Figure 118. Tidal cracks in Tiksi Bay — winter of 1933-1934. 



Figure 119 shows the ice profile made in Archangel on 8 December 1941 from the pier of the 

 port of Ekonomiya to the shallows. Typical in the figure are the increase in ice thickness alongside 

 the pier and swelling of ice over the shallows. These elements, as we have seen, are completely 

 explained by tidal and other variations of level and must be taken into consideration in practice. 



In cases when ships must pass enforced or intentional winterings along nautural shores or 

 quays in harbors where strong tides occur, the ship should first of all be placed for the winter in 

 such a way that it will in no case freeze into an ice zone where tidal or wind-driving cracks appear 

 but will remain completely in ice which is always afloat. 



During the wintering the hull of the vessel, particularly an iron hull, due to the great heat- 

 conductivity of iron will always have its sub-surface part frozen over and frozen to the surrounding 

 ice. If the vessel freezes into the ice in such a manner that a part of its hull is in fast ice and the 

 other part in floating ice, the unavoidable stresses may injure the hull. There have been cases 

 where ships passing the winter alongside harbor piers in Archangel have ignored these factors and 

 in the spring tides have listed up to 25°. 



Tidal cracks are important also in construction of all types of roads and crossings on the ice. 

 A particular type of construction is required which will assure a smooth descent and ascent from 

 the shore and return. This is particularly important in laying of railroad lines. In fact, the sharp 



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