JUSTIFICATION OF THE FEASIBILITY OF RECONSTRUCTING ONE TRACK OF A DOUBLE-TRACK SECTION TO THE EUROPEAN STANDARD GAUGE (1435 mm)

The article systematizes scientific developments concerning the design and reconstruction of railway lines to the European track gauge of 1435 mm. Drawing on the experience of European countries, the study investigates the conditions under which it is feasible to implement a project solution involving the reconstruction of a double-track section into two single-track sections with different gauges: one track remains at 1520 mm, while the other is converted to 1435 mm. The research was conducted using graph-analytical modeling methods. The methodology involves the use of a developed mathematical model that allows for evaluating different scenarios of line capacity using transportation mastery graphs. The study forecasts transportation volumes under pessimistic, rational, and optimistic scenarios, under which the reconstruction of a double-track section into two single-track sections with gauges of 1435 mm and 1520 mm may be justified. A scientific approach is proposed, enabling the evaluation of various capacity scenarios for two single-track sections with gauges of 1520 mm (existing) and 1435 mm (reconstructed), using graph-analytical modeling methods. Based on the results of domestic and foreign scientific developments, potential solutions are outlined for the construction of European standard railways in Ukraine, considering existing infrastructure, geopolitical, topographical, and other conditions. The advantages of this solution include cost savings (as one track does not need to be rebuilt), maintaining connections with countries that use the 1520 mm gauge, and the ability to organize train movements with different track gauges.