Project Description

Separate Position 2 - Engineering, Reconstruction, and Modernization of the Telephone Cable Network and Equipment in the DP NKZHI in the Levski-Gorna Oryahovitsa, Butovo-Nedan Section

Construction of 2nd Group 1 Category
Preparation of working project:
Along the railway line in the section from Levski Railway Station to Gorna Oryahovitsa Railway Station, an optical cable, dielectric, self-supporting with a track-resistant coating for installation at voltages of 25 kV/50 Hz, is installed on the concrete or iron lattice poles of the contact network, secured by a tensioning device (anchoring) providing a firm attachment to the pole, and a supporting device (roller) enabling the cable to be suspended on the intermediate poles.
Suitable dielectric joints are used for connecting cable lengths and deviations from the cable, installed underground in the shafts during excavation laying of the cable or on the poles of the contact network during aerial cable construction. The fibers of the optical cables are connected in the joints by thermal fusion-splicing, protected at the splice point with heat-shrink sleeves arranged in the splice cassettes.
Deviation from the main trunk cable is made in substations, sub-regions, sectional posts, and cabins (containers) for inter-station equipment of the electrical distribution network located in the inter-station areas.
Underground entry into buildings and operational points is carried out through constructed duct networks where available, or by excavation in non-combustible protective HDPE pipes with sealed ends, leaving a cable reserve.
Branching joints with reserves for data transmission from the equipment at the crossing to the remote information panel and for video surveillance are installed at the crossings.
In tunnels, the optical cable passes through protective HDPE pipes.
The optical cable is terminated at all stations, separation posts, and power facilities of the electrical distribution division in the section, either fully or partially on optical distribution frames (ODF) mounted in a 19" standard lockable cabinet located in designated telecommunication equipment rooms.
SDH (Synchronous Digital Hierarchy), Multiplex Equipment, and Station Concentrator include:
SDH-STM4 transmission system in Levski ATC, Pavlikeni Station, and Gorna Oryahovitsa Station, with upgrades to the existing multiplex equipment; SDH-STM1 transmission system in Resen Station and Polikraishte Station; optical modems for connections to Butovo PDC, Nedan Special Facility, and Lesicheri PDC; access equipment - MUX - low-frequency multiplexing in Levski ATC, Butovo PDC, Pavlikeni Station, Lesicheri PDC, Resen Station, Polikraishte Station, and Gorna Oryahovitsa Railway Station; new power supply devices 220V/48V and establishment of grounding for the communication equipment in Levski ATC, Butovo PDC, Pavlikeni Station, Lesicheri PDC, Resen Station, Polikraishte Station, and Gorna Oryahovitsa Railway Station; digital station concentrators to provide specialized telecommunication links for duty officers in Levski ATC, Butovo PDC, Pavlikeni Station, Lesicheri PDC, Resen Station, Polikraishte Station, and Gorna Oryahovitsa Railway Station; rectifiers and storage batteries, grounding of telecommunication equipment.
Repair parts are delivered.