If you recall in Laurence's video, narrowboat crews were seen rocking their boats from side to side; this also breaks the friction, and is accomplished on large icebreakers by pumping fairly large quantities of water ballast from one side of the ship to the other. On smaller icebreakers, which also service floating aids to navigation during the summer, the inclining of the vessel is accomplished by swinging one or two buoy anchors on the vessel's derrick. The anchors used are usually in the 3 to five ton range.
cheers, Phil & Anne Irons The 1950s German icebreakers had a thing called the 'Hitzler-Stampfanlage' in the bow which was a pair of wheels about 10+ feet in diameter with a 1000+kg weight on one side rotating at 100+ rpm to give the effect of a lot of people jumping up and down. Presumably Hitzler (perhaps Adolf's white-sheep cousin?) had studied how they did it in Brum. Sean [Non-text portions of this message have been removed]
