Encl (2) to COMDTINST 16010.8
Domestic Icebreaking
Why We Act
The Coast Guard conducts icebreaking activities during the winter months to facilitate
commerce. During the ice season, 15 million tons of commerce is shipped over the Great
Lakes; maintaining a winter shipping season through icebreaking facilitates the
efficient transportation of this commerce. Along New York's Hudson River, reliable
vessels to transit ice- choked harbors in Maine ensures fisherman can continue to
support their families, and provide much-demanded seafood to the nation.
Key Factors
Ice blockage reduces mobility and delays winter navigation. Icebreaking performance is
affected by ice thickness that is linked to the severity of winter weather patterns. It
is also dependent on wind conditions: ice may be blown back into a cleared track so that
commercial vessels cannot transit. Analyzing past winter weather patterns, and
maintaining the readiness to break ice in even severe winter conditions is critical to
maintaining winter navigation mobility. Some sources of delay, such as lock closures,
must be addressed by other agencies, such as the Army Corps of Engineers, and the Saint
Lawrence Seaway Authority of Canada.
Strategies
The Coast Guard ensures the continued movement of commerce by maintaining the readiness
of a fleet of capable of breaking ice and allowing ships to pass through. The fleet
includes a heavy icebreaker, icebreaking tugs, and buoy tenders. Not only do the
icebreakers clear tracks, but they also free commercial vessels that are trapped in ice.
In addition, icebreaking provides secondary benefits of improved search and rescue,
waterways.
Coordination
The Coast Guard and the Canadian Coast Guard operate under a cooperative agreement to
meet icebreaking requirements in the Great Lakes and Saint Lawrence Seaway. There is a
very limited icebreaking capabilities provided by commercial tugs at the request of
commercial carriers.
32 Mobility