Analysis of conducting freezing operations methods and the investigation of the formation patterns of an underwater channel from the ratio of the hydrostatic pressure of the depth and the pressure inside the shell under the bottom of a flat-bottomed

The article presents an analysis of existing methods of freezing ships and the methods that served as the basis for the development of agreed methods of freezing operations. The method of "Conducting freezing operations" according to the patent of the Russian Federation for invention No. 2067141 is characterized as the most guaranteeing the shape of the created underwater channel under the hull of the vessel. The dependence of the shape and size of the formed underwater ice channel was studied depending on the initial diameter of the shell used, the pressure in it and the depth under the hull of the vessel. The dimensions of the shell under the pressure of the pumped cold air determine the resulting shape and dimensions of the underwater channel intended for carrying out work on defecation, repair and maintenance of hull structures. These dimensions should satisfactorily ensure that the specified work can be carried out in freezing conditions. The shell shape was studied by means of a model experiment with an object with transparent walls on which a frame assembled from rulers with a millimeter scale was fixed, which made it possible to fix the zone of attachment of the inflatable shell under the body. In addition, the size of the shell was photographed using underwater photography and endoscope photography from inside the inflatable shell. Patterns of the shape and size of the shell located under the body of the object are obtained at different ratios of the pressure values in the shell and the depth of its immersion, fixed by the indentation marks made from rulers with a millimeter scale.