  Due to their large mass and small aspect ratio, icebergs pose a threat to
boats and offshore structures. Small icebergs and bergy bits can cause harm to
platform hulls and are more difficult to discover remotely. As icebergs are
dynamic mediums, the study of icebergs in relation to safe human operations
requires the rigorous analysis of the ice-ocean interaction, in particular with
waves and currents. In this paper, we present iceberg towing experiments and
analyze iceberg stability from GPS tracks and inertial motion unit data. The
towline tension as well as the boat motion relative to the iceberg was
measured. Different scenarios were investigated by changing the towing strategy
with regards to towing speed, direction (straight or curved trajectory) and
acceleration. Large amplitude roll oscillations with period of approximately 30
s were observed immediately after the load dropped and the iceberg returned to
a stable static position. In two of the cases, the iceberg flipped over partly
or entirely after some towing time. From the load cell, we observed
oscillations in the system with periods of approximately 6 s, which were
attributed to the rope elastic properties and the iceberg response. The load
oscillations increased when the towing direction was against the waves as
opposed to perpendicular to the waves.
