The project covers the modernisation of three HDVs located on the main railway line Ruse-Varna, part of the extended trans-European transport network. A map with the location of the project is presented in Appendix 5 of the attached “major project” form according to Regulation 2015/207.The project includes the implementation of the following activities:1. Planning and design — constructive photographing, auditing and preparation of constructive expertise of existing buildings for HDV Varna and Razgrad, and preparation of technical and working design for the relevant equipment and vertical planning and fences, depending on the specific design for the three HDVs; 2. Construction works — construction of foundations and cable channels, new 110 kV and 25 kV RD; new site of Ruse HDV, outside the CFC; modernisation of the Krivnya and Samuil SP; replacement of station breakers at stops to Varna HDV; implementation SCADA system;3. Supply and installation of equipment and equipment for the three HDV equipment for 110 kV and 25 kV RD; compensation, feeders and reverse feeders; dashboards for control, signalling, power supply and protection, etc. A detailed description of the technical elements of the project is given in the attached technical specifications. For the full implementation of the project, the following supporting activities are also foreseen, detailed in point 7:4. Organisation and management;5. Assessment of compliance with the essential requirements and construction supervision under the SDA;6. Assessment of conformity with the interoperability requirements;7. Publication.The starting date of the project was accepted the start date of the preparation of tender documents for the selection of contractors — 21 May 2019, which was assigned by orders of experts from the Sofia-Dragoman ZPIP. The end date of the project is the estimated date for the completion of the construction works for the Ruse HDV — 10 November 2023. The total deadline for implementation is 54 months.