ft) at the Pole. The
maximum ice thickness (excluding ridges) was 3.54 m (11 ft).
The data set derived from this voyage is the largest ever collected on a
single deployment and doubles the quantity of information collected on pre-
vious collaborative USCGCCG projects. The ongoing analysis will reduce
the strain data to pressure loads and assess the trends in data versus ice and
ship operating conditions, compute extreme value statistics and compare re-
sults between other areas of this ship and other ship experiments.
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