International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The majority of railway projects in our country aim at the maximum utilization of existing railway infrastructure, increase of the operation parameters, frequently at the condition of achieving interoperability. Increasing permissible speeds of trains invariably requires increasing the radii and lengths of curves. However, at small delta angles the use of the minimum design speed radius gives suboptimal results in terms of the total length of the curve. The report presents a parametric method for optimizing the railway curves at small delta angles in view of the necessity of achieving higher speeds on existing lines.

In this paper, the problems in redesigning a new track layout of an existing railway station according to the reqirements in the TSI “Infrastructure” and Ordinance No. 55 are examined and analyzed in the case of maintaining mainline operation during construction. The paper has been compiled on the basis of experience in designing the track layout of 3 existing railway stations from the Bulgarian network, as well as experience working with the current regulations and interoperability reqirements of the railway systems in the EU. The necessities for making changes in vertical and horizontal track alignment and switch layout are considered in opposition to the technolog ical, electrical and gauge limitations when carrying out construction works without the complete disruption of railway traffic. The conclusions of the report are formulated as guidelines for good practices when redesigning an existing layout – the practices that fully satisfy the imperative norms and balances between contradictory  equirements.