Calculation of transport and operational indicators of an improved flat-flow unit

To implement an economically profitable initial and main timber rafting in raft units, the development of modern flat-raft units with high transport and operational performance is required. A highly efficient flat raft unit with a simple design and a high coefficient of raft section density is considered. The above advantages of a flat raft unit are formed due to the specific design of round timber laying in the rows of a flat unit, when each round timber of the upper row is stacked between two round timbers of the lower row with internal and external transverse gaskets. The use of the considered highly efficient flat-flow unit, regardless of its operating conditions, necessarily requires the correct calculation of its overall dimensions. The method to substantiate geometric parameters of the developed flat raft unit is proposed, where the emphasis is placed on determining the design and actual length, width and height of the raft unit. The geometric parameters of the flat raft unit were justified by taking into account the design features of the raft unit, the design of round timber laying in rows, the minimum width and depth of the floating road. The obtained dependences for calculating the design width, length and height of a flat raft unit allow the authors to determine the maximum possible overall dimensions of a flat unit. In turn, the obtained dependences for calculating the actual length, width and height of a flat raft unit are working formulas that take into account the maximum possible laying of round timber in a row and the number of stacked rows, and are used in calculating the overall dimensions of the manufactured flat raft unit for specific navigation conditions. The use of the proposed highly efficient flat-flow unit for the initial and main timber rafting will make it possible to ensure cost-effective delivery of wood to consumers from hard-to-reach places that lack a developed network of roads and railways.